Possession Detonator Protection

[Tin Rocket]

Does anyone know the reason why the standard distance for possession protection is 440 yards beyond the protecting entrance signal/points
Cheers

 

[Gloster]

I presume that it is related to there being mileposts every quarter-mile (if that isn’t an oxymoron), so there was a simple method of calculating where to put the detonators. “The signal/obstruction is about thirty-five paces from the milepost, so I put the dets down thirty-five paces beyond the next milepost”.

 

[Tin Rocket]

I presume that it is related to there being mileposts every quarter-mile (if that isn’t an oxymoron), so there was a simple method of calculating where to put the detonators. “The signal/obstruction is about thirty-five paces from the milepost, so I put the dets down thirty-five paces beyond the next milepost”.

I think historically it may have something to do with the

I presume that it is related to there being mileposts every quarter-mile (if that isn’t an oxymoron), so there was a simple method of calculating where to put the detonators. “The signal/obstruction is about thirty-five paces from the milepost, so I put the dets down thirty-five paces beyond the next milepost”.

I think it may be related to train length in some way but obviously not sure.
Thanks

 

[edwin_m]

Possibly related to the clearing point in absolute block traditionally being 440 yards beyond the box's first stop signal?

 

[Gloster]

I believe that the requirement to install distance markers every quarter-mile dates from 1845, pre-dating any form of signalling, and probably establishing a quarter-mile as the default distance. Supposedly, their original purpose was to allow passengers to check that they had been charged for travelling the correct distance.

 

[Tin Rocket]

Possibly related to the clearing point in absolute block traditionally being 440 yards beyond the box's first stop signal?

Ok thanks