FIELD, British Columbia — Hours before a Canadian Pacific train derailed in the rugged mountains of British Columbia, killing three railroaders, the previous crew had struggled to keep the doomed grain train under control on a steep grade. On T...
http://trn.trains.com/news/news-wire/2019/04/19-canadian-investigators-prior-crew-struggled-with-train-involved-in-fatal-wreck
Brian Schmidt, Editor, Classic Trains magazine
In the earlier thread about this wreck, I speculated that the release of the emergency application was due to the pressure leaking off through the brake cylinder piston packing which is a rubber cup. I believe the cold temperature stiffened up that rubber packing cup to the point where the rubber lost its memory and would not return to a tight seal against air pressure.
When these packing cups are new, I am sure they are fully capable of maintaining a seal in the coldest weather encountered. But rubber ages and becomes less resilient. So there must be maintenance instructions that call for replacing these packing cups at specified intervals.
Interestingly while the regulatory body tells us that tests revealed that the car’s air brake system failed to maintain constant pressure over time, they don’t say what components failed in this mission. Surely they know if they conducted extensive testing that revealed that the system was unable to maintain pressure. My bet is on defective brake cylinder piston packing that was not properly maintained.
From the news article:
“After the derailment, investigators took the 12 grain cars that did not derail and conducted extensive tests to the air brake systems, with weather conditions similar to the night of the derailment. The tests revealed that the car’s air brake system failed to maintain constant pressure over time. “The air brake system on these cars would not provide adequate braking effectiveness to ensure the safe operation of a loaded unit grain train in a situation where the air brakes are required to remain applied for an extended duration, such as while descending a steep grade,” TSB officials write.”
Hand Brakes, Hand Brakes, Hand Brakes! Original crew set the trap that was sprung on the relief crew.
Never too old to have a happy childhood!
BaltACD Hand Brakes, Hand Brakes, Hand Brakes! Original crew set the trap that was sprung on the relief crew.
No—maintain the brake cylinder packing, maintain the brake cylinder packing, maintain the brake cylinder packing!
There was no requirement to set handbrakes. The original crew did not set any trap that was sprung on the relief crew. All they did was save the train and their lives by complying with the requirement to dump the air because their train was running away.
The trap that was sprung on the relief crew was the decision to proceed down the grade without knowing what the problem was that caused the train to run away with the original crew.
Euclid BaltACD Hand Brakes, Hand Brakes, Hand Brakes! Original crew set the trap that was sprung on the relief crew. No—maintain the brake cylinder packing, maintain the brake cylinder packing, maintain the brake cylinder packing! There was no requirement to set handbrakes. The original crew did not set any trap that was sprung on the relief crew. All they did was save the train and their lives by complying with the requirement to dump the air because their train was running away. The trap that was sprung on the relief crew was the decision to proceed down the grade without knowing what the problem was that caused the train to run away with the original crew.
The trap was NOT SECURING THE TRAIN - to figure out why it was not braking properly! Self preservation trumps rules or the lack therof. Were I your Trainmaster Euclid - you would be on the street for 30 days or fired outright!
Why was the train parked for nearly three hours while waiting for another crew?
charlie hebdo Why was the train parked for nearly three hours while waiting for another crew?
I don't know. I recall some reporting about spending time inspecting the train. The previous crew had stopped by making an emergency application. Does that then require an inspection? I am guessing it would, but I don't know for sure. But aside from the train having been stopped by an emergency application, there was a real emergency in the form of the brakes not holding the train's speed down to where it should have been and was expected to be when descending the hill. That would indicate a very serious problem.
I would think that somebody higher up than the second crew had to make the decision for the train to depart. It seems evident that whatever the problem was that produced the insufficient braking experience by the first crew, it was the same problem that caused the emergency application to leak off as experienced by the second crew.
So that suggests that the inspection never found the problem. If it did not find the problem, how does one conclude that the problem does not still exist and is waiting to do the second crew what it did to the first crew?
