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

Hello Bikermike

If we had machined the splay out, the end of the wings would have been too thin. It went back to the foundry and they engaged a specialist pressing company who persuaded the wings back to the correct alignment. No you're not being too simplistic. Essentially, the bogie design is common to all BR standards with a bogie, including the 2-6-4 tanks.

Centre Slide - The width (across the bogie) varies - class 6 and 7 one size, class 8, 4 and 5 another and a different size for the 2-6-4 tanks
Side Control Spring - Class 6, 7 and 8 share the same springs, the others (understandably) share a different spring. Class 8 has more movement and a higher load at maximum movement
Frame Plates - common to Class 5, 6, 7 and 8
Spring Links - I'm not sure about differences as the drawing is difficult to decipher. It looks to be common for the bogie
Pivot Pin Bolts - Class 8 uses 8 off 1- 1/4" CX /4-1/8" HD which is a nomenclature we understand (from the standard nuts and bolts drawing). Class 7/8 uses 10 C 11Y/32 - I cant find out how it is defined.
Main Springs - identical
Cannon Boxes - I'm not sure here. The BR drawing is essentially a rebadge of the Timken drawing - the loco allocation isn't shown. The NRM microfilm list shows that the drawing is applicable to Class 5, 6, 7. however, there's no reference to a class 8 drawing in the document

So essentially the same apart from the centre slide - controlling the degree of side control

Hope that helps

Ian

 

Gosh! thank you for a prompt response. It's nice to see that some things were actually standardised across the standards...

Interesting about the pressing, I was wondering how you could amend a casting other than machining it....

 

Deleted

 

Not quite correct. The bogies on the Class 4 4-6-0s and 2-6-4 tanks were fitted with plain bearings, not roller bearings.
Also, the main springs on the bogie fitted to the Class 4 2-6-4 tank had 24 leaves. The main springs fitted to the bogies on the other Classes had 21 leaves.
I think that the code for the bolts is a reference to an LMS drawing.

 

Yes, I'd forgotten about the plain bearings. If anyone knows how to decode the LMS bolt definition, please let us know

 

The latest news item seems to show just how carefully this project is being checked and adjusted as it progresses.
Will this be the most accurately engineered locomotive build yet?
How many mms. are you taking off the edges?
Impressed that additional engineering resources are so available, proves the advantage of building in the steel town of Sheffield.
Well done folks!

 

The frames were due to be transported back to CTL Seal today. Pattinsons reported that there was 0.5 mm difference along the frames. They removed 20 thou inch of material to produce a square, flat edge all along the bottom edge of the frames.

We do feel that getting the frames plates to be aligned and sitting correctly on the stretchers is a really important foundation for the locomotive.

Ian

 

Great progress - despite the obvious difficulties at present. Well Done to all concerned.

 

Absolutely concur Ian! If you are not sitting comfortably then you cannot begin and build upwards.

 

Like the sight of the growing frames, especially the protection to the plate edges as they are being turned!
Not long before the frames are complete with all the other metal parts we have ready, that will be a real point of achievement for the project.
Great work lads!!!!!!
Looking forward to reading the 'News' with all the other information about the project.
Really happy to be involved with this new-build job.

 

never know when 20 thou under the loading gauge might come in Handy !

 

Indeed! It's good to see those capabilities still available.

I was also impressed that the complete frames could apparently easily be moved from one to another en bloc. Yes, not as large/heavy as a complete engine, but it's not on wheels!

Noel

 

Not yet!!!!

 

We're pushing on now to get the frames onto the hornguide machining process. Once that burr on the front stretcher is removed we should be able to confirm that the gap will close up. CTL Seal will then fit the frame keeps (upside down) to get the horizontal positioning correct and tighten down the stretchers onto the frames with chains. We're told that the other way used was to jack the stretchers up. Then we can start drilling out the bolt holes to the final size for the fitted bolts. This will be a 3 stage step. First we will use a undersize rotor broach as the holes are slightly out of concentric. Then a slightly undersize drill followed by reaming to the required size. Once all of the bolts are fitted, it's off to the machine shop as soon as we can get a slot.

Ian

 

It is good to see continuing progress of the locomotive build on the website - there are so many parts that we never think about - until they need to be made!

 

Hello Phil

I used to just look at steam locomotives, I now home in on the detail! For the last few months I have been deciphering the main pipework and lubrication drawings; cataloging all of the parts, fittings and brackets - yes it takes that long. It doesn't help that Derby didn't update the drawings in 1959 for the new pipe ends. This was a change from swaged pipe ends to turned, coned fittings brazed on to the pipes. Swindon, Brighton and Doncaster did update their drawings so that led to a bit of confusion. Fortunately, Peter Winstanley from BRSLOG has been very helpful in helping me to identify the corect fittings. We need to start thinking about pipework now because some needs to go in at an early stage before other components are fitted.

 

There will be quite a bit of electrical conduit required as well. Probably a bit early to think about that yet?

 

I think so. It could be argued that most wiring will just go from the front of the loco to the back. We were thinking that the main place for the electrics would be on the tender to keep them away from steam. There will need to be control boxes in the cab. We were having a debate the other day about oil pressure transducers on the lubrication lines from the lubricators. Wiring does tend to be a lot more flexible than 4-3/4" copper pipe (exhaust steam to injector)!

Ian

 

Some hot off the press news for you. Today, we're at CTL Seal and Varley Boilers are replacing some of the frame bolts with rivets. In the DSC_0086 image, the bolts marked "R" are too close to the frame keep bolts. So we are replacing them with hot riveting. Some of the bolts are 1-1/4" diameter so the rivets take a bit of knocking in.

 

Fantastic pictures! Thanks.

Noel