Not only did Trevor eventually make the patterns for the double chimney, he made those for the blast pipe and safety valve bonnet. In addition, he got all the items cast by an amateur foundryman in the back garden of a Wolverhampton home. The chimney was cleverly cast in three sections, the centre section of copper so that it would form the copper cap. All this pattern work was done on the kitchen table of Trevor’s home and I will always be eternally grateful. Whilst I did all the engineering on the project myself, this was not to be the last time that I would use Trevor’s extraordinary expertise.
After some two years’ work on the engine, I felt that I should begin some work on the tender. I didn’t want to get the engine nearly finished and then start work afresh on the tender, which in itself was a lengthy project. I eventually bought 3,000 one sixteenth brass rivets and there was not many left on completion. The brass plate was purchased from a supplier near Snow Hill Station, Birmingham, and I was not at all eager to drive through the city centre at my time of life. Large sheets of brass plate are also not conducive to bus travel. I therefore felt that the best plan would be to go by train when it was quiet. The weather then turned sour just as I left the trade counter, somewhat loaded. The wind was so wild that it took all my wits and strength to walk in a straight line back to the station. On arrival at the station there had been a substantial signal failure and the platforms were now akin to the Aston Villa terraces on Saturday afternoon. I also now could not get on a bus as I was seriously in danger of lacerating someone’s arms or feet! An errand that should have taken an hour now took most of the day, as I had to wait until the crowds had gone once the service was up and running again. I think they term it ‘Sod’s Law’!
As the years of work went on I began to realise why Trevor had never seen an engine finished built to his design. Some issues were also extremely challenging, yet very absorbing. I think it is possible that it was the fact that so many people were now showing an interest in my project which was the incentive to keep my momentum going. And at my age, I was never quite sure how much remaining time I had!
Three years’ work and the boiler is almost ready to be offered up to the chassis.
One of the outstanding features of Great Western four-cylinder engines is the outside steam pipes from the smokebox to the cylinders. I was at a loss as to how I was going to overcome this issue, and again I consulted Trevor; I really wanted these features to look right.
A few weeks later he was back with not only the answer to the problem, but more patterns. I was impressed by Trevor’s first patterns, but his latest work was totally baffling to me as to how he even arrived at the idea. That is, without having to offer them up to the actual job, as I would have had to do.
The firebox back plate with some of the fittings.
Again, a few weeks later Trevor came back with the castings in aluminium. Also, he had an extra casting made of the core, together with an extension, making this item easy to hold. On this core, when it had been cleaned up, I could attach the pipe cover shells for final finishing. Trevor’s forethought was again to be admired. How I respected his craftsmanship, it was a privilege to be acquainted with such men.
Trevor then came up with an encore; he came with heavy aluminium-cast formers for the cleading on the throatplate and the firebox back plate. These allowed me to form the remainder of the boiler cleading out of guilding metal.
I estimated when I took on this project that it would take all of ten years, when in fact it was complete, but untried, in seven years. I feel that this was only due to Trevor making so much available to me, items that I would have had to source, or indeed make.
I did not have fond memories of working on the engine with the bell on the front. It may have been coincidence, but engine No. 6000 King George V didn’t appear to be a star performer despite its notoriety. Many sparkling performances have been recorded by enthusiasts logging journeys from Paddington to Plymouth. I have yet to see the flagship of the class get a mention, so perhaps I haven’t been biased. I decided to number my engine 6011 King James I, as it was the engine that I worked the most. Being based at Stafford Road Depot, Wolverhampton, it was regularly diagrammed on trains that Tyseley enginemen worked, and I never recall an indifferent trip.
There will always be those who can find fault, so it did not surprise me when a gentleman advised me that I had got the tender transfer on the wrong way round; the lion should be facing forward, I was reminded, and I was very disappointed that I had failed to notice this. However, the gods were with me; I found a photograph of 6011 after the engine’s final general overhaul at Swindon. The lion on the tender transfer was facing backwards!
The outside steam pipe cover shells before cleaning up. The cores right were cast to aid the finishing process.
The outside steam pipe shells mounted on the core for easy finishing.
The outside steam pipe cover shell fitted to the engine.
6011 King James I after the engine’s final overhaul at Swindon. The lion on the tender transfer does face backwards.
The ‘King’ tender under construction. I bought 3000 brass rivets and there weren’t many left.
The double chimney made to Trevor Shortland’s pattern.
The double blast pipe casting made to Trevor Shortland’s pattern.
One of the experimental valve heads showing how the P.T.F.E. expanded into the ports making removal very difficult.
One of the steam chest liners showing the shiny high points because the reamer had taken slightly more metal from where the ports had been cut.
One of the steam chest liners, showing the valve head at the point of allowing a full port of steam to the cylinder. Only the inner valve ring makes a seal, the outer and centre ring is over the exhaust port and therefore not making an effective seal.
