Sandringham New Build(s)

I think the answer is they would have been forged (made by hammering) rather than machining. There's a tendency these days to produce components by machining from solid because, with CNC, the process is comparatively cheap once you have a drawing. Whereas in the days of manual machining, that would have been an expensive way to do things, that you could instead forge. There's a photo here of the smokebox door on Beachy Head, and it looks to be a far simpler fabrication, without any significant machining - just a strap with a rolled end, subtly curved and fixed to the door by rivets.

I couldn't quite work out what was happening with the door straps from the video: they looked like they had both ends machine into a complex shape, whereas the photos of originals seem to just show you have a hinge at one end and a plain strap. There's a drawing here from the B17 website of the CAD design and while it has the same forked hinge at one end, I can't work out what has happened at the other end of the parts that have been produced.

From the video, it looked like the inner part of the smokebox door dart was going to be machined. It will no doubt look beautiful when done, whereas an original would have been a fairly crude lump of hammered steel ...

Tom

 

I couldn't quite work out what was happening with the door straps from the video: they looked like they had both ends machine into a complex shape, whereas the photos of originals seem to just show you have a hinge at one end and a plain strap. There's a drawing here from the B17 website of the CAD design and while it has the same forked hinge at one end, I can't work out what has happened at the other end of the parts that have been produced.


Tom[/QUOTE]

I asked the question and apparently we are looking at the end of the original steel bar used to machine the whole strap, before it is finally cut off and cleaned up at the end of the job.

 

Thanks for that - makes more sense.

Tom

 

All a bit OTT. The originals would probably have been plain straps riveted to the door. The hinge ends would then have been adjusted with heat.

 

Great to see Daniela bringing all those years spent with David Elliott to bear to the benefit of the new build movement. You can see Hengist in the background too.

 

Aye, a bit of heat and a hammer is the way to do it.

 

Correct but you make things with the equipment and processes available. In ye olden days a team of well-muscled men with a large forge and drop hammers would have made short work of this. I doubt that Daniela's workshop has this facility! Two hinges are being made, not a production run.

 

But if one of those hinges breaks and causes an incident the RAIB would look at the original drawing and ask the question " these hinges are shown as being forged. Why wern't they?"

 

Only if the theoretical incident was as a result of the method of manufacture. It’s a new locomotive with no grandfather rights so would be built to whatever drawings are used, old and new.

 

There are some exciting developments coming up over the next few months in respect of the construction of B17/6 no. 61673 Spirit of Sandringham. In advance of this, I should like to offer the opportunity of all followers of the National Preservation Forum to receive for free, the last issue of the Trust’s magazine, The Spirit. If you email me on my personal address, alanwarren.18@gmail.com I will send you (within 24 hours) an electronic copy of the last issue of our magazine for your information. If you respond to this request, I will also subsequently send you the next issue which is due for publication in the middle of August 2025. So 2 issues for free! This is in response to our commitment to the Railway 200 celebrations in 2025. Onwards and upwards for the future of new build steam!

 

Very kind, email sent

 

Ditto!

 

Construction Update – July 2025

Rolling Chassis
Somers Forge of Halesowen have finished forging the crank stub axles and the sweep webs with heat treatment and initial machining. The crank pin will be delivered soon. All these items will be shipped to Daniela Works at Shildon for final machining, where the coupled axleboxes and cannonboxes already reside, fully machined. These items, along with the driving wheels will then all be shipped down to South Devon Engineering on receipt of the two rear plain axles – the tyre plugs and the Timken roller bearings are already there.
Also, the horn stay material has arrived at CTL Seal and will be machined in the coming weeks, ready for the arrival of the completed wheelsets.

Smokebox
Work has continued on the smokebox door assembly with the second dart handle, the retaining bar, its brackets and the inner smokebox door baffle all now available. Minor machining was found necessary with the fibre glass yarn in place, to ensure a perfect gas tight seal at the point of closure and checking continues. Welding of the smokebox ring was put on hold so the whole assembly could be displayed at the ‘Greatest Gathering’ event at Alstom’s works at Derby on 1st - 3st August.

Cab
Work on the CAD drawings is proceeding on two fronts. The main contractor (Elvar Engineering in Buckinghamshire) is close to completing the CAD of the main cab features, prior to ordering the cutting of the steel sections, whilst our own member is working on the details of the cab floor and parts of the footplate. A supporter of the Trust is also manufacturing the wooden window frames in his home workshop.

Chimney
The cast chimney, which was on display at the Open Day in April, has now been shipped to Shildon, where Daniela Works will machine it.

Bogie
A report has been prepared in conjunction with the B17 and A1/P2 design teams to review the engineering justification for the design change to the bogie from the original LNER design. Principally a change from the original steel casting to a fabricated solution. It also covers the inclusion of roller bearings/cannonboxes and how this affects ride quality and other safety issues. further testing will take place as part of acceptance when the engine is complete using standard and dynamic testing methods with instrumented loaded test runs.

Cylinders
The design for a fabricated solution and the production of the associated full manufacturing drawings has been completed and initial discussions have been held with CTL Seal with a view to the work being offered to their fabrication and machining teams and a quotation for this work requested. The cylinders will be the focus of the next appeal to be launched later this year.