Canadian Railroads > on this day 2006

Nov 28, 2006.  Took a few images of the newer DPU screen on a BCR 4600 Dash 9.  Everything is now electronic, all done with push button menu on the screen, including unit setup lead / trail, brakes in / out as well as the menu to setup for DPU operation.  Also these units were equipped with electronic air brakes, something that I did not care for was the new brake valve handle as compared to the older style brake handle. I found the newer electronic handle to be stiff and sometimes difficult to just trim one more pound of air off the equalizing reservoir.  Also there was not much air blow to hear when making a reduction on the automatic brake valve. Ah, maybe all the complaints was just me, can't teach an old dog new tricks.  Doug

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Doug, a question this brings up: does the independent brake control only the lead locomtive's brakes, or the the whole locomotive consist's brakes (head end)? I assume you can set it up either way. Could you have a dead in tow unit's brakes cut in for extra independent braking? Is there a reason you wouldn't want to - such as skidded wheels?

Mike N.



Edited 2 time(s). Last edit at 11/28/16 21:58 by Helo-Mech.

Mike, all trailing units in a consist would be setup in "trail", automatic brake handle in suppression, feed / pilot valve  "trail" position, independent brake handle in the release position. Also various circuit breakers "off" or "on" and the MU headlight selector switch in either short / long hood lead / trail or "middle unit". Once all locomotives are properly conditioned for either lead or trail, then the independent (engine brakes) operate in unison as per handle operation on the lead locomotive.
The lead locomotive would be setup for lead, ie: air brake feed cut-in, independent brake valve in, headlight setup etc etc. Also the brakes can be physically cut out on a locomotive, a valve opened that vents air directly to atmosphere instead of into the brake cylinders. For obvious reasons of safety, brakes on the leading locomotive must be fully functional.
The slave DPU unit would be setup as "lead" in the same way as the leading /controlling unit, although as "DPU mode". any other units in the slave DPU consist would be setup as trail.

The new DPU system & electronic brake setup, the DPU locomotive brakes duplicate what the lead "master" unit are doing. If the DPU units are set-out or left standing by themselves with or without other equipment attached, the DPU unit will be "isolated", feed valve "out", full independent brake application and brake pipe vented down or in emergency. As required per rules , hand brake(s) applied.

The older Locotrol II operation was similar, although the automatic (train brake) and independent (engine) brakes were operated by push button. The locomotive Engineer could operate the lead units independent brakes with out the remote control units mimicking the lead unit. If the push buttons were used then the remote control consist would duplicate the lead unit.

Hopefully this has answered your question. It's too early for me to thinks about this stuff, only had one cup of coffee and the brain is still somewhat in loss of signal mode.
Doug







 

hoggerdoug Wrote:
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> ... Also these units were equipped with electronic air brakes, something that I did not
> care for was the new brake valve handle as compared to the older style brake handle. I found
> the newer electronic handle to be stiff and sometimes difficult to just trim one more pound of
> air off the equalizing reservoir.  Also there was not much air blow to hear when making a reduction
> on the automatic brake valve. Ah, maybe all the complaints was just me, can't teach an old dog new
> tricks.  Doug

​At least you had a "brake valve". When we got the first DP units in Eugene, Oregon, for use in the Cascades we got the old C40/41's here. The wide-nosed C41's had push button​ "brake valves" - talk about something to hate!!! I never did get comfortable with those units and was very happy when the early C44AC's started arriving.

images of the Locotrol I push button air brake & the Locotrol II push button.  With DPU & electronic brake it was all done in the automatic and independent handles.  Doug

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> The new DPU system & electronic brake setup, the
> DPU locomotive brakes duplicate what the lead
> "master" unit are doing. If the DPU units are
> set-out or left standing by themselves with or
> without other equipment attached, the DPU unit
> will be "isolated", feed valve "out", full
> independent brake application and brake pipe
> vented down or in emergency. As required per rules
> , hand brake(s) applied.
>
> The older Locotrol II operation was similar,
> although the automatic (train brake) and
> independent (engine) brakes were operated by push
> button. The locomotive Engineer could operate the
> lead units independent brakes with out the remote
> control units mimicking the lead unit. If the push
> buttons were used then the remote control consist
> would duplicate the lead unit.
>
> Hopefully this has answered your question. It's
> too early for me to thinks about this stuff, only
> had one cup of coffee and the brain is still
> somewhat in loss of signal mode.
> Doug

Doug, sure does thanks for the thurough explanation.

With the electronic braking / DPU - I assume you can select if you want the DPU to mimic the "master" or lead unit? (as able to do with Locotrol II) I imagine there would be instances when you don't want your mid train slave to apply braking at the same time.

Was wondering if you could apply the mid train brakes independently from the leader too, until I realized that's probably something you would never want to happen! Or that it would cause more problems than be of use.

A+ explanation for just one cup too!

Mike N.