Light Saber Weed War Weapon

[Victrola1]

You might not see leaves as hazards, but train operators would beg to differ -- foilage on the tracks not only makes it harder for trains to stop, but messes with anti-collision signals. The greenery might not be much of a danger for much longer, however. Dutch Railways istesting a laser system that zaps leaves (and other organic material) before it reaches the wheels, keeping the tracks clean.    

Burning foliage off the track brings to mind, "An elegant weapon from a more civilized time." 

http://www.engadget.com/2014/12/09/trains-get-lasers-to-clear-tracks/  

http://www.worthpoint.com/worthopedia/cb-q-92-plano-illinois-weed-burner-vintage-train

 

[tree68]

Never mind stopping or signals - we have problems every fall with not being able to go due to leaves on the rails.

And, as we don't operate over 40 MPH, that won't be a limitation.

The catch is going to be the cost of the device itself.  

[samfp1943]

tree68

Never mind stopping or signals - we have problems every fall with not being able to go due to leaves on the rails.

And, as we don't operate over 40 MPH, that won't be a limitation.

The catch is going to be the cost of the device itself.  

 

Leaves on tracks a problem?  Just ask the Arkansas & Missouri RR.

Oct 16,2014 they had a stalled train, and sent rescue locomotives from a near-by freight to' rescue' the stalled train. Aparent cause of slippery rails- leaves on tracks?

The result was the folowing story @ http://5newsonline.com/2014/10/16/washington-county-deputies-respond-to-train-derailment/  

The laser weed burner would have been cheap at twice the price?? .

 

[mudchicken]

Cold steam leaf and vegetation control was being pitched (and failed) less than 10 years ago to Amtrak, BNSF and others. As the tagged articles are hinting at, the computer power and speed needed to focus the light beam isn't there yet along with the hardware. Close enuf won't work here. I don't think Obi Wan, Luke  or Darth will hire out and somehow the liability issue appears unresolved. (Don't worry, Congress will wave its magic wand and mandate that this happens along w/PTC)

[Paul of Covington]

  I remember seeing pictures of locomotives in the very early years with little brooms attached to the front to sweep the tracks.   Maybe they could try that again.   It would be cheaper.

[gardendance]

I've seen bicycle racing support motor vehicles with brooms attached too, and wondered how much good they did.

[tree68]

samfp1943

Leaves on tracks a problem?  Just ask the Arkansas & Missouri RR.

I think you'd see better traction with grease than you do with leaves.  

Assuming such a device could be made practically (probably a reach right now, as MC points out), for us it would come down to whether the cost would be less than what we might lose in revenue (ie, having to give refunds) over an acceptable time period.

The idea of some sort of steel rotating brush has occurred to me, and probably wouldn't be that hard to implement.  It would really have to scream in order to have significant effects at higher speeds, though.  And the brush itself would have to be easy to replace in the field, depending on how much wear occurred.

[Paul_D_North_Jr]

From the 1st comment to the 1st linked article:

"I need to get my tech news from a more reliable source.  I'm thinking The Onion." 

- Paul North. 

[diningcar]

Paul_D_North_Jr

From the 1st comment to the 1st linked article:

"I need to get my tech news from a more reliable source.  I'm thinking The Onion." 

- Paul North. 

 

Paul_D_North_Jr

From the 1st comment to the 1st linked article:

"I need to get my tech news from a more reliable source.  I'm thinking The Onion." 

- Paul North. 

 

[Norm48327]

Railroads have "Weed Weasels", why not "Leaf Weasels".

[narig01]

Metro North has specialty equipment to clean the tracks of leafy residue pectin. http://www.mta.info/news-metro-north-metro-north-slip-slide/2014/10/15/working-reduce-slip-slide-your-ride-metro-north Rgds IGN

[samfp1943]

narig01

Metro North has specialty equipment to clean the tracks of leafy residue pectin. http://www.mta.info/news-metro-north-metro-north-slip-slide/2014/10/15/working-reduce-slip-slide-your-ride-metro-north Rgds IGN

 

Heated up the link for you,IGN ! @  http://www.mta.info/news-metro-north-metro-north-slip-slide/2014/10/15/working-reduce-slip-slide-your-ride-metro-north

P.S. Here's a 2 minute video of how Metro North does it @ https://www.youtube.com/watch?v=H0uUGCnzEbw

[Euclid]

 

Apparently, this would be able to raise the temperature of the leaf so high that it would vaporize and dissipate despite the conductive heat loss to the rail. I assume that this action would occur very close to the wheel, so it would have to be completed in an extremely brief time period.  I would be astounded if this were practical.  Particularly farfetched sounding is the idea that this will also raise the temperature of the rails to prevent leaves from sticking. 

 

[gardendance]

I'm too lazy to read the article again, but I thought the idea it presented was to heat the water enough that the leaves would be light enough to blow off the rails.

[Wizlish]

mudchicken

Cold steam leaf and vegetation control was being pitched (and failed) less than 10 years ago to Amtrak, BNSF and others. As the tagged articles are hinting at, the computer power and speed needed to focus the light beam isn't there yet along with the hardware.

"Cold steam" is a completely different (and probably almost unworkable, on diesels) technology - I don't think it is practically any different from the rail washers used on some steam locomotives.  (Cold steam is a steam/water mixture; the steam provides the impulse and the water serves as the mass flow to move the material).  There is a European approach that uses 16000psi pressure washing - don't cross the streams! ;-) - perhaps followed up by that polar opposite of TOR lubrication, Sandite...

The chief enabling technology that makes the laser ablation more practical now is the introduction of cheap high-power diode, disk and perhaps fiber lasers within the last couple of years. These have a much smaller form factor and better efficiency, and are much cheaper.   [Edit: note that this is different both from solid-state diode pumping of a YAG laser, as in the Rofin-Sinar design, and from the use of fiber optics to guide the beams...]

The 'older' approach involved diode-pumped Nd:YAG (2kW at 1064nm IR, Q-switched for high peak power in each pulse).

Here is a short clip with some information on that approach:

.

Note that the idea is physical ablation of the relatively dark organic material, not excitation or heating of the water.  It might be appropriate here to note that this isn't the same kind of problem as when your car skids on wet leaves -- the high contact pressure creates a very different sort of deposit that is almost plastic-like, and very difficult to remove physically from the affected area of the railhead. Note that there will be deposits on both the wheeltread and railhead, and both should be "treated" (as is shown).

I suspect that Strukton could provide details of its lens system and 'triple suspension' arrangement to anyone with further interest in the details; I need to look back over the back numbers of publications like Laser Focus World to see if they covered it.