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overshooting and dead mans switch


3rd Avenue El

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okay i really want to know what this means and why they don't do it. some people have said that overshooting is a major problem. now that is correct. and i have seen people post ideas to prevent an overshoot. now they said why not when the train reaches the 10 or 8 marker to throw the dead mans switch and people say it should not be done. but i want to know what is the dead mans switch and why can it not be used or done. what are the effects of that? :confused::confused:

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okay i really want to know what this means and why they don't do it. some people have said that overshooting is a major problem. now that is correct. and i have seen people post ideas to prevent an overshoot. now they said why not when the train reaches the 10 or 8 marker to throw the dead mans switch and people say it should not be done. but i want to know what is the dead mans switch and why can it not be used or done. what are the effects of that? :confused::confused:

 

To properly answer the your question, the dead man's switch is the safety device on the master controller that triggers the emergency brakes (or full service, depending on the make and model) on the train. If the operator releases his hold on the master controller, the dead man's switch automatically kicks in, supplying maximum braking force. However, as the others have mentioned, the T/O should be in complete control so as to not need to utilize such a method. Applying full service braking at a regular interval decreases brake life and causes a whole host of other problems, such as increased brake shoe dust and increased risk of track fires from that dust, not to mentioned the increased maintenance costs resulting from the higher replacement rates. In short, not a recommended method to prevent overshooting.

 

Hope that explains it.

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and there is the fact that going "Brakes In Emergency", or BIE, tends to send everyone flying as the train comes to a dead stop. I've been on trains that have gone BIE about 7 times (once 4 times in one day on a Low V trip) and the KACKOW of the breakline venting is a very unplesant sound to hear, more so when it happens under the river and you've got someplace to be.

 

That only happens if your on a train with cast iron shoes like the museum trains or a work train. Everything else is painfully slow to stop because of the composition shoes.

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This is interesting.I know when T/O's let of the Master Controller b\c I hear it and the train goes full service or whatever for SMEE's.But if a T/O lets go of the MC with a NTT will it go BIE?

And many T/O's I would say about 25-40% let go of the MC when they're near the 8 or 10 car stopping position while the train is down to about 3-5MPH.I'm always in the front so I can hear when the controller is released.

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With ANY train, if you let go of the MC and the brakes are not if full service, the train will go BIE.

Also, who are you to critique the operation of any operating employees?

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I had a t/o on the Brighton that had let lose of the "T" to get something in her bag as the train was moving along the exp tracks. The train just went into full service.

 

Impossible, if you let go of the MC in any position other then full service, the emergency brakes are activated. If anything, the T/O placed the MC in full service then got up.

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With ANY train, if you let go of the MC and the brakes are not if full service, the train will go BIE.

Also, who are you to critique the operation of any operating employees?

So what's the point of letting go of the MC when the handle is in full service? So you are saying when the MC is let go the train will go BIE when there is not a full service application or when the MC is let go and the train is in full service it will contine to brake in full service.

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I had a t/o on the Brighton that had let lose of the "T" to get something in her bag as the train was moving along the exp tracks. The train just went into full service.

 

You clearly know nothing about Train Operation.

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So what's the point of letting go of the MC when the handle is in full service? So you are saying when the MC is let go the train will go BIE when there is not a full service application or when the MC is let go and the train is in full service it will contine to brake in full service.

 

The train will BIE. This is not rocket science.

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The train will BIE. This is not rocket science.

Thanks! Umm 1 more thing what about the R-46's I remember a few times I was on the (G) the T/O let go near the OPTO while coasting in some stations at about 10-15mph and it didn't go BIE and the train couldn't be in Full Service b\c there was no brakes being applied unless it was minimum brake applied.

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Thanks! Umm 1 more thing what about the R-46's I remember a few times I was on the (G) the T/O let go near the OPTO while coasting in some stations at about 10-15mph and it didn't go BIE and the train couldn't be in Full Service b\c there was no brakes being applied unless it was minimum brake applied.

 

He had to let go in full service or else the train would have went BIE if he let go in any other position.

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So what's the point of letting go of the MC when the handle is in full service? So you are saying when the MC is let go the train will go BIE when there is not a full service application or when the MC is let go and the train is in full service it will contine to brake in full service.

 

Simple. So a T/O can get up from the controls (for whatever reason) and not worry about the whole train dumping.

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Simple. So a T/O can get up from the controls (for whatever reason) and not worry about the whole train dumping.

 

i.e. punching (activating route request) or just giving a break, its tiring holding the button down.

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To properly answer the your question, the dead man's switch is the safety device on the master controller that triggers the emergency brakes (or full service, depending on the make and model) on the train. If the operator releases his hold on the master controller, the dead man's switch automatically kicks in, supplying maximum braking force. However, as the others have mentioned, the T/O should be in complete control so as to not need to utilize such a method. Applying full service braking at a regular interval decreases brake life and causes a whole host of other problems, such as increased brake shoe dust and increased risk of track fires from that dust, not to mentioned the increased maintenance costs resulting from the higher replacement rates. In short, not a recommended method to prevent overshooting.

 

Hope that explains it.

 

Full service braking and emergency braking are NOT the same thing. The deadman feature of the Master Controller - more properly referred to as a Pilot Valve - only applies the train's brakes in Emergency, never Full Service.

 

Full service is a perfectly acceptable braking position; however, T/Os are taught not to use it as a way to stop the train under normal circumstances. After all, if you use Full Service and there isn't enough braking effort, where do you find more?

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I know the M/C positions on the Cineston M/Cs, the 4th and last position in the power side (P4) is the highest you can go, so that should be full service, so I have to assume if you let go of the Cineston M/C at P1, P2 or P3, the train could go into BIE.

 

However, I still dont know the Knorr M/C on the R160s and 01800s Red Line Cars, but I assume the positions are the same (P4) being highest down to P1. On the negative side on the M/C as far as I know on the Cinestons' N1 (negative, on the brake side) means to apply the brakes, then N2 means to brake even further, N3 means voluntarily putting the train into BIE, then N4 means a complete shutdown. I think the same could be said for the Knorr type M/Cs

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