ROCHDALE ELECTRIC WELDING
Playing about with traction engines was all very well but it’s time to describe what REW was all about. As with so many essential trades, very little has ever been written by people who actually did the jobs so I want to give a fairly full account of my work for John.
The phrase ‘The Steam Age’ is often heard nowadays and is usually used in what is almost a pejorative sense, it is a shorthand description for times past, something that, though useful in its time, is now obsolete. Anyone who uses it in this way is demonstrating their woeful lack of knowledge. We are still living in the ‘Steam Age’. As yet, we haven’t found a better method of conveying heat in a useful form which can be converted into something else. As an example, by far the greater part of electricity that we use is produced by generator sets driven by steam turbines. Even atomic power uses steam. The reactor is nothing more or less than a heat source which is used to make steam and the steam drives the generators. Another huge use of steam is as ‘process steam’. Any factory where substances have to be heated, pressurised or sterilised is a steam user. Large heating systems use steam to transfer heat from boilers to where it is needed. Pressurised hot water is also used in many industries and in commercial and domestic heating systems. This is produced in boilers also but at lower temperatures and pressures.
Wherever steam or hot water is being used, you will find a boiler, a vessel which holds water and which is heated by a variety of fuels, coal, oil, gas, electricity or waste products. The pressure of the steam or hot water dictates how heavily the boiler is constructed. All these vessels have one thing in common, because of the nature of the process, high temperatures in the furnace and the corrosive nature of hot water, they need regular maintenance and occasional heavy repairs. This was the function of Rochdale Electric Welding, the maintenance and repair of large pressure vessels.
In 1930 when John’s grandfather William Rawson Ingoe, started REW, most of the boilers in use were riveted Lancashire boilers. In other words, the individual plates making up the vessel were joined together by rivets which were inserted hot and clenched over. As they cooled and contracted the rivets drew the plates together so tightly that, if properly done, the result was a steam and water tight joint. Most of the repairs needed to these boilers involved riveting but even in those days there were some repairs that were more efficiently done by welding. The standard method of welding had always been to use a flame produced by burning oxygen and acetylene together in a special torch but a new process was becoming generally accepted which was to use coated metal electrodes which had a heavy direct current applied to it. When this is earthed on to the metal to be repaired the resulting electric arc melts both the electrode and the article to be repaired. The molten metal and the base to be repaired mixes together in the arc and produces a homogenous repair. The coating on the rod melts to form a protective coating on the weld, this protects it from oxidisation while it cools down. The residue is called ‘slag’ and has to be removed before the next run of weld is laid down. On a flat joint, if everything is just right, the slag automatically peels off as it cools and I remember Mark Roberts telling me once that the sight of that happening was the nearest a welder ever got to an involuntary orgasm! What Mark actually meant that this is as good a sign as you can get that the weld is perfect.
Apart from joining separate pieces of metal together, arc welding can be very useful when building up worn parts, for instance a part of the boiler which has been rendered thin by corrosion. There was still a place for oxy-acetylene gas mixtures for specialised welding and brazing and, when used in a cutting torch, for cutting thick steel plates. Flame cutting can make a surprisingly neat job of cutting steel up to six inches thick. Remember that John had the new gears for his traction engine made by flame cutting them out of blanks. One further complication for you, it is possible to cut steel by electricity using special electrodes and very heavy currents and this process was commonly used.
As time went on different designs of boiler became common. These were all tubed boilers in which the internal heating area of the furnace is increased by passing the hot gases through steel tubes immersed in the water in the boiler. This gives a more efficient heat transfer and can raise the thermal efficiency of a boiler while at the same time allowing greater steam raising capacity in a smaller space. Most modern industrial boilers are ‘firetube’, in other words the tubes are full of the flue gases and surrounded by water. However, some, particularly the largest boilers such as those used in power stations have ‘water tubes’ in other words the tubes are full of water and bathed in the hot flue gases. All modern boilers are tubed boilers but many of the old riveted boilers still survive. As boilers changed, so did the range of skills needed by boiler repairers. REW kept up with these improvements and were always capable of undertaking the heaviest boiler repairs.
Another complication which existed was the fact that all boilers have to be insured. The ultimate authority in any boiler repair or maintenance is the Insurance Surveyor who is the representative of the insurance company carrying the risk on the boiler. Very often retired marine engineers, these were very skilled men of great experience and under their guidance the whole system of modern regulation of boilers evolved. Higher and higher standards were demanded, not only in respect of the design and maintenance of the boilers but in testing and approval of the operatives who did the repairs and the processes used. Every welder at REW has a qualification known as ‘Coding’, he is tested once a year by having to weld specialised test pieces which are then destructively tested to make sure that they are of a sufficiently high standard. The procedure and materials used have to be coded as well. The end result is a highly skilled workforce and very reliable repairs.
Like all the good firms I have ever worked for, REW had a very simple management structure. John, together with Joyce, his secretary, ran the office. Paul Greenwood was senior hand and acted as manager when John wasn’t about. Every morning the staff met in the shop and the days work was handed out and John would spend some of the day going round looking at new jobs and visiting those that were in progress. One of the features of boiler repair is that it can be an emergency situation. If a message came in at four in the afternoon that a boiler was down and needed repair, the first gang in or the nearest gang to the broken down boiler would be sent to start work. Once started they would work all night and if necessary, be relieved by another gang in the morning. Basically, the work went on non-stop until the boiler was back on line. It was nothing unusual for gangs to work straight through over a weekend to rectify a fault.
So, in 1993 when I went to work for John I was employed in a firm which knew its job inside out and had a very good reputation in the trade. In addition, the men who were working for John were all highly skilled. There were four two man gangs basically, they usually worked with the same mate and over the years had built up relationships. This wasn’t always the case, sometimes there were jobs that needed just one man. I’ll get round to naming everyone as I tell the story but you’ve already met some of them, Paul Greenwood and Stuart Lomas were the blokes who helped me to erect the Whitelees Engine. Two more of the older end, Dennis Sterricker and his mate Joe Elston had done work for me at Bancroft on the boiler so I knew them. Dennis was one of the old school, raised as a riveter and progressed to coded welding. All told, I felt very comfortable about going down to Rochdale to work with them. My position was dogsbody, I wasn’t qualified to do anything but sweep the floor and tidy the shop up. At least I knew where I was!
Slowly, this started to change. I suppose the first sign of this was when John gave me the job of sorting Annie the traction engine out. Things progressed until I was getting any job in the shop that nobody else had the time to do. If one of the air tools broke down I would strip it and do it up again. One job that I got fairly regularly was marking out and drilling special blanks for pressure vessels which were under test after heavy repair.
We once had a job for Akzo Chemicals at Littleborough which illustrates several aspects of the type of work we did. John was asked to quote for a modification on a specialised pressure vessel at the company’s works. It was a very complicated job as the vessel worked under unusual conditions at very high pressure and the modification involved welding a fixture into the side of the vessel to take an additional connection to an internal stainless steel heating coil. The insurance company required a special coding for the welders and the procedure. This entailed setting up a piece of steel plate identical in thickness and composition to the wall of the vessel on a steel bench in the shop. This had to be pierced with a hole four inches in diameter and the new connection welded in. Because the wall was so thick, the insurance company demanded very close control over the temperature gradient in the surrounding metal and so we had to get an outside firm in to attach thermocouples to the surface of the test piece and monitor the temperature while the welding was proceeding. It was left to the welder to judge how long he could carry on without exceeding the limits that were set. The consultant recorded the temperatures as evidence for the insurance company that their parameters had not been exceeded. Once the test piece had been welded it was sent to a laboratory for x-ray examination of the crystalline structure in the steel and destructive testing. This coding of the welder and the procedure cost about £6,000 before the job had even started!
Once all these hurdles had been overcome, arrangements were made for the plant to be shut down and we moved in to work as fast as we could to do the job and get the vessel back in production again. None of this was any part of my job but one essential element of the process was that we should pressure test the vessel when the repair was done.
Hydraulic pressure testing is a very practical and reliable way of testing the integrity of a pressure vessel. Essentially what you do is fill the vessel absolutely full of water, close it off completely and then, using a small pump, raise the pressure to a value decided by the insurance company and inspect for leakage or failure. Water is used because, being incompressible, any slight leakage immediately drops the pressure and so there is no risk of an explosion. If air was used it would be very dangerous. The test pressure was usually 50% higher than the normal working pressure but occasionally the insurance companies would ask for a greater safety margin. Because of the unusual working conditions in the vessel in question, they asked for double the normal working pressure.
In order to prepare the vessel for testing it is necessary to close off all outlets. In many cases this can be done by simply closing a valve but some openings had to be stripped back to the shell and special blanking plates fitted. All flanged connections are made to standard sizes and in the shop we had a large selection of blanking plates in stock. However, in this case, because of the large size of one of the openings and the high pressures involved, I had to make a special blank. It was a large pipe connection so John ordered a disk of steel of the correct diameter and thickness, it was about two feet diameter and three inches thick. I was given the specification of the standard flange on the outlet and marked out and drilled the blank for the holding down bolts. When I finished it I took it down to the site and got a couple of surprises.
