Cyril Haearn wrote:The cess is the ditch below the tracks, right?
Yes, and by extension all the area between the bottom of the ballast shoulder and the fence
Cyril Haearn wrote: Seems much too dangerous to work on the lines when trains are running but what are the alternatives? Night work or closing the line. How many workers are killed working on the PW?
Working with trains running is still necessary for some things, but is tightly controlled and minimised, and only done in daylight. If the system of work is set up properly it is safe, but setting up work like that needs more experience and ideally a good knowledge of the location. A lot of maintenance work is done at night in "engineering hours" in the timetable white periods, but the problem there is there's so little time. Most places, only 00:30 to 04:30 available (so maybe 3 hours work time if you need an OLE or 3rd rail too), and if the last passenger train is running late it's less again. Also, freight runs overnight, in some places with 4 tracks you can only ever get a midweek night maintenance block on 2 of the 4 lines, never 4 out of 4. Bigger track renewal jobs are done in 36 or 48 hours all lines closed blocks over the weekend- these are booked 104 weeks in advance, and diversions/rail replacement buses put in place.
Not many trackworkers killed these days, the last trackworker fatality (from trains) was a few years ago, more likely to be killed in a road accident these days. However, it is true that historically there's been quite a few trackworker fatalities.
Cyril Haearn wrote:Many lines run on banks or in cuttings, by building retaining walls space could be created here
Not in cuttings, just not enough space. On embankments- well, maybe- but the engineering required would be significant, better to add Dutch-style facilities to roads. And there is often less space than looks from the train.