Crossing Trigger Placement Charts

J

Jacob7f1

New member
So, while searching the DLS I found a wonderful trigger by dricketts that does a horn sequence for crossings, <kuid:135229:100378>. (Thanks!) With a little searching on google and some math, I made a speed and distance chart for how far away you should put the horn sequence trigger and ATLS triggers based on a 25 second activation time. (MPH and feet)
Sound Trigger-Formula: Speed of Locomotive X 44= Distance (ft)
5mph= 220ft
10mph= 440ft
15mph= 660ft
20mph= 880ft
25mph= 1100ft
30mph= 1320ft
35mph= 1540ft
40mph= 1760ft
45mph= 1980ft
50mph= 2200ft
55mph= 2420ft
60mph= 2640ft
65mph= 2860ft
70mph= 3080ft
75mph= 3300ft
79mph= 3476ft
*these may or may not be completely accurate.
ATLS Trigger-Formula: Speed of Locomotive X 25= Distance (ft)
5mph= 125ft
10mph= 250ft
15mph= 375ft
20mph= 500ft
25mph= 625ft
30mph= 750ft
35mph= 875ft
40mph= 1000ft
45mph= 1125ft
50mph= 1250ft
55mph= 1375ft
60mph= 1500ft
65mph= 1625ft
70mph= 1750ft
75mph= 1875ft
79mph= 1975ft
*these agian may not be completely accurate.
I hope these help someone in making a route or anyone who didn't know these!:) -Jacob
 
The Federal Railroad Administration says that grade crossing gates must be down (not lowering, but down) for at least 7 seconds before the train is AT the road, and no more than 60 seconds.

Cheers,
Joshua
 
Ill have to work on the timings on the ATLS triggers then. Thanks for the info! -Jacob EDIT: tested it, it was a little more then 7 seconds, so were good ;)
 
Last edited:
Very useful info. Thanks for taking the time to do that Jacob. ATLS triggers are something I usually place by trial and error.
 
Jacob7f1 said:
So, while searching the DLS I found a wonderful trigger by dricketts that does a horn sequence for crossings, <kuid:135229:100378>. (Thanks!) With a little searching on google and some math, I made a speed and distance chart for how far away you should put the horn sequence trigger and ATLS triggers based on a 25 second activation time. (MPH and feet)
Sound Trigger-Formula: Speed of Locomotive X 44= Distance (ft)
5mph= 220ft
10mph= 440ft
15mph= 660ft
20mph= 880ft
25mph= 1100ft
30mph= 1320ft
35mph= 1540ft
40mph= 1760ft
45mph= 1980ft
50mph= 2200ft
55mph= 2420ft
60mph= 2640ft
65mph= 2860ft
70mph= 3080ft
75mph= 3300ft
79mph= 3476ft
*these may or may not be completely accurate.
ATLS Trigger-Formula: Speed of Locomotive X 25= Distance (ft)
5mph= 125ft
10mph= 250ft
15mph= 375ft
20mph= 500ft
25mph= 625ft
30mph= 750ft
35mph= 875ft
40mph= 1000ft
45mph= 1125ft
50mph= 1250ft
55mph= 1375ft
60mph= 1500ft
65mph= 1625ft
70mph= 1750ft
75mph= 1875ft
79mph= 1975ft
*these agian may not be completely accurate.
I hope these help someone in making a route or anyone who didn't know these!:) -Jacob
Click to expand...

I am not too familiar with the imperial system, so I did some calculation on my own. If a mile is 5,280 feet and the sound trigger is activated 25 seconds before the train enters the road crossing, then the distance between the trigger and the crossing should be calculated from the formula:
s = v * t * 5280 / 3600
where
s is distance expressed in feet
v is velocity expressed in miles per hour
t is time expressed in seconds

The fraction 5280 / 3600 is required to convert hours to seconds and miles to feet (there is 3600 seconds in an hour and 5280 feet in a mile).

It is possible to simply this formula as:
s = v * t * 1.4667

but then you lose accuracy when dealing with high speed trains (like these in Spain).

So, according to this formula, for speed of 40 mph and delay of 25 seconds, the distance between the trigger and the crossing is:
s = 40 * 25 * 1.4667 = 1467 feet (approximately)

This is about 467 feet more than in the calculation done by the author of this thread.

The advantage of using the formula is that you don't need to carry a table with many entries. You can use the formula to calculate the distance for any speed and delay interval. Personally, I use MS Excel spreadsheet for things like this. I have many spreadsheets just for Trainz: To calculate train breaking distance, arc tangent and length, track gradient, etc. These are extremely helpful and once you make sure they contain correct data, you always get correct result (see an example below)

For those working in metric system, the formula is:
s = v * t * 1000 / 3600
or
s = v * t * 0.2778
where
s is distance expressed in meters
v is speed expressed in kilometers per hour
t is time expressed in seconds

Delay (s) 25
Speed (mph) Distance (ft)
5 183
10 367
15 550
20 733
25 917
30 1100
35 1283
40 1467
45 1650
50 1833
55 2017
60 2200
65 2383
70 2567
75 2750
80 2933
85 3117
90 3300
95 3483
100 3667
 
I use a similar method with a modified B&M whistle post. speed times 20 gives me distance in feet on where to place the post so the fourth long blast is done as the lead engine plow exits the crossings, I then use the position of the post to estimate where the atls trigger should be to initiate crossing.prior to sequence.
 
Dunno if this will help or not... but the GCOR states that horn/whistle signals for crossings are to be started no closer than 1/4 mile from the crossing, if distance permits... Which equals 1,320 feet. I usually place my whistle posts and ATLS activation triggers about that far back. I find that running about 35 or 40 MPH, it's about right... of course this will stretch out into next week if you're running 15 or 20. Just takes some tinkering. BTW if train speed is fairly low, the horn signal can be prolonged or repeated until the locomotive occupies the crossing.
 
Just a further note on this subject, in the UK, gates are shut for 35 seconds upwards before the arrival of a train. ATLS gates take approximately 13 seconds to lower from being triggered so taking that into account, the formula to work out the trigger distance for an approximately accurate UK set up is as follows - Speed (mph) x 70.4 = Distance (feet).
 
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