brake van use on express

[royvince]

About the time of the end of the war, I was travelling to Newcastle from London. On the approaches to Newcastle we were in the guards compartment at the rear of the train and the guard wound on the screw type handbrak hard. this was a fair way before the station an d it wad held on all the way into the station and was obviously an assistance to the train brake. It was a very long train, maybe 20 coaches, but surely the train through braking system would be the norm , or was this a procedure used during these difficult times. Note these trains were heavy with people standing all the way London to newcastle. Any comments appreciated

[Hatfield Shed]

The continuous brake on the vacuum system took time to progress the brake application along the train. At the rear end of twenty coaches the brake would go on an appreciable time after the driver made the brake application. I have a dim recollection that something like 30 coaches was reckoned the effective limit for the vacuum system as a truly continuous brake; the train would have been stopped by the braking up front before the last coach's brake went on.

Famously, Mallard did the belting along while officially testing the 'Quick Service Application' improvement produced by Westinghouse. This used auxiliary valves which opened the pipe to air on each coach as soon as a significant pressure drop occurred, thus accelerating the brake application. When you think that this was considered worth testing for a maximum nine coach set - albeit one that was regularly going to travel faster than average- it does hint at the soggy response of the vacuum system.

[royvince]

Thanks for very logical response, makes you wonder why the compressed air system was not used as the norm due to its greater efficiency

[65447]

Thanks for very logical response, makes you wonder why the compressed air system was not used as the norm due to its greater efficiency

Reasons here: viewtopic.php?f=5&t=11089#p111903

[1H was 2E]

Just a thought based on first principles - might not have worked in practice; but the delay in application of vacuum brakes was presumably because when the driver braked by admitting air on the engine the first brake cylinder would need to have the vacuum almost totally destroyed before it carried on down the pipe to the second, and the process was repeated down the train.
So wouldn't it be more effective for the guard to open his brake valve at the rear (allowing the vacuum to be destroyed from the rear as well), rather than use the handbrake? Of course, it might not produce a smooth stop...
The LNER did run fully fitted freight trains (already covered; on the thread about brake vans, I think) whereas other railways seem to prefer part fitted; although coaches have (I think) 2 brake cylinders, and freight stock only one, the observation about 15 coach passenger trains applies equally to 30 vehicle freight trains.
Bulleid apparently did test an electrically triggered vacuum brake system (still, pedantically E.P.!); another example of developing existing technology rather than trying new. Joined Leader in not catching on.

[Seagull]

Bulleid apparently did test an electrically triggered vacuum brake system (still, pedantically E.P.!); another example of developing existing technology rather than trying new. Joined Leader in not catching on.

Funny I read this a few days ago and only just now something hit me.

About 25 years ago (Oops showing my age!) I had the misfortune to be involved in the maintenance of some air operated, electrically controlled fire doors. The air and electric sides were supposed to be completely seperate. Supposed to be!

Somehow all of the electrical faults involved were caused by water laden compressed air getting into the electrical components.
I even started getting all the water traps drained daily but we still had ongong problems.

The classic event being looking up a a bunch of passengers who were looking out of a fire door jammed open 10 feet above me!

Maybe OVS had similar problems.

Alan

[melton]

maybe the brake was a swinger

[Andy W]

Screwing the brake on partially (or fully) was a habit that died hard on the ECML. I was still detaching brake coaches at KX in the early 1980's on LHCS where the handbrake had been left on. Usually London End van when it had been left partially on since the previous down working and Country End van when the guard had forgotten to wind it back en route.

You used to get very hot wheels quite quickly if partially left on and on very rare occasions severe flats when it was screwed down. If the tyres were o.k. we used to check behind the wheels to see if there had been any movement of the Gibson ring (the clip that holds the tyre to the wheelset). If there had been movement then out it came with the help of 1 Shunt (the station pilot) and into the milk dock it went.

After it had cooled down a bit, it would be taken out to Ferme Park for a trip to Bounds Green heavy repair shop and some new wheelsets.