Bordercollie
Senior Member
So basically as long as the train can run and it makes money that's fine even if it kills people? But the government won't introduce safer rules because the railways would object? Sounds like a broken system to me.
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General railway discussions
- Thread starter Urban Sky
- Start date
Darwinkgo
Active Member
I wonder if solar charged, battery, run wireless controlled, handbreak actuators would be possible.
rbt
Senior Member
I think fully wireless would be very hard to get right.
There would need to be a physical mechanism to indicate that the wireless device should only accept commands from Train X (the one it's connected to) while ignoring all other commands, both accidental like other trains within 1 mile and malicious from 3rd parties. You might be able to establish command authorization via NFC chips near the coupler (I'm car Y connected to Train X), then allowing broadcast control from that point on but that sounds fragile.
Probably have better luck setting up a low-speed network via the rails themselves.
crs1026
Senior Member
The wifi bit seems moderately simple, if one assumes very low power and some sort of directional antenna on each end of each car. Might be a challenge to make it error free in yards, where even with directionality there could be misconnection between adjacent tracks, but a maximum range of 2-3 feet is all that’s required.
The harder part is the amount of energy required to “pull the pin” to couple or uncouple. Existing couplers can be very balky. When coupling, there is a need to align the two drawbars and ensure the pins are out and knuckles opened. Easy to do on smaller fleets with high maintenance routines, eg subway cars…. much harder on a large fleet where cars may sit in odd places and unused for months at a time.
The use of compressed air to provide power for freight car accessories is not wrong minded. It’s trying to overlay a control system on top, and then provide reliable and granular feedback to the operator, that’s the bridge too far.
A “smart” freight car network with wifi connections is quite doable even without the coupling or braking mechanics. If every car’s brake system can be monitored from the engine, a huge increase in safety is achieved. Simply being able to see each car’s brake cylinder and air reservoir status would inform operation much better. That’s a “passive” application. Adding in any control functionality would be gravy.
An engineer of my acquaintance describes each run as a “science experiment every day”…. ie no two trains brake identically, and each run requires the operator to discover and acclimatise to how the brakes are performing, with weather and temperature having their own impacts.
With hundreds of thousands of freight cars out there, even a $1000 per car enhancement generates pushback from railways. But in a world where an entire fleet of new aircraft is grounded until a deficiency is chased to the root cause and solved, the price is not wrongheaded. As @Bordercollie notes, this is about not killing people.
- Paul
The harder part is the amount of energy required to “pull the pin” to couple or uncouple. Existing couplers can be very balky. When coupling, there is a need to align the two drawbars and ensure the pins are out and knuckles opened. Easy to do on smaller fleets with high maintenance routines, eg subway cars…. much harder on a large fleet where cars may sit in odd places and unused for months at a time.
The use of compressed air to provide power for freight car accessories is not wrong minded. It’s trying to overlay a control system on top, and then provide reliable and granular feedback to the operator, that’s the bridge too far.
A “smart” freight car network with wifi connections is quite doable even without the coupling or braking mechanics. If every car’s brake system can be monitored from the engine, a huge increase in safety is achieved. Simply being able to see each car’s brake cylinder and air reservoir status would inform operation much better. That’s a “passive” application. Adding in any control functionality would be gravy.
An engineer of my acquaintance describes each run as a “science experiment every day”…. ie no two trains brake identically, and each run requires the operator to discover and acclimatise to how the brakes are performing, with weather and temperature having their own impacts.
With hundreds of thousands of freight cars out there, even a $1000 per car enhancement generates pushback from railways. But in a world where an entire fleet of new aircraft is grounded until a deficiency is chased to the root cause and solved, the price is not wrongheaded. As @Bordercollie notes, this is about not killing people.
- Paul
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smallspy
Senior Member
Wireless, save for things like the radio control of locomotives, is a bit of a technological dead-end I suspect.
That said, one thing that has been showing promise for quite some time is "E-braking" - as well as the legacy pneumatic system, the train brakes are controlled by what is ostensibly a hardened Cat5 connection between cars which is used to control the brakes on the train. The pneumatic system remains as a fallback in case of failure, but electronically activating the brakes allows for far greater control. (For instance, all of the train's brakes will apply virtually at the same time with an electronic system. With straight air, it can take 15 to 20 seconds for the brakes to apply on the last car.)
It's already making appearances on passenger equipment, with the all of GO's CEM equipment being so-equipped. The new VIA trainsets will communicate within themselves with the Cat5 connection instead of the industry-standard 27-pin MU connection. But retrofitting hundreds of thousands of pieces of freight rolling stock is another matter altogether, despite its advantages.