The first surprise was when I looked at the flange on the vessel. It looked wrong so I measured it up and found that I had been given the wrong specification, instead of measuring the pipe diameter, the chief engineer at the plant had measured the overall diameter of the flange! The blank I had made was far too big. I asked where he was and was told he was on holiday so I put the blank back in the van to take it back to the shop and weigh up whether I could get away with drilling holes on the correct pitch circle and still achieve a seal. While I was there I had a look at the actual job.
The vessel was under a roof but exposed to the elements on all sides and John Besjuik, DJB as we called him, was, together with Mark Roberts, perched half way up the side of the vessel working on the repair. In the yard below were three trailers of compressed hydrogen which supplied the plant with raw material! Hydrogen is a very explosive gas and there were several safety men and fire officers supplied by the company supervising the work and monitoring for safety. I was, to say the least, impressed by both the technology and the danger. I asked one of the men who worked on the site what this vessel was used for. It turned out that it was a reactor in which the essential ingredient of domestic fabric softener was manufactured. I stood in wonder and reflected that all this complicated technology was being used to produce a liquid which was only necessary because the detergent makers manufactured a product that created harshness in clothes and had to be compensated for by using fabric softener. In other words it was simply a ploy to sell more product to the customers!
I went back to the shop, re-made the blank and delivered it. The vessel was tested after the repair to 450psi and all was well. Another job well done but all that time, money and effort for something that the world could well do without!
As I said earlier, I had sold my old Wilson lathe to John and as I was the only turner in the shop, repairs that needed any lathe work fell to me. This was mainly the reconditioning of steam valves. Old steam valves were originally made to a very high standard and even when worn after many years of service, it was possible to refurbish them to a standard where they were actually better than modern valves. A good lathe was the perfect tool for doing this.
A large part of the work in the shop was the total reconditioning of used boilers. If we installed a new boiler we would always buy the old boiler if it was a reasonable age. In addition, John was always on the lookout for good redundant boilers because there was a ready market for a properly reconditioned boiler. John had a major advantage here because he had all the skills and the equipment to do the job. Whenever outside work was slack, John would set his men to work on the boilers stood in the shop. Under the supervision of the insurance company’s surveyor, the boilers would be thoroughly inspected using Non Destructive Testing (NDT), this was the use of ultra-sound and magnetic flux to examine the welds for flaws. If any were found they were marked up, the affected weld or plate was cut out, a new piece made and welded in and the whole repair inspected by NDT again. The result was a boiler which could be better than a brand new vessel and which could be sold at a good profit.
Whilst the welders were working on the shell of the boiler I would strip off all the valves and fittings, refurbish them, replace them on the boiler except for the safety valve and after blanking the safety valve flange, I would pressure test the boiler in the presence of the inspector. The standard method of getting the boiler up to pressure was by using a hand pump. This was not as onerous as it sounds because we filled the boiler up with the hose and once it was absolutely full it needed very little additional water to achieve the required test pressure. Having said this, it could occasionally get very frustrating as the boiler might have some air bubbles trapped on the surface of the plate which had to be compressed, this made the job much harder. Additionally, as you raise the pressure on the boiler the construction stretches and it could sometimes take a lot of hard pumping to achieve the pressure.
We once reconditioned a boiler for installation on a paper works in London. It had been built as a high pressure boiler, to work at 250psi but had been used all its life at a lower pressure. Because we were reverting to the higher pressure the insurance company demanded a manufacturing test, in other words they wanted double the working pressure plus a safety margin. This meant we had to achieve a test pressure of 575psi and I wasn’t looking forward to this! I had a thought and after a bit of pipe fitting connected the jet washer we used for washing the vans up to the boiler. John laughed at me when he saw what I had done, I don’t think he thought it was man enough for the job. I tried it out and got my pressure with no effort. The inspector came, we tested the boiler and he went away satisfied. After that, on a large vessel, I always used the electric pump! The usual practice was to maintain the pressure for about twenty minutes or so in case any leaks developed. One thing I noticed when we tested that boiler was that the pressure fell slowly even though there were no leaks. The inspector and I agreed that it was due to the pressure stretching the shell and we cut the test short after ten minutes for that reason. We were probably doing more harm than good by maintaining the pressure. It would have been quite feasible to raise the pressure to a point where the shell would have split and a balance always has to be maintained between sensible testing and destructive testing.
One more word about hydraulic tests. Many firms used to test the boilers with the fittings off and all the holes blanked. I always favoured testing with the fittings on as this meant you were testing all the fittings as well. If they stood up to test in the shop they would almost certainly be all right under working conditions. The only proviso to be added to this is that temperature can make a difference to the connecting joints where the fittings meet the boiler and it is always a good thing to check the tightness of any bolted joints by nipping the nuts up as the boiler is coming up to temperature and pressure for the first time. This has to be done very carefully however because any failure of a joint with steam on would be catastrophic, it’s a very skilled job and you rely on your instinct and experience.
My dad once told me about an accident that happened when he worked at Armstrong Whitworths in Trafford Park, Manchester after he deserted from the Australian Army after the war. There was a subway running under some railway lines in the factory and a high pressure steam main ran through it. A fitter was going through there one day and some hot water fell out of the joint on to the back of his neck. It wasn’t the first time this had happened and at lunch time he told his mates he was going to cure it. He went off with a couple of spanners and must have tried to nip the flange bolts on the joint. This never works on an old joint and should never be attempted because you don’t know what condition the bolts are in, they can be wasted by corrosion because of the leakage. The joint fractured and he was blown to bits by superheated steam at very high pressure in the confined space. Father said that the force of the steam drove the joint apart eighteen inches when it blew. The message is, unless you know exactly what you are doing, never mess about with a joint under high pressure!
Working in the shop on boilers was made much easier by the fact that we had a travelling crane. I don’t need to reiterate my views on sky hooks here, you all know they are my favourite asset. The crane we had in the shop was nominally five ton capacity but was in fact a ten ton crane that had been de-rated at some time to lower insurance costs perhaps. Suffice it to say that it had to be a very heavy boiler before we had to revert to more labour intensive ways of moving them. I had my share of adventures with the crane because I probably used it more than most. At some time the automatic stop on the crane had been disabled and one day, in an unguarded moment I wound the block right up to the drum. This broke the rope and the 500lb. Block fell 25ft. to the floor missing me by a couple of feet. John was there and did his share of shouting about it but secretly he was very relieved that I had enough sense to keep out from under the load when using the crane. When the hoist maintenance man came to put a new rope on it I asked him to have a look at the automatic stop mechanism. He reported that it was perfect, all it needed was putting back into gear and we had solved that one! Once again, John never made any complaint about this, he realised how dangerous it was in its previous state. The safety gear had a fault in that it stopped the lift well before the block was in danger of breaking the rope. This was a definite disadvantage when we were working on the mezzanine floor at the end of the shop as it meant you could be short of lift. I have little doubt that this was why the safety gear had been disabled in the first place.
The crane was handy for other things. I remember that one afternoon we had a boiler delivered into the yard. It was brought to the shop on our low loader and lifted off by a large hired crane. It weighed about forty tons and was a substantial piece of kit. I was on my own in the shop at the time and as he went out to visit some customers John told me in passing that he’d like the boiler bringing in and parking right at the back of the shop in the corner. It was a joke of course, he never thought for one minute that I’d do it. If he did, he was paying me a hell of a compliment! I didn’t say anything but as I sat there having my lunch I did a bit of plotting and decided that as I was on my own that afternoon, I’d have a go when I’d finished my tea!
The usual method of shifting a large weight like this is to jack it up and insert ‘skates’ under each corner. A skate is a very heavily made metal box with four sets of steel rollers fitted inside on heavy axles. If you place them under one of the girders which formed the base of the boiler with the rollers downwards on the floor, you reduced the coefficient of friction sufficiently to allow the boiler to be moved if enough weight can be applied to it horizontally.
The old-fashioned and effective way of inducing this horizontal force was the ‘Tirfor’ ratchet winch. This was a compact mechanism with a hole through the middle big enough to accept a heavy steel rope. This winch was anchored to something solid like a stanchion base. A heavy hooked rope was fastened to the object to be moved and the tail end of this was threaded through the Tirfor and out the back. A lever was fitted on the winch and if pumped back and forth , the rope was gripped by the internal mechanism and drawn through the winch in very small increments, about two inches at a time for the heaviest loads. A very considerable pull could be exerted by the Tirfor, even in a restricted space and they were a useful tool. They were also very tiring! However, I had a plan.
