View Full Version : The wrong type of Rain!!!

Big Hilly
28th Apr 2004, 15:16
The brand new, state of the art, Jewel in the Crown of London's Public Transport: The Heathrow Express is currently closed. . . . Due to flooding! :*

Am I getting old or did we really not used to suffer from the wrong type of snow, leaves, rain, sun, pixies on the line. . . . .?


28th Apr 2004, 17:30
No. Railways have always suffered with leaves - it's a question of mechanics. Steel on steel = not much spare friction. In days of steam trains, of course, the hot ashes and glowing coals tended to keep back the foliage...but they still needed to lay sand on the tracks sometimes.

Snow? In the golden post-war years, of course, some winters had railway lines shut for weeks. Tracks buckle when it is either very hot or very cold. Beat physics! If there is water feet deep over the tracks, it doesn't matter whether Network Rail, the Fat Controller, or God is in charge. I somehow doubt many trains ran in the south east in the 1953 floods...

28th Apr 2004, 17:57
A great deal of engineering from earliest times has been devoted to beating physics, or rather using physics to beat problems. Some are better at it than others.

Boss Raptor
28th Apr 2004, 19:55
I always thought proper trains had sand boxes that could release sand in front of the driving wheels in cases of ice or slipping? or was the sand just ballast...I dont think so...

The old 'Deltic' diesel of recent Pprune Spotters Club fame certainly did...

28th Apr 2004, 22:03
Ssshhhhhhhhhhhh.......they'll hear you and start over here! :P

29th Apr 2004, 07:50
There are "Sandtite" units in the UK that are supposed to spread their cargo onto the tracks so that service trains will run OK. They have been used for years....so you can tell how successful they are at dealing with the problem.

A mate of mine invented a new system. It was tried by the old Railtrack on several lines over a number of years. He was given every encouragement to carry on ploughing his money into the invention. Result was they kept him hanging so long that he went bust and his idea died.

Now I ask the question, "did someone in Railtrack have shares in sand pits?:suspect:

Evening Star
29th Apr 2004, 11:40
No. Things like leaf control, snow ploughs, breakdown trains and so on sat in the sidings for most of the year so were not cost effective assets for Railtrack, that shining beacon of privatisation. Afterall, such wasteful assets might affect the dividends.

As for new inventions. Not needed here. Might affect profits.

And so what if for a couple of weeks a year leaves turn the rails into a skating rink, or snow blocks a line, or there is only one breakdown train to go around? The only line that is important is the bottom line.

Any bets if Notwork, sorry, I mean Network, Rail will be any more clued in?

(Mind, the 'wrong type of snow' story is such a media distortion that somebody should submit it to Snopes.)

tony draper
29th Apr 2004, 11:49
I remember when the Tyne and Wear Metro System first opened,very hot summer day, overhead copper lines that supply the juice to the pantographs expanded as per Mr Davaars laws of physics,counter weighs existed that were supposed to drop down and take up the slack again,of course this they did, until they reached ground level,but cables continued to expand until they hovered dangerously just above the lines, so they shut the system down, great panic ensued, consultants were called in and payed enormous sums to solve this problem,Drapes suggested they just dig pits at the base of the poles so counter weights could fall further,want to guess what engineering solution said overpayed consultants came up with? they could have saved themselves all that wedge had they but listened to Drapes.


Don't Tell Him Pike
29th Apr 2004, 12:22
If I remember rightly from my days as a Wagon Basher, the leaves on the line problem was mainly that crushed wet leaves formed a sort of varnish on the wheels. This then insulated the wheels, so the track circuiting didn't work. The track circuiting passes a current through one rail, then throught the wheels and axle to the other rail, and lights up a bulb on a map, so the signalman know where the train is. This wasn't such a problem in the old days when brake shoes rubbed on the wheel rims, and cleaned off the crud. Most new vehicles have disk brakes, so the wheels are uncleaned.

The wrong type of snow was the powdery stuff. The train passing would billow it up, from where it would go in to the cooling air inlets of the traction motors, melt with the heat, and short the things out! Drat!