Friday 8 March 2013

Winter Maintenance Summary


As reported previously, we got off to a flying start on this year’s winter maintenance by getting the axle box work done before Christmas. In January we re-started the work by replacing the safety valve springs with the spares and did a steam test. The valves  were different to those we had taken off. They performed better not lifting until about 220 psig and maxing out at 226 psig. Good though this is, we hope to improve on it by switching to square section springs which are even stiffer. These new springs were expected before now but due to a manufacturing fault one of them had to be replaced and so 2807 has gone into the season with the ‘old’ springs.

Other early work included a detailed examination of the retaining valve to establish why it seems to stick in service. Excessive clearances were found and the bore of the valve was found not to be true. So a new piston ring has been made, a new head machined, and the bore reamed true. Hopefully that has sorted the problem. The valve gear was inspected. There was much less wear and tear noted on the spindles than last year. More than we would like but at least it meant that no rectification work was required this year. So we cleaned up the valve heads and put them back in the loco.

The next job was to inspect the connecting rod big ends for wear. When the con rods were removed and the bushes and bosses measured there was little sign of wear. This was good news and meant that we did not have to proceed with the repairs to the white metalling in the bushes.  Whilst the con rods were off, we investigated the bottom pad on the LHS crosshead which had been using too much oil. The pad was found to be relatively loose. A new one was made to replace it. Then the motion was reassembled.

The packing rings in the piston rod glands had been noted as having excessive wear. New ones had been made before the winter maintenance period. These were fitted.

The Mason’s valve had failed on the last day of service. The problem was identified as a cracked sealing disc inside the valve. A new copper disc was made and fitted.


The reversing lever had been reported as having too much play.  The problem seemed to be with the arm on the wayshaft.  The tapered pin had broken at one end and there was significant movement of the arm relative to the shaft.  Simple fix?  The trouble started when the tapered pin refused to cooperate.  We had to buy a new drawing tool, use right angle drills, punches, heavy hammers, repair consequent damage to holes in the arm and the shaft before this “10 minute” job was finally finished!


Another job that didn’t go to plan was the intent to renew tapered motion pins & expansion link bushes. Unfortunately we only managed to get the RHS done. The problem was limited machine shop time, partly due to the prolonged period of bad weather.








A few other odds and sods were completed. For example, one of the unfinished cladding sheet jobs when the loco left Llangollen was to correct the number 5 cladding band. This had been put on as a straight band but really it needed to be a tapered band – correcting it is a simple, but time consuming, cutting and welding job and it wasn’t a high priority item. Well, finally and nearly 3 years later, we got round to doing it this winter.









The tender spring we removed in November had been refurbished. So the refurbished spring and our other spare were fitted to the trailing axle of the tender. That leaves the two middle axle springs to be refurbished and replaced at some future date but this is a low priority task now that the four corner springs have been done.

Many thanks go out to those who have helped with winter maintenance including those people from the loco department who gave lots of valuable time and effort.


Turning now to our siphon vehicle, the wood required to replace the cladding was delivered and is now being fitted to phase one in place of the rather ‘weathered’ existing boards.  Phase one is just one corner of the vehicle, and work will now start of phase 2, replacing all rotten wood in the frames before that too is clad.  We are still planning the replacement of the roofing, and are looking for a way to do this in ‘bite sized’ pieces rather than a ‘big bang’.



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