The yard was just compressed soil and wouldn’t allow skates to be used so I laid some steel plate down in the yard up to where the concrete floor began and oiled them. I fixed up the Tirfor at the back of the shop and anchored it to the base of one of the main stanchions that held the shop up. Then I put a heavy chain right round the base of the boiler, connected this to the Tirfor with the heavy wire rope and then put as much tension on the wire as I could. Then came the fancy bit! I brought the crane over the top of the centre point of the heavy wire, dropped the hook until I could get the wire into it and then lifted up on the wire with the crane. The crane would exert a dead pull of over fifteen tons on the wire and because it was not a direct pull on the boiler this was at least doubled by the set-up. It was a piece of cake. Every time I lifted the wire I gained about three feet on the boiler. I then let the hook down, took up the slack with the Tirfor and took another bite at it. As soon as it had slid onto the concrete floor of the shop I jacked each corner and fitted a skate at each one. From then on I could steer the boiler by adjusting the direction the skates were pointing. By half past three I had the boiler tight up in the corner of the shop and another half an hour saw all the tackle cleared away. I thought I deserved a smoke and a pint of tea then so I brewed up and sat down. Shortly afterwards John came in, made a comment about me always being sat down with a pot of tea when he came in and vanished into the office without another word. This suited me, there was no need for him to say anything about the boiler. I didn’t have to be told I’d done a good job or that John was pleased because a problem had been solved. I know for a fact that he mentioned it to other people afterwards but never said a word to me.
There’s something here that needs a bit of explanation. What I’m going to describe is often seen as a Northern trait but is, more accurately, to be found wherever you are dealing with intensely practical people. It is the capacity for understatement and an avoidance of anything that could be described as fulsome praise. I remember once having a very eminent man from English Heritage helping me to run the Ellenroad Engine. He had never seen it running before and as it started to roll over he went into transports of delight. I had to rein him in, “You’re going to have to stop that Oliver. You’ve got to cultivate the Northern capacity for understatement. The furthest you can go is to say that it’s ‘alreight’!”
This is often misunderstood but there’s a very good reason for it. If you’re a good man at your job and satisfied with what you’ve done, you don’t expect any praise from your peers because it’s superfluous, you know they know you’ve done well. They know that you know and it is taken as read. The most that will be said is something like “That’s all right then!” or, and this is more likely, a leg pull; “Should it be bent like that?” or in my case with the boiler, “Great, but I wanted it facing the other way!” This also explains why there is often a bad reaction if a casual observer tells a craftsman he has done a good job. The mechanism that is at work is this, how the hell does an amateur know what the difference is between a good job and a bad job? It's almost as though they are setting themselves up as your equal or superior by feeling qualified to pass judgement. This can be so bloody annoying, you wouldn't’ believe it! A word of advice, if you want to congratulate someone in those circumstances say something like "“How did you do that?"” or “How long does it take to learn how to do that?” In other words, convey the admiration without implying a judgement.
The crane was invaluable when we were bending plate. There are many occasions when a plate has to be bent to a radius to make a boiler shell or a patch that has to fit a boiler shell. We had a medium sized set of bending rolls up on the mezzanine which could handle a piece of plate six feet square and about ¾” thick. This size of plate is a fair weight and during the process of bending could kick severely when the rolls got to the edge so the crane was essential to hold and control the plate. Large valves could weigh up to 500 lbs and the crane was used to lift them into place on the top of the boiler. Another use was when refitting the lid on the top of the boiler. These lids are let down into the boiler at an angle and then lifted up against the seating and two heavy ‘dogs’ or bridge pieces fitted over the holding studs before being nutted up. The principle is that the more pressure there was on the lid the tighter it fitted to its internal seat. The problem was holding the lid up by hand while the bridge pieces and the nuts were fitted. If an eye bolt was fitted in the centre it was a doddle to lift the lid into place with the crane and drop the dogs on before tightening down. It made the job so much easier on a big boiler.
We had a six feet radius radial drill which was a very good tool and could work on large pieces of plate. The crane was very handy for lifting large plates into place and holding them while drilling them. The biggest drilling job I ever had at REW was when John took on a contract to build a combustion chamber for a large boiler in the North East of England which burned household waste pelleted with coal dust to produce steam for district heating. We had already installed new furnace tubes in the boiler, this in itself was a massive job. The combustion chambers were to be added to the boilers in an attempt to slow down erosion of the furnace tubes by the pellets as they were fired in and burned.
The chamber was in effect a large, open ended box the sides of which were made of a double wall of 50mm thick plate with a three inch gap which was filled with water and acted as a steam raiser. In common with all flat sided pressure vessels, it was heavily stayed by 50mm thick pins which spanned the gap and were welded in 50mm holes drilled in the plate and then countersunk. The stays were welded into these holes and had a three inch deep hole drilled in each end. This was known as the ‘tell tale’ and the idea was that when corrosion attacked the stay severely enough to weaken it the hole would dribble water thus warning of failure. David Sterriker, Dennis’s son and I marked out all the holes on the plates. I forget how many there were but I think it was about 700. These had to be drilled 50mm in exactly the right place and then countersunk the full depth of the plate. This was serious drilling and countersinking and stretched both the drill and Stanley to the limit! Boiler plate is specially formulated to be ductile, in other words it is tough but relatively soft and is almost ‘sticky’ when you are cutting it because, unless the tool you are using is perfectly sharp it will deform under the cutting pressure and ‘rag up’.
In addition, the stays had to be made. John got the 50mm bar ready cut to length and I spent days at the lathe drilling 1/8” holes three inches deep in each end of them. This is not an easy job as you have to keep withdrawing the drill to clear the chips. If you don’t, the drill will bind in the hole and shear off which gives you a serious problem. When I got them finished I happened to be looking at the drawings in preparation for marking the holes. I had a thought about the stays and checked up on the length of them. They were all the wrong size! I forget the actual numbers but what had happened was that John had ordered say 350 pieces at 400mm long and they had delivered 400 at 350mm! Luckily , he had a copy of the order and sent them all back with the stipulation that they provide the correct stays with holes ready drilled.
We marked the plates out and drilled them and I started countersinking. The countersink was a very good one but had to be sharpened by a specialised tool and cutter grinder. The nearest one was in Accrington and I lost count of the number of times I went across there to have it touched up! We got on well and the lads started welding the first sections together. All the work had to be done under the supervision of the insurance company as it was new construction. It soon became obvious that things weren’t going at all well. Due to the design of the sections, it was impossible to weld them without warping. This is one of the biggest problems with welding, the heat has to be applied in small quantities and at opposing points so that the stresses cancel each other out. With heavy sections like the ones we were dealing with it was impossible to keep the heat down without slowing the job down to the point where it was impossible to break even, never mind make a profit. This was a design fault not a manufacturing deficiency. The further we went with the job the more obvious it became that we had a big problem.
Give John his due, he soon made up his mind what the solution was. He came to me one morning when everyone was out on outside jobs and told me that a wagon was calling for the sections we were making. He said I was to load them all on and tidy the shop up. The wagon was from the scrapyard! John had decided that the first loss was the best so he scrapped the job. He rang the firm we were contracted to and told them and they were not happy. However, it was too late, the plates were gone and so were all the problems. This experience must have cost John the best part of £10,000 but it was the right decision. Even if we had made them to everyone's satisfaction we would never have heard the end of them. What hurt John was the fact that we had taken a job on and not finished it. It was the only time I saw this happen.
We did some interesting jobs on traction engines. We were one of the few firms left in the country who could do heavy riveted repairs and because we had our own engine we were known on the circuit and people came to us. A bloke from Swinton near Manchester sent his engine to us for a new firebox. What made it interesting was the fact that he wanted it making exactly like the original, in other words, a fully riveted construction. It was funny to see Dennis and Paul vying with each other for the job because they were both riveters. It came to us completely stripped down as a bare boiler and I’ll describe the job as it was so unusual.
The first thing we had to do was cut out all the boiler tubes and remove them as, at the back end, they fitted into the throat plate which was the front wall of the firebox. Then we removed the solid stays which ran from back to front and I made new ones in the lathe. The next job was to burn out all the stays, the stiffening bars which bridged the water space between the firebox and the outer wrapper plate of the boiler. Dennis did this with the oxy acetylene burner and it was a very skilled job as he had to burn the ends out without damaging the plate they were riveted into. The stays had to be cut out from the inside of the firebox as well but this didn’t need doing too carefully as the firebox was scrap anyway. At the bottom of the firebox, the space between the bottom edge and the wrapper was filled with a wrought iron foundation ring. All the rivets through this had to be washed off with the burner and the rivets driven out completely. There was a similar ring round the firebox hole in the back plate and this had to be treated the same. Once all the rivets were out the boiler was lifted up so the firebox could be dropped out. This was not easy as the foundation ring was a very tight fit in the wrapper. Eventually we got it loose and dropped it out on to the floor. Two things struck me when we got it out. Due to the hammering we had given the firebox to get it out all the rust had spalled off it and it was like a lace curtain. It was only the rust that had been holding it together! The other thing was the lack of corrosion on the foundation ring and the bottom of the wrapper and the firebox. The ring and the surfaces it had fitted to were as good as the day the engine was built. This was a tribute to the way the ring had been fitted by the manufacturers.
