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Hey Cisco Kid!
I have a story about train traction. My family used to have a farm just south of Barrie, Ontario. The CNR or CPR (I'm not sure which) track crossed the back portion of the farm and the track was on a bit of an uphill grade as it headed into Barrie. I was told by my grandfather that one day in the steam era a rather large pig got loose and ended up on the tracks and was subsequently run down by a locomotive. Unfortunately the engineer decided to stop the train. Apparently no amount of sanding could overcome the grease on the tracks and it took several hours to clean the track sufficiently before the train could continue on its way. Half dollars aside, the last thing any engineer wants to run over is a large pig!
I have absolutely no proof that the story is true so I will let it stand on its own. At least it is a bit entertaining.
Regards to everyone,
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
Bacon grease is very slick! My area commuter lines have 2 "Aqua Trains", which are very large, very powerful power washers, similar to what you would use to clean a deck or house. Their purpose is to wash oil and debris from falling leaves that coat the tracks this time of year. Trains can (and have) slide right through a station if they hit leaf debris. The speedometer goes from 10mph to 0 as the brakes lock the wheels, but the train is still doing 10 ! Once stopped, it can be a challenge to get started again, depending on the lay of the land.
pajrr:
The past President of our model railway club is a retired TTC (Toronto Transit Commission) driver. He said he was thankful for never having been assigned to Toronto's famous 'Red Rocket' street cars. One of Doug's reasons was the leaf slippage problem. IIRC he referred to it as "black rails".
There is a place in Sth Australia where caterpillars are in abundance at certain times of year, they can cause a train to stop and stay... They use different methods to keep them clear of the wheels... Still to this day they are a problem...
Dont take much to create slippage but can take a bit to stop it...
Wheel profiles have to be kept right and rail profile too.. Can be a sight to see when a rail grinder goes down the line...
Simple: too much weight on the drawbar, not enough weight on the drivers.
http://mprailway.blogspot.com
"The first transition era - wood to steel!"
The other reason why trains slip is because the low friction between steel wheels and steel rails. An individual can push at least 20tons on flat level track. This is why trains are so efficent. Try pushing a car, a bit harder comared to amount of weight because of friction from rubber on asphalt.
Unfortanutely, low friction means low traction. There is a great photo of a Milwaukee GP7 shooting a shower sparks out from under the wheels. Supposedly they had no sand in winter since it frozen (they were to poor to own dryers). I hear ice is really bad on the railhead.
If I remember correctly, it's Vermont Public TV's "Northern Railroads" video that has a story of the last run on the Woodstock Railroad. Someone had put heavy grease on the tracks, thus it took a lot of work and long time to make the last run.
Have fun,
Richard
Speaking of greased tracks, they are part of the hijinks in "Emperor of the North Pole", a favorite of mine.
https://en.wikipedia.org/wiki/Emperor_of_the_North_Pole
CG