BNSF (and maybe others, I don't know) is replacing standard switches with ICS models. Why? What is the advantage supposed to be?
(1) Perceived faster time exiting & entering main tracks in dark territory.
(2) Fewer complaints from wimpy trainmen about hard to throw switches. (Ergonomics)
(3) In some places, fewer run-through switches and split point derails.
(*) But you are still supposed to inspect the switch before you throw it.
mudchicken (2) Fewer complaints from wimpy trainmen about hard to throw switches. (Ergonomics)
We are now told that if a switch requires more than a quick sweep to clean, we are to leave it and go on to the next task, and report it to track maintenance. Same goes for iced over crossings, regardless of whether they are on railroad or customer owned track, we aren't even allowed to try running the engine through first to bust up the ice/snow/mud.
#snownogo
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-an Articulate Malcontent
BILL GRIFFIN BNSF (and maybe others, I don't know) is replacing standard switches with ICS models. Why? What is the advantage supposed to be?
What is the difference between "standard switches" and "independently controlled switches"?
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"A stranger's just a friend you ain't met yet." --- Dave Gardner
I'm guessing we're talking about the radio controlled power switches. Enter a code to query the switch, another to line it one way, another to line it the other.
Jeff
In a traditional interlocking, if you have a crossover and the two switches are lined differently, you can't clear a signal over either track. For instance, if the crossover switch on Main 1 is lined and locked for straight movement, but the other half of the crossover on Main 2 is not lined and locked for straight movement, you can't clear a signal over Main 1.
On BNSF, Independently Controlled Switches (ICS) refers to a crossover where this is not true - in the situation above, the dispatcher could run trains on Main 1 regardless of what's happening on Main 2. So a maintainer can do regular testing and adjustment on one switch at a time without shutting down the whole railroad.
This is what the term ICS means. But it is not new, and has been implemented pretty much every time a control point has been resignaled for well over a decade. So I'm not sure if this is actually what you are referring to?
Sometimes people use the term to refer to control points that are set up so that maintenance workers can get authority over one of the switches while still running trains on other parts of that same track. For instance, suppose you have a double crossover, where the switches on Main 1 are far apart from each other and the switches on Main 2 are set close to each other - so, if you draw a schematic with Main 1 on top and Main 2 below, the crossover makes a "V" shape. If it is possible to get an authority over one of the two crossover switches on Main 1, while still running trains through the other crossover, some people will refer to those as "ICS" switches as well - but I don't think that's technically correct. The decision of whether to set up the CP this way is totally independent of whether the switches within each crossover can be maintained independently, and even older interlocking and crossovers were often set up this way, while ICS is a somewhat more recent development. (But still not particularly new.)
The trick for making ICS work is that, before clearing a signal for straight movement on one track, the system has to ensure that a train is not occupying the crossover and fouling that track. This requires having an insulated joint in the closure rail of each switch, and that IJ has to be far enough away from the other track that it protects the fouling zone of that other track. That means that a crossover with tight track centers and high-angle turnouts (i.e. with low frog numbers) may be incompatible with ICS.
Dan
dpeltier BILL GRIFFIN BNSF (and maybe others, I don't know) is replacing standard switches with ICS models. Why? What is the advantage supposed to be? In a traditional interlocking, if you have a crossover and the two switches are lined differently, you can't clear a signal over either track. For instance, if the crossover switch on Main 1 is lined and locked for straight movement, but the other half of the crossover on Main 2 is not lined and locked for straight movement, you can't clear a signal over Main 1. On BNSF, Independently Controlled Switches (ICS) refers to a crossover where this is not true - in the situation above, the dispatcher could run trains on Main 1 regardless of what's happening on Main 2. So a maintainer can do regular testing and adjustment on one switch at a time without shutting down the whole railroad. This is what the term ICS means. But it is not new, and has been implemented pretty much every time a control point has been resignaled for well over a decade. So I'm not sure if this is actually what you are referring to? Sometimes people use the term to refer to control points that are set up so that maintenance workers can get authority over one of the switches while still running trains on other parts of that same track. For instance, suppose you have a double crossover, where the switches on Main 1 are far apart from each other and the switches on Main 2 are set close to each other - so, if you draw a schematic with Main 1 on top and Main 2 below, the crossover makes a "V" shape. If it is possible to get an authority over one of the two crossover switches on Main 1, while still running trains through the other crossover, some people will refer to those as "ICS" switches as well - but I don't think that's technically correct. The decision of whether to set up the CP this way is totally independent of whether the switches within each crossover can be maintained independently, and even older interlocking and crossovers were often set up this way, while ICS is a somewhat more recent development. (But still not particularly new.) The trick for making ICS work is that, before clearing a signal for straight movement on one track, the system has to ensure that a train is not occupying the crossover and fouling that track. This requires having an insulated joint in the closure rail of each switch, and that IJ has to be far enough away from the other track that it protects the fouling zone of that other track. That means that a crossover with tight track centers and high-angle turnouts (i.e. with low frog numbers) may be incompatible with ICS. Dan
I did not see what you are describing as being allowed in the CSX CADS installation. Both ends of crossovers had to be properly lined and locked before signalled movement was allowed on either track, even when maintaners doing their normal testing.
Never too old to have a happy childhood!
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