Once out on the floor Paul measured the firebox up and we ordered the plates for it. We got the wrapper made in two pieces and the front and back plates were flanged so that the resulting corner was a curve. When we got them we welded the wrapper plates together along a seam on the top and then temporarily tacked them to the flanged ends with weld while we marked them up for drilling for the rivets and the tubes. The stay holes on the sides and the top weren’t drilled at this point, we would drill them through the existing holes in the outer wrapper so we knew we had them in line. Once all these were done and the firebox hole cut in the back end we bolted the firebox together through every other rivet hole and the firebox was ready for Dennis and Paul to start riveting.
I don’t suppose anybody who reads this will know the first thing about hot riveting and it’s a lost art now so I’ll describe the process in full as we’ll be doing a bit more later. Hot riveting is a wonderful way of joining steel plates together to make a pressure vessel. It has the advantage over welding that it is reasonably flexible, the structure can breathe slightly and this wards against failure by thermal stress. The basic principle of the process is that an iron rivet, which is a piece of low carbon steel bar with a half round head on one end, is heated white hot, inserted in the holes through the plates to be joined , ‘held up’ into the hole at the head end and the other end is hammered down into a domed shape while hot. This hammering expands the rivet in the hole and forms another head on the plain end. As the rivet cools it shrinks and pulls the two plates tightly together.
‘Holding up’ is the job of the second man on the team. He has to be in position on the opposite side of the plate from the riveter who is hammering the rivet to shape the head on what was the plain end of the rivet. In the case of an enclosed pressure vessel, this means he has to be inside the vessel. His function is to apply resistance to the pre-formed head of the rivet to hold it in place and give the riveter something to hammer against. In its simplest form, holding up is achieved by holding a heavy hammer head against the rivet but for a really tight joint the hold has to be solid. This is achieved by using a holding up bar which is placed on the head of the rivet and jammed against something solid. As this has to be done very quickly so as not to allow the rivet to cool down a special strut with an enclosed cylinder and piston is used. If compressed air is applied to this strut it lengthens and gives a very quick hold which is dead solid. It may have occurred to you that the process of riveting the head up will be noisy! You’re quite right, it is the worst and most damaging noise you can imagine especially if you are in a confined space in a vessel. All riveters eventually get serious ear damage, Dennis and Joe were both very hard of hearing for this reason even though they had usually used ear protection.
Knocking up the plain end of the rivet could be done with a hand hammer but unless there was a very good reason, was always done with a pneumatic gun which delivers blows in very quick succession. It has the facility of being able to accept a variety of shaped heads for the actual contact with the rivet. These were in the form of a hardened steel cup and ensured that an even and well shaped head was formed. Apart from the other skills involved it is essential to have a rivet which is exactly the right length, in other words, which has sufficient metal protruding from the plate to allow a good head to be formed.
So, we have two men, the riveter and the second man holding up. There is a third man in the team who’s job is to heat the rivets in a portable forge. He has to have the rivets white hot and just beginning to sparkle. When a piece of iron reaches a temperature where it is hot enough to start burning because of combination with the oxygen in the air, it sparkles like a firework. This actually damages the structure of the iron in the rivet so the trick is to get them to a point where this process is just starting. This means that the rivet is as soft as it can be without damage. The portable forge is a shallow tray on a stand which has a fire in it fuelled by ‘breeze’ which is very small coke. Coke is coal which has been heated until all the volatiles have been driven off and thus burns without smoke but with plenty of clear fumes! The fire is livened up by blowing compressed air into the base of the tray and this can easily get hot enough to melt iron. As we are using compressed air at about 150psi for the riveting gun and the holding up bar it is easy to arrange a branch off this supply for the forge.
Back to the firebox. We have it stood in the middle of the floor, Paul is at the forge, Joe is inside the box with his holding up bar and Dennis is stood ready with his gun on the outside. Paul passes a hot rivet, white hot and sparkling from the fire, to Joe who inserts it in the hole, gets his bar in place quickly and then he gives Dennis a shout to let him know he has it dead firm. Dennis immediately applies the gun and starts hammering the rivet straight down into the plate. This first series of blows ‘upsets’ the rivet, in other words it forces it to expand in the hole until it has filled it completely, it flows to the shape of the hole. Experience tells Dennis when this is achieved and he then carries on but swings the handle of the gun round in a circle so that he is hitting the rivet head from all sides. He has chosen a cup size which will allow him to do this without the plate interfering with this action. He does this until the rivet has cooled down to black heat and is perfectly formed. Recognise that when he stops, the rivet continues to cool and as it does it grips the plates together even tighter than the force that the riveting process has applied. This is the beauty of hot riveting, the squeeze that comes into play as the rivet cools.
Once you have got set up, this process goes on very rapidly. While Dennis is knocking the first rivet up, Paul is heating the next, in fact he has a series of rivets in the fire warming up and as he passes one to Joe he moves them all nearer the heart of the fire so that there is a progression. On a very big job like ship-building, the forge may be some distance from the riveters and the hot rivets are thrown and caught by a succession of lads until they get to the job. As long as you have a thick pair of gloves this is a very quick way of getting rivets from forge to hole.
Once every empty hole has a rivet in, the bolts which were the temporary hold are taken out and the remaining holes riveted up. There is a lot of skill in deciding which rivets go in first as the process of squeezing the plates up together alters the shape of the construction slightly because the plates, even though they are cold, swell slightly as they are forced together. This is particularly important on corners and curved surfaces. There is the added complication that in order to accommodate the shape of a vessel it is often necessary to have three thickness’ of plate at some point. These may have to be tapered off before riveting starts so that a perfect joint can be assured.
You may be wondering how watertight a vessel made like this can be. I have seen us make boilers which had to be hydraulically tested to almost 600psi and the riveted joints were tight even at that pressure. Sometimes there can be a tiny weep in a joint. This is not seen as a problem because if left alone it will ‘heal up’ very quickly as corrosion builds in the joint. This can be accelerated by putting a bit of sal ammoniac (ammonium chloride) in the water, a very common practice in the old days. Some old boiler makers advocated pissing in the boiler before filling it with water! What was certain was that, once in service, the natural formation of limescale on the internal surfaces would ensure that these minor leaks healed up very quickly. This was the point where you needed an experienced boiler inspector because he would know what was an acceptable weep as opposed to a leak. The younger, modern inspectors don’t have this depth of experience and this can lead to serious problems as they demand a level of perfection which isn’t actually necessary.
Once the firebox was riveted together, the foundation ring had to be fitted to the base of the firebox. This was done without distorting the ring because it was already a perfect fit in the wrapper having been in there before. This was done by grinding off metal from the inside of the ring where it was proud and building up with weld where it was short. Once we were sure we had a good fit and the ring would still enter the bottom of the wrapper we were ready for putting the box in.
Before the box was fitted we did a thorough inspection of the interior of the wrapper and boiler because it was all easily accessible at this point. Any pits caused by corrosion were built up with weld and ground flat. Once we were sure we were as near perfect as possible, the firehole door ring had to be temporarily fixed in place while we put the firebox in the wrapper. This was easily done by tacking it in place with a few blobs of weld which could easily be ground out once we had some bolts in. We couldn’t put the bolts in to hold it of course because there was only just enough room to get the firebox in the wrapper without any bolts getting in the way. The firebox was put in place under the boiler as it hung on the crane and then the boiler was lowered slowly and the firebox persuaded into place by a few hammer blows where necessary. It was a tight fit on the foundation ring but we eventually got it in place. I had been making special long bolts in the lathe which were a good fit in the rivet holes through the foundation ring. We put one of these bolts through every other hole and tightened them dead tight. The same was done round the firing hole and the firebox was then in its correct position.
We lifted the boiler and blocked it up so that it was at a comfortable height for working on and started riveting again on the foundation ring. Joe got inside with the holding up bar, Paul got the riveting forge into action and Dennis riveted up until all the holes were filled. Some of them had to be drifted into position with a tapered bar and one or two needed cleaning up with the drill but eventually we got to the stage where we could take the temporary fixing bolts out and replace them with rivets. These were done one at a time so as to minimise movement in the wrapper and box as the work progressed. Once the foundation ring was dealt with, the rivets in the firebox hole ring were put in and closed up. When all the rivets were in place the next stage began, fitting the stays. Take note that we were able to lift the boiler and set it on blocks at the perfect working height. In situ repairs don’t allow this luxury and accessibility can be a big problem.