How does one assume that the problem is gone just because it can't be found? Yet that is apparently what happened. Or maybe they were still inspecting when the emergency application leaked off and thus were blindsided to the same extent as the second crew.
Maybe the inspection found no problem with the air charging and brake application and release, and concluded that the problem must have just been snow on the brake shoes.
charlie hebdoWhy was the train parked for nearly three hours while waiting for another crew?
Getting recrews to trains that are stopped in remote areas is not the easiest thing to do - especially if it had been considered that the crew that went into emergency was figured to have sufficient time to make their crew change point prior to having their problems.
Don't know the particular realities of this location. In the US all crews get a nominal 2 hour notification before their on duty time. Once on duty they must be transported to the location where the prior crew went HOS. Sometime the conveyance taking the recrew to the HOS site will bring the 'dead' crew back to the terminal, other times two conveyances will be used and the 'dead' crew will be long gone from the scene.
Sort of like what happened to the Challenger. Dold weather made the O rings hard allowing leakage. Maybe a redesign in the brake cylinders would be called for. I am NO engineer, but too many of these are occuring.
Here are some mileage numbers from the Canadian Trackside Guide 2013.
The Laggan sub begins at Calgary, passes through Yoho (between the two tunnels) at m.p. 129.8, and ends at Field, at m.p.138.6. Field was the west end of the Prairie Division.
Does this help?
Johnny
I have two questions about the problems in this accident.
1) Would use of retainers helped with the control of the train?
2) If locomotives assigned to operate a train over a significant grade such as Kicking Horse can start a train up the grade, could they not hold that train stopped on the grade? Said another way how can you start a train if you can not overcome gravities pull on the train. I know that DC motors are not designed to handle the currents that would be incurred if a locomotive is run in reverse to the trains travel but can AC motors create torque when reversed? I am not clear on the issues here. In dynamic braking the electric motors are operated as generators and the braking force drops to zero as the speed drops but if the motor was reversed ( as if it going to push the train backwards) can an AC motor create a force that could stop a train?
For some operational background per the 2006 timetable go here, pages 11 thru 15:
http://www.multimodalways.org/docs/railroads/companies/CP/CP%20ETTs/CP%20Alberta%20SA%20ETT%20%2342%2011-22-2006.pdf
My copy of the 2012 ETT shows only a few subtle changes to that (see Footnotes pasted below), most notably under Footnote 11.3, which instructed crews when "abnormal conditions such as weather or poor braking" are present to "apply a hand brake on every car" in 2006 vs. "apply a hand brake on at least 75 percent of the cars" in 2012.
The crew arriving Partridge with the train in question had reported braking problems.
I can't say whether the ETT in effect at the time of the accident included further changes to those train handling procedures. After the accident, CP issued Revised Train Handling Procedures on Mountain Grades which call for hand brakes on 25 cars and retainers set to HP position on all cars before attempting to recover from the first emergency brake application, and hand brakes on ALL cars and retainers set to HP position before attempting to recover from a second emergency brake application.
[Excerpt below from Nov 2012 ETT]
11.3 The train handling procedure on page 5/7, and the
following instructions in paragraphs A, B, C and D
apply to westward freight trains in which the weight
per operative brake is 100 tons or greater.
Note: All westward trains experiencing an emergency
brake application beyond mile 123.5 must communicate
with the on duty Trainmaster via the RTC
and be governed by their instructions.
A. Emergency brake recovery procedure – If an
emergency brake application is experienced between
Stephen and mile 125.5, the train brakes
may be released and the train allowed to proceed
to mile 125.5, where it must be stopped
and the brake pipe fully recharged. Trains
which are stopped between mile 125.5 and Signal
1363 Field with the train air brakes in emergency,
must be governed as follows:
First Emergency Brake Application:
Before the emergency PCS is recovered, all
crew members (ie: locomotive engineer and
conductor and Trainmaster) must perform a job
briefing to discuss with each other the use of retainer
valves. In the application GOI section 15,
item 14.3 and 29.3, set retaining valves to the
HP (high pressure) position on at least 75 percent
of the loaded cars.
