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Hello. I am trying to write an action/adventure story, and i am hung up on an important detail. This scene is set in a fictional train station in the Washington, D.C. area. Two trains are going to collide because of deliberate saotage of the computer system that routes the trains. Our hero is trying to stop this by switching one of the on-coming trains to an empty siding. Is there a way to do this manually? To override the computer system and divert one of the trains? I have this image in my mind of a manual switch, like a huge lever that you would shove in the direction you would want the rails to go, but I'll admit to being totally clueless as to the feasibilty of this. Ilike for my stories to have at least a glimmer of realism and would appreciate any assistance. Thanks. Polgana
jrr7 Member # 1475
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Some areas still have the manual lever-operated throw switches, usually for out-of-the-way areas and/or swithces that are rarely used.
In most cases though the switch is electronically controlled. If I were writing an action/adventure I'd have the protagonist go to the switch location, disconnect the switch from the computer system, find an alternate source of power, and apply current directly to the switch motor. This would definitely result in damage to the switch controller if the voltages don't match (The switch may not move all the way, if you want to increase the drama)
Polgana Member # 1528
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Thank you. Can you describe how the manual switch looks and operates? Can one person operate it? The set up for this scene is crucial to the climax. The hero has to be out in the open for the villain to have one more shot at him before on of the trains comes between them. Also, how close to the place where the track switches would the manual control be? You have no idea how much I appreciate this information. It's easy for me to get most of the medical details right since that is my field, but it is so hard to find experts in other fields. Again, Thank you.
Sinerely. Polghana
Gil Abar Member # 990
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You need to do a lot of research concerning signal systems if you want an accurate story or you can describe any weird system and fool most of the public. Signal systems are designed on the fail safe principal so that any failure will not cause an unsafe system regardless of what the computer tells it to do. Try a search on the web.
------------------ SignalGil
Ken V Member # 1466
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I don't know about most places, but around here there are many switches described as "dual control". This means they can be set to either automatic (remote) position or hand (manual) position. Typically these switches have a very short lever (electronic?) used to move them.
------------------ Any time could be train time! Ken V.
[This message has been edited by Ken V (edited 04-07-2002).]
jrr7 Member # 1475
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The key thing about signalling systems is the "block signal" system. There is a signal running through both rails, and when a train is on the rails, the signal passes through the axle and to the other rail, signalling that there is a train in that section of rail. Each block partially overlaps the next block(s). When a train is in a block, the signals behind it automatically go red until the train is out of the block. This enforces a good distnace between trains.
If a track is used for bidirectional operation, the signals do not allow a train to enter the track unless the switches are set in such a way that no train heading the opposite direction can enter the track.
In order for two trains to get onto the same track, a saboteur would have to hit quite a number of pieces of equipment in such a way that it wouldn't be noticed (if it's just broken or removed, that's noticeable). And at least one of the engineers would have to be compromised (or blinded) also, or control taken away from him.
One of the train disasters in NJ involved a head-on collision. The engineer of one train was colorblind and could not tell that the signal was red. So he pulled ahead onto a bidrectional track and ran into a train that was coming around a curve.
Steve4031 Member # 1517
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In light of 9/11, we should be careful about providing information about rail operations that could be used to cause a wreck.
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