The firebox was connected to the crown and wrapper sides by steel stays which were thinned down slightly in the middle and threaded at each end. I had made these in the lathe while the other jobs were going on. The trick with making these was to cut the thread on both ends in one pass so that they were in pitch with each other. As both holes were tapped at the same time, this meant that the stays screwed in easily with no distortion of the plate. The original stay holes were already drilled and cleaned up in the outer wrapper and these were used as a guide for drilling right through into the firebox. Once these holes were drilled they were all tapped straight through from the outside using a special, long stay tap which cleaned the thread in the wrapper and made a new thread in the firebox. When all these had been tapped the stays were fitted.
The stays were screwed in from the outside until enough thread protruded into the firebox to take a nut. These nuts were all fitted and tightened dead tight. This left enough thread protruding on the outside of the wrapper to form into a head but of course they were cold. Dennis brought them up to a bright red heat with the oxy acetylene burner and then riveted them over into a good head. Once all the stays had been treated like this the firebox was immovably held in the wrapper.
The next job was to fix the long stays in the boiler. The long stays are two long steel bars which pass through the front plate of the shell, in the smokebox at the front and pass right down the boiler, over the crown of the firebox and fix into the backplate of the boiler on the footplate. These were made with a larger diameter thread on the front end so that they could be easily inserted from the smoke box end. At the backplate end there was a shoulder on the stay so that it could be screwed up hard against the plate when in place. The whole of the stay was thinned down enough so that it would pass through the large backing nut at the front. We inserted the stay, slipped the front backing nut on by reaching through the boiler manhole, inserted the stay in the backplate and tightened it up and then screwed the large backing nut up behind the front plate. The nuts were then fitted on the outside at each end of the boiler and tightened dead tight. We were ready for the boiler tubes.
The basic method of fixing boiler tubes is to get them in place and then, using a special rotary, expanding mandrel, expand the end of the tube so that is a tight fit in the hole. In some cases the insurance companies demand a run of weld round the tube once it is in place. This can be a good thing in the firebox as it gives extra metal to withstand the erosion of the hot gases as they enter the tubes. The tubes are cut to length, inserted in the boiler with the correct protrusion at each end and then jammed into place at the smokebox end with a nail, flattened out into a wedge shape at the end. This is to stop the tube turning under the action of the mandrel as the firebox end is expanded. All the tubes are fitted and expanded in the firebox and then the same is done at the front end.
We’re almost finished now, all we have to do is fit the fusible plug in the crown of the firebox. This is a bronze boss threaded to fit a hole in the crown. It is drilled right through but the drilling is filled with a special tin alloy which melts at a lower temperature than bronze. This is a safety device which, if properly maintained, ensures that if the water level drops below the crown, the fusible plug will melt and steam and water will blow down onto the fire and extinguish it. In case you’re wondering why the plug didn’t blow at Harewood when I was driving the saw, we found out later that it was choked with scale and therefore hadn’t worked!
We are ready now for the last job, pressure testing the boiler. All the holes in the boiler shell have to be blanked off and a connection made for the pump. The boiler is filled with water, shut up and pumped up to whatever the insurance company has decided will be the test pressure. Normally, this is 50% higher than working pressure but after a heavy repair like this it is common for the inspector to ask for 100%. This is a very severe test on the boiler and we used to do everything we could to get them to allow a lower test. This wasn’t because we weren’t sure the boiler could stand the pressure but it was possible to do a lot of harm to a boiler by over-testing it. It’s amazing how a boiler can stretch when you get up to high test pressures like this.
There is one problem with hydraulic testing which is peculiar to traction engines. The cylinder block is riveted on to the top of the boiler and the last thing you want to do is disturb this. The problem is that the seal on the boiler depends on the regulator valve on the cylinder being in good order. A joint will leak water cold when it is perfectly tight under steam and very few regulator valves are perfectly seated. The trick is to get to the valve and put a thin sheet of rubber between the valve and the seat. This makes a good seal but you’ve got to remember to take it out afterwards!
We had no problems with this boiler. The required pressure was applied and apart from a couple of small weeps which would heal up in the first few hours of service, the boiler was tight and passed for duty. We saw it a few months later in Swinton after it had been rebuilt and it was as good as new. While we are on the subject of small leaks, I have something to say about amateurs running steam engines! Paul and I used to go round the shows looking at other people’s engines while they were running. Most of them were OK but occasionally you would come across one which had leaking rivets in the foundation ring, badly made joints and various other faults and I was forced to the conclusion that some of the owners must have had very friendly boiler surveyors or very incompetent ones! You can’t afford to take short cuts with live steam, the consequences are to fearful to contemplate particularly when members of the public are stood three feet from the boiler. The regulations are very tight as they stand but in my opinion ought to be even more stringent when the boilers are to be run in public by amateurs. There are no qualifications at all needed in order to be allowed to operate a steam boiler in public beyond those applying to the boiler.
Right, now you know all about making fireboxes for traction engines! Believe me, it isn’t all plain sailing, I’ve given you the edited version. All sorts of strange things can happen, for instance, when the firebox is being riveted together before fitting in the wrapper it expands because of the pressure of the rivets and this has to be taken into account when the plates are measured. A thread might be damaged in the wrapper and this has to be carefully built up, ground to shape and re-tapped before the stay is fitted. The corners of the firebox are very difficult to rivet and get tight and there isn’t room for a conventional head inside the radius so these have to be screwed in and riveted like stays. Surmounting these problems is all part of the skills which can only be acquired through years of experience. Men like Dennis, Paul and Joe are absolutely vital if you have to do jobs like these.
Things sometimes went wrong. There was a good example of this at REW. I noticed once that in the yard at the shop was a complete Lancashire boiler end plate. This was a serious lump of metal, nine feet in diameter and an inch thick. It was drilled and pierced for all the rivets, stays, tubes and fittings ready for fixing in place and I couldn’t understand why it was in the yard so I asked John. He told me that many years before they had the job of fixing a new front plate in a Lancashire boiler. They took particulars, bought the plate, marked it all out, cut the holes for the tubes and drilled all the other holes and took it to the mill where it was to be used. The boiler was shut down and cooled and the gang set to to remove the old front plate and prepare everything for fitting the new one. All went well until they offered the new plate up into place and realised that the rivet holes around the periphery were out of pitch. After a quick reckon up they realised that someone had committed the classic error of counting one of the holes twice when taking the particulars. This meant the plate was useless and a new one had to be made before they could complete the job. Matt Ingoe said the bum plate had to be kept in the yard to remind everyone of the mistake. It was all very embarrassing but occasionally these things happen, human beings are fallible!
We had another riveting job one day which I thought was fascinating. I went with Joe and Dennis to a factory near Bury where they were to replace some rivets in a pressure vessel while I was preparing a boiler for an NDT of its shell. This was a lousy job as it involved cutting the lagging off the exterior of the boiler and polishing the shall along all the welded seams so that the NDT man could get to it to do his stuff. During a break in the proceedings I wandered into the main factory to see what Dennis and Joe were up to. It was a wonderful place! It had originally been a dye works and in those days, dyeing was done in special vessels called kiers. It was one of these that Dennis and Joe were working on.
A kier is like a large metal football about fifteen feet in diameter and made of spherically shaped segments of steel plate one inch thick. Don’t ask me how they made them this shape because I don’t know. I think they were hammered on a large die while red hot but we are talking about plates weighing up to four tons apiece! They have two large steel trunnions mounted on each side and sit in pedestal bearings. There is a large manhole in the shell so placed that when the kier is rotated by means of an electric motor and gearing it coincides with a hole in the floor above. The kier was rotated to this position, the manhole cover unbolted and lifted off and cloth, water and dyestuff loaded in. Then the manhole cover was replaced and the kier brought up to temperature and pressure by injecting steam through one of the trunnions which was made hollow for this purpose. Then the whole thing was rotated for however long it took to fix the dye in the cloth. At the end of the process it was stopped below the hole in the floor above, the cover was taken off and the kier rotated through 180 degrees so that the cloth and the dye fell out into a pit below. From here the dye ran away to waste and the cloth was recovered for further processing.
There were two banks of these kiers in the building. I think there were eight on each side. I was talking to the manager who had come to see how we were doing and he told me that there used to be three buildings like this but they had been gradually demolishing them and converting the factory to modern methods. Then they found out that the kiers were suitable for an entirely different process and switched over to it. What they were doing was filling the kiers with wood shavings and caustic soda and rotating them while under pressure, This extracted the cellulose from the wood and the end use of this was a material which was used to make tea bags and sausage skins! He told me that they now regretted having demolished the other kiers but all I could do was try to make some estimates of what it would cost nowadays to make a new bank of kiers. Assuming the skills were available I am sure we were talking about millions! Dennis and Joe were replacing rivets which went right through the trunnions and two layers of plate. It took the three days to replace four rivets it was so hard.
