ATLS trigger placement for different speeds

[stouthm]

An idle thought. Has anyone done a chart/survey as to how far away to place a trigger for a loco's speed? For example - at 50mph place a trigger x feet from crossing. Don't know if there's a formula you could use or do it by trial and error. Any thoughts?

 

[pfx]

It so happens I have one. But it's for UK crossing times. Not sure how these compare to US timings?

 

[justinroth]

I found speed X 20 gives me a good distance and timing

 

[stouthm]

@ justinroth _ I'm assuming that the results are in feet. At 50 mph x20 = 1000 ft.

 

[justinroth]

yeah. I use it for a modified b&m whistlepost so the fourth horn blast finishes as it passes the crossing. I then place the trigger a couple hundred feet before the post. its hard to get it prototypical especially when a.I. doesn't always go the same speed.

 

[stouthm]

From what I've been reading the gates/lights and bells are suppose to start when the train is about 30 seconds away and the gate should be down at about 20 seconds away. I can't find any charts or list with mph and feet. I might do some testing to see how far a trigger should be placed for a loco traveling at different speeds and the gate activating when the train is 30 seconds away. May take awhile but if I do I will post the results here.

 

[stouthm]

I didn't do a lot of testing but it seems that a factor 30-40 seems about right. That's speed x factor.