Interlaced or Trap Retarder?

[Tetchytyke]

In the case of loops it’s quite difficult to imagine how an overrun of the exit signal could lead to collision (with no trap)

Isn’t that exactly what happened at Winsford?

 

[edwin_m]

Isn’t that exactly what happened at Winsford?

No. Winsford was at the convergence of a four track section into a double track, not the end of a loop. So trains could be approaching in both tracks at the same time.

 

[bishdunster]

there are two different examples in the middle sidings at Bournemouth.

 

[Falcon1200]

In the case of loops it’s quite difficult to imagine how an overrun of the exit signal could lead to collision (with no trap).

Indeed, and in addition to your excellent explanation, there can also be a timer, which does not allow the route to be cleared for the main line until a couple of minutes since the looped train arrived have elapsed, so minimising the risk of the looped train passing a signal at danger and entering the main line just as the overtaking train approaches.