Adam H. Kerman wrote:
> mroberds@att.net wrote:
>>Section 14 of the CPR GOI
>> http://www.tcrc76.com/Legislative/GOI/GOI%20Section%2014%20-%
02009%20Final.pdf
>>, item 3.0, "Leaving a Train Unattended", on paper page 177, PDF page
>>5 of 8, says (in part):
>
>> CPR# . Automatic brake cut-IN and handle in RELEASE.
>
> Why not leave the automatic brakes applied?
I don't *know*. You'd have to ask Canadian Pacific.
I have a couple of *guesses*. Guess one:
If you were running down this checklist of items, you might be doing so
as just about the last thing you did before climbing off of the
locomotive to go home (or to another train, or whatever). If you put
the brakes in "release", and the train moves, this indicates that maybe
you need to set some more handbrakes, or that there is some other
problem that requires attention.
In other words, it's another way to say "try moving the train after you
set some handbrakes, to see if you have set enough". Since it relies on
gravity, it's not as good of a handbrake test as trying to move the
train with the engine, but perhaps the though is that it is better than
nothing.
Guess two:
Sometimes it gets a little bit cold in Canada. If the automatic brakes
were applied, you'd have all the brake shoes on the train pressed
against all the wheels, possibly for many hours. Maybe the concern is
that the brakes (shoes or linkage) might tend to get frozen in place by
ice/snow/sleet. If only a few brakes get stuck, OK - visit those cars
and try to unstick them. If the brakes on most of the train get stuck,
there will be a lot of time and effort to get them unstuck again.
The same concern over freezing brakes would exist on cars that have
their handbrakes set, but since (as seen in the rules) the handbrakes
are usually not set on *all* the cars, the whole train probably wouldn't
have its brakes stuck. When the train needs to move again, an employee
has to go touch each car with the handbrake set anyway, so they can see
if the brakes release and possibly fix it if they don't release.
> The report said that RSC wiring was fucked up on every retrofitted GE
> locomotive that the railroad owned. As penalty brake application with
> power loss isn't a function enforced by government regulatory
> standard, the shop wasn't required to check that the feature worked.
I understand that it didn't legally *have* to work that way. If it
*did* work that way, it's just another thing that would have helped
prevent the problem.
> Seriously: Wired directly to the battery. Is that frightening or what?
> Who the hell makes a mistake like that? How did that idiot not
> electrocute himself when wiring it up?
I've worked hot on DC systems from 12 V to 144 V, with available fault
currents of way less than an amp (telephone) to several hundred amps
(starting and traction batteries). It's not my favorite thing in the
world to do, but it's possible. You can get tools with insulated
handles rated to a few hundred volts (expensive), or you can just wrap
the tools you have with electrical tape (cheap).
To be clear, I'm not saying that the way the thing was wired was *good*,
just that it's *possible* to do it that way.
The minor thing that sucks about going straight to the battery is that
it almost always creates a small drain on the battery. If the battery
isn't that big, or if the vehicle sits unused for a long time (days or
weeks), this gives you a dead battery. If you have a huge battery, or
run the vehicle often, then you don't notice the battery drain.
>> Or if somebody in a shop had realized that JB Weld (or similar)
>> wasn't the best product to use on the camshaft bearing housing of a
>> 3,000 hp diesel engine.
>
> How? They thought overtightening the housing around the bearing was
> the correct procedure for stopping the oil leak. Surprise, surprise:
> The bearing cracked.
The main report (TSB Canada R13D0054) links to a lab report (TSB Canada
LP181/2013) that has more detail about this. Section 2.3.5 of the lab
report has photos:
http://www.tsb.gc.ca/eng/lab/rail/2013/lp1812013/LP1812013.asp
The original problem was that part of the casting around the cam bearing
bore broke away. This is part of the engine casting - maybe "housing"
was a poor description on my part. The missing piece of casting was
filled in with "a polymeric material (likely some type of epoxy)".
Apparently this wasn't good enough to hold the bearing, so the retaining
bolt loosened up. Section 3.2 of the lab report:
TSBC# It is considered likely that the cam bearing mounting bolt had
TSBC# loosened at this location because the bearing was not seating
TSBC# properly in the previously damaged and deformed bearing bore. It
TSBC# is considered most probable that the R4/R5 cam bearing bolt was
TSBC# over-tightened in an effort to stop the leak. As a result, the
TSBC# bolt and threaded insert were pulled out of the cam bearing and
TSBC# the cam bearing separated in overstress. It is not known when the
TSBC# portion of the adjacent polymeric material repair broke off. The
TSBC# repair material failure was adhesive in nature close to the
TSBC# bearing bore indicating the bond between the block and the repair
TSBC# material failed (refer to Figure 36). Further outboard of the cam
TSBC# bearing the repair material failed in a cohesive manner,
TSBC# indicating it was unable to withstand the applied stress. This
TSBC# could have been a result of the oil pressure at start up following
TSBC# the repair or later when the mounting bolt was over-tightened.
> How much does it cost to rent a locomotive in good working order to
> give your shop enough time to make proper repairs?
"There's never time to do it right, but always time to do it over."
Matt Roberds
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