When discussing the use of retainers and/ or
hand brakes, consider train location, amount of
train on the mountain grade weather and rail
conditions and any other conditions present that
may affect the braking of that train. If abnormal
conditions such as weather or poor braking train
dictate that the application of hand brakes is
necessary to secure the train while re-charging,
then apply a hand brake on at least 75 percent
of the cars and set retaining valves to the HP
position on at least 75 percent of the loaded
cars.
Second Emergency Brake Application:
Apply retainers on 100% of the loaded cars and
40 hand brakes on the head end of train. Allow
the train to fully recharge the brake pipe.
Note: If there is doubt or uncertainty regarding
the continued operation of the train, then contact
the RTC and request to speak directly to a
Trainmaster.
B. When stop required at or between Mile 125.5
and Field
Brakes applied: An attempt to move the train
with the train air brakes applied must be made,
using care to avoid a train separation.
Standing Recharge: If a train air brake release
is required, and the locomotives are sufficient to
prevent the train from moving, then completely
recharge the train air brake system before proceeding.
Running Recharge: If a train air brake release
is required, but the locomotives are not sufficient
to prevent the train from moving, then the train
air brake must be re-applied at a speed not exceeding
5 MPH. This application must be made
as per GOI instructions for trains which are not
fully charged (e.g. GOI Section 16 item 3.0).
C. An attempt must be made to pull the train over
the ascending grade between miles 124.5 and
125.5 (beside Wapta Lake) without releasing the
train air brake. If a running release is required
between miles 124.5 and 125.5, the following
steps must be followed:
Step 1: Do not exceed 10 MPH from the point
of brake release through to the east siding
switch Partridge.
Step 2: Make an effective minimum brake application
before the lead locomotive passes mile
126.7 (east siding switch Partridge). This application
must be made as per GOI instructions for
trains which are not fully charged (e.g. formula
method TG-FG = X + 7 = required amount of
equalizing reservoir reduction for effective minimum
brake).
Step 3: Once lead locomotive passes the east
siding switch Partridge, monitor speed until it is
known that a combination of train air brakes and
mid-range DB are sufficient to control train
speed at 15 MPH.
D. Train handling Procedure – As weather conditions
worsen, make initial and supplementary
brake applications before the points indicated in
figure on page 5/7 of time table. Train crews are
reminded to make sure that it is known that a
combination of train air brakes and mid-range
dynamic brake are sufficient to control train
11.4 All westward trains experiencing an undesired release
of the train air brakes while descending the
grade on Field hill between mile 125.5 and Field,
must immediately bring the train to a stop (if possible
avoid stopping train inside spiral tunnels). Retainers
must be set in the High Pressure (HP) position on
75% of the loaded cars. All undesired releases of
the brakes must be reported immediately to the
RTC, who in turn will advise a Trainmaster.
I understand your point about setting handbrakes to secure the train as logically being the first priority. Without handbrakes being set, the train stopped by an emergency application can run away any time if the air leaks off. So, secure the train by handbrakes before spending time looking for a brake problem that lead to stopping the train. Once the train is safely secured by handbrakes, take all the time in the world if necessary to correct the air brake problem. That makes perfect sense.
The question I have is whether or not setting handbrakes after stopping was required by the rules. I have yet to see any news report, expert interview, or NTSB information say that a rule requiring the setting handbrakes was broken, or that any such rule applied to the train in this runaway accident.
If there is no such rule to set handbrakes, I do not understand how the company deals with the risk of an emergency application releasing on its own at any time after it has been made.
However, that risk also exists with a requirement to set handbrakes because it takes a couple hours or so to set enough handbrakes to achieve reliable securement. The risk is that the emergency application releases before that handbrake securement is achieved.
If there was no rule requiring securing the train with handbrakes, how can you conclude that the first crew set a trap for the second crew by not setting handbrakes?
If there was no rule to set handbrakes, should the first crew have set them regardless just because it added safety?
