"Clive D. W. Feather" wrote in message ...

If the last train reaches the depot at 01:00, you need until 02:00 to
get the power off, check it, and get all your people and equipment in
place to re-start the work you stopped last night.

At 04:30 you need to start packing up and ensuring the line is safe and
everybody is off it so that the power can be switched on in time for the
first train at 05:30.

Suppose we're talking about track replacement. At finishing time you've
got to assemble the joint between the last new rail and the first old
one, and check that all track circuits in the area you've worked on are
working correctly. Then the first thing you're going to do the next
evening is disassemble that same joint and break the track circuit.
Wasted effort.

Result: 2.5 hours work for 4.5 hours effort and probably a full day's
pay at night rate. The rest of the time is wasted. To get 100 hours of
genuine work (e.g. rail replacement) you use up 40 days.

If you shut the line for a long weekend (say Thursday lunchtime to
Tuesday morning) you can get that same 100 hours in one long run. Which
is better? Yes, it's more disruptive, but it's far more productive.

There has been debate for years as to whether it is better to cause
the minimum disruption for the maximum time, or vica versa. Current
thinking tends to favour the latter; I this is probably the beter way
in many cases.

When a stretch of line is handed back after a possesion, isn't there
always a very small, but non zero, possibility that something could
have been overlooked, and the line left in an unsafe state? If this
is the case, then surely one long possesion would also have less risk
than many short ones.