From: ce11son@yahoo.ca   
      
   On Sat, 21 Feb 2015 20:27:58 -0500, Nick Sandru   
    wrote:   
      
   >On 02/16/2015 10:25 AM, Adam H. Kerman wrote:   
   >> bob  wrote:   
   >>> On 2015-02-13 20:23:01 +0000, Marc Van Dyck said:   
   >>>> rcp27g@gmail.com explained on 13-02-15 :   
   >>   
   >>>>> or putting in positive singalling control on others (ie where the   
   >>>>> crossing is protected by railway signals that aren't cleared for the   
   >>>>> train until the barriers are down and the crossing positively checked   
   >>>>> to be clear).   
   >>   
   >>>> This is perfectly feasable but requires to order the gates to go down   
   >>>> at a distance that is longer than the braking distance of the train.   
   >>>> This means there will be a long delay between the gate going down and   
   >>>> the train actually passing the grade crossing.   
   >>   
   >>> Indeed, this is the case.  It is less convenient but allows for   
   >>> positive safety.   
   >>   
   >>>> As it has been mentioned,   
   >>>> motorists are unpatient creatures; if the delay is too long, people   
   >>>> think the gates are faulty and start turning around them. You might end   
   >>>> up this way with a grade crossing that is inherently less safe, because   
   >>>> of human nature...   
   >>   
   >>> Solved by making the barriers block the whole road.  As the crossing is   
   >>> positively checked to ensure the barriers are down and the crossing is   
   >>> clear before clearing the signals for the trains, the issue of cars   
   >>> being trapped within the crossing is avoided.   
   >>   
   >> Clearing level crossings several minutes before the train arrives mitigates   
   >> against non-existant risk, and it's quite labor intensive. How is the   
   >> cost of delay justified? How is the personnel cost justified?   
   >>   
   >> No lives have been saved except during the 5 or 10 seconds before the   
   >> train arrives.   
   >>   
   >>> The usual design in the UK, for example, is for the road to be blocked   
   >>> by four barriers: each covering half the roadway on each side of the   
   >>> railway.  The warning lights/klaxon start first, then the "entry" side   
   >>> barriers come down, then the "exit" side barriers come down, then the   
   >>> klaxon stops (it gets irritating, and once the barriers are down, is   
   >>> redundant).  Then the crossing is checked to be clear, either by a   
   >>> person in a local signal box or by CCTV cameras, and if it is clear,   
   >>> the signals are cleared for the train or trains passing.  It is safe,   
   >>> but means waits at the crossing can be a couple of minutes before the   
   >>> train actually arrives.  The crossing sequence is initiated by the   
   >>> signalman, who can keep the crossing down if there are multiple trains.   
   >>> They can be annoying, but they are safe.   
   >>   
   >> I've heard of crossings getting closed five minutes ahead of arrival   
   >> of the train.   
   >>   
   >>> Not all crossings in the UK are of this sort, there are also "automatic   
   >>> half-barrier" crossings that do not block the whole road and are   
   >>> triggered automatically by the train approaching, without positive   
   >>> safety, but designed for the minimum road-closed time, so the barriers   
   >>> come down about 20s before the train arrives.  Such a crossing was   
   >>> involved in the Ufton Nervet crash, and they are only used on quiet   
   >>> roads with little traffic, and on railway lines with lower speeds.   
   >>   
   >> That's common in the US.   
   >>   
   >   
   >The Russians have found a much more efficient solution to keep the   
   >idiots off the tracks:   
   >   
   >http://erkkit.smugmug.com/Motorcycles/Return/i-L8HhJ9/0/L/image336-L.jpg   
   >   
   I'm getting a blank page.   
      
   >The steel plates in the roadway are raised when the gates come down.   
   >Vehicles caught in the crossing can move away from the crossing as the   
   >plates are pushed down by the vehicle's weight. But if you want to beat   
   >the train then you will need a pair of new tires...   
   >   
   >Of course, if such a solution would be introduced in the US, railroads   
   >would be forced out of business as they would have to defend themselves   
   >from being sued by idiots whose care got damaged.   
   >   
   http://www.barriergatearm.com/Motorized-Traffic-Spike-Systems.html   
      
   >An there is also the   
   >sovereign citizen/libertarian crowd who would never relinquish their   
   >$DEITY given right to be killed by a train.   
      
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