Lasers to blast leaves from rails

[zardoz]

A most interesting concept. I sure wish there was something like than back when I was running. Sanders were (are?) just not up to the task, plus the sand helped make some nasty flatspots if (when) the wheels picked up and lost traction.

From New Scientist, issue 2998, December 6 2014:

"Every autumn, fallen leaves are a dangerous problem for railways in much of Europe and North America. Passing trains squash leaves on the track into a hard Teflon-like residue that coats the rails, making it difficult for wheels to grip them. The reduced contact between wheels and track also affects signalling systems that are meant to keep trains from colliding. According to Network Rail in the UK, leaves caused 4.5 million hours of passenger delays in 2013."

More at: http://www.newscientist.com/article/mg22429984.800-lockedon-lasers-burn-through-leaves-on-train-lines.html#.VLRHYtLF98E

 

[tree68]

Seems like I was just involved in a discussion about this.  

I'd certainly appreciate such a device.  Our bread and butter is the fall foliage trains - and it doesn't go over well if we can't get where we're going.  I've gotten stuck with two RS11u's and six cars...

I don't know about Teflon, though.  I'd liken the leaves to grease.

[Murphy Siding]

     How do you keep from starting a fire in the dry leaves not on the track?

[Paul of Covington]

  Here is the earlier discussion:

http://cs.trains.com/trn/f/111/t/242430.aspx

[MikeF90]

What caught my eye, literally, from the original article above was this statement:

"According to Malcolm Higgins, the founder of LaserThor, who is also an adviser for the Dutch project, lasers will not damage the tracks. This is because their wavelength of 1064 nanometres means they are absorbed by the leaves and other organic matter such as oil, but not by metal, so energy from the lasers is reflected off the rails." 

As this wavelength of laser emission is very hazardous to the human retina, I would think they would have substantial measures to prevent specular reflections. A lawsuit waiting to happen? 

[Boyd]

Why not just rotating brushes,, or some kind of blower blowing them off?

[gardendance]

Murphy Siding

 

     How do you keep from starting a fire in the dry leaves not on the track?

 

 

from the 1st post's linked article

http://www.newscientist.com/article/mg22429984.800-lockedon-lasers-burn-through-leaves-on-train-lines.html#.VLRHYtLF98E

"Their system also briefly shuts off the laser whenever vibrations make it miss the rail."

If their shutoff system works then it seems the direct laser will never touch anything not on the track. I guess reflections, as MikeF90 mentions, might be a concern.

 

Boyd

Why not just rotating brushes,, or some kind of blower blowing them off?

 

 

While reading that prior thread, http://cs.trains.com/trn/f/111/t/242430.aspx, thank you Paul of Covington, and surfing through its links I vaguely remember at least one article that says somthing like "other methods have mixed results", but I don't remember the particulars. One thing I can think of is that the lasers might have fewer moving parts than any mechanical or blowing method.

Is there some way we can get these 2 threads combined?

[tree68]

Boyd

Why not just rotating brushes,, or some kind of blower blowing them off? 

Not sure that rotating brushes could adequately remove all of the leaf residue. Once a leaf is run over (which can also happen mid-train), it spreads out pretty well.

A blower would remove freshly fallen leaves from the rails (as wood a brush), but if they blow in as a train passes and get run over (a good possibility, especially in "tree tunnel" cuts) and are squashed, the air stream will be virtually useless.

Some combination of the two might be useful - keep new stuff off the tracks, and burn off what's already there.