Also remember that not all cab signal systems have speed enforcement for each restrictive aspect. Those that don't would allow a train or engine to go by a red signal at track speed as long as the engineer pressed the acknowledgement button each time the cab signal changed to the next more restrictive aspect.
Jeff
Thanks to all of you who have mentioned that sensible control systems would tell the train what the safe speed is, and the train would know not to exceed the speed. My dinosaur brain was thinking of wayside signals, or even cab signals which I believe are just wayside devices whose aspects display in the cab.
One other old fashioned thought was that some of these control systems seem to give a warning first, and have a time lag before they actually impose the speed restriction, turn off the acceleration and apply the brakes. I hope a sensible system would not just give a warning if the train was speeding.
Patrick Boylan
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gardendanceOne other old fashioned thought was that some of these control systems seem to give a warning first, and have a time lag before they actually impose the speed restriction, turn off the acceleration and apply the brakes. I hope a sensible system would not just give a warning if the train was speeding.
Other critical concept. Railroad signal systems are not about the last signal, they are about the next signal, about what's coming up. So in a sense all signals warn about a restriction, but don't take action until the restriction is exceeded. The whole point of a block signal system is to give you warning.
An approach signal isn't a signal to stop. Its a signal that tells you at the next signal you may have to stop. Depending on the system you would have to acknowledge the restrictive indication, but you don't have to stop until the next signal and under existing cab signal systems, it won't penalize the train until the train passes the red signal without stopping. In most cab signal systems it doesn't impose a "speed restriction", it stops the train. If you do not comply the train stops.
Dave H. Painted side goes up. My website : wnbranch.com
A good place to start is the Wikipedia page for PTC
Wiki PTC
There are two systems that meet the mandated PTC requirements offered in the US.
ACSES which is what Amtrak chose and subsequently so did Commuter Agencies that operate on the NEC.
The Class I freight railroads chose Wabtec's ETMS system; with BNSF choosing the "Cadillac" version V-ETMS and the other Class Is choosing the "Chevy" version, I-ETMS. The V-ETMS version has additional functionalities beyond what is required to meet the mandated PTC requirements and will be a "vital" system with dual on-board systems. Locomotives equipped with either version will be able to operate on a railroad that the lineside equipment and still meet PTC requirements.
Note that Amtrak and NS are discussing equipping a portion of the NEC with both ACSES for Amtrak trains and V-ETMS for NS trains so that NS will not need a dedicated fleet of locomotives for its trains that need to use the NEC in Maryland and Delaware. Presumeably the V-ETMS equipment would be at NS' expense.
Gee , I guess the laws of physics and kinetics can't be violated, if they are , serious consequences happen even that electricity at 186.000 mph.This is what my 1936 physics book for dummys says. But that was then , but this is now. switch7frg
Y6bs evergreen in my mind
switch7frg Gee , I guess the laws of physics and kinetics can't be violated, if they are , serious consequences happen even that electricity at 186.000 mph.This is what my 1936 physics book for dummys says. But that was then , but this is now. switch7frg
When did electricity slow down to 186,000 MPH - I have always been taught it is at 186,000 MPSecond.
Never too old to have a happy childhood!
It's not just a good idea, it's the law.
.].BaltACD, I am embarrassed. Myfault, I hit the wrong key. I shall hide my head in shame.
switch7frgGee , I guess the laws of physics and kinetics can't be violated, if they are , serious consequences happen even that electricity at 186.000 mph.This is what my 1936 physics book for dummys says
Electricity isn't the same thing as electromagnetic radiation. Only the latter propagates at 'lightspeed'. Actual motion of electrons -- which have mass -- is less than that (if I recall correctly, about .91c) and electrons in a wire can be much, much slower ... erikem will have the number at his fingertips, but I think drift speed of an electron in DC through copper wire can be very slow. Of course the effect is quicker than that, as popping an electron into one end of the wire will 'quickly' result in another one popping out at the other end, but again that doesn't happen with a timing corresponding to movement or propagation at c.
So not as much a topic for 'dummies' as might be thought...
Now someone will probably dredge up the old physics textbook chestnut about how fast you have to accelerate the ACS-64 to blue-shift the red signal aspect to where it appears to be green. The correct answer: who cares; Amtrak uses position as well as color in the lights...
Wizlish Now someone will probably dredge up the old physics textbook chestnut about how fast you have to accelerate the ACS-64 to blue-shift the red signal aspect to where it appears to be green. The correct answer: who cares; Amtrak uses position as well as color in the lights...
But is has applicability to all the new signals that are being installed everywhere but the NEC for PTC as they are all Color Light signals, not Position Light or Color Position Light.
However, with that shift, if all signal heads displayed Green, that would be a improperly displayed signal - as there is no Green over Green - only signals with a Single Head could be corrupted by the phase shift.
I guess it's not proper for me to complain about you guys not being on topic, since the title asks if locomotives can be too fast, and I have contributed my own small ridiculousness, but we are just about reaching the outer limits of ridiculousness, and at ludicrous, or maybe even, plaid, speed.
gardendanceouter limits of ridiculousness, and at ludicrous, or maybe even, plaid, speed.
Is plaid speed faster than warp speed, Captain?
C&NW, CA&E, MILW, CGW and IC fan
I think that plaid speed has a checkered past.
Semper Vaporo
Pkgs.
schlimm Is plaid speed faster than warp speed, Captain?
Especially for 2nd Officer and Engineer Scott.
Semper Vaporo I think that plaid speed has a checkered past.
Tweed speed?
Got a swatch of a dead man’s switch?
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