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

The only reference I can find in the Locomotive Standards Sub Committee is the October 1960 minutes which under the heading of "Bogie and Pony Truck Wheels" states

Further to Mr. Sykes' letter of 15/9/60 to Chief Mechanical Engineer (copies circulated to all Chief Mechanical & Electrical Engineers) referring to further cases of fractured wheel centres, Brighton has prepared schemes for a strengthened design see drawing SL/BR/1670).

Brighton will arrange to have pattern altered for replacement wheels on Southern Region. This modification is available to other Regions.

 

Sorry IanH I dont actually know which drawings we have, i have the list of Ex. Derby drawings that the NRM have but as this a Brighton one not likely to be on unless they unless had/made a copy themselves and i think ..

 

There is a list of drawings for BR Standards which you can find at https://www.railwaymuseum.org.uk/research-and-archive/further-resources/catalogues and selecting the A-E option

When I starting cataloguing the drawings and looking for drawings for Class 6, I came across SL/DE/1678 with the BFB design. It looks like Brighton were tasked in 1960 with looking at the problem of fractured wheel centres and perhaps (inevitably!) came up with a BFB design.

 

The only reference I've read giving a specific reason for this is Winkworth's 'Bulleid's Pacifics' which states (on page 26 in my copy): "Reduction in boiler pressure from 280 to 250 lb per sq in was commenced in March 1954, permitting a standard grade of steel to be used for firebox stays instead of a special grade difficult to obtain. A side effect of this reduction was the better functioning of the injectors."

 

Not previously aware of that reference. Many thanks.

 

I seem to recall somewhere (Bradley?) that the change came about after prolonged observation on the footplate showed that the locos were driven in a way that very rarely exceeded 250psi on the steam chest pressure gauge; presumably at that point the benefits of reduction you outline could be shown to have relatively minimal adverse impact on real-world (as opposed to theoretical) performance.

Tom

 

I've read that too, but it went further. Because of the unreliability of the steam reverser, which tended to lengthen the cut off as the engine ran, drivers gave up trying to pull it back and ended up driving on the regulator, so the chances of using full regulator were very limited.

Or so it said . . .

 

Bradley gives a list of dates for the reduction in pressure for each loco (p29), commencing in July 1952. Interestingly, Burrows and Wallace do not comment on the pressure reduction in their paper on experience with the steel fireboxes given to the ILocoE of February 1958. Their only comment on change in stay material was in connection with the replacement of steel by monel in the breaking areas.

There is a similar comment in the Jarvis biography (p.127).

 

Theres a Jarvis Biog ?

 

Ron Jarvis by J E Chacksfield, Oakwood Press.

 

I see some more slow and steady progress is being made!!
I admire your determination to work in the current conditions lads, in-door you may well be but it is still a cold environment.
see https://www.theclanproject.org/Clan_News.php

 

We think we're pretty close to hitting a major milestone this week - the completion of the bogie wheelsets. The only drawings we had were the arrangement drawings which were a BR "rebadge" of a Timken drawing. These drawings gave the dimesnions of the solid cann boxes but we have not been able to locate any detailed drawings for the internal components. After creating our own manufacturing drawings, Timken, very helpfully, agreed to check them for us. The actual build has been fairly straightforward and no major issues have emerged with assembly at South Devon Railway Engineering. Of course, the proof of the pudding will come when they actually run on a railway!

See https://www.theclanproject.org/Clan_News.php for photos

 

The latest news shows what lengths the Team is going to to make sure this engine fits together properly.
Did they go to such lengths at Crewe I wonder?
https://www.theclanproject.org/Clan_News.php

 

Eh!

 

It's a question I wondered about, too - are the Clan Group actually using finer tolerances than Crewe were able to in the 1950s?

 

I would have thought "finer tolerances" would maybe, in certain areas, create problems. The whole structure of a locomotive flexes considerably which it has been learned over the many years. I think quality control is more the area of great benefit that you may be alluding to, which is evident here.

 

Really interesting, many thanks.

 

At the time Tornado was being built I heard various mutterings that it was being built to too tight tolerances by a bunch of aerospace engineers and would seize solid the first time it would run.........

 

Which all goes to show that mutterers are there to be ignored. None of them are aware of the Swindon Engineering Society and the Ordinary Meeting of October 25th 1955.

 

KJ Cook ?