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

Initially, to a Derby design, but Royal Scots were fitted with a De-Glen type bogie in 1932. The same bogie was used on the rebuilds. There were a few problems with rough running on the rebuilds. This was attributed to problems with the rear boxes and the side control springs on the bogie. The side control springs were modified in 1953.

 

That, I assume, would have been a Stanier modification? If so, it was early after has appointment and well before his visit to India to investigate derailments of Pacifics in that country.

 

Can see that machining a spring out of a cylinder would not have the correct properties even if you could get a cylinder made out of spring steel. Is it not possible to machine two parallel flat faces onto a circular cross section rod though ? ( yes as long as the rod isnt 15ft long ????)

 

I think you are suggesting that the profile for the correct steel could be machined then rolled to make those special springs? But the problem is actually rolling the springs according to an earlier post.

 

No thats not what im saying, as i understand it rolling steel is done in relatively high qties (relative to the needs of this project or even the potential future needs of the the whole stud of Standards/whatever else mightuse this stuff) and would require a set of rollers to roll to the correct profile Im suggesting taking stock circular cross section rods that are over diameter and machining away to two parallel flat surfaces... however 1 suspect the length of rod needed to produce a spring is many yards long and feeding this into an appropriate machine - i dont know how this could be done. The spring coiling machine i presume has abetter chance with 'part round ' than fully square

Presumably the resistance force the spring offers is primarily governed by the nature of the material used and its cross sectional area - (the rhomboid section offering the highest cross sectional area in a given space and the maximum 'flat face' against either itself when fully compressed or against any internal guide or external face which would offer some support versus deformation).

Predicting the required dimensions of a spring of a different cross sectional shape to give a similar property is therefore not going to be rocket science, but it would almost certainly take up more space.

 

I think we are actually talking about the same thing - ish. I believe they use a trapezoidal cross section which, when coiled into a spring reduces the outside face width to become a rectangular section coiled spring. The problem reported earlier (Post 1982) is to find a manufacturer who can coil that trapezoidal cross-section.

 

You'd have to start with 9' of spring steel round bar of over 1 3/4" diameter, then mill it down on two non parallel faces, to make a trapezium 15/32" wide on the top narrowest face, 1 1/16" on the wide bottom face, and 1 3/4" tall. Whether you would end up with a material that provided the correct spring rate, and whether anyone has the equipment to twist it into the shape required lord only knows

 

How does a machined and coiled section compare vs (say) an extruded and coiled section, when it comes to relative strengths, surface hardness, internal metallurgical properties? Best say, this isn't even vaguely familiar territory for me. Merely curious.

 

I believe is called Timmins section springs.

 

If what you are starting with is extruded or drawn already then i guess it depends how 'carefully' you machine it ? if it can be machined to the correct section - as Phil said earlier you still need a spring coiler who can process it, hence the suggestion of machining two faces only..... anyway it'll all come out in the wash.

 

When it comes to design detail, not too sure about that last eight words! I've been watching Hengist since the first attempt went belly up and (check back) have been very impressed by the professionalism and enthusiasm of the current team. It's been one hell of a great turnaround.

 

Exactly.

 

Our pattern maker, Tony up in Scotland, has managed to get hold of his jig for making the cores in the cylinder pattern. You can see progress here

https://www.theclanproject.org/build/Clan_BuildTopic.php?topic=CYL&description=MainCylinders&page=11

Ian C is also doing sterling work on bogie lubrication components

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

The Monday gang is due back at CTL Seal on March 29

Ian

 

....... and even more progress by Tony and James is detailed on the up-dated website this weekend.
The lads will be looking forward to getting back next week.

 

Yes, the Monday gang is back on Monday. We're in the process of finalising the work package for frame assembly phase 3 with CTL Seal which is the assembly of components around the dragbox. We want to do the riveting of the front buffer beam and the dragbox components at the same time. Hopefully all will be complete by the Open day on June 26

Ian

 

I see that the £90,000 has been raised for the front bogie, congratulations! I suspect this was achieved within about 6 or 7 months so it could indicate a turnaround for the financial support for the project. Many thanks to all who have helped with this and the folk who have to spend the money wisely.

 

How are you planning to do riveting with social distancing please? I'm not trying to be awkward/funny, last I saw another group had decided that as it's a non-essential activity and they can't maintain social distancing, they'll defer riveting until after restrictions have been lifted. It looks like you've found a way, and I thought I'd share it

TIA

Patrick

 

Back in Sheffield yesterday so progress can be found here

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

Unfortunately, flaws have been found in the bogie cannon boxes so they have to go back for recasting.

 

Because of that line, I can't really just give your post a 'like', but thanks for the update.

Seal seems to be doing a great job; you all must be very happy you picked them! Hopefully, it's working out well for them, too; in addition to the positive press (and hopefully they find the project intrinsically interesting, too), I imagine the Hengist work gives them a nice 'backlog' to keep their staff busy with, when there's no more urgent/renumerative work to do.

Noel

 

Great news of progress and planned work in latest Members Newsletter. Gradual progress on the bogie can be maintained now appeal is completed. Allows other work to progress as well.