CHAPTER NINE
Working on the ‘King’ project brought home to me the importance of being a member of a model engineering society; so many members were to bend over backwards to offer help. The engine had also become considerably heavy and Barrie Chalmers made a wonderful loco stand for me, assisted by Brian Chapman, another ex-B.R. fireman. Barrie drove to Hemel Hempstead and back for the extruded rail and wanted nothing in return. Frank Abbott, the society’s chief engineer, expertly TIG welded my stainless superheater tubes. Not an easy problem for an amateur to overcome due to the temperature these fittings are subject to.
There again, materials came my way from all quarters and I shall always be so very grateful. The engine also had become impossible for me to transport alone; it would hardly go into my 1982 Mini Estate!
The day drew near when the first running test was to take place, something I really wanted to keep under wraps to some extent. I certainly did not want to be embarrassed, as had happened in days gone by. The first runs are always most unpredictable.
Whilst many extraordinary model engineers that work on similar projects seem content just to have their work admired, I could not wait to see my engine breathe fire.
I should have foreseen the amount of interest that would follow. Naturally, an awful lot of folk turned out to see the engine run.
Society members Frank Abbott and James Gorton transported the engine for me. James, being a very capable driver, did most of the preparation work under my guidance, as it was new to us all.
My engine nearing completion, stood on the stand that Barrie Chalmers and Brian Chapman kindly made for me.
We towed the engine around the track initially with the society’s petrol engine. The track curves are down to fifty feet radius and we needed to see if the engine negotiated these freely.
The first problem to manifest itself was that the tender was prone to derail. Disappointed as I was, I felt we would steam the engine and do some tests on the straight sections of track where the tender seemed content.
However, the steaming did not go well; the piston valves bypassed steam rather more than I would have hoped, even bearing in mind that they generally need to bed in for a while. In turn, the ex
tra draught raised the temperature of the fire, making the new boiler foam badly. Water then entered the cylinders and small debris washed from the boiler blocked the scale small bore of the drain cocks. There was now some possibility that the cylinder covers may blow off; these being made to scale made it more than likely as this was known to occur in full size. So the test was brief, yet there were positives – the injectors worked perfectly and we were able to do the steam test for the boiler certificate. Nevertheless, the day was a sickening disappointment.
However, after a night’s sleep I felt differently and next morning I was back in the workshop pondering over the anomalies. Foremost, I tackled the problem of the tender springs. This was easily solved, I thought, by inserting stout coil springs into the spring cushions after removing the rubber shock-absorbing material. These coil springs were commercially available and when assembled they are just visible when the tender has no weight on it. Therefore, they do not spoil the aesthetics of the tender chassis and this modification seemed to cure the problem of derailment. The tender rode well too, the hard leaf springs tended to soften any ‘bottoming out’.
My problem with the piston valves passing steam had long become the bane of my life, but in no way do I wish to be critical of Trevor Shortland’s expertise. He did an incredible job scaling the down the original Swindon drawings, and there were no calculators available to him then!
My first set of eight valve heads were made to the drawing, each valve head having five component parts. The only piston valves that I had made previously to those were of the plain bobbin type for my 5" Gauge ‘Speedy’ and a 3½" Gauge ‘County’.
The tender springs after modifying. The coil springs are just visible with no load on.
Knowing, therefore, that these components must be made to exacting standards, I took every care that I knew how. Unfortunately, when the first tests were made while running the chassis on air pressure, these valves proved to be more than disappointing. Following this initial test, the valves were taken out many, many times for additional work. I spent innumerable hours lapping the sealing surfaces together with flour of emery in an effort to conquer the problem. These countless adjustments all proved to be of no avail. It did cross my mind at the time as to whether there was in fact a design problem. The .125" square section of the valve rings seemed far too inflexible to me; they also tended to make the valves feel tight in the liners. Would it not be better to have a solid valve head with rings of lighter section? There again, whether my standard of engineering was good enough was also a further consideration.
A valve head, as per the drawings, having five component parts.
A further idea was to go ‘modern’ and fit P.T.F.E. bobbins, although at my age, I do tend to be rather stuck in my ways and do everything traditionally. Suggesting to me to go modern was rather like me telling my grandmother that she should wear a mini skirt!
However, I eventually bowed to making P.T.F.E. bobbins, the results of which, when running the chassis again on air, were quite heartening.
Sometime later came the first static steam test at home with the wheels jacked up from the rail. Alas, when the regulator was opened the engine refused to make a single revolution. The reverser too, bound up solid, which again I feared pointed to further valve problems.
At this point I was pretty gutted; I really didn’t quite know what to do next. When these P.T.F.E. valves were taken out, I might add with some difficulty, the material had obviously expanded to some degree. The pattern of the steam ports was well and truly imprinted on each valve head where the material had forced its way into the ports. Obviously, when using P.T.F.E. some allowance for expansion is necessary. In my case this could only ever have been achieved by experimenting to get the best results for the particular diameter of the steam chest. This may have taken any amount of steam tests and could undoubtedly have become a very drawn-out process.
