A brief update for the new year

Work continues on the tender chassis and making it ready for re-wheeling. A lot of attention has been focussed on the steam brake system and in particular the manufacture of a new brake shaft to replace the unserviceable original.

The original tender brake shaft on the bench. The degree of pitting and general corrosion resulted in the decision to make a new one.

The orignal shaft was used to fabricate a special purpose jig to allow us to set the relative posiiton of the various arms in the correct locations when the refurbished arms are installed on the new shaft.

Jig for setting steam brake arms, with the original shaft in position.

The various arms which are attached to the shaft were cut-off, and each of them has now undergone an extensive amount of repair. This consists of building up the corroded areas with weld, restoring holes to the correct sizes, and re-bushing. This will ensure that everything is “in tolerance” and in as near to as new condition as we can get.

The original main steam brake arm after being cut off the shaft. Worn bushes and pitting from corrosion to be attended to.
The arm during the process of weld-buildup to restore thickness to the metal
Arm during machining to correct dimensions
The shaft end of the arm after machining
One of the brake pull rod arms after machining and re-bushing
Bushes are made either from steel or gunmetal bronze as per the originals. Each bush has its own drawing showing the required dimensions and tolerances for the pin clearance and interference fit into the hole
Here we see the tender steam brake piston rod before refurbishment with the original bushes removed
And here it is after cleanup and with new bushes installed.

The original steam brake cylinder and piston have been retreived from storage, cleaned-up and dimensionally inspected. The restuls indicate that there is hardly any wear in eithe the cylinder or on the piston, which is is good news as it means that both can be re-used with only minor remedial work being required.

Tender steam brake piston after cleanup
Steam brake cylinder after cleanup. The original machining marks from Crewe works may still be seen if one looks closely in the bore

The original brake shaft intermediate bearing blocks have also been skim-machined to bring them back to true roundness, as they had worn a bit oval.

One of the brake shaft intermediate bearing blocks being machined
The other block with the bore turned back into roundness

Other work on the tender chassis includes re-busing the spring hangar links and ongoing production of the numerous pins for the spring and brake gear. We have decided to make all pins and bushes from new so that all dimensions and tolerances are ‘as new’. None of this is particularly glamourous work, but it will result in the tender chassis being as high quality as we can make it, and we believe result in longevity and minimal maintenance in the long run.

Getting ready to press in a new bush to one of the tender spring hangar links. This is being done in our 100T hand-operated hydraulic press
Pressing in part 1
Pressing in part 2
All the way in.

That’s about it for this update. Hopefully there will be some more new soon on the manufacture of the new tender brake shaft and setting up of the hornguides on the tender.

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