Trees Trees Everywhere I can't see the Wood for the Trees

[whole diary]

[chrisr_75]

Excessive vegetation, trees and shrubs leads to damage to rolling stock and risk of lineside fires 

I very much doubt rolling stock is damaged by the outer branches and leaves of standing trees as passing vehicles will cause a continuous pruning effect, so heavy branches will not develop, assuming there is a regular passage of trains. Probably sounds worse from inside the train than it actually is.

Could you also explain what you think the source of ignition is for these line side fires and how it is able to ignite living vegetation?

and subsidence of cuttings sides and embankment slopes. Think of the downwards pressure exerted on a slope by a hefty tree.  Roots can also affect drainage.

Bit more complex than this. Tree roots will commonly find their way into solid rock and will even interact with rock at the level of the crystal/grain structure (i.e. an interaction with weak chemical bonds). The root structure generally reinforces surface soils & sediments (think of re-bar in concrete) and ties everything to the underlying geology where the surface deposits are not too thick, so is generally a good thing for slope stabilisation. A dense canopy also has a significant slowing effect on rainfall (canopy throughfall) which can reduce surface erosion considerably. Removal of trees on clay rich soils can cause all sorts of problems with water retention and clay swelling, so it is critically important to look at soil and subsoil type, particularly where slopes are involved.

Of course every site is different and this ongoing study by NR^» (Network Rail - home page) should identify which sites require attention in a more scientific manner than has previously been the case. The basic principles of lineside vegetation management remain unchanged as far as I can see.

[ChrisB]

NR^» (Network Rail - home page) are cutting back to 7 metres clearance as they don't want it to *scratch* the IEPs^▸ (Intercity Express Program / Project.).....

[TonyK]

The greening of the valleys since the coal mines were shut down is in my opinion one of the more positive aspects of the industrial changes which occurred in the 70s and 80s.  Though as they are still some way short of a tourist attraction then I would agree that tree clearance to give passengers views should probably come fairly low down NR^» (Network Rail - home page)'s its of priorities, unlike in Scotland where I believe there is an effort being made on the Highland lines to do so.   

"Such a scene of urban dereliction. I remember when this was all pitheads and steelworks!"

[Witham Bobby]

Excessive vegetation, trees and shrubs leads to damage to rolling stock and risk of lineside fires 

I very much doubt rolling stock is damaged by the outer branches and leaves of standing trees as passing vehicles will cause a continuous pruning effect, so heavy branches will not develop, assuming there is a regular passage of trains. Probably sounds worse from inside the train than it actually is.

Could you also explain what you think the source of ignition is for these line side fires and how it is able to ignite living vegetation?

The knocking of branches on the roof and sides of the unit we were travelling in was quite pronounced, and the exterior finish (a vinyl wrap, I presume) showed the scratches left from the encounters with the trees.

Fires start in the dead undergrowth and will spread to live vegetation, when hot enough.  Possible ignition sources include discarded, empty glass bottles  and vandalism.  In my days working on the railways, I saw both. 

and subsidence of cuttings sides and embankment slopes. Think of the downwards pressure exerted on a slope by a hefty tree.  Roots can also affect drainage.

Bit more complex than this. Tree roots will commonly find their way into solid rock and will even interact with rock at the level of the crystal/grain structure (i.e. an interaction with weak chemical bonds). The root structure generally reinforces surface soils & sediments (think of re-bar in concrete) and ties everything to the underlying geology where the surface deposits are not too thick, so is generally a good thing for slope stabilisation. A dense canopy also has a significant slowing effect on rainfall (canopy throughfall) which can reduce surface erosion considerably. Removal of trees on clay rich soils can cause all sorts of problems with water retention and clay swelling, so it is critically important to look at soil and subsoil type, particularly where slopes are involved.

Of course every site is different and this ongoing study by NR^» (Network Rail - home page) should identify which sites require attention in a more scientific manner than has previously been the case. The basic principles of lineside vegetation management remain unchanged as far as I can see.

