At least we know the autopilot works …

[zanthrus]

Why is this thread about trains on an aviation forum? Better question is, why is it STILL here?

[2016parks]

Originally Posted by zanthrus

Why is this thread about trains on an aviation forum? Better question is, why is it STILL here?

Let's see ... single driver ... autopilot ... loss of control ... gee, uh, those topics wouldn't be relevant to the topic of aviation, or to any known aviation accident, now would they?

[zanthrus]

No because its on a TRAIN! It can't go anywhere other than where the rails take it. It can't go up and down either.

[SOPS]

Originally Posted by Capn Rex Havoc

Did you jump off for a smoko SOPS?

Seriously though do you get a briefing on the cause of this?

i was sitting there there having a cup of tea under a tree, and all of a sudden... 😄😄

Seriously... I assume we will see a report.

One thing I know is that the power levers did not have to be open for a train, that heavy, to run away. Even on the trains I drive, on a small down hill gradiet , with the power in ‘off’, they will accelerate very quickly!

[KRviator]

Originally Posted by megan

The question to ask with the BHP train is what happened with the dead man system.

There is no dead-man system as such on freight trains in Australia. Suburbans, yes, but not freight. What we have is usually called a Vigilance system (or an Alerter if you use the American terminology). This is a button that you have to press every 30-45 seconds, or the brakes apply. However, to save Driver's having to press it every 30 seconds when the train is stopped, it is inhibited when you have more than 200Kpa in the Independent (locomotive) brakes. Which you always have applied when you stop anywhere. So no Vigo to stop it.

Originally Posted by Matt48

You just have to marvel at how the brakes released themselves, how the throttles were nearly fully opened and why the driver couldn't have reboarded the train, as it took off like a tired snail. It covered 120 KM in about 50 Mins, at an average speed of 110kmh.

It was on a descending 1:66 grade - the steepest on their network. You don't need power to get moving - and get moving bloody quickly - on a grade like that, with a train like that. I work trains on 1:50 descending grades, and if you release the brakes you'll get upto well over 100kph in the length of your train no worries at all - all on a 1.15* descent angle, less than half what an airliner achieves from TOD with idle thrust...And the railway rumour mill has the datalogger showing speeds well in excess of the average reported. FWIW, thee is one hill I come over the top of, and I can coast, without touching the throttle, for 55km at track speed, then apply power over one hill for 4km and roll another 12km.

Originally Posted by megan

The Devonport train was remotely controlled - no onboard driver.

Only insofar as on the leading locomotive. The driver was doing what is known as RCS, remote controlled shunting, whereby he has a control unit on a harness around his neck, and uses that to move the train. IT is supposed to be failsafe if it loses comms with the loco, or vice versa, the brakes are supposed to come on. I'm keen to see why they didn't.

What is unusual is BHP utilises Automatic Train Protection on their network, to facilitate Driver-Only Operation. ATP has safeguards against rollaway, overspeed and passing a signal at stop. Why the Rollaway and Overspeed protections failed is interesting. Depending how their braking system is configured would depend on whether or not it would function effectively with an ECP braking fault. Traditional railway airbrakes work by pressurizing the Brake Pipe, then reducing this pressure to apply the brakes. This makes if fail-safe, in that a brake command by yours truly, or a snapped train, results in the brakes coming on. BHP, like all the mines up there now, use Electronically Controlled Pneumatic brakes, where the brake pipe does not reduce to apply the brakes, rather, an electronic signal is transmitted and a manifold on each ore wagon applies the brakes to the %-age commanded by the driver. If ATP is configured to work exclusively with ECP when ECP is active it would not function to command a pneumatic emergency brake.

If an ECP cable separates, this will trigger an ECP Emergency brake - 120% of braking capacity - but it will not reduce Brake Pipe Pressure. The potential problem with this, is the ECP cars *not* talking to the locomotive now start a timer, and after a pre-configured delay (usually an hour, depends on the operator), revert to standard pneumatic braking. IF the Brake Pipe is still charged, the brakes will release in pneumatic on those wagons, and you are then relying on the front X number of wagons to try to hold the train stationary. IF he was 50 back fixing the cable, only 50 cars with brakes isn't likely enough to hold a full train on a grade like that. Without knowing BHP's procedures, I'd think they would require the Driver command a full pneumatic emergency brake application before getting off the loco to guard against a fault like this - which if forgotten could lead to such a scenario as they had.