As I’ve said before, deafness was an occupational disease of riveters and both Dennis and Joe were very hard of hearing. This led to some funny things happening! John came into the shop one day from the office and he was laughing so much there were tears in his eyes. We asked what the crack was and he said he’d just been speaking to Joe on the phone. He’d asked Joe what time they would be finished and Joe had replied “Three and a half inches outside diameter.” And put down the phone! Another time he rang the shop and asked for the trepanning gear to be taken out to them, “Where are you?” “In the phone box opposite the mill!” He then hung up and the problem was that no one knew which mill they were at. We had to wait until they rang in again before we could get the gear to them!
One memorable day, Dennis and Joe fell out. They had been working together for years but occasionally had a bit of a falling out do. I think they were at Burnley Paperworks repairing a boiler. Dennis shouted to Joe, “Where are you?” and Joe answered “Here!” Of course Dennis then shouted “Where’s here!” and one thing led to another until Joe lost his temper, got in the wagon and drove off leaving Dennis on the job. I don’t know how Dennis got back to Rochdale but when he got to the shop he wasn’t in the best of health and temper and started into John as soon as he saw him. The upshot was he handed his notice in but just as he was doing this Joe came in the shop and heard what was going on. “If he’s finishing I am too!” he shouted. John looked at the pair of them and suggested they go and have a pint and talk this over. Of course, common sense prevailed but there was no way Joe was going to lose his mate if he could help it!
Dennis and Joe weren’t the only comedians on the firm. There was always something going on to have a laugh about. I remember being on a job on a housing estate in Salford with Mark Roberts. We were repairing leaks in the district hot water system which had led to it being closed down. As this was early November we were popular blokes! The local kids were watching us closely looking out for any plunder that was going. You had to lock everything and keep an eye on any tackle you were using or it would vanish. The kids were fascinated by what they thought were the big sparklers that Mark was using to weld the pipe. Guy Fawkes night was coming up and they decided they would pester Mark for some sparklers. He gave them a bunch as we were leaving and I have often wondered how many boxes of matches were used trying to set those welding rods on fire!
Paul was always up to something. I had always been in the habit of carrying a bag round with me which contained all the necessary bits which couldn’t be left lying about like my multimeter, set of drills, measuring tackle and all sorts of other odds and sods. Every now and again the contents expanded and the bag had to be cleaned out. I realised one day that it was far too heavy and when I dug down to the bottom there was a 1 ½ inch rivet a foot long nestling in the bag. Paul had put it in there a week before and I had been carrying about seven pounds of iron round with me! He was a brilliant cartoonist and would occasionally chalk one up in the shop. There was a great one of me travelling round the world with my swag and a kangaroo called Eigg! Stuart had a rise taken out of him when he came back after a couple of days off to have a vasectomy. There was a very scurrilous and totally hilarious caricature of him drawn on one of the steel plates on the floor. I should mention that we had a very good storage place for our stock of steel plate. We laid the sheets flat on the floor and used them as a working surface. When we needed a piece we extracted it with the crane, only problem was that sometimes we had put a boiler on top of it! This meant a bit of shuffling about until we could get at it. It sounds like a daft system but was actually very efficient.
WELDING AND RE-TUBING
Very little of the day to day workload was repairs to riveted vessels, by far the greater number of boilers were welded shell economics, in other words, modern tubed boilers. Most of the repairs we did were to rectify faults found during routine annual inspections by the insurance company surveyors. This could vary from minor matters like a crack in a tube plate to a fault being found in one of the welds on the shell of the boiler or, more commonly, in the welds in the combustion chamber. A lot of these faults were actually of long standing and some dated back to faulty welding during manufacture. Available methods of inspection of the welds had improved so dramatically that NDT was detecting faults that couldn’t have been found ten years before. These were usually slag inclusions in the weld due to careless work when building the boiler, failing to clean the slag off a weld before adding a fresh layer on top.
If a fault like this was found during inspection the insurance company would insist that it be put right before the boiler could be steamed again. This wasn’t necessarily a disaster for the firm that owned the boiler as a good engineer would make sure that a boiler was inspected when it would have been off load anyway. For instance, a boiler used for heating only could be inspected and repaired at any time during the summer. A firm which needed process steam all the time would, if properly equipped, have a set of boilers with spare capacity so that one boiler could be off line at almost any time during the year. It didn’t always work out like this, we sometimes got a job at a firm with a single boiler and work in the factory was stopped until we repaired the fault. In circumstances like this 24 hour working was the rule until the job was finished. This was expensive for the firm but they were paying the price for not making the extra investment in the first place. Some firms had Loss of Profits insurance policies which kicked in after the factory had been stopped for two or three days and this eased the burden for them.
Occasionally we saw real cock-ups where the engineer had really blown it. We once had a call to go to a very large chemical works who operated night and day using six boilers. They had a problem with the feed water on one of the boilers during an inspection and the inspector, smelling a rat, looked a bit further into the installation and shut five of the boilers down! This meant the factory was stopped and the loss of profits was something like £10,000 a day. It took us a week to get the boilers back on line and the factory working again. The root cause of this was that they had been economising by not paying a full time, skilled boilerman to keep an eye on the plant and ensure it was working at top efficiency. This is very common nowadays and is usually a false economy because a good boilerman pays his wage by minimising downtime, maximising efficiency and prolonging the life of the plant by good maintenance.
We did have one trick up our sleeve that could be a life saver for a single boiler firm with a problem. In our spare time we built some complete boiler plants on forty foot trailers. These were oil-fired and completely self contained. If a boiler had gone down we could take the whole outfit to a factory, drop the trailer outside the boiler house, couple it up to a water main, an electricity supply and the main steam pipe from the boiler to the factory main. Press button ‘B’ and away we went, the factory had steam, we had the rent for the boiler, and all the time in the world to attack the fault on the permanent boiler. This was very popular with firms in trouble because it was an instant solution and very often the insurance company paid a large part of the costs.
I’ll describe a typical repair to a boiler which failed NDT. Most package or economic boilers have a large insulated door on the front which carries the burner and, when opened, gives direct access to the combustion chamber. This chamber was a large heavy tube about three feet in diameter welded into the front plate of the boiler and connected at the back by flues to the tubes which passed the products of combustion back and forth through the water in the boiler shell to give maximum heat transfer. It was very common to have a failure in the weld where the large combustion tube was attached to the front plate. If it was a small fault the repair was to cut out the weld by grinding and re-weld the joint. However, many inspectors were very wary about the quality of the metal in the front plate which could have been damaged by very high heat gradients during manufacture. In a case like this they would demand that part of the front plate be cut out as well as the weld and the whole lot had to be replaced.
The inspector, working with the NDT man would mark the sections he wanted replacing and these sections would be cut out with an oxy acetylene burner and the edges ground back to good metal giving a vee shape to the edge which is the essential preparation for any weld in thick plate. A cardboard template was cut to the shape of the hole and back at the shop a patch was cut from boiler quality steel and roughly finished. Boiler plate is very specialised steel and is all batch tested before sale. Each plate carries an identification number and this has to be punched into the section which has been cut for the patch. This identifies the plate as boiler quality for the inspector and means that in case of any failure the original test on the plate can be traced back to the manufacturer.
Back on the job the patch is dressed up with a small hand grinder until it fits the hole perfectly with just enough gap at the root of the vee to allow the first weld to penetrate and make a small bead on the inside of the vessel. Once the fit is right, the patch is tackled into place with a few small welds in the root. The welder can settle down now to a long, slow job. A good man will get himself comfortable, if the weld is at low level a seat will be rigged up and all the tackle placed close to hand. The more comfortable the welder, the better the quality of the job.
We are dealing here with plate at least ¾ of an inch thick and in many cases thicker. A casual onlooker would expect to see very thick welding rods working at high currents and depositing heavy beads of weld. Not so, this would be all right if the vessel was not pressurised, say in ship-building but in boiler repair the secret is to use the minimum current to avoid overheating the plate. There are two reasons for this, one is to avoid damaging changes to the crystalline structure of the steel by high temperature gradients into the parent plate, this can lead to what is known as brittle zone failure. The other reason is that as heat is put into the weld, local expansion can distort the front plate or the patch and this can spoil the fit of the patch and introduce tremendous strains in the welded joint as the plates cool and shrink. So, the heaviest rod used will be about 1/8 inch thick and very often smaller than this. As each bead is laid down the welder stops welding and grinds out the top of the bead he has just laid down. This gives a clean base for the next layer and ensures that there is no slag inclusion. The slag is formed as the bead is laid down by the melting of a special coating on the outside of the welding rod. This coating directs the arc and the molten slag, cooling on the bead, protects it from oxidisation until it has cooled down. It is essential to the process but fatal to a finished weld as it has no mechanical strength.
In a thick plate the top of the vee gap can be up to two inches wide and thus takes a lot of filling. If there is more than one section to replace the welder will do a spell on one patch and then move to the other to equalise stresses in the front plate and keep the temperature gradient to a minimum. Eventually the gap is filled and ground off smooth. A good repair is invisible and the only clue to its position is the polished metal. When the weld or welds are complete the NDT man comes in and examines the weld by using ultrasonic testing. It was very unusual for there to be any failures at this stage and if there were they could almost always be traced back to bad testing and not the quality of the weld. If all was correct the boiler was closed up and hydraulically tested. After a repair like this the boiler was actually better than new and went back into service.
