BR Standard class 6 No. 72010 'Hengist' and Clan Discussion Thread

Progress continues on completing the structure of the frames. Once the drag box is fitted then that is the backbone of 'Hengist' done.
It will have taken a long time and many hours of stress and worry over the years but it will be a celebratory moment.
https://www.theclanproject.org/Clan_News.php

Well done the working team and CTL.

 

Big step!
I do love their engineering website, the sheer "we made a thing! And another thing!" whether it's a bolt or a huge and complex assembly is brilliant.

 

Latest news

1. Pony Truck wheels are now on order with Trefoil Steel in Sheffield. The job will involve casting and machining to 3mm over diameter. That machining allowance is left for when South Devon Railway Engineering will fit the tyres
2. We hope to get our hands on the dragbox next week. We can then start the job of fitting them to the frames. The sides of the dragbox will be bolted to the frame extensions and gussets; it will be riveted to the hind beam. Getting in to drill/ream the holes at the sides will be tricky as the gussets are deep. So we will manufacture a drilling jig. Stage 1 will be to use the jig to drill/ream the holes in the frame extensions/dragbox; stage 2 will use the jig to drill/ream the holes in the gussets using the jig on the frame side of the gussets. Hopefully all of the holes will line up!
3. On the bogie, the key job of fitting the axlebox guides will take a while

• The axlebox guides are a shallow "U" vertically, the liners are a shallow "U" horizontally
• Our next job is to fit the liners to the guides so they are a tight fit. This will probably involve some hand fitting.
• We then pass the liner/guide assembly to CTL Seal so that they can drill/ream the guide/liner bolt holes]
• After that the liners will be removed from the guides. Both liner and guide will be marked as each is a unique combination
• We then have to drill/ream all of the bolt holes that secure the guide to the bogie frame plates - 7 holes on each guide, 8 guides, 56 holes to form to final size
• The guides will be fitted to the frames with fitted bolts
• The liners will then be bolted to the guides.
• We then need to carefully dimension the distances between working faces of the manganese liners. It is unlikely at this stage that they will be truly parallel.
• We will need to work out what material needs to be removed from the steel liner face (i.e. the face abutting the guide) to produce a parallel fit with the correct working clearance between the manganese steel on the liner and the manganese steel on the axle cannon box.

 

Excellent stuff!

 

Big announcement today. William Cook Cast Products are going to cast and machine the 6 driving wheels for 72010. You can read about it here

https://www.theclanproject.org/Clan_News.php

The axlebox guides/liners are now ready for the bolt holes to be drilled.

In order to fix the dragbox, we need to drill the bolt holes that will fasten the dragbox to the frame extensions and gussets. We can't do this in a single pass so we have developed a requirement for a drilling jig. The frame extensions and dragbox will be drilled/reamed in one operation, the gussets a second. The drill jig should ensure all holes line up correctly.

 

Ian, this is great news …. I think. it’s s not exactly clear in the press release how the wheels are to be funded?


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a generous sponsor I believe...

 

Brilliant, surprising and very welcome news for this member.

To be honest I’m actually surprised there hasn’t been more comment - not every day a new build project announces someone has offered to fund and build all the driving wheels.

a very welcome shot in the arm.

 

Sheff

The casting and machining of the driving wheels has been generously sponsored by William Cook Cast Products. We still need all the other bits for the wheelsets! Axles, tyres, cannon axleboxes, bearing and crank pins. All donations very welcome!

We hope to have the pony truck wheels back from the machine shop for display at the Open Day this Saturday

Ian

 

Do you have a price for this work to be done yet?

Is this appeal now going to be the priority for the fundraising, or are you currently funding elsewhere with the wheels being a separate funding on its own?

 

Interesting that manganese steel liners are used on the bogie hornguides as the wheelsets transmit no tractive or braking forces. Presumably that means they are used on the tender horns as those wheelsets do transmit braking forces?

 

On 72010, manganese steel liners are used on all hornguide faces including the tender. Cox discusses these in his book BR Standard Steam Locomotives. He had followed the evolution of axleboxes from the L.Y.R through the L.M.s and states that with "manganese steel liners on the horn-block faces, over 100,000 miles could be run by these boxes between repairs". Manganese liners are also used in other areas, for example on either side of the pony truck spring beam that goes across the top of the coil springs.

