What is the pressure range for a train air brake system in normal operation and how long would it take to charge a system? I know for trucks the law states air pressure must be within 552 to 932 kpa, and that pressure must build from 583 kpa to 690 kpa within 2 minutes or the air system is deemed to be defective. Are there similar laws and standards for trains?
Translating into psi, 552 to 932 kpa is 80 to 135 psi, 583 to 690 is 84.5 to 100 psi. kpa sand for kilopascals, where 1 Pascal is the pressure of 1 newton per square meter (1 newton = 1/4.44 pounds).
I am quite sure that there is a law covering air brake performance - figure someone else will jump in and fill in the details.
With the brakes released, trainline pressure is 90 psi. Locomotive reservoir pressure is 105 psi. Charge time depends on the length of train. The longer the train, the longer it takes to charge the system. Check applicable laws and railway specific operating rules for the nitty gritty details.
Air brakes on a train at the top end cannot exceed 90 lps psi and a 20 lbs psi reduction will give you a full set on the brakes , usually you are looking at 80 lbs and 60lbs as the operating norms for an initial terminal air test .
As far how long it takes to get a full release will depend on the number of cars and the outside temp. but usually a couple of minutes .
Here is a copy of the current FRA Rules
§ 232.103 General requirements for all train brake systems.
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(a) The primary brake system of a train shall be capable of stopping the train with a service application
from its maximum operating speed within the signal spacing existing on the track over which the train is
operating.
(b) If the integrity of the train line of a train brake system is broken, the train shall be stopped. If a train
line uses other than solely pneumatic technology, the integrity of the train line shall be monitored by the
brake control system.
(c) A train brake system shall respond as intended to signals from the train line.
(d) One hundred percent of the brakes on a train shall be effective and operative brakes prior to use or
departure from any location where a Class I brake test is required to be performed on the train pursuant
to §232.205.
(e) A train shall not move if less than 85 percent of the cars in that train have operative and effective
brakes.
(f) Each car in a train shall have its air brakes in effective operating condition unless the car is being
moved for repairs in accordance with §232.15. The air brakes on a car are not in effective operating
condition if its brakes are cut-out or otherwise inoperative or if the piston travel exceeds:
(1) 10 1/2 inches for cars equipped with nominal 12-inch stroke brake cylinders; or
(2) The piston travel limits indicated on the stencil, sticker, or badge plate for the brake cylinder with
which the car is equipped.
(g) Except for cars equipped with nominal 12-inch stroke (8
Here’s the charging times given in the Conrail EC-99 Brake Rules:
EC-99 calls out a brake pipe pressure of 110 psi for passenger service.
The max brake pipe pressure for freight is 90 Psi
The max brake pipe pressure for passenger equipment is 110 PSI with a 24 Psi reduction for max brake.
Some TrailerVan trains use to be run with 110 Psi brakepipe too
That’s good info…if there is a drop in system pressure due to a line breakage it must be quite a job to find out where the problem is. What would a train crew do if, for example, pressure dropped and the emergency brakes were applied. Would they have to walk the length of the train to find the leak or disconnect? Are train crews expected to be able to fix air line problems? Must be alot of fun in the cold winter months when your train is stalled on Rogers Pass,and a cold wind is blowing.
60 minimum to trip the truck idiot light, 90 to move, 120 is optimal.
Air should not leak more than a few pounds after first service application, no more than a few pounds over several minutes.
And a supply of bic plastic pens, knife and clamps.
In the old days we had air for everything. Engine start, steering, suspension, wipers etc… the whole nine yards.
Yes.
To a certain extent. There are extra hoses and gaskets available on the locomotive, and tools.
It’s a lot of fun no matter where you’re stuck. [;)]