Tree's on the MET.

It could well be root growth, tree roots are insidious buggers and could well cause problems with nearby trackbeds.

If you've ever seen a street with the pavement pushed up by tree roots you'll know what I mean.

Not me I hope?

Someone has also butchered line side greenery on the District's Wimbledon branch between Southfields and the East Putney Tunnel.

I must admit though, I cannot tell the difference between a weed and a flower, so never ever let me loose on a garden!

Parts of the embankment between Pinner and North Harrow is being regraded. Assessment has found the factor of safety against shoulder slip is below what LU standards require. If left alone the cable runs will eventually fall over.

The weight of the trees on embankment is actually a contributary factor in landslips. Removing the trees helps reduce these as well as solving the leaf fall problem that all Drivers struggle with. It is a shame to remove established trees but the only reason that they have become established is because embankment control has been neglected for so long in the name of keepng costs down. The trick is to keep them under control and not let them grow back like Network Rail seem to do.

I thought that the railways had the legal authority to do whatever they liked to vegetation that gets in the way of any part of their operation, regardless of the source. i.e they can cut back the portion of vegetation that is within the railway boundary.

This is a very fraught issue in terms of property generally,for instance,someone I know recently got a letter from his neighbour's insurers,demanding that all trees in the vicinity of a (badly built) extension be felled,as the foundations were sumping.
This is a common tactic by insurers,and indeed landowners in general,but the truth is that the effect of the presence or absence of trees is pretty unpredictable,and any changes may have the opposite effect of what was intended.
For example,removal of trees may cause heaving of clay soil,or flooding,because the water they abstracted is left in the soil.On the other hand,it may cause shrinkage or loosening as the root system rots.
As I see it,the best plan is to have well-managed trees along the railway boundary....years ago,I read an article about LT's Gardening Unit,who planted trees on railway land for the purposes of bank stabilisation,and graded shrubs lower toward the track to reduce leaf and sighting problems.Also plants' effective role in sound insulation for neighbouring properties was a consideration.Is this Unit still at work?
NR seems to have made a rod for its own back,a result of the short-termism of the last 30-40 years or so.
In the Steam Age,embankments were kept effectively as meadows,mown short a couple of times a year to reduce the risk of fires.Mature trees were allowed only on the property line.
After steam,in the atmosphere of cost-cutting,embankment mowing was effectively stopped as it seemed an easy economy.
What a surprise! 20 years later,in the 80s,the embankments are covered with semi-mature trees right up to the cess,and leaf-fall is a problem in autumn,causing wheelslip etc.
So the response is to take the trees out entirely.
In the meantime,people have got used to the wooded view of the railway,and the screening benefits of trackside vegetation,as well as the wildlife issues (*pace New Cross Cutting!)
and NR has a fight on its hands,as well as the fact that the embankments have reached an accomodation with the trees,and may not take kindly to their sudden absence.
The answer is,of course,what LT's Unit had been doing all along:Manage tree growth continuously,leave the trees on the proprerty line,and grade the vegetation for height toward the track.
Fortunately,though,what NRs contractors seem to be doing,in many places,is to coppice the semi-mature trees.This is exactly what should have been done originally,but the process must be repeated every 5 years or so to keep them managed.If they don't,we'll have exactly the same palaver in 20 years time again.

Thanks for the advice but I already own a copy which I read from time to time.

I believe some 'landscaping' will be carried out as part of the embankment works at North Harrow.

As a statutory undertaker LU can overturn a tree preservation order. I did hear about a local resident chaining themself to a tree in RLB Kensington. Amongst other powers they have authority to access railway land through private property or remove third party structures posing a danger to safety.

A colleague who was researching property deeds for some work said to beware buying property on ex-railway land. There are all sorts of convenants that allow requistioning of land.