If there was no rule to set handbrakes, and if the first crew set them anyway, would the company find that action acceptable? Do crews have the company sanctioned option to secure a train with handbrakes any time they wish?
If there was a company sanctioned option for the first crew to set handbrakes, and they chose not to, would that amount to setting a trap for the second crew?
A requirement for setting a trap is that the danger is hidden. So, how could the fact that the first crew did not set handbrakes amount to “setting a trap” for the second crew when the second crew new full well that the train was not secured by handbrakes when they accepted the assignment?
I think the failure of a decent training program is obvious here.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.
Well, Zug, it seems that here again we have the unlearned training the ignorant.
One can wonder if the trainers were hired off the street and were givren instructions as to running trains but not as to stopping and holding them after they were stopped, especially on grades.
DeggestyWell, Zug, it seems that here again we have the unlearned training the ignorant. One can wonder if the trainers were hired off the street and were givren instructions as to running trains but not as to stopping and holding them after they were stopped, especially on grades.
Suspect EHH cronies were the trainers with the mantra - Hand Brakes are for sissies!.
EuclidThe question I have is whether or not setting handbrakes after stopping was required by the rules.
If you read Bruce Kelly's posting a few hours earlier than yours, you would not have to ask the question. Read, and understand! It is required NOW, but as a result of an emergency order issued by Transport Canada a couple of days after the runaway.
Also, folks, there is additional relevant discussion following the posting on the Newswire section.
Not a single cause but the fatal combination of bitter cold, leaky seals on older grain cars and a prolonged wait showed the weakness of the usual procedure.
cx500 Euclid The question I have is whether or not setting handbrakes after stopping was required by the rules. If you read Bruce Kelly's posting a few hours earlier than yours, you would not have to ask the question. Read, and understand! It is required NOW, but as a result of an emergency order issued by Transport Canada a couple of days after the runaway. Also, folks, there is additional relevant discussion following the posting on the Newswire section. Not a single cause but the fatal combination of bitter cold, leaky seals on older grain cars and a prolonged wait showed the weakness of the usual procedure.
Euclid The question I have is whether or not setting handbrakes after stopping was required by the rules.
I have read Bruce Kelly's post several times, but with layer upon layer of provisions and conditions, and not knowing the locations listed, the answer to my very simple question does not exactly pop out at me.
I realize that it is required now. But I have been told that the first crew should have securred the train with handbrakes. I would assume that if requiring it now was a change, as has been reported, then it must not have been required during at the time of the runaway. If it was not required at the time of the runaway, why would anybody insist that the crew was negligent for not setting handbrakes?
The question I am asking is just a simple yes or no.
Bruce KellyMy copy of the 2012 ETT shows only a few subtle changes to that (see Footnotes pasted below), most notably under Footnote 11.3, which instructed crews when "abnormal conditions such as weather or poor braking" are present to "apply a hand brake on every car" in 2006 vs. "apply a hand brake on at least 75 percent of the cars" in 2012. The crew arriving Partridge with the train in question had reported braking problems. I can't say whether the ETT in effect at the time of the accident included further changes to those train handling procedures.
Bruce,
You provided the handbrake securement rules from the 2006 timetable and from the 2012 timetable. And you say you do not know if the 2012 handbrake securement rules applied at the time of the runaway accident. Is there any information that you have that would confirm what the handbrake securement rules were at the time of the accident?
EuclidI realize that it is required now. But I have been told that the first crew should have securred the train with handbrakes. I would assume that if requiring it now was a change, as has been reported, then it must not have been required during at the time of the runaway. If it was not required at the time of the runaway, why would anybody insist that the crew was negligent for not setting handbrakes? The question I am asking is just a simple yes or no.
The result speaks for itself! Every railroad rule book has the statement 'In case of doubt the safe course must be taken' or other words to that effect.
BaltACD Euclid I realize that it is required now. But I have been told that the first crew should have securred the train with handbrakes. I would assume that if requiring it now was a change, as has been reported, then it must not have been required during at the time of the runaway. If it was not required at the time of the runaway, why would anybody insist that the crew was negligent for not setting handbrakes? The question I am asking is just a simple yes or no. The result speaks for itself! Every railroad rule book has the statement 'In case of doubt the safe course must be taken' or other words to that effect.
