Build Diary entries for May 2021
Here are the diary entries for this month. You can use the forward and backward links to see the next or previous months. Most photos taken before 2018 are small size. From 2018 onwards, most photos you see below will have a link to a full size image by clicking on the photo.
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|Front Firebox Support Stretcher|
|We are making preparations to fit the frame extensions at the rear end of the main frames. The frame extension plates are 2" thick and extend below the firebox to the dragbox at the rear of the engine. In order to machine the hornguides, we fitted the front firebox support stretcher which you can see in the photo. The frame extensions could not be fitted at the time as the frame assembly would have been too long for the machining station. Therefore we had to make up some temporary 2" packing plates to fill the gap where the frame extensions would normally be fitted between the main frames and the stretcher. The firebox support stretcher has now been removed and the final task of countersinking 4 holes has been completed.
In the photo, the top of the firebox support stretcher is to the left. 2 front firebox support shoes are bolted to the bottom of the firebox and rest on the 2 liner plates that you can see on top of the stretcher. Wedged keys run in the slots where the countersinks have been drilled and the key sits on top of the support shoe. The key allows the firebox shoe to move backwards and forwards as the boiler expands and cools - the boiler is only fixed at the smokebox end. The key prevents vertical movement of the shoe. The stretcher also houses the trailing truck pivot pin. The grey shield prevents ash from the firebox falling onto the pivot
|Fitting of Smokebox Saddle|
|Over the last couple of weeks, we’ve been posting pictures of new parts. This week’s update shows some work on the smokebox saddle.
We were unhappy with the fit of the smokebox saddle in the frames and decided that it had to come out for checks. It is only fitted with temporary bolts and can only be finally bolted up when the cylinders are in place. The bolts for the final fit will be 90 ‘fitted bolts’, each made to be an exact interference fit for its hole and run from the cylinder, through the frame and smokebox saddle.
We found small localised high spots that meant the saddle was not sitting flat on the frame. The adjustments took place over a couple of days last week and the high spots were ground off the frame and saddle. Each side was dealt with separately and it was grind, refit, bolt up tight to get witness marks, remove, inspect. This was repeated till the size of the witness mark was satisfactory and we were happy with the fit.
Here you can see the saddle being lifted into the frames. The side face of the saddle has been covered with engineers blue. Once all of the bolts have been tightened, the blue will transfer to the frames to show where the saddle is touching the frames.
You can see a short time-lapse video is off the team lifting the saddle in and bolted it up for the last time by following this link.
The next jobs on the frames are hot riveting the front buffer beam and fitting the frame extensions at the rear of the engine.
|Grinding the Frames|
|Dave at work with the grinding disc|
|Today we had a trial fit of the bogie pivot in the bogie pivot stretcher. The stretcher was out of the frames so this was a good opportunity. Once the protective paint was removed with emery cloth the pivot fitted perfectly. Note how the pivot has a convex curve to allow the bogie to roll and pitch relative to the main frames.|
|Frame Extension Preparation|
|These are the frame extensions that will be bolted to the rear of the main frames. They extend underneath the firebox to the hind beam and dragbox. The BR drawings for the plates say "All corners to be rounded to a radius which, where not dimensioned, is to be from 1/16" to 1/8" ". Damien from CTL Seal gets busy with the angle grinder to form the radius.|
|Bogie Spring Cradle Distance Pieces|
|Just in today from Alpenbury Engineering in Rotherham are these 4 distance pieces for the bogie spring cradle. The spring cradle lies alongside the bogie frame plates and contains the main suspension leaf spring. The cradle consists of 2 plates with these distance pieces at the ends to hold them the correct distance apart. The right hand distance piece has a trial fit of the pivot pin which sits in a cup fitted on top of the axle boxes.|
|Build of Frame Extensions Started|
|CTL Seal have started to erect the frame extensions and the components at the rear of the frame extensions. In the photo, on the right, the front firebox support stretcher has been refitted. On the left is the dragbox. The frame extensions and components will be assembled with loose bolts so that the components can be checked for squareness. It will also be important to set the rear ends of the frame extensions at the right height relative to the main frames.|
|Build of Frame Extensions Started (2)|
|Another view of the frame extensions being fitted to the main frames.|