You obviously have superior knowledge.  But I will say that the old-school P-way inspectors (whose role seems to have been superseded these days) preferred to cut trees down before they got too big, citing pressure on slopes and the loosening effect on the soil (usually clay on embankment sides) when trees move in the wind, particularly when the soil is wet.  Maybe they were just looking something for their gangs to be working on in-between those lucrative Saturday night/Sunday morning relaying jobs?  The PWI I am thinking of had 50 years experience on the railways of the westcountry.

[IndustryInsider]

You can certainly see the effects in scratches on the vinyls, and sometimes leaves and small branches in the carriage.  You don't usually hit anything too substantial but the first train through after a heavy shower weighs down the leaves and branches and can result in more than what you'd call a gentle brushing.  Also of course, the closer the trees to the track, the more likely you are to hit fallen or damaged branches that may be brought down by winds.

[AMLAG]

PWI Charlie Curtis of Westbury or Dick Sloman of Yeovil ?!

Not only do encroaching trees /vegetation scratch rolling stock paintwork, impair and even prevent use of the lineside cess by Rail staff and in emergencies others - even passengers being evacuated from a train, but it has an adverse aerodynamic effect in slightly impeeding a train's movement. Also train staff may, say at slow speed, need to put their head out to check something.

Seriously encroaching unmanaged lineside vegetation 'hedges', currently kept trimmed by trains, are increasingly noticeable on the former GWR^▸ (Great Western Railway)/WR  lines.
Make a journey on the former Southern main line between Salisbury and Whimple and
it is very evident that much effort and cost has been expended in recent years in cutting down trees etc well back from the line.
The Southern of course planted a certain species of pine tree on their linesides in many places throughout their system and these can still be seen to this day, the benefits were no leaves and a tendency to restrict  surrounding vegetation growth.

[Richard Fairhurst]

Was desperately needed on the Cotswold Line anyway as it had been allowed to grow to ridiculous levels in some places.

The cuts in recent years at Hanborough do appear to have led to a real improvement in leaf-fall season - I remember many times Turbos slip-sliding-away when leaving the station previously.

Interested by eightf48544's original observation about South Wales. It's a frequent complaint of those who cruise the Monmouthshire & Brecon Canal too, on the eastern edge of the Valleys: tree growth in recent years has been such as to obscure the famously lovely views over the Usk valley.

[John R]

I remember many times Turbos slip-sliding-away when leaving the station previously.

Was Paul Simon driving?

[Western Pathfinder]

Everyone loves the sound of a train in the distance !.

[Witham Bobby]

PWI Charlie Curtis of Westbury or Dick Sloman of Yeovil ?!

Not only do encroaching trees /vegetation scratch rolling stock paintwork, impair and even prevent use of the lineside cess by Rail staff and in emergencies others - even passengers being evacuated from a train, but it has an adverse aerodynamic effect in slightly impeeding a train's movement. Also train staff may, say at slow speed, need to put their head out to check something.

Seriously encroaching unmanaged lineside vegetation 'hedges', currently kept trimmed by trains, are increasingly noticeable on the former GWR^▸ (Great Western Railway)/WR  lines.

I was thinking of Harold "Larky" Blackmore, actually, whose big-railway career ended on the Taunton District.  After retirement, he spent a good many years "part-time" getting the West Somerset Railway into some kind of fettle, after all the years of neglect.  Anything he didn't know about PW^▸ (Permanent Way) was, frankly, not worth knowing.

[bobm]

The Gwili Railway near Carmarthen seems to heavily tree laden - with the added risk of lineside fires.  Some of the most intensive tree growth I have seen next to a railway line.

[grahame]

From Wales Online

A train crash left two people in hospital after it hit a tree on the tracks.

The crash took place near Llanbradach railway station, in Caerphilly , at around 10.05pm, with Arriva Trains Wales’ Rhymney service affected.

[eightf48544]

Hot off the press

From Get Surrey website http://www.getsurrey.co.uk/news/surrey-news/south-west-trains-disruption-train-13143128

High winds played havoc with Surrey's rail services on Tuesday morning (June 6) as one train was forced to stop just outside Guildford when it was hit by a tree.