Nene Valley Railway, Wansford Station, Stibbington, Peterborough, PE8 6LR
Tel: 01780 784444
6th November 2017.
One of the big jobs around the motion is the extraction of the wedges that secure the crossheads to the piston rods. This is achieved by welding a screw thread to the top of the wedge and then using a 'bridge' against which a nut is tightened to extract the wedge. Serious force is required to start the release but once the initial grip was broken, the RHS came out quite smoothly. The LHS fought all the way and when finally out, the wedge was seen to be 'banana' shaped. Inspected later in the day by a visting engineer, he opined that it was the result of priming in the LH cylinder, confirmed (he said) by the 'step' that could be felt at the leading edge of the hole through the crosshead/psiton rod.
The second part of this job is to release the taper-
A bit of tidying up around the outside of the cylinders has been done -
Under the footplate, battle commenced with the bracket that holds the hinge for the brake actuation. Brute force (Philip, with Ian & David) removed the first 2 (of 16) bolts and, on Sunday, Alan used heat and force to take out a further 4. That leaves two outers to come off, then a very difficult-
Outside on the boiler, at the front end, StanD and Dennis have been knocking soot and scale and rust out of the insides of the superheater flue ends to ease the job of the oxy-
Crosshead with wedge removed
Brake actuation bracket. Held by 16 rust-
10th November 2017.
Highlight of the week was the crosshead/piston rod separation going far easier than anyone anticpated. Well done to DOC who make the great big, non-
Less glamourous but still hard work is the brake linkage bracket under the footplate. Phil, Ian and David, often with an audience of thousands, attacked and removed/destroyed the remaining 10 bolts but the bracket remains stubbornly attached to the drag box. Wedges and jacks are proposed for next week.
Outside, Graham B took the final handrail standoff off the boiler -
Getting started with the component overhaul was a bit slow -
Looking forward down the LH cylinder. Note the scratches where broken rings have rubbed against the cylinder wall.
19th November 2017.
Lots of normally hidden stuff this week. Pistons out, expansion links down, expansion link bearings exposed.
First, the pistons. The BR drawings show a piston with two rings separated by a relatively wide gap. Our pistons have 3 equi-
Secondly, the expansion links. These appear quite worn, the ‘loops’ at each end are very shallow, suggesting that the slides have been ground out at some stage. Careful measurement and reference to MT276 is needed to determine whether these can be re-
Thirdly, expansion link bearings. Something is badly wrong here. It looks like a complete lubrication failure and we’ll need some new pieces of phosphor-
RH piston, showing 3-
The two nuts were loosened before the piston rod was freed from the crosshead, to give a strong hold against which to turn the nuts. One (the thin one) is a LH thread, the other is RH. A thin washer separates the two nuts and the whole assembly delivers a very firm hold of the piston on the rod.
Expansion links, Left and Right
Expansion link bearing. Dreadful scoring inside the bush. The matching part is equally distressed.
28th November 2017.
As well as the exciting motion disassembly, more mundane matters continue to be attended to.
When pipes were being taken down, focus was correctly on labelling and recording the routing of them. Now we need to get all the brackets and clamps away from the frames, so that both they, and the frames, can be made ready for painting.
Not particularly photogenic, a couple of examples are featured. Just look at the state of the frames -
Component 73935, the curved piece on the right, already has its tag affixed. The piece on the left will also be tagged before removal to the container and eventual cleaning and repainting.
Trying to be helpful, the fitters hand has managed to angle the tag so that the number cannot be read. Fortunately it has been logged, so we know where it goes.
Parts removed count:
|Early days at Peterborough|
|The start of the NVR|
|The Brotherhood Overhaul|
|Running in Green 1980-1989|
|The first NVR overhaul|
|Running in Black 2005-2014|
|Somerset & Dorset|
|The North West|
|Blog March 2017|
|Blog April 2017|
|Blog May 2017|
|Blog June 2017|
|Blog July 2017|
|Blog August 2017|
|Blog January 2018|
|Blog February 2018|
|Blog March 2018|
|Blog April 2018|