Sandringham New Build(s)

Divided drive on a B17/Sandringham, unified on a D49 and other Gresley 3-cylinder types. Axles cranked in order to give clearance to connecting rods were not particularly unusual and there were other methods of dealing with the issue with the GER Class 55 providing one example. It was something that could be done in order to achieve design objectives, one item on a list to be used if needed.

 

If I am understanding the drawing correctly, it shows the crank for the middle valve gear with a shorter throw than the driving crank from the outside cylinder, similar to the throw of the return crank for the outside valve gear. That would be consistent with calling it a "mini-crankaxle". But I can't see how that description can apply to the wheelset shown in post #409.

 

The one shown in the photo is the driving axle for the inside engine, i.e. the second axle.

The point about the third axle also having a small throw offset crank to drive the valve gear is interesting from an engineering point of view, but it is not the axle shown in the photo.

Tom

 

Correct.

Note that the 3rd axle wheel sets also have thinner flanges than the others.

 

Thank you. Now it finally makes sense to me. Sorry I was so slow. I should have realised that the third axle would have longer crank pins for coupling and connecting rods.
Now back to the Sandringham.

 

August Update

August has seen a flurry of items to report. Not only is there positive news on the Coupled Wheel front, but also progress on the Bogie, the Smokebox and the Cab.

Coupled (Driving) wheels: Machining has continued and is now complete. The crank bosses have been drilled for all six wheels and then the wheels finished to the correct thickness, by placing them back on the rig that machined smooth the first side of each wheel. Finally, the keyways were cut last week. When all the various cannonbox components (see next section) are completed, we have everything we need for the wheelsets, so now just await delivery of the plain axles.

Cannonbox and Axlebox (for the leading Driver) components: With the cannonboxes and axleboxes machined, attention has turned to the multitude of spacers and rings needed within them. The photos below show various rings. The whole job of machining these rings is almost done, although we still need to machine four thin split spacers and weld up the oil covers. As you can judge from the photos, it has been a massive undertaking, as everything is of very precise dimensions and finish.

Bogie: Work continues with Ricardo Rail, to get overall approval for the design and in particular to get the authority to proceed with casting of the two bogie cannonboxes and the four twelve spoke wheels, the patterns for which we already have. Casting will be done at William Cooks.

Smokebox: As previously reported, the smokebox wrapper and liner are already in situ in Sheffield on the frames. The smokebox door has now been delivered to Shildon (Daniela Works Ltd.) for finishing (see photo below), whilst at the same time the next component needed, the smokebox ring and seal groove has been ordered from Tees Components Ltd. This only leaves minor components to be made (dart, hinge, locking bar etc.); the manufacturing drawing for these are currently being finished, from the CAD drawings already available.

Cab: Using the scanned in copy of the original North British drawings, available through the NRM, we went out to tender to three companies. The work to manufacture the cab in steel plate (to BS EN10025 S275) has been awarded to Leaky Finders Ltd. of Exeter, Devon. The cab will in finished in primer, ready for final painting once at our manufacturing base in Sheffield.

 

More positive news on the B17. Yesterday they ordered the forgings for the crank axle (for the lead driving wheel - the one driven by the inside cylinder), from Somers Forge in Halesowen. This order is to forge the two Stub Axles, the Inner Crank Pin and the two Sweep Webs.
So now, every major component needed to complete the rolling chassis has either been manufactured or ordered.. Great news indeed!

 

Whilst the various components mentioned in the last update are being manufactured (including the smokebox door and ring just delivered from Tees Components), CAD design work has been proceeding on the next major components, the cylinders, all 3 of them! Attached are photos of this work output together with the photo supplied by Tees Components of the smokebox ring.

 

Are there any cast iron liners in those cylinders? It's not obvious to my poor eyesight.

 

The bore is shown in a darker colour than the rest of the cylinder, so I would assume so.

 

A quick construction update for January 2025 on the progress with new build Spirit of Sandringham. There is also some exciting news which can not be revealed just yet so watch this space!

Main (Coupled) Wheels: work on the Cannonboxes for the main driving wheels continues at Shildon (Daniela Works Ltd, with the production of various components to hang the springs from – these are pictured below. In parallel, some machining has been completed on the two axleboxes (for the front coupled driving wheel), in readiness for the crank axle forgings which are currently on order from Somers Forge. An additional lubrication point has been drilled into the two Cannonboxes at each end, a learning from Tornado’s recent overhaul.

Smokebox: The purchase order was placed at the end of January with Daniela Works Ltd in Shildon, to manufacture the various components needed to complete the smokebox, and thus attach the smokebox door to the ring and seal. These include items such as the hinges, the hinge brackets and pin, the various dart components, the internal locking bar and others.

Chimney: With the manufacturing drawing completed, a contract has been placed with William Cook Castings/Ductile Castings Ltd. to both make the wooden pattern and then cast the chimney (in Iron). The height from top of rail level to the top of chimney has been checked/verified to be within and compliant with the loading gauge of 13 feet. It is hoped the chimney pattern and chimney should be on display at the CTL Seal Open Day in April.

Cab: Work continues at Leaky Finders (the company contracted to make the cab) on producing the CAD model; at the last contact the model was 70% completed although nature has intervened and the consultant producing the CAD is on paternity leave! However, timescales have unfortunately slipped, due to pressure from existing orders.

Bogie: Some final detail has been added to the report to be sent to the Rail Regulator, seeking their approval for the bogie design changes (to accommodate Timken tapered roller bearings fitted to each of two axles to be housed inside their respective Cannonbox, (which the original B17s didn’t have), as well as the design change to the bogie centre (chassis) which is to be a fabrication and not a casting as was the original.

 

Whilst no-one wants to see the A1 pain, nice to see that learning has been made and used.
Good luck to all on the project!

 

The B17 Steam Locomotive Trust has been approached by an anonymous donor who wishes to contribute significant funds to the project. The offer is to provide match funding up to £50,000 over the next 2½ months for all donations received by 30th April 2025.

If any National Preservation Forum member would like to support this initiative, the Trusts details are: Account number 53357821 Sort Code 20-41-12, noting your donation as "MATCH'

Thank you.

 

Are you guys at Ally Pally again? Will there be some good publicity boards mentioning this and to try to get people to donate to the match appeal there too? Ill make a donation at the show if you are there.

 

Yes, we will be at Ally Pally in March (although I won't be as I am one of the Directors of the Trust who lives in Canada so quite a way to come for me!). I like the idea of publicity boards and will discuss this with the other Directors. And thank you for your kind offer of a donation, it is much appreciated.

 

The art of the pattern maker lives on! The chimney pattern for 61673 Spirit of Sandringham has just been completed at William Cooks. It is anticipated the completed cast chimney will be on display at the forthcoming CTL Seal Open Day in April.

 

An interesting video prepared by Tom Ingall of BBC North showing how the B17s smokebox door is being put together at Daniela Works in Shildon. A lot more complicated than I thought!

 

Impressive stuff.

The video says the hinge took 17 cuts on a CNC machine and another 5 on a manual machine... So how would they have been made in pre-CNC days?

 

Ah ....but engineering is easy according to some on this forum..

 

They may have been forged by a blacksmith in the works, or lots of manual machining.