Patches like this were a run of the mill job for us. The section cut out wasn’t always confined to the front plate but could be inside the chamber as well. We rolled the plate to the correct profile and cut and fitted the patch in the usual way. Occasionally the inspector would fail the whole combustion chamber and this would be cut out and replaced. These could be very big jobs, one that was done while I was there weighed 11 tons! The skill needed to effect repairs like these was amazing, there were so many ways that you could get it wrong.
Occasionally the welds would fail while the boiler was under pressure. This usually resulted in catastrophic explosion and this still happens occasionally for a variety of reasons. We went to one boiler at a slaughterhouse in Hull and I couldn’t understand how they’d managed to get away without a serious accident. The shell of the boiler had split open at the seam where it met the front plate right at the top of the front of the boiler. I wouldn’t have liked to have been there when it happened but they had been incredibly lucky. We put a portable boiler in there to keep them going and repaired the shell in about ten days. This was a complicated job as the distorted plate of the outer shell had to be cut out and replaced as well.
These welding jobs on the outside of the shell were fairly accessible and the welder had the luxury of working in the open with plenty of ventilation. It wasn’t always like this, sometimes welding had to be done in very confined spaces or inside the vessel itself. This brings me to my polemic on the subject of Health and Safety at work.
One of the biggest problems John had to face in doing repair jobs was conforming to Health and Safety regulations. I have nothing against the regulations themselves, they are essential and application of them has improved working conditions wonderfully in the last fifty years. However, there are jobs which still have to be done and which are impossible within the regulations. The rules have to be bent to accomplish the repair. The problem is that many of the larger companies have a ploy to get rid of their responsibilities under the act. When a gang goes in to do a job the Safety Officer at the factory conducts an ‘Orientation Procedure’ where he lectures men who know more about safety than he does on simple rules like no smoking next to flammable liquids and don’t put your fingers in a live socket. Having given this lecture he gets signatures from the men and then turns them loose on the job. If anything should go wrong the company is covered because they have told the men what they can’t do and responsibility is dropped on the shoulders of the workers. If an accident results in injury they are told that it is their fault and no compensation will be paid. This is fraud because the owners of the factory know, in many cases, that in order to do the job rules have to be broken in the interests of speed and efficiency.
A good example of this would be re-welding Galloway Tubes in a Lancashire boiler. These are vertical water tubes which pass through the firetubes of the boiler and are welded at top and bottom. These welds fail occasionally and have to be renewed. This isn’t a common job now as these boilers are rare but the job is a good illustration of the problems that have to be overcome when effecting repairs in confined spaces. The top weld is no problem as you are working downhill and have a reasonable amount of room, about four feet above the tube. The bottom weld is an entirely different kettle of fish. There is only about eighteen inches of space below the tube. In order to get at the bottom seam the welder has to lie on his back in a confined space and operate on a seam six inches from his face and directly above him. Any molten slag or metal drops directly on the welders face and splatters about all over the place. Of course, the welding screen, the heavy mask with a dark glass set in it to protect the eyes from the glare of the arc is some protection but slag and metal can get in round the sides. The usual protection is for his mate to be with him and keep as much of him as possible covered with a sheet of leather. Leather is very good for this as it is resistant to heat and fire. Even with all these preparations the welder is going to get burns, it’s amazing where a blob of hot metal can get to once it has dropped down your neck. I remember Mark Roberts getting one under his overalls and it finished up burning a hole in his scrotum. He just had to lie there and stand it. He said he could follow the track almost all the way afterwards and it had left a burn right down his chest and belly on the way to its final destination. Mark said that it was ‘character building!’
Another instance is welding stainless steel inside a vessel. All metals vaporise when they are being welded with electric arc. They disperse into the surrounding atmosphere like an aerosol and are breathed in. Only the best breathing masks will stop this but it is impossible to work all day in these. Normal steels aren’t too much of a problem in small quantities because the minute particles of steel oxidise inside the lungs and are cleared out by mucus. Stainless steel doesn’t oxidise and once it gets in your lungs it stays there. The cumulative effect over the years is severe loss of lung capacity. This could be avoided by sophisticated ventilation systems and masking but nobody is prepared to pay the price for precautions like this so the welders breathe the vapour.
Welders aren’t the only people who suffer because economics rules the job. There are many jobs still being done today in the same way they were tackled in the 19th century. Nobody is interested in finding a better way because it would be too expensive. Cleaning boilers and flues is another area where there is long term damage. There was an excuse for this years ago when the dangers weren’t fully appreciated but not today. It was exploitation fifty years ago but it is cynical exploitation now.
Another large component of the work we did was tubing boilers. This could be the replacement of a tube that had failed and was leaking or, in a well run plant, the routine replacement of all the tubes in a boiler when the plant engineer judged they had reached the end of their useful life. If you had a boiler which was dropping a tube fairly regularly it was a sign that the tubes were giving notice that they were on their last legs. The cheapest solution was to arrange for the boiler to be off load and replace the lot.
Re-tubing was fairly simple but could be hard work. The tubes were expanded into the plates front and back and could also be welded to make them more resistant to erosion. The first job after opening the boiler up was to cut the tubes free front and back by eroding the metal of the tube away with a special cutting rod. Basically this was like a welding rod but formulated to give a very powerful burning arc at very high currents. A good man could ‘wash’ the metal of the tube away without damaging the tube plate. Any accidental nicks could always be filled with a drop of weld afterwards and re-ground to profile. Once all the tubes were freed from the tube plates it was theoretically simple to withdraw them. However, all was not plain sailing at times!
Paul and I once went to renew a couple of tubes in a new boiler at Dunlop’s factory in Manchester. The manufacturers of the boiler had farmed the job out to us of replacing the defective tubes under guarantee as this was cheaper than sending their own men. As soon as we walked in the boiler house I could see we had a problem. Paul had seen it as well and he told me to get the engineer and sort it out while he got set up. I got hold of the engineer and he came down to the boiler house. He was only a young chap and I don’t think he had any idea of what was involved in replacing his tubes. “What’s the problem?” I told him that there wasn’t room at the front of the boiler to withdraw the tubes. They were twelve feet long and the wall of the boiler house was only eight feet from the boiler! His face lit up as he identified the solution. “Pull them out six feet, cut them off and then withdraw the other six foot length.” I pointed out to him that this wouldn’t do as we couldn’t cut the new tubes when we put them back in. What I wanted off him was permission to cut a hole in the wall of his new boiler house on the same level as the tubes so we could draw them out from outside. He eventually saw the problem and said it would be OK. He had some builders working on site and would send them down to make the hole good after lunch.
Paul and I got going, I knocked a hole in the wall for the tubes and we were almost finished after lunch when I heard sounds of activity outside. I went out round the back of the boiler house and there was a chippy working on a trestle fitting a splendid little frame and door over the hole where we had drawn the tubes out. He told me that the engineer had told him to do this so that next time they could just open the door instead of knocking a hole in the wall. I pointed out that his door would only accommodate two or three of the 180 tubes in the boiler and that they would finish up with a wall full of holes! He saw the point and went off to recommend that one large door be made and fitted! You would be surprised how many boiler houses were made like this with no room around the boiler for essential maintenance.
The other big problem when drawing old tubes out was that after say ten or fifteen years of use they were no longer smooth and shiny but corroded and crusted with scale from the minerals in the water. In order to get the new tubes tight the holes had to be as near the external diameter of the tube as possible so they wouldn’t come out of the hole easily. The cure was to drive the tube inside the boiler and grind the hole out slightly larger with a high speed grinder. Once we had one tube out we would use this larger hole to get its mates out and then repeat the operation when necessary on another hole. These larger holes were still serviceable because we could expand the tube to fit but we didn’t like doing it. Even with a larger hole the tubes could still cause trouble, especially the ones near the feed water inlet into the boiler where the scale build up was worst. I’ve seen me and Paul go to great lengths to set up a block and tackle so we could drag the tubes out like that.
Once all the old tubes were out we could set to with the spindle grinders and clean the tube holes up. The better the finish, the better the tube would grip and the longer they would last. Some of the tubes in the boiler were ‘stay tubes’, these were very heavy walled tubes which acted as strengthening stays between the two tube plates. Normally these didn’t need replacing but on an old boiler these might have to be done as well. These were welded into place front and back.
When all the preparation was done we could start replacing the tubes and expanding them. We had an air operated torque arm which we used for driving the expanders but in some places they had to be done by hand with a ratchet and that was hard work. When they were all back we would fill the boiler and hydraulic test them. We didn’t need the inspector present for this, it was our check on tube tightness and he wasn’t interested as long as the tubes were tight when the boiler was running.