Dan
That said, one thing that has been showing promise for quite some time is "E-braking" - as well as the legacy pneumatic system, the train brakes are controlled by what is ostensibly a hardened Cat5 connection between cars which is used to control the brakes on the train. The pneumatic system remains as a fallback in case of failure, but electronically activating the brakes allows for far greater control. (For instance, all of the train's brakes will apply virtually at the same time with an electronic system. With straight air, it can take 15 to 20 seconds for the brakes to apply on the last car.)
It's already making appearances on passenger equipment, with the all of GO's CEM equipment being so-equipped. The new VIA trainsets will communicate within themselves with the Cat5 connection instead of the industry-standard 27-pin MU connection. But retrofitting hundreds of thousands of pieces of freight rolling stock is another matter altogether, despite its advantages.
Dan
Fritter
Active Member
Someone correct me if I am wrong, but I thought rail car breaks operated on a negative air pressure system. If there is no air pressure, then the breaks are locked in place, it takes air pressure to release the brakes to move.
In other words if there is no air pressure, the railcar will not move. The default position is stop, and it take air pressure in the system to actually make a railcar move.
In other words if there is no air pressure, the railcar will not move. The default position is stop, and it take air pressure in the system to actually make a railcar move.
crs1026
Senior Member
Some systems work that way, but in North America brakes require air pressure to remain applied. The air that works the brakes is supplied from the locomotive but stored in a reservoir in each car. When that reservoir of air is used up, unless the locomotive supplies more the brakes release.
- Paul
lenaitch
Senior Member
I know - it seems rather counterintuitive, and I find it difficult to find an explanation that brings it down to my brain level. The way I understand it - very simplified - the actual braking force is provided by compressed air from each individual cars' air tank, but the application of that air is triggered by a reduction of air pressure in the train (supply) line through a valving arrangement. An increase in trainline pressure causes the brakes to release replenishes the tanks. Or something like that.
roger1818
Active Member
I know - it seems rather counterintuitive, and I find it difficult to find an explanation that brings it down to my brain level. The way I understand it - very simplified - the actual braking force is provided by compressed air from each individual cars' air tank, but the application of that air is triggered by a reduction of air pressure in the train (supply) line through a valving arrangement. An increase in trainline pressure causes the brakes to release replenishes the tanks. Or something like that.
That sounds about right. Here is an interesting article that explains how air brakes work on trains here in North America.
Understanding a Runaway Train: How Do Air Brakes Work?
Air brakes have been around for almost 150 years, but when they fail the results can be disastrous, as the world saw during the Quebec train derailment. Here's what you need to know about the tech.
www.popularmechanics.com
Edit: Here is an even better description with pictures
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crs1026
Senior Member
Yeah, the counterintuitive part is…. what happens in the trainline does not match what goes on at each car. If the trainline pressure drops, the brake cylinder pressure rises (applying the brakes) while if the trainline pressure goes up, the brake cylinders exhaust and braking pressure drops.
The trainline pressure serves about three different functions - it’s a power supply, in that it provides air pressure that is stored in the reservoirs to power the brakes…..and it’s a control sytem, in that, the small changes in pressure controlled by the engineer tell the brakes whether to apply or release….. and it’s a fail-safe in that a sudden complete loss of pressure (eg if the train separates, or the engineer initiates a panic stop) will cause the brakes to go into emergency.
It’s ingenious, and it’s baffling, but it has quirks that create difficult scenarios, and for this reason it has become a bit arcane.
- Paul
The trainline pressure serves about three different functions - it’s a power supply, in that it provides air pressure that is stored in the reservoirs to power the brakes…..and it’s a control sytem, in that, the small changes in pressure controlled by the engineer tell the brakes whether to apply or release….. and it’s a fail-safe in that a sudden complete loss of pressure (eg if the train separates, or the engineer initiates a panic stop) will cause the brakes to go into emergency.
It’s ingenious, and it’s baffling, but it has quirks that create difficult scenarios, and for this reason it has become a bit arcane.
- Paul
Allandale25
Senior Member
Article is paywalled. Is he suggesting exported by rail?
Northern Light
Superstar
Yes.
Non-paywalled article on same subject from the Winnipeg Sun:
Poilievre makes pitch for Manitoba votes at campaign rally
If he becomes Conservative Party of Canada leader and the next prime minister, Pierre Poilievre has big things plans for Manitoba’s Port of Churchill by…
winnipegsun.com
From the above:
CapitalSeven
Senior Member
Of course the ground is so unstable they can barely keep the railway operating, so what could go wrong with shipping oil across the tundra as it melts due to ... burning oil? Skippy thinks it through again.
Bordercollie
Senior Member
With the revenue coming in they could make improvements to the track, you can drill down to under the tundra to create a base using bedrock. You could refrigerate the tundra under the rails to keep it solid, there are tons of technologies that you can use. It just costs $$. Hopefully they can build passing sidings and increase the track speed.
Darwinkgo
Active Member
It won't happen, because the economics don't work. There is more than enough pipeline capacity now. This is just resource extraction populism which happens to sound visionary.