Whilst I toyed with this problem, the Elmdon society’s 7¼" Gauge ‘Highlander’ developed a steam chest problem. As the society has a commitment to run trains on the Wythall Museum open days, I have always put time aside for maintaining the society’s engines. As a very small society we survive under the shadow of the giant Birmingham S.M.E. with all their wonderful facilities; my thoughts have always been, therefore, that our club engines are its heart. These engines are also important to maintain the interest of our younger members who cannot afford to buy a locomotive, or indeed the tools to make one. We certainly do have to value every member, particularly the younger folk.
The valves on our ‘Black Five’ locomotive had run for many years without problem, or any attention, so removing these was to prove very interesting to me at that particular point in time.
The ‘Highlander’ piston valves proved not made to the original Martin Evans drawings, but had two 3/32" wide rings fitted on solid heads. Two of these rings had, however, cracked, and there was also a chip of metal missing from one of the valve heads.
I made a new valve head and the grooves were conveniently cut with a .093" parting tool. The rings were then made by turning a cast iron round bar down to the exact diameter of the steam chest bore. The inside was then bored out to leave a .050" thick tube and then parted off in rings of .093" in width. This was quickly achieved by locking the lathe traverse and using the micrometre dial on the top slide. The rings came out little more than a thou over size and were lapped down to a good fit in the grooves. Each ring was then put in the vice and cracked using an adjustable spanner to a snug fit. A piece of .093" metal was then held in the vice and the ring opened until it gripped the piece of metal. A blow lamp was then applied to the ring away from the split until the stress in the ring decreased and allowed it to flop over. An article that I had read earlier gave instructions to apply heat for some twenty minutes, but when I did this the ring distorted in the vicinity of the crack. Heating for just a short period does appear to be quite satisfactory.
A piston ring held ready for heating.
Once these new valves were refitted to the engine and the timing reset, the ‘Black Five’ went around the track with the reverser notched well back towards mid gear and the regulator wide open. There was no blow by and the engine still had four crisp exhaust beats. This experience was to give me great encouragement as to my standard of engineering. So impressed was I, that I decided to copy this design for my ‘King’, although my engine steam chest bore is only 1", in comparison to the Black Five’s 1¼".
With this design of valve eventually fitted to my engine, I first ran the chassis on air. Incidentally, when I had made the later new valves, each valve head was mounted on a mandrel and inserted into a jig bored out to 1" diameter. With the rings fitted to the bobbins, they were then lightly lapped in with flour emery until the valve heads made it difficult to withdraw the valve head from the jig, so good was the suction. An encouraging sign was that there was a considerable ‘pop’ when every valve head came out of the bore. After, the valve heads were washed in paraffin and cleaned thoroughly before being attached to the valve spindles. After refitting all the valves to the engine I now felt quite confident that I had finally cracked the problem. Regrettably, when another test run on air was made I could still feel some blow up the chimney before the engine started to run, making an even closer examination necessary.
I started work on the right-hand outside cylinder by uncoupling the valve spindle and removing the cladding from the external steam pipe. I then coupled an air-line to this steam chest only and with the valve central the air was turned on. There proved to be no blow of air up the chimney at all. This certainly indicated that this valve was capable of making a good seal. However, when I moved the valve to either end of the steam chest, there was a noticeable draught up the chimney.
On studying the drawings, I then realised that when the valve was allowing steam into either end of the cylinder, which is the most likely place for a valve to pass steam, only the inner valve ring was effectively making a seal. The outer ring was now over t
he exhaust port and therefore ineffective. I was quite heartened by noticing this, as the valve head is unlikely to be totally steam tight in this position, as some steam would always pass through the gap of a single ring. A little steam from eight valve heads adds up to a lot of waste steam up the chimney, I thought. I now felt that possibly fitting a central ring to all the valve heads may be a simple solution to this difficulty. Alas, I was soon to discover that the fitting of this third central ring to the valve heads was to do little at all to improve matters.
I now took the bull by the horns, as I was fully prepared for many more weeks’ work. I knew then that a second track run would be a long time coming. Eventually, I decided to extract the steam chest liners from the right-hand cylinder with a series of extractors. The issue then proved to be rather more than a valve head problem.
The new modified solid valve heads, with the third ring.
The reason for the trouble now became apparent. My procedure for making the liners had been, after cutting out the exhaust and steam ports, I finally put a 1" reamer through them all to bring them to size. Regretfully, on doing this, the reamer had removed very slightly more metal from where the ports were cut away and left the intersections slightly proud. This was now only noticeable because the valve rings had polished some high spots, yet when I made the liners initially, after reaming they looked perfect.
The Mettle for Metal Page 8