hra fb twitter
sheffield
header

Build Diary entries for October 2010

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.

    uparrow Return to 2010 Next Month la
Cast Steel Frame Stretcher
03/10/2010
  Highslide JS
  Due to a very generous benefactor we can now place the order with Brian Oldford to make the pattern for the cast steel frame stretcher and steam brake support. This is the last vertical frame stretcher and is one of the re-designs that was to have been carried out on the lot 242 'Clans'.

The patterns for the trailing frame keeps foot (pictured above) are now at the foundry and the castings should be ready in 6-7 weeks time. These are steel castings and are also a modification for the lot 242 'Clans'. The project is also supplying the cast iron smoke box door number plate and the reverser indicator drum casting for 76084.
   
Reverser Weightshaft Spring
11/10/2010
  pic
  We now have the reverser or weighshaft spring. Paul Burns took delivery of this item today October 11th 2010. It is a huge spring and is shown fully relaxed at its maximum length.

It is housed inside a tube on the fireman's side just below the running plate behind the weigh bar. If you look through your books you will see that on some B.R. Standards this spring is fully exposed and not stored inside a tube. It counters the force of gravity acting upon the expansion block and expansion links so that the action of adjusting the cut off is as easy for the driver to set in reverse gear as it is to set in forward gear. This spring was made for us by Ashfield Springs Nottinghamshire.
   
Motion Combination Link
26/10/2010
  Highslide JS
  The picture above is of an original un-machined B.R. forging for a combination lever. This we are reliably informed was found on the last day before closure in Eastleigh Works! It was rescued as a spare for a rebuilt Bullied which are fitted with B.R. Standard motion (Class 4).

However it was too big. On closer examination alongside the drawings, it turns out to be for a Class 6 or 7, which is great, so it now belongs to 72010. We are investigating the cost of manufacturing its opposite number and the machining of the pair, we will be offering these components up for sponsorship. The combination lever is the vertical link that unites the valve cross head with the piston cross head so that their relative movements and that of the expansion link are all integrated or combined. This provides the correct 'lead', irrespective of the position of cut off, in both forward and reverse gear. The 'lead' is the small amount by which a valve opens to admit steam prior to front or back dead centres to help 'smooth' the piston cycle and improve efficiency at speed. This small amount of steam enters as the piston has reached its full travel, filling the void between the piston and the cylinder cover just before the piston changes direction which has a 'cushioning' effect that reduces wear on the cross head bearings, it also ensures maximum steam pressure at the start of the next working stroke.