Re: [NSW] Tangara braking - was: Today (Sat) on 22 plat. Central

[David Johnson <trainman@ozemail.com.au>]

Chris Downs wrote:

> David & Tezza,
>
> Is this because of a slower application rate and no blended
> regenerative/rheostatic braking or are there other reasons?

When you go past a trip, the brake pipe air reduces.  As soon as it gets below
250 kpa, the control governor drops out and the regen brake drops out.  The
train then surges forward as at least half of your braking effort disappears.

> How would service versus emergency applications compare at 115km/h when the
> slower application rate is less of an issue?

As Tezza said, emergency is more effective down to about 70 - 80 km/h, but then
regen is much better.  Also, you need to empty the brake pipe, which takes time
- Electric brakes are quicker.  The maximum braking effort is acheived by:
1) Turn wheelslip circuit breakers off
2) Full service EP application, plus slide the brake handle slightly into
emergency (not too far) and reduce the brake pipe to about 300 kpa, then return
the handle to the lap position to hold the brake pipe.  This gives 300 kpa in
the brake cylinders, and full regen brake.
3) Put Parking Brake on.
4) Pray.



--
David Johnson
trainman@ozemail.com.au
http://www.ozemail.com.au/~trainman/
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