Euclid I realize that it is required now. But I have been told that the first crew should have securred the train with handbrakes. I would assume that if requiring it now was a change, as has been reported, then it must not have been required during at the time of the runaway. If it was not required at the time of the runaway, why would anybody insist that the crew was negligent for not setting handbrakes? The question I am asking is just a simple yes or no.
With all of the rules they have governing braking and train handling through that area, I don’t see how there could be any doubt. But then again, the rules seem to include a requirement to meet with others to discuss the situation and then make a group decision. So that would seem to be an avenue to input one’s feeling of doubt.
And then also, the rule about “when in doubt” does not specify if it is okay to doubt the advisability of rules and instructions, and therefore take action that goes against them. That rule about “when in doubt” seems to imply that it only refers to situations that appear to be not covered in the rules or instructions. Why else would there be doubt?
So if the rules allowed for not securing the train with handbrakes, I am sure they would have decided that safest course of action was to have no doubt.
What I doubt is that the first crew made the decision on their own to not apply handbrakes. That decision was made higher up, and may have also been what the rules called for. So if the decision was wrong, it was the fault of the institution, and not the fault first crew setting a trap for the second crew. The institution set a trap for itself.
But the place in this scenario where the “when in doubt” rule really came into play was when the second crew found themselves departing on the train when their emergency application leaked off and unexpectedly released the brakes. I would sure like to hear the conversation they had with the supervisors and officials at that moment. What could possibly have overcome the doubt about staying on the train?
EuclidI have read Bruce Kelly's post several times, but with layer upon layer of provisions and conditions, and not knowing the locations listed, the answer to my very simple question does not exactly pop out at me. I realize that it is required now. But I have been told that the first crew should have securred the train with
The relevant part of the rules That Bruce Kelly posted read as follows:
"First Emergency Brake Application:
"Before the emergency PCS is recovered, all crew members (ie: locomotive engineer and conductor and Trainmaster) must perform a job briefing to discuss with each other the use of retainer valves. In the application GOI section 15, item 14.3 and 29.3, set retaining valves to the HP (high pressure) position on at least 75 percent of the loaded cars.
"When discussing the use of retainers and/or hand brakes, consider train location, amount of train on the mountain grade, weather and rail conditions and any other conditions present that may affect the braking of that train. If abnormal conditions such as weather or poor braking train dictate that the application of hand brakes is necessary to secure the train while re-charging, then apply a hand brake on at least 75 percent of the cars and set retaining valves to the HP position on at least 75 percent of the loaded cars."
The use of handbrakes was not required but optional if this was the first use of the emergency brake application. Given the prevailing weather and other conditions, the discussion should have concluded the handbrakes were required in this situation, but that is hindsight and armchair quarterbacking. The rules prevailing at the time did not "require" them.
Somebody's judgement was faulty but until we see a transcript, if any, of the radio discussion we cannot start pointing fingers and accusing any one party of negligence.
cx500 Euclid I have read Bruce Kelly's post several times, but with layer upon layer of provisions and conditions, and not knowing the locations listed, the answer to my very simple question does not exactly pop out at me. I realize that it is required now. But I have been told that the first crew should have securred the train with The relevant part of the rules That Bruce Kelly posted read as follows: "First Emergency Brake Application: "Before the emergency PCS is recovered, all crew members (ie: locomotive engineer and conductor and Trainmaster) must perform a job briefing to discuss with each other the use of retainer valves. In the application GOI section 15, item 14.3 and 29.3, set retaining valves to the HP (high pressure) position on at least 75 percent of the loaded cars. "When discussing the use of retainers and/or hand brakes, consider train location, amount of train on the mountain grade, weather and rail conditions and any other conditions present that may affect the braking of that train. If abnormal conditions such as weather or poor braking train dictate that the application of hand brakes is necessary to secure the train while re-charging, then apply a hand brake on at least 75 percent of the cars and set retaining valves to the HP position on at least 75 percent of the loaded cars." The use of handbrakes was not required but optional if this was the first use of the emergency brake application. Given the prevailing weather and other conditions, the discussion should have concluded the handbrakes were required in this situation, but that is hindsight and armchair quarterbacking. The rules prevailing at the time did not "require" them. Somebody's judgement was faulty but until we see a transcript, if any, of the radio discussion we cannot start pointing fingers and accusing any one party of negligence.
