Silly season? - The K3 project

Where do I sign up?

 

I wonder how the Germans got on with the bogie brakes on their various 01 Pacifics that lasted until the 70s? Can't have been too much of a problem if they weren't removed.

 

I wondered how British DMUs managed as well!

 

If someone seriously wanted to go to the trouble of building a steam locomotive for the sole purpose of breaking the steam railway speed record, they would be better off designing it from first principles. All the record breaker would need to be able to do is go very fast, stay on the rails, be safe for the driver or crew to operate and be capable of stopping. Surely something small, light unconventional would be the way to go.

Come to think of it, why not just adapt this thing to run on rails -
http://www.dailymail.co.uk/sciencet...r-smashes-100-year-old-land-speed-record.htmlnd

Still a crazy idea, but there's always the danger someone will take it seriously!

 

But would they have run Lady of Lyons at two miles a minute without bogie brakes to help stop it afterwards?

 

One exception was the SR Q1. Whilst more powerfull than a Q the weight saving meant they could pull more than they could stop. I believe there were a few sticky moments on unfitteds

 

The brake tenders were about weight though weren't they? The hydraulics were relatively light, which meant less adhesion, and I've heard the theory had been that there would be next to no unfitted goods trains left by the time they were in service. Like so much planning in that era that turned out to be wrong, so the need for what was effectively a short fitted head to the train

I believe everyone could have sticky moments on unfitted trains. After all, same train weight and, what 3 axles worth of braking on the train (and that under separate control) instead of 40... Obviously speeds were and clearly had to be very much lower. But as with the hydraulics less locomotive weight meant less braking. Maybe Bulleid should have built some Q1 brake tenders [grin]

 

That, though does not explain their use, sometimes in pairs, behind Class 40s and Peaks, and while these certainly had a weight problem, it was because thay had rather a lot of it!

Goods train speeds in steam days rarely went much above 30 mph for this very reason. A loco exploding three shots had no more than three quarters of a mile to stop in, and throwing the brake hard over wasn't an option; first the driver had to brake gently to gather that train together before full braking could begin, and that took time. Throwing the brake straight in was very likely to seriously injure the guard as his van lost several mph in a matter of milliseconds, and in extreme cases could cause a derailment.

Not all steam locos had good brakes, even goods engines, and the LNWR Super Ds were notorious. They improved later, but the original set-up had a single brake cylinder, steam or vacuum, pulling brake blocks on to all eight coupled wheels, and through a complicated linkage on to the rear of all six tender wheels. As the braking took effect, the train pushed the tender up against the loco, shortening the distance between them, and so pattially reducing the brake force. Later, the engine and tender were given seperate systems and the loco got a second cylinder to operate the brake to the leading four wheels, which improved things. Even so, Buxton men insisted that they were loaded to no more than a 4F as they couldn't stop their full load on the banks.

But most steam locos had good brakes, including the handbrake (as a driver at Edge Hill told me about the Class 4os, "When you tied a steam engine down, it stayed tied down, not like these bloody things!" The 8Fs had a very good brake, better than the 9Fs, despite the number of wheels. The S&D 2-8-0s' brake was superb, but I believe they required reblocking every two days.

This is serious thread drift, but far more interesting than the original subject matter!

 

Dave Goulder made a song about one such incident, "The day we ran away".

It is indeed. I suggest hiving it off into a separate thread "Steam locomotive brakes".

 

I'm pretty sure that at one time the S&D 7f's had brake blocks lined with Ferodo friction material at one time, as per car brake shoes. That would no doubt provide the impressive performance, though I imagine if they were too good you'd risk picking up the wheels too easily.

 

With regard the Q1, I'm not sure the brakes were poor in absolute terms, it's just that you had a loco that was not a lot bigger than a typical 0-6-0 freight engine, but with the haulage capacity not far off an S15...

Bulleid carried out some trials early one Sunday (with the line suitably cleared in front!). A train with I believe about 40 or so loaded unfitted wagons was taken over the summit at about 40mph on the way to Winchester. The brake was applied when the Wallers Ash down distant came into sight: the home signal went sailing past the cab and the train eventually stopped about 1.75miles past where it should have. A comparative trial with an S15 with double bogie tender stopped in the right place. Bulleid then asked the Brighton drawing office to come up with a solution, but it always seemed to go to the bottom of the "to do" list. No doubt they had their work cut out with getting the Light Pacifics into service. But the Q1s remained definitely class 5FA not 5FB.

Tom

 

Yes, it probably explains the need for frequent blocking too!

 

Ah, Dave Goulder. Very clever chap. Former steam loco fireman, master dry stone wall builder, teacher, song-writer, poet, singer and probably several other things besides! An all-round gent. If you get the chance to hear him in concert, take it! But that's even further thread drift than the brakes dicussion...

 

I understood that the main reason for the provision of the diesel brake tenders was because the diesels couldn't dissipate the braking energy sufficiently. It was not about adhesion. The small disc wheels became too hot too quickly when on unfiited mineral trains causing both brake fade and slipped tyres. A steam loco wheel has both a lot more mass of metal to heat up and a much larger surface area giving a better cooling effect.

 

You are correct.

 

I believe a WD 2-8-0 was trialled on the S&D and whilst it could haul anything a 7F could, it couldn't stop it.

 

Many an engine failed the S&D's brake test!