 

Undeed, even unpowered axles are constantly moving up and down and to a lesser extent back and forth in their guides, wear will still occur.
CTL Seal soon to become 'CTL wheels' at this rate...

 

Thank you Ian. It is somewhat ironic that more recent technology does not employ horns at all, even on powered axles. The De Glehn bogie with inverted leaf springs seems to be particularly kind on the axleboxes as no load is transmitted through the bogie frames which serve only to hold the axleboxes in position.
I suspect Cox was referring above primarily to coupled axleboxes, the problem of course being the fore and aft thrust. In his 1944 paper to the ILocoE on axleboxes, Cox notes in the brief section on bogie and tender axleboxes: "Considered by themselves, bogie and tender boxes would run on the average 100,000-120,000 miles before developing enough wear to require reconditioning, so that a further advance in their rate of wear is not urgent until coupled axleboxes have been improved to give their level of performance." Now the paper focuses rather more on the box than the horns so one cannot be totally dogmatic (although your own Cox quote is slightly ambiguous as it refers just to the box in relation to the mileage), but it does not suggest that wear in the horns of the bogies or tenders was a big issue.
I note however that one of the contributors (Graff-Baker of the London Underground) said that they used manganese steel liners on all their stock - "A curious thing was that they never wore at all. They ran with little or no lubrication, and there was no apparent defect. The cars were brought in at 200,000 miles for overhaul, and theywent out with the same axleboxes and the same horn guides, and nothing was done to them at all." (I see you are anticipating lubrication though )

 

There is recurrently valuable stuff in the remarks when people rose on discussion after the papers were delivered to the Engineering Institutions.
One of the things in steamindex.com is that Kevin Jones who originally created it was well aware of this. It is often well worth getting hold of the full original text.

 

There's am interesting comment in Peter Townend's book, LNER Pacifics Remembered. In the Chapter written by H. Rowley, he states

Manganese liners came into use for the faces and side cheeks of the solid horns and caused many problems of securement. Moreover, when these liners were originally fitted the engines had to be withdrawn from traffic after three months service for special adjustment due to excessive play development. Once the surface of the manganese steel had work hardened the wear did not increase any further but a method had to be devised to obtain the degree of work hardness required before being fitted and so avoid returning the engine to Works. This was done by devising a roller fitment to a horizoontal milling machine and by passing the manganese liners under the rollers whilst pressure was applied the requisite degree of work hardening could be obtained. The milling machine operator, H. Milner, did not like his machine being used in this way and refused to undertake the work until his machine's makers had been consulted. Manganese liners were used on the Cartazzi horn faces and axleboxes before the War and were pegged on.

I haven't found anything on manganese liner initial wear in BR standard books. Anyone heard of anything.

For your interest, Tom Ingalls has created a new video. You can view it here

 

Data sheets on managanese steel are readily available online e.g. https://ajmarshall.com/wp-content/uploads/2017/07/12-14-Manganese.pdf and make reference to work hardening and the low coefficient of friction. I guess if you grind it in preparation for fitting to axlebox faces/horns, that gives it some degree of work hardening. There are a couple of mentions on the 60007 overhaul blog - see https://blog.railwaymuseum.org.uk/sir-nigel-gresley-overhaul-update-47/ and https://blog.railwaymuseum.org.uk/sir-nigel-gresley-overhaul-update-48/ for instance. 47 says that the Cartazzi horn liners were worn through but 48 seems to say that the steel Cartazzi wedges and the "trailing" [Cartazzi?] loco horns should have been manganese steel lined but were lined with mild steel anad the impression is that they were not going to use manganese steel at the overhaul. One would have thought that there must be lots of experience out there on the basis that there are a lot of Standards in preservation.

 

Error

 

Check out Mangalloy or Hadfield Steel on wiki.

 

Would be surprised if this material was not more widely employed on all ex BR locos, regardless of grouping origin, especially so on ex. LMS locos....