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Something i have always wondered, How do the Train crossing signals work?? with the flashing lights and gates. Can anyone here answer this question??
Posts: 56 | From: Sonoma CA USA | Registered: Nov 2000
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grrrr off topic!! oh well, i emailed the mod and got no responce the mod's email is the only i can find. if i cant get a name change soon i'l just ditch this and get a new one, k?
Edit: new name, SD40-2
[This message has been edited by DrunkEngineer (edited 04-30-2001).]
Posts: 56 | From: Sonoma CA USA | Registered: Nov 2000
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On our system,the gates are activated by track circuit or island circuit in the case of running against the current of traffic. The island circuit is located just prior to the grade crossing so that when running against the current you operate up to the crossing, stop and proceed when the gates come down and it is safe. For normal operation, the train crosses the track circuit and that tells the gates you are on approach. Depending on the permitted speed of the train in the area the gates are activated. In our case as we make station stops to board/deboard passengers at nearside stations (stations that are at a grade crossing) the gates are held up for a period of time allowing traffic to move while we are in the station. After a pre determined time interval, the gates activate, the cars make one last ditch effort to avoid waiting there, and the gates are down. Hope that answers your question.
Posts: 13 | From: La Mesa, CA. USA | Registered: Mar 2001
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LightRail, That is interesting how the modern systems are different from "traditional" railroads. The trains are REQUIRED to stop and wait at the platform for the gates to be lowered in time. Is it possible to modify the system to allow light rail trains to run in "express mode", where they would only stop at 2 or 3 stations along a route and just bypass other stations? In these cases the gates would need to be approach activated, just like on heavy rail. I had raised this question with a local SoCal expert re: the LA MTA Blue Line, and the response was that the system was not set up for this type of running. Crossings adjacent to bypassed stations would need a flagman to protect the crossing.
Posts: 874 | From: South Bay (LA County), Calif, USA | Registered: Aug 2000
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Yes, it is possible to run express. We have a TWC (Train to wayside control) panel in the cab with a thumbwheel that we set depending on our route. A wayside indicator will indicate on approach either with an illuminated S or E for station stop or express. Due to an unfortunate incident a few years ago all of our Light Rail trains are required to make a 20sec. station stop regardless of whether they are in revenue service or not. I say that because S.D.& Imperial Valley RR uses our track at night to deliver freight and they don't stop at the stations. In their case, gate activation is on track circuit and the hold off feature we have when stopped at a station is not used. I hope that explains what I was trying to say in the first post. Our system is like traditional RR except that we can program the gates to hold off at near side stations only, not all grade crossings. In the event of a broken/malfunctioning gate at regular grade crossings it is still up to the Operator to operate on sight and do all possible to avoid an incident at an unprotected crossing.
Posts: 13 | From: La Mesa, CA. USA | Registered: Mar 2001
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LightRail, I recall reading about that accident in the Union-Tribune, where a car was hit on a grade crossing. I don't remember the details -- it was maybe 4 or 5 years ago. I think it was a non-revenue (training?) run where the LRV went by a station without stopping, and the adjacent crossing gates needed that 20-second delay to start functioning. MP
Posts: 874 | From: South Bay (LA County), Calif, USA | Registered: Aug 2000
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the mod's email is the only i can find. if i cant get a name change soon i'l just ditch this and get a new one, k? 
consider DrunkEngineer f#@%ed.
