Loop Lengths

[MarkyT]

"A loop has only one signal section - two signal sections or more is a slow line." - R. Sumner.

As to loop entry and exit speeds, most freight can reach over 40mph (on the flat) in the length of the train, so 50 turnouts are a better choice, IMHO. Therefore the toe to toe length of the loop is the toe-to-CP for the entrance T/O +, 775m (train) + 2x20m (loco and demic) + 5m (inaccurate stopping) + 20m signal standback +a signal overlap (nominally 180m, can be a bit shorter at 50mph) +CP-to-toe for the exit T/O.

The more signalling engineers you put in a room the bigger the bill ...

On the other hand, if you get a good one in right at the beginning before PW and structure designs are finalised, you can often avoid a lot of rework and cost! Extra points for good coverage of overlap considerations Mr. Locke. Sometimes it might be possible to put in an overlap spur with a friction buffer stop in lieu of the full overlap length, if further lengthening at either end is particularly difficult.

 

[Joseph_Locke]

On the other hand, if you get a good one in right at the beginning before PW and structure designs are finalised, you can often avoid a lot of rework and cost! Extra points for good coverage of overlap considerations Mr. Locke. Sometimes it might be possible to put in an overlap spur with a friction buffer stop in lieu of the full overlap length, if further lengthening at either end is particularly difficult.

Not a first choice: RAIB Bromsgrove,

 

[edwin_m]

Not a first choice: RAIB Bromsgrove,

Although to be fair that accident wouldn't have happened had there been a friction buffer stop as suggested by @MarkyT.