In days of steam locos, sparks from these engines used to burn the edges of the formation. Saplings were destroyed before they became big trees and so there were NO LEAVES deposited on the track to cause loss of traction.
Yes in the days of steam there was a problem with lineside fires and I think the railways used to keep vegetation cut back to prevent this. The fires themselves were not relied upon to keep the vegetaion cut back. However there was not a lot of steam on most of the London metro routes even as far back as the 1950s ?. I think it was freight and long distance (e.g. Kent Coast).
If, as was normal on the nineteen fifties railway, you still had a ganger to every mile of track, armed with a mobile phone. you would not even have needed the helicopters!
I thought I was at the forefront of technology but I did not get a mobile phone until the 1990s - not the 1950s. Staff costs in this modern world are too high to allow keeping lots of staff. Its those rising costs of manpower that led to line closures in the 1960s. The lines nowadays are designed to require less maintenance and as much as possible is done by track machines.
I think rather a lot of people are fond of the vegetaion that lines our rail lines and the other wildlife that populates it. Couple that with the cost of keeping that vegetation under control and I can understand that it is easier to wait and see what happens every twenty five years.
I would also suspect that you would have to cut back more than ten metres to ensure larger trees do not reach the tracks. Bear in mind with the nearer trees gone the trees further back will get more light and so grow taller. I seem to recall that the railways do carry out coppicing (or pollarding) in risky locations. Coppicing (EDIT not Pollarding) means cutting the trees back to the base of the trunk every ten years or so. Was done in whole forests to produce wood that is the right size for fencing etc. But also meant there were never large trees around and Network Rail do it in certain locations.
Postive points - How many people died on Monday morning in the storm and how many of them died on the railways ?. So was the railways approach proportionate to the risk ?.
Another solution is to cut back on the huge numbers of humans cluttering the planet and let alternative types of nature survive !. Go back 2000 years and I am sure things ran a lot smoother. Never read about rail disruption in my history lessons - anyone else ?.
