As title, how was this done? Specifically at lot of shunting engines were
unfitted but surely there were times when stock had to be moved around to
make up a train, thinking of the interwar period was there some device on
fitted stock that locked off the brakes enabling them to be pushed and
pulled around or was it a case having to use an engine fitted with the
appropriate braking system?
=>As title, how was this done? Specifically at lot of shunting engines were
=>unfitted but surely there were times when stock had to be moved around to
=>make up a train, thinking of the interwar period was there some device on
=>fitted stock that locked off the brakes enabling them to be pushed and
=>pulled around or was it a case having to use an engine fitted with the
=>appropriate braking system?
A worker would go along the cut of cars and make sure that the brakes were
off. There's a hand-operated valve on fitted stock that does this. Engine
brakes (and sometimes a brakevan) were used to brake the train. When the
train was assembled, the fitted stocks' vacuum lines were connected. AFAIK,
trains of mixed fitted and unfitted stock were rare -- short, local runs
Now that all stock is fitted, the same problem exists, and the same solution
- a man/woman on the ground who walks up and down the train setting and
unsetting brakes as needed.
Sitting there watching one of my little shunters shift a parcels van to the
front of some passenger stock I just got to wondering, "How on earth can it
do that?" It was just one of those silly things that niggle 'till you've had
the definitive answer.
"Paul Stevenson" wrote
I may be way off tack here but I was under the impression that in a
fail-safe braking system, including vacuum braking, the effect of applying
the vacuum was to release the brakes. Release the vacuum and the brakes
I recall reading somewhere in the distant past that on loco's with faulty
vacuum ejectors it sometimes proved impossible to generate enough vacuum to
release the brakes.
If this is true Paul, your hypothesis is totally wrong.
You need to read up on how vacuum, and for that matter, airbrakes work, as
the principles of both are the same, but different.
Simply put, both vacuum and airbrakes rely on a balance between reservoirs.
To apply the brakes, you reduce the pressure/vacuum on one side of the brake
piston, and the brakes apply. Reapply the vacuum/air pressure and the
brakes release. Equilibrium = brakes released.
To move a fitted vehicle, you destroy the vacuum/air pressure by uncoupling
the brake pipe. This will apply the brake automatically. On each vehicle,
you then destroy the vacuum/air pressure in the reservoir on each vehicle.
"Pulling the strings", you now have no brake pipe pressure and no reservoir
vacuum/air pressure on the vehicle. result, brake cylinder now is equalised
(No pressure either side of the piston) and the thus you have no brakes.
The above is very simply put.
The release cord releases the vacuum (or air if it's air braking) in the
Vacuum (or Auxiliary) reservoir - This being de - pressurised (or
pressurised) is what keeps the brakes on - see
for Vacuum info and
for air info.
At the railway I work at (Ruislip Lido Railway,
we use air braking in the same way as shewn on the page above, with release
buttons (as opposed to cords) to allow coaches etc. to roll freely without
trainpipe pressure (eg: when hand - shunting)
R M S
excuse me if this had already been made clear but..........
i as i remember it when were making up a train, i occasionally would
find a wagon that would not move, the brakes were locked on solid !,
after scratching my head and then checking the hand brake was off, i
would remember to pull the string (indicated by star painted on the sole
bar) and as if by magic and a slight hiss the wagon would move.
david a. pritchard
On air braked stock, each vehicle has an auxiliary air reservoir, which
is pumped up to pressure by the train airline. The triple valve (each
vehicle), is held shut by the train line pressure, and this valve retains
the pressure in the aux. reservoir. The actual brake cylinder is open to
atmosphere through the triple valve, and a spring in the brake cylinder
holds up the piston and keeps the brakes off. Application of the brakes, or
parting of the train line drops the pressure in this line, this causes the
triple valve to connect the aux.reservoir to the brake cylinder, the piston
is pushed down and so applies the brakes. The brakes are held on by the air
in the aux. cylinder, if you want to release the brakes you pull the tit,
string, chain or whatever, this allows the air in the aux. cyl to escape and
the spring in the brake cyl. pushes up the piston and so the brakes come
off. When making up a train, all the aux, cylinders must be pumped back up
to pressure through the train air line, so you just can't hook up all the
air hoses and immediately move off, or if you do you'll be without any
"Chris Wilson" wrote Sitting there watching one of
my little shunters shift a parcels van to the
Prototypically, unless the wagon was also vacuum braked, it would not go
between the loco and coaches as this would mean an unfitted train (Unless
the wagon were through piped, i.e the vacuum pipes at both end, but not
actually braked). The said wagon would run after the coaches and be termed
where I work as a "swinger". I have seen this done on a preservation line
and to aid the braking, a brake van was added after the wagon which was
after the coaches.
Hope this helps... Any more advice, buzz me off list!
Churnet Valley Model Railway Department
(Remove the Standard Tank from E-mail to reply)