C2 Project News
Update October 2015
News from the September and October Working Parties.
Being rather overdue, it was decided to hold the C2 Project Annual General Meeting at the end of September instead of working in Wales. Sam hosted the event, and a very enjoyable time was had by all once the hangovers had worn off. After dealing with the formal business, the meeting also discussed many of the technical aspects of the project. It took six or seven hours, but was very worthwhile. We now have clear plans for taking the project forwards.
Andrew and Dave arrived in Wales a day early for the October working party. The long parallels were located at Boston Lodge, the big internal micrometer was retrieved from Dinas, and the horn face plates were fitted to the locomotive frames. With all the kit in place, we were ready to start taking measurements the following day.
Saturday was spent measuring the lateral position of the sides of the horn face plates. The position of each plate was determined relative to the others, and to the planed faces on the frames, including the cylinder mounting faces. Dave took the measurements, Andrew put them into a spreadsheet, and Paul processed the data. This enabled us to define a theoretical longitudinal centreline of the frames. We were then able to calculate how much material to remove from the side of each horn face plate such that, when refitted, the edges of the horn face plates along each side will all be in perfectly straight lines, and parallel to each other and to the theoretical centreline.
A similar exercise was carried out on Sunday, but this time focussing on the front faces of the rear horn face plates, i.e. those which control the parallelism of the axles. We need to ensure that the axles will be parallel to each other, at the correct spacing relative to each other, and square to the theoretical longitudinal centreline.
All of the above measurements have been carried out to a high degree of accuracy; normally to the nearest thou. For the locomotive to run true, without crabbing and without experiencing excessive wear, aligning the wheelsets and cylinders is critical, especially so with an eight-coupled locomotive. The position of the wheelsets is controlled by the position of the axleboxes, which is in turn controlled by the position of the horn face plates, hence our desire to align the latter components perfectly.
We now have sufficient information to start grinding the horn face plates; a task which we intend to proceed with at the next working party.
While the measuring was going on, Sam started retapping the threaded holes in the cylinder casting which was previously cleaned. There are a surprising number of threaded holes; used to fix steam and exhaust pipe flanges, lubrication pipes and cylinder cladding sheets. Edward and Andrew continued this work on Sunday.
Dave decided to stay an extra day after the weekend, to carry out some of the more minor tasks. What he had not anticipated was that Boston Lodge would be full of locomotive cleaners that day, and that, after the booked locomotives had gone off shed in the morning, they would all be looking for something to do. Will, Kate, Henry, Thomas, Ben and Charles all provided assistance, and by the end of the day the new tender horn guides were fully profiled, the flame cut edges of five of the six horn cutouts in the tender frames had been ground smooth, and a second coat of heat resistant paint had been applied to the cleaned cylinder. Dave also devised a clamping arrangement to enable machining of the tender horn guides to be commenced at the next working party. Great progress which we had not planned on!