Euclid I have read Bruce Kelly's post several times, but with layer upon layer of provisions and conditions, and not knowing the locations listed, the answer to my very simple question does not exactly pop out at me. I realize that it is required now. But I have been told that the first crew should have securred the train with
Okay, thanks for clarifying that. The language is interesting because it requires the crew to consider many facets of danger, and whether they are normal or abnormal; and then decide on whether handbrakes are necessary to address the abnormal danger.
But like you say, it all comes down to making the setting of handbrakes optional. That can be done by simply deciding that the danger exists and is even abnormal, but it still the abnormal danger does not “dictate” the need to set handbrakes.
With that much latitude, I don’t see how the decision to not set handbrakes can be seconded guessed or challenged. According to the language, the setting of handbrakes was optional, and they chose the option of not setting them.
In my opinion, the blame has to lie with the regulator that approved those rules.
Are we talking the original crew or relief crew? I mean, someone would have had to set handbrakes. How else were they planning on recharging the trainline?
Euclid cx500 Euclid I have read Bruce Kelly's post several times, but with layer upon layer of provisions and conditions, and not knowing the locations listed, the answer to my very simple question does not exactly pop out at me. I realize that it is required now. But I have been told that the first crew should have securred the train with The relevant part of the rules That Bruce Kelly posted read as follows: "First Emergency Brake Application: "Before the emergency PCS is recovered, all crew members (ie: locomotive engineer and conductor and Trainmaster) must perform a job briefing to discuss with each other the use of retainer valves. In the application GOI section 15, item 14.3 and 29.3, set retaining valves to the HP (high pressure) position on at least 75 percent of the loaded cars. "When discussing the use of retainers and/or hand brakes, consider train location, amount of train on the mountain grade, weather and rail conditions and any other conditions present that may affect the braking of that train. If abnormal conditions such as weather or poor braking train dictate that the application of hand brakes is necessary to secure the train while re-charging, then apply a hand brake on at least 75 percent of the cars and set retaining valves to the HP position on at least 75 percent of the loaded cars." The use of handbrakes was not required but optional if this was the first use of the emergency brake application. Given the prevailing weather and other conditions, the discussion should have concluded the handbrakes were required in this situation, but that is hindsight and armchair quarterbacking. The rules prevailing at the time did not "require" them. Somebody's judgement was faulty but until we see a transcript, if any, of the radio discussion we cannot start pointing fingers and accusing any one party of negligence. Okay, thanks for clarifying that. The language is interesting because it requires the crew to consider many facets of danger, and whether they are normal or abnormal; and then decide on whether handbrakes are necessary to address the abnormal danger. But like you say, it all comes down to making the setting of handbrakes optional. That can be done by simply deciding that the danger exists and is even abnormal, but it still the abnormal danger does not “dictate” the need to set handbrakes. With that much latitude, I don’t see how the decision to not set handbrakes can be seconded guessed or challenged. According to the language, the setting of handbrakes was optional, and they chose the option of not setting them. In my opinion, the blame has to lie with the regulator that approved those rules.
The original crew was having braking issues - THAT IS WHY the put the train in emergency. Therefore, the train and it's operation were already in the 'abnormal danger zone'.
Common sense, which in this entire incident regarding BOTH crews. which was totally lacking. The original crew with their issues SHOULD have started setting up retainers and tying on hand brakes while they were trying to figure out the condition of their condition.
The recrew, once the train started rolling and their braking effort was proving ineffective, SHOULD have dismounted - there was nothing more that they could do to keep the train from running away.
