V4 2-6-2 No. 3403

Bulleid had a different idea, on his Pacifics the engine is team braked and the tender is vacuum

 

I believe that both Urie & Maunsell had also favoured the arrangement of steam-braked engine with vacuum-braked tender. But I don't know of that combination being used outside of the SR.

 

Maunsell may have favoured it, I'm not sure, but the GAs for the Urie 4-6-0s show 24" vacuum cylinders ahead of the leading coupled axle on the N15 and S15, with a 21" vacuum cylinder under the cab floor for the H15. The big tanks were steam braked, but of course they didn't have a tender to be vacuum braked.

 

Is correct.
My personal belief about the cylinder location on the H15 is that using available dragbox patterns from Mr. Drummond's 4-6-0s dictated the position. There was no good reason for not placing it in the forward position except, of course, the time factor in producing a new design in a remarkably short time. Indeed, I wonder whether the 'rebuilds' of 1924-5 may have re-used the dragboxes. I guess we'll never know.
Pat

 

I have always wondered whether safety chains would actually work or would break with the sudden snatch when the main coupling (which should be stronger) fails.
If you find you've suddenly left the tender behind, besides wanting to stop ASAP wouldn't you also be worried about having no water for the injectors?

 

I don't think a lack of water for the injectors would be quite as big a worry as having absolutely nothing behind you to stop you falling off the locomotive, but presumably chucking the fire out would be the very next thing to do after stopping.

 

I suspect standing on the footplate and watching the tender rapidly recede into the distance behind you probably counts as just your first "oh ****" moment of what might be several in rapid succession!

Tom

 

This assumes that you are not stood on the fall plate as things split

 

Not on a Britannia - the cab floor goes right back to the tender (rather than separate cab and tender floors with a fall plate to bridge the gap).

At least you've got a rocking grate!

Interestingly, the incident at Diss doesn't seem to have had an investigation report that has made it to https://www.railwaysarchive.co.uk/, presumably because ultimately there was no accident involving injury or loss of live or significant damage.

Tom

 

Chains are quite resilient when subject to snatch loads, especially the long link ones usually used and will deform if overloaded rather than break. Think of three link couplings. Yes, they did break from time to time but it wasn't an everyday event and they would be subject to far greater snatch loads on a daily basis than would have happened in this case.

 

Just because its managed to get so far doenst mean it can keep expanding. I have sat in a board meeting today talking about fundraising in one part, and its very very clear that there isnt enough money out their for every project to get completed. No matter how positive we try to be about it all. When preservation started, steam was still on the mainline, with so many people who had proper experience in both operations and maintenance of railways, due to the fact that railways were a massive employer, and as a %there wa bound to be some who wished to volunteer as they enjoyed it. While we have lost a lot of the early and older volunteers due to age, preservation has survived very well due to the amount of kids who were railway enthusiasts growing up, keeping the passion and eventually getting into the hobby or making donations etc etc. And while there are clearly young people still involved and getting into the hobby its not in the same numbers as it was, and for those youngsters the price of houses vs wages has gone up massively, never mind other costs, so there wont be the same levels of excess money to spend going into the future overall (there will be the odd project that is different no doubt). Add in the rising age of retirement as well, equals less free time for volunteers.

I dont try to be doom and gloom, i try to see all the possibilities, but long term I do see a struggle.

There is one slight glimmer of hope for some projects, and the F5 is benefitting from this, and its legacies, which could see some projects that are currently struggling manage to get over the line.

As for the V4, im sure the A1 would love to do it, but is it really viable? Im not in a position to say, i just question, if there is the money to make it happen. If it was a logical reasoning, i would have thought that the A1 and B17 should come together after the P2 and get that done in a much quicker time scale as it has already made a good start, and with the A1 behind it as well I think this could see it over the line.

These are all my own thoughts and not representative of any organisation im involved in, and i definitely dont wish to offend anyone.

But hey, hopefully im wrong and we will get everything we want to see out and working.

 

.....As you watch the shovel and other fire irons disappearing in the distance on the tender.......

 

Depends on the engine: GWR types had them - sensibly - on the engine on the running plate ahead of the cab, but the Brits (and all other BR Standard types) had a rocking grate and hopper ashpan to drop the fire. Again, the bar for this was on the engine - in a bracket attached to the firebox backplate.

 

Didn't the WDs also have the irons ahead of the cab too?

 

Only the Western Region ones, I think.

 

Yes, in a tunnel. The normal ones had a set of uprights on the side of the tender to keep them in position.

 

And your sandwiches, jacket.........

 

Unwritten rule no.1 broken then - Never be separated from your food.

 

I’ve had to have a very serious conversation with my co manager about eating my white chocolate digestives this week… Although to be fair the bloke who’s reconstructing his kneecaps is supposed to be the best in the business

 

Apologies - I stand corrected. I had thought that both LSWR & SECR had adopted the steam-braked engine plus vacuum-braked tender combination, but apparently not.

For the record, here is Bradley's description of the braking on the Maunsell N-class Mogul:

"The braking conformed to Ashford's standard practice of having steam on the engine and vacuum on the tender. A pair of 7½in diameter steam brake cylinders positioned below the footplate acted on a brakeshaft which was connected to the brake hangers by double pull rods, inside the coupled wheels, and operated brake blocks to the front of each wheel. On the tender, there was a vacuum brake cylinder at the front and brake shoes to the rear of all wheels."

Given that this thread is meant to be about the planned new-build V4, perhaps we should note that the original V4s had vacuum braking for engine and tender (and train). Whereas I assume that No 3403, if built, will follow the Tornado pattern of air-braking for engine and tender (and both air and vacuum for train).