Originally Posted by 2016parks

Let's see ... single driver ... autopilot ... loss of control ... gee, uh, those topics wouldn't be relevant to the topic of aviation, or to any known aviation accident, now would they

Add in fatigue, systems knowledge, SOP compliance and a relatively laissez faire approach from some operators and the regulator and you can begin to draw some parallels between the two.

[DHC8 Driver]

Originally Posted by megan

Tut,tut, OH & S would never allow it. Instead of single driver, how about two. Cost of crash could have paid the salary of a second driver for a few thousand years probably.

good idea. While we’re at it why not three crew in the cockpit on all commercial flights.might have prevented GermanWings?

[machtuk]

Originally Posted by DHC8 Driver

good idea. While we’re at it why not three crew in the cockpit on all commercial flights.might have prevented GermanWings?

They did have 3 in the cockpit (briefly) for a while there after that nutter shook up the boffins, since been rescinded & it's back to one driver at the wheel with an organ we know virtually nothing about, the brain!

[megan]

good idea. While we’re at it why not three crew in the cockpit on all commercial flights.might have prevented GermanWings?

There's times when you might need an entire army in the cockpit, and someone with an aerobatic rating.

https://en.wikipedia.org/wiki/Federa...ess_Flight_705

Many thanks for the educational insight KRviator.

[SOPS]

KRviator. Thanks for the great info. Just one point (after 35 years and 22000 hours) I now drive trains (suburban) for a living. We dont have "dead man" but a Vigilance system. And ATP.

[jportzer]

Originally Posted by SOPS

KRviator. Thanks for the great info. Just one point (after 35 years and 22000 hours) I now drive trains (suburban) for a living. We dont have "dead man" but a Vigilance system. And ATP.

It depends on which suburban system and which generation of trains you're talking about. In Sydney for example, the older "Silver Sets" (K, S, and C), originally used a "dead-man's handle" while the newer sets have a vigilance system. The inadequacy of the deadman's pedal and handles on Tangara sets was one of the major contributing factors to the Waterfall crash in 2003, as I'm sure you know. this resulted in the retrofitting of vigilance systems to most older sets, but not necessarily all (some older S sets, now withdrawn, didn't get them IIRC).

[KRviator]

Originally Posted by KRviator

If ATP is configured to work exclusively with ECP when ECP is active it would not function to command a pneumatic emergency brake.

If an ECP cable separates, this will trigger an ECP Emergency brake - 120% of braking capacity - but it will not reduce Brake Pipe Pressure. The potential problem with this, is the ECP cars *not* talking to the locomotive now start a timer, and after a pre-configured delay (usually an hour, depends on the operator), revert to standard pneumatic braking. IF the Brake Pipe is still charged, the brakes will release in pneumatic on those wagons, and you are then relying on the front X number of wagons to try to hold the train stationary. IF he was 50 back fixing the cable, only 50 cars with brakes isn't likely enough to hold a full train on a grade like that. Without knowing BHP's procedures, I'd think they would require the Driver command a full pneumatic emergency brake application before getting off the loco to guard against a fault like this - which if forgotten could lead to such a scenario as they had.

It seems this hypothesis has been confirmed by BHP's press release, with the company saying the ECP Cable separated which triggered the initial ECP Emergency brake application, but the Driver didn't apply a pneumatic emergency application before walking the train. This kept the brake pipe charged such that when the out-of-comm wagons reverted to pneumatic braking, they released the emergency application and away she went - and as their ATP was only configured to work with ECP it couldn't stop the train.

This has concerned the rail regulator enough for them to put out a Safety Alert highlighting the risks of this happening. It shouldn't be the case that a single-point failure - a Driver remembering procedure 100%, 100% of the time - has led to this, but this is what happens when you don't utilise all available safeguards...