I am assuming both crews were experienced professional railroaders and knew the 'in's and out's' of what was required to SAFELY operate trains on this segment of railroad - the results of this incident just go to PROVE my assumption is IN ERROR. The blame, as always, goes to those who improperly applied the rules to their own situation. Neither crew 'did themselves proud'.
I've never worked with retainers, and am not a car knocker, so I have a question: If the emergency application leaked off due to the seals, would an application that was "held" by the retainers also leak off? Or is that another part of the valve thingie?
zugmann I've never worked with retainers, and am not a car knocker, so I have a question: If the emergency application leaked off due to the seals, would an application that was "held" by the retainers also leak off? Or is that another part of the valve thingie?
However, that retained air is bottled up in a leaking brake cylinder (if cylinders were leaking due to the packing not sealing in the cold weather), so I don't see how the retainers could retain any pressure at all. It seems like it all would leak out through the cylinder packing leaks.
Euclid zugmann I've never worked with retainers, and am not a car knocker, so I have a question: If the emergency application leaked off due to the seals, would an application that was "held" by the retainers also leak off? Or is that another part of the valve thingie? I was wondering about that too. As I understand, when the emergency application is holding, the air in the brake cylinders is equalized with the air remaining in the emergency reservoirs. I don't really understand what the retainers do, but I would assume they prevent a portion of the air stored in both the emergency reserviors and the brake cylinders combined, from venting through the car brake valves during the recharge. However, that retained air is bottled up in a leaking brake cylinder (if cylinders were leaking due to the packing not sealing in the cold weather), so I don't see how the retainers could retain any pressure at all. It seems like it all would leak out through the cylinder packing leaks.
I was wondering about that too. As I understand, when the emergency application is holding, the air in the brake cylinders is equalized with the air remaining in the emergency reservoirs. I don't really understand what the retainers do, but I would assume they prevent a portion of the air stored in both the emergency reserviors and the brake cylinders combined, from venting through the car brake valves during the recharge.
Euclid is correct, if the brake cylinder or reservoir air pressure is leaking directly to the atmosphere setting retainers will do nothing to hold the brake application.
If the triple valve itself is leaking, and air is escaping out the exhaust pipe then setting the retainer will keep the brake applied on that car, but in HP position the retainer only holds 20 PSI in the brake cylinder, it allows everything else to exhaust to the atmosphere. 20 PSI is about what you would get from a minimum application of the automatic brake, and is nowhere near the braking effort that an emergency application should give.
This of course assumes that the retainer is functioning properly, as they are only rarely used anymore they are very low on the priority list for maintenance and tests, it is likely that most retainers have never been tested since they were built.
Greetings from Alberta
-an Articulate Malcontent
Yet what was CP's reaction to the TSB's request to the application of handbrakes if something like this happens again. They sued the TSB in court for meddling in how they run the railroad.
BaltACDThe recrew, once the train started rolling and their braking effort was proving ineffective, SHOULD have dismounted - there was nothing more that they could do to keep the train from running away.
Unfortunately bailing off quickly became virtually impossible, since the start of the upper Spiral Tunnel is just beyond the west switch. Trying to jump into a confined space in the dark (on a 10 degree curve) is not easily done. I imagine by the time they emerged from the lower portal speed would be a problem.
BaltACDI am assuming both crews were experienced professional railroaders and knew the 'in's and out's' of what was required to SAFELY operate trains on this segment of railroad - the results of this incident just go to PROVE my assumption is IN ERROR. The blame, as always, goes to those who improperly applied the rules to their own situation. Neither crew 'did themselves proud'.
I have seen nothing about the experience of the original crew. The relief crew did have an engineer with considerable experience, but by the time he arrived the trap had been set. Perhaps relevant might be the (unknown) experience of the managers involved. Old style railroading usually promoted men from the field whoe demonstrated the necessary knowledge and smarts. Modern practice parachutes in university grads who know the rules and the theory, but often lack the specific detailed and hard earned experience.
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