In an emergency, if a boiler had done a tube but couldn’t be taken off line, we would make steel plug and weld them in each end of the faulty tube. This would keep the boiler on line but the inspectors didn’t like it. I’ve seen them cured with a wooden plug driven in tight in an emergency!
The standard of maintenance on boilers varied from firm to firm. It was a constant source of wonder to me that a company that lived and died by the ability of their boilers to raise steam would try to save £10,000 a year by not having a full time boilerman. A lot of the problems this caused were actually down to the boiler inspector. If he was lax in his annual inspections problems could build up until they made a good job impossible. A good example of this was a boiler we went to once at a paper works. They had several boilers connected to one main going into the works and we were called to weld up some cracks in the tube plate of one of the boilers which was off line. I was with Dennis at the time and while he did the tube plate I made a new valve for the feed water tank. As soon as we opened the boiler up we knew we were in trouble, it was like an oven in the combustion chamber! We soon realised that this was due to the fact that the Board of Trade Valve which was the statutory isolation valve that should have shut the boiler off from the steam main so that steam from the other boilers couldn’t leak back, was faulty and passing steam. There was another isolation valve, the crown valve on the boiler. When I tried to close that it was seized solid! This is very dangerous and doesn’t happen all of a sudden, it takes years of neglect to allow a valve to get into that state. By fiddling around we got the valve working but it was still leaking. We got the temperature down enough to allow Dennis to get in the chamber to do his repair welding but I told John that if they wanted a hydraulic test they’d better do it themselves.
Another thing that intrigued me at this works was the fact that the large safety valve on the steam main was leaking very badly. Most safety valves will ‘feather’ a bit under pressure but this one was roaring steam out. John said that it had been like that for years because in order to repair it they would have to close the plant down. The amount of steam they were wasting meant that a 24hour shut down would be a very cheap option but no, they just carried on. Things like this were down to the engineer in charge and one wondered many a time about their competence.
We took a big job on up at a works in Cumbria at one time. The plant was dedicated to converting slaughterhouse waste into ‘protein granules’ which were used in the manufacture of pet foods. All these plants used a lot of steam for the processes and we used to hate going to them because of the small! This one wasn’t so bad because the plant had been rebuilt after a long closure due to fire and we were re-commissioning the boilers for them. To give you an idea of how bad the smell could get, on the night the plant caught fire, the locals all drove their cars up and parked them in the lane down to the plant so that the fire brigade couldn’t get down to put the fire out! By the time the police had traced the owners the plant was destroyed.
Our job was to get the two large boilers back on steam. Basically it was a simple job, remove all the fittings, take them back to the shop and refurbish them all to new standard and then refit them and steam test the boilers with the inspector in attendance. One of the boilers was a bit more complicated as it had a bulge in the wall of the combustion chamber. This was a sign that the plate had overheated at some point under pressure and distorted. It wasn’t too bad so the cure for that was to jack it back into its correct position but the inspector said it would be alright as it was! John told me afterwards that this had puzzled him as well, however, once he had said this it wasn’t our responsibility. If it had been really bad we would have had to remove the tube and fit another one which would have been a very big job. I remember this job particularly because as I was doing one of the large eight inch safety valves in the shop a spectator who was watching over my shoulder took me to task because of the time I was taking re-cutting the valve seats. He reckoned I had done enough but I knew I hadn’t got it just right and so ignored him and did it my way. I made several trips up there to remove fittings and then replace them afterwards.
A couple of weeks later John sent me up to be there when the boilers were given their steam test by the inspector. The test consisted of firing the boiler from cold, watching for any leaks and rectifying them, testing the safety systems and then firing right up to maximum pressure and ensuring that the safety valve lifted at the correct pressure. This last item was in the lap of the gods because, having skimmed the valve seating surfaces you had to set the spring pressure on the valve by guesswork. We fired the first boiler on ‘kindle’ which was the lowest flame setting and the first thing I noticed was that the flame, which should have been about six feet long, filled the whole of the furnace! God alone knew what it would be like on high. The boilers had been notoriously hard pressed before the fire and I pointed out to the inspector that they must have opened the burners up as wide as possible to keep pressure up and this was probably what had overheated the combustion chamber and caused the bulge.
We carried on with the test and watched the pressure gauge carefully. You can usually expect a bit of feathering as you get close to the lifting pressure but the valve never wept at all. The inspector looked at me as we hit 150psi and said “You’ve slipped up with this one!” Just as he said it the valve snapped open and unloaded with a roar like Concord taking off. I think I must have jumped a foot in the air, he certainly did! The pressure dropped back five pounds and the valve snapped shut as suddenly as it had opened. Just at that moment the engineer came in and said, “That’s how they ought to work, sounded like a pop valve on a loco!” I looked at him and told him I was pleased with the way it was working but I could do without shocks like that! I was very suited actually because that was exactly how a safety valve should function but they seldom did. Another thing about it was the fact that because it was so tight, there would be no feathering and so the seat wouldn’t get eroded. It would be a good valve long after I had lost interest. We tested the other boiler, this wasn’t quite as sudden as the first but was still perfectly acceptable. I went of down the road feeling quite pleased with myself!
We often had to go and put right boilers after there had been quite serious failures. We went to one at Stainland which was a complete refurbishment after a flue explosion. The boiler was in a derelict mill and it was doubtful if it would ever run again but because the insurance company would only pay for the repair and not shell out cash just to fulfil the terms of the policy, we had to go in and make it like new. What had happened was that two ‘experts’ had been called in to commission the boiler to make sure it was in running order in case a buyer was found for it. They had looked the boiler over, decided it was running on black oil and had turned the oil heaters on to get ready for a start the next day.
Black fuel oil is very thick oil refiners residue which, at normal temperatures, has the consistency of very thick treacle. In order to get it liquid enough to flow through the burners it has to be heated to a temperature not far short of boiling water. By turning the electric heaters on the two experts had made sure the oil would be hot enough to flow the following day. What they hadn’t realised was that the boiler was running on 28 second oil which was nearer the consistency of kerosene and didn’t need any heat. During the night the heaters boiled the oil and the flues filled with explosive vapour. They came in the following day, opened a couple of valves and pressed button ‘B’. They got the shock of their lives and were very lucky. The vapour exploded and blew the flue covers of both ends of the boiler. I was talking to an old bloke who had been walking his dog nearby when it happened, he said a big cloud of soot blew out of the chimney and then these two blokes staggered out of the boiler house and seemed a bit disoriented! I’ll bet they were! We were there about ten days putting everything to rights and I often wonder if the boiler ever got moved or whether it is just laid there, rotting quietly away.
We often had to install completely new boiler houses. We did one in Yorkshire and the contract included a new chimney. We had a second-hand chimney in the yard and John decided that this could be refurbished. My job was to take the old cladding off it and give it a coat of aluminium paint before it was lagged and covered with new aluminium cladding. The chimney was in two sections and I painted the bottom half outside before we brought it in for lagging and cladding. I painted the second half inside and because it was winter I closed the workshop doors. After a while, Les the tinsmith realised I was acting in a peculiar manner and came down to me. I had got too many of the paint fumes down me and was definitely drunk! I soon came to but had a whale of a headache afterwards!
The chimney was about 80 ft. high and on the day when they were lifting the top half on to it I was called out to them to take some heavy bolts for the flanged joint between the two halves which they had forgotten. When I got there David Sterricker asked me if I’d go up and help Mark put the bolts in as he had no head for heights. After my chimney climbing days this was no problem so he brewed up while Mark and I bolted the top half of the chimney on. As a matter of interest, in case you ever have to do one, I’d better tell you how we managed to lift the chimney up and get the slings off it without having to climb to the top. We welded two pieces of plate into the top of the chimney diametrically opposite each other. These were shaped so that when they were in place there was a horn of metal pointing downwards on each side. Two chain slings are caught on these horns and as long as the weight is on the lift they will stay in place quite safely. Once the chimney is in position the crane driver has to be careful not to let the weight go off the lift until the bolts are in place. Once this is done, he lets the chains down and with a bit of luck they will swing clear of the horns, if not, a bit of judicious jib wagging will get them clear. Job solved, simple isn’t it!
I did almost four years at REW and it saw me over the move back into Barlick but it was hard work. I had to be away from home by 06:45 winter and summer to be at Rochdale on time for work. As is usual in these cases I was almost always the first one there even though I had furthest to go! I enjoyed the work and learned a lot of new stuff but come 1997 the government were making some changes to the way self-employment was treated and it became obvious that while John wasn’t going to sack me, it would be a good idea to look out for something different. I also had the idea in my head that it would be better if I was nearer home. I remember going home early one day and as I was coming up to Barlick there was a delay in traffic and I found myself stopped in the middle of the road waiting for the blockage to clear. I noticed I was level with the lane that led down to Lower Park Marina on the canal and on the spur of the moment, drew across the road and went down the lane. I’d see if they had any work!
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