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LOCO REPORT July 2006
July 2006 proved to be a very positive month as during the middle ten days ”Clan Line” cleared three important hurdles on its progress back to operational status. The first hurdle was that of re-weighing the locomotive and tender, a process in our experience, which although necessary, is not undertaken lightly. The reason for weighing a locomotive is not of course the find out the total weight of the machine, but to adjust the load on each individual axle bearing to their design weight, thereby reducing the chances of running a ‘hot box‘ and all of the associated problems that will cause. When correctly weighed, the locomotive is properly balanced with the total weight correctly distributed over all axles, it being particularly important that the correct weights are available on the driving axles.
The second success was a paper exercise, so did not involve the regulars at Stewarts Lane, although there was some input from the engineering team. As part of the re-registration process which will allow our locomotive access to the main line, an application for derogation against certain modern railway standards must be submitted to the Rail Safety and Standards Board. This document gives a brief history of No.35028 and over many pages of detailed submission describes each area where Clan Line does not conform to current practice, and continues by way of mitigation to explain why it is still safe to operate the locomotive on the modern mainline. Basically I suppose it is what is called these days a ’risk assessment’. This document was compiled on our behalf by our V.A.B. (Vehicle Assessment Body) and is the first part of their contribution to providing us with the necessary certification for “Clan Line” to operate on the main line.
Our third success during the month has been the official hydraulic test of the boiler; this again is another tick in the box for our V.A.B. enabling them to eventually issue certification. Progress is good at present as we approach completion. Mechanically there is little left to do, but it is likely that the installation of T.P.W.S. (Train Protection and Warning System) and O.T.M.R (On Train Monitoring and Recording) will occupy us right up to the last minute and then the fun begins with all of the system testing. Until this is checked and approved No.35028 cannot turn a wheel on the big railway. Provisionally we have requested test running in the last quarter of 2006, so theoretically by the time you read the next report from me, our five and a half year slog will be over and “Clan Line” will be roaming the rail network once more.
Back to reality again and the continuing steam pipe saga. I mentioned last time, the problems encountered with their fitting. Two of the three were fairly easy to deal with although they took longer to secure than estimated, however the third, the drivers side, turned out to be a bit of a marathon taking something like five working days to install. No matter what was done we could not reconcile getting each end of the steam pipe together with its seating rings and the steam pipe gland to fit correctly at the same time. Eventually lateral thinking played a part in the solution, and subsequent tests connected with the boiler hydraulic test indicated that we should have no steam leaks. With the steam pipes fitted it was now time to fit the remaining smoke box furniture starting with the blast pipe and chimney alignment. Now that we have a brand new smoke box, all items fixed to it require their fixing holes to be marked off and drilled. With the use of a simple plumb bob and straight edge, and having ensured that the loco was sitting level, it was a fairly simple task to position the chimney over the blast pipe very accurately. However drilling the holes for the securing bolts was more of a problem being some twelve feet above rail height! With the chimney fitted, the chimney petticoat could be bolted to it, to be followed by a completely new stainless steel blower ring. The connecting pipework for the blower ring and ejector exhaust are now in place as well as the refurbished spark arrestor which fits between the blast pipe and chimney petticoat. Finally new special packing has been fitted to the sealing ring on the front of the smoke box and the refurbished smoke box door assembled. At the other end of the locomotive, work has continued on installing the rocking grate components and the fitting of the ashpan sprays. Due to the proximity of the ashpans to the frame stretchers, some of the pipework was less than ideal, and the opportunity has been taken to improve this situation, and with the grate installed, the fully overhauled fire hole door has been fitted.
It was now time to consider attempting our own hydraulic boiler test following the fitting of the overhauled gauge frames and blanking off the pads where the clack valves are located. The safety valves prior to fitting had been set at 260 p.s.i., the boiler filled and the pump connected. Inevitably there is air trapped somewhere in the boiler and this must be compressed before any pressure is indicated on the calibrated gauge. Slowly pressure is indicated and raised slowly in stages until the test pressure is reached. In this first attempt three problems presented themselves which would require attention. The packings for the gauge glass cocks were leaking badly despite being adjusted (not a problem as these can easily be renewed), several leaks were apparent from the studs securing the regulator stuffing box cover (these could easily be sealed), but more seriously the regulator valve appeared to be leaking badly as water was appearing in copious quantities from the steam chest drain pipes. Head scratching time. The regulator valve and mating seat had been machined and lapped in order to produce a steam tight seal. That was the theory, so what was wrong? There was only one way to find out, but this required the removal of the dome cover, something not easily done due to its weight and without the use of a crane. The problem was soon found, and ’Sod’s Law’ had intervened once more. With hindsight dimensional checks should have been made, but they weren’t. Over many years (mainly B.R.) the regulator valve and seat have been machined to restore its condition so that it will hold boiler pressure without leakage. For the first time that I can recall we have machined the seatings in a similar fashion removing the minimum material (at most 1/32” from each face). Of course over time all of this machining adds up with the effect of lowering the seating position in relationship to the linkage that operates it. What we found was that with the regulator handle in the cab in the fully closed position, the linkage in the dome was fouling the regulator main casting thus preventing the valve from closing onto its seat. Having dismantled the valve and checked dimensions against drawings, we were able to determine just how much had been machined away over the years, and therefore how much restoration was necessary to bring the assembly back to the original position. After much discussion the solution decided on was to machine a spacer and place it underneath the valve seat thus raising it to its original height and in so doing raising the linkage likewise. With these three problems dealt with, a second hydraulic test was attempted which proved our repairs satisfactory, only to find further problems with leaking washout plugs. Washout plugs have never been a problem to us since they were all renewed and the threads in the boiler re-tapped during our previous overhaul at Southall. Now several decided to leak, and would not tighten further. Following inspection having removed the plugs, a decision was made to purchase a new tap to re-cut the boiler threads and fit new plugs, which fortunately for us was achieved within a week due to extremely good service from one of our suppliers ’South Coast Steam’. A third society hydraulic test proved satisfactory paving the way for the official test. A point to make here is that now the official test has been accepted, the boiler ‘clock’ has started ticking on its ten year course!!
