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+--- Thread: 2 aspect headway calculation. (/showthread.php?tid=2450)
2 aspect headway calculation. - jimmyinin - 13-10-2023
Hi all, I have attempted the question on calculating the headway for 2 aspect signalling with the following parameters and I was wondering if I have the gist correct
Line speed = 70km/hr - converted into m/s = 19.44m/s
Sighting Distance = 200m
Overlap =300m
Distance between 2 signals = 2km = 2000m
· ¾ loaded super freighter 5x81 class + 58 wagons (see GW-40).
1 in 60 falling grade
Calculated Braking Distance = BD= Line Speed x2/2a ( acceleration rate of 1.0m/s2 from NIST 012 ( Velocity DMU)
BD = 19.44x2/2(1.0)= 19.44m/s
Headway Distance = BD+d+OL+Length of train+Sighting Distance = 4119.44
Headway Time = Headway Distance/V= 4119.44/19.44= 211.9 seconds = 3.53minutes
I get the gist for 3 aspect and 4 aspect but struggle with 2 aspect calculations. Can someone advise if I have done the calculations correctly.
Thanks,
Jimmy