Current news items are listed below. If the Acrobat icon is shown, then click on the icon to read the attachment. If an image is shown, you can click it for a full size image. You can find old news items in the News Archive.
|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 uptight 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. The first fit failed as we found that someone had painted the clearance fit hole in the stretcher that a boss on the pivot engages in. Some quick work with some emery cloth removed the paint and the pivot fitted on the second attempt. Note how the pivot has a convex curve to allow the bogie to roll and pitch relative to the main frames.|
|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
|Bogie Lubrication Parts Completed|
|A big thank you to Ian C who has completed all of the components for the bogie lubrication pipework. Most of the pipework is 1/4" diameter and is for grease lubrication. The 2 angled connectors at the top are for the oil lubrication feed to the centre slide. They will be bolted to the bogie pivot stretcher on the frames and flexible pipes will be connected to the angled ends. The flexible pipes then drop down to the centre slide on the bogie. At the bottom are the brass cones which will silver soldered to the 1/4" pipes. The steel connectors are bulkhead connectors and grease nipples will be fitted in them.|
|Bogie Centre Slide|
|The bogie centre slide was released from the machine shop today. Geoff, Alan and Keith ran a check to see if the pivot bush will fit in the slide. The pivot bush is made from cast iron and is an interference fit in the centre slide. We will fit it by freezing the bush in liquid nitrogen and giving it time to shrink. Hopefully the bush will then just drop into its place and expand as it warms up. The bush is secured by 2 set screws which hold the bush in position.
Today's check was to make sure that it was just over size and that when frozen, it should fit in place.