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The problem under the dome cover Photo: Mike Turner
Many smaller jobs have been completed recently including the fitting of all new vacuum and air hoses together with new water bags which transfer water from the tender to the injectors. New oil trimmings have been made for the trimming boxes and where required on the motion, and soon it will be time to fill the lubricators, axle box trays etc. and fit new corks ready for test running. The smoke box sandboxes have been fitted and filled as have those on the gangways. Also now fitted are the steam pipe covers, however the latter will require a few minor repairs, and so we will send for ’Jones the Steam’ who worked marvels on the boiler cladding repairs. A new section of the pipe which supplies steam to the air compressor has been made and fitted. This has been necessary due to the corrosion it suffered under the footplate, and also we have taken the opportunity to make a better job of it this time around, as previously it was a bit of a rush job during the final days of the Southall overhaul. With the imminent weighing of the loco/tender, thought was given to fully loading the tender (the locomotive boiler already being full). It was an easy enough to fill the tender with water, however with no availability of motive power the tender was uncoupled and moved by hand beneath an overhead crane in order to load 7½ tons of coal. Fully laden the tender was then pushed back and temporarily re-coupled to the loco. We had been informed that the ’North York’s Moors’ operated a mobile locomotive weighing service and we commissioned them to weigh “Clan Line”. Past experience for us has been somewhat mixed in our attempts to balance our locomotive, although our results have never resulted in running any ‘hot boxes’. We were most impressed when their representative Brian Crouch reported for duty with a fully laden van at 8.30 a.m. sharp on Monday 10th July. Heavy beams and levers were familiar to us as we had used similar equipment previously, but where ours used hydraulics and pressure gauges calibrated in tons, his had been modified and used load cells and digital readouts calibrated to 1% accuracy. The equipment took quite a time to set up but had the advantage that it could accurately weigh and display the weights on all of the wheels on the loco at the same time. Firstly the position of the axles was marked in chalk on the rails and the loco/tender moved clear. Next the beams and levers were laid across the pit between the rails coinciding with the chalk marks and the loco moved back over the equipment. The load cells were next assembled to the levers and pivot blocks placed between beams and levers. These were then adjusted until the outer end of the levers rested underneath the flange of the loco tyres. Load was then gradually applied to the load cells until the tread of each tyre was raised above the rail by the same amount using a feeler gauge. The load on each wheel was thus displayed on the digital readout in metric tons, and at a glance it could be seen where the load was too heavy or conversely too light. A decision then has to be made on just where to make an adjustment, which is done on our locomotive’s driving wheels by substituting thicker or thinner cotters using a small hydraulic jack to compress the spring. Having made the primary adjustment the clearance between each wheel and rail was checked and adjusted as necessary and the readings consulted to see if improvements had been made. It is a little like trying to balance a jelly, because if load is applied in one place it will be removed from somewhere else and not always where predicted. The bogie and bissel truck have coil springs and are therefore easier to adjust, but to get the correct designed weights on all wheels is all but impossible. The other parameter you have to consider is that the buffer heights must also be correct. Improvements were soon made, each attempt usually being better, and by 4 o‘clock we were satisfied. Brian said to us that if we could get within 1 ton of the design figure we would be lucky. Well we did far better than that with the comment that he hadn‘t seen a better result particularly across the axles (that is left and right weights on the same axle) previously. The following day it was the turn of the tender to be adjusted, and this is a different ball game altogether! Same procedure, only to add or subtract weight, the tender (fully laden some 55 tons) must be manually jacked up high enough to leave the spring to be adjusted clear enough from its axle box to add or remove a spacer. More time consuming, but arguably fewer springs to deal with. Some inspired guesswork meant we had a superb result with correct buffer heights soon after lunch.
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The beams and levers as described in the article Photo: Stuart Holman
The digital readout display unit Photo: Stuart Holman
A final few words about T.P.W.S / O.T.M.R. and here I have consulted with our electrician to ensure it is technically correct and up to date and I quote. “Installation of T.P.W.S. and O.T.M.R. continues, most of the new conduit for the cabling of T.P.W.S. is in place and our V.A.B. has agreed in principle the location of the various controls. We are trying to preserve the appearance of the drivers’ side of the cab whilst incorporating the new controls and indicators and have discussed aspects of the layout with some of the regular drivers in an attempt at getting the best result. The
O.T.M.R. equipment is located in a locker on the tender cab face. The design for the box containing the various pressure transducers has been completed and will be located under the cab floor, and will also contain the various connectors that are necessary for carrying the various inputs to the O.T.M.R. and to enable the separation of the loco and tender when this is required for maintenance. It is expected that the cabling for the whole installation will commence soon. The design of the combined T.P.W.S. and O.T.M.R. system for “Clan Line“ has evolved following much discussion and inspection of other installations and we have been fortunate to receive many helpful comments from our consultants and other locomotive owners“.
Although we are within sight of our return to the main line, we are still short of money. We need funds urgently and if you share that worthy goal, then please help.
Andy Davies
To view the previous Loco Report (April 2006) Click Here
©MNLPS 2006
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