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

In extremis there is always Germany, US or South Africa.

 

Perhaps you can try these people?

 

We have tried a number of suppliers in the States without success. One British spring manufactured has proposed a 2 spring solution with an inner and outer spring. Initial calculations from the supplier look good and we are going to do our own load check calculations for confirmation

 

If you want to end up with a square section spring you start off with a trapezoidal section rod. I don't think there is any difficulty in winding the spring, I believe it is the difficulty of getting hold of the section that is the problem, nowadays. It has been suggested to me that you could machine the section required out of square bar but that would be a costly operation. I presume that you have tried the Tested Spring Co. with no success?

 

Steve. Thanks, thats interesting to know. You're probably right about getting hold of the right section material. Yes, we did approach the Tested Spring Co and they have provided the 2 spring alternative solution. We think this is probably the best solution and have worked up a design. I aim to put up a picture on the web site later on

 

Do you have a link to the Upgraded web page Mr IanH. ?

 

Just use the usual link https://www.theclanproject.org/ It works every time for me...

 

Thats the one. Ian

 

Will any eventual solution will be of potential interest to the owners of all BR 'Standards'?

 

Yes, I would have thought so. if you go to the web site and follow Construction >> Build >>Front Bogie, you can see a drawing of the proposal.

 

Thanks Ian. What loco is the bogie shown at the Mid Hants from? It appears to have independent (suspension) springs.

(may be of interest to others) There are some images of 70000's bogie showing the side control springs at http://fraserker.com/winson/britannia_pix/very_old_page_01.htm

 

I don't know. I've been trying to find a good bogie photograph. Someone gave this to me and I wanted illustrate how the centre slide moves - it seemed to do the job

 

I think it may be a Maunsell bogie. Other thoughts on the side control spring issue:

1. Have you tried https://www.roehrs-springs.com/springs-products/compression-springs/flat-wire-compression-springs ?
2. Perhaps consider machining from solid 6.25 inch diameter bar (drill a hole, fit a former (core) and then screw cut (or thread mill) through to the former) before hardening and tempering.
3. Use a stack of Belleville washers.

 

That is a very good and interesting find. Thanks for the info.

 

Thanks, I've passed it on to our engineering group. Ian

 

There is a good chance of a photo in ' Britannia, birth of a locomotive '. Will bring it along to the Open day if there is one.

 

I have made an enquiry with Roehrs regarding the production of LMS/BR rectangular section pony truck side control springs. They got back to me fairly quickly. Their answer "We are not capable of producing a spring from such a massive wire profile".

 

That's a pity. I found them by Googling images for "flat section helical spring".

 

Yes, that was the reply we got. They responded very quickly.

There isn't a good picture of the front bogie in the "Britannia" book. There is one of the trailing truck (or pony truck as Geoff likes to call it)

 

huochemi - thanks for the post

Item 1 has resulted in a "no can do" response from the supplier. They were very quick in responding
Items 2 and 3 were run past our certification contact and were rejected.