Bachmann Online Forum

Discussion Boards => General Discussion => Topic started by: ryeguyisme on August 29, 2011, 11:55:36 AM

Title: proof that track in real life is more forgiving than in scale
Post by: ryeguyisme on August 29, 2011, 11:55:36 AM
watch:
http://www.youtube.com/watch?v=D-8gV4DJZUw

i was amazed
Title: Re: proof that track in real life is more forgiving than in scale
Post by: Doneldon on August 29, 2011, 10:09:46 PM
rye-

Wow! What a fun bit of video. If only the narrator could have put some more genuine feeling into his surprise that the trains stayed on the rails.

I'm not so sure this is a big surprise, though. Train wheels function as big, heavy gyroscopes so one would expect them to stay in the same plane unless some powerful crosswise forces act on them. Plus, as Newton taught, objects in motion tend to remain in motion and, though Newton didn't say this at first, they also tend to stay moving in the same fashion. This would explain how difficult it was to wreck the demonstration train. The trial where the train did go on the ground had an additional factor: the wheels began plowing up rails and ties which interfered with either the wheels or train moving as it had been. When you dissect a train wreck this is almost always found. Things don't go completely crazy until external forces push the wheels and/or train itself away from its previous trajectory.

Thanks for posting this. I enjoyed it.
                                                                             -- D
Title: Re: proof that track in real life is more forgiving than in scale
Post by: Jim Banner on August 29, 2011, 11:39:57 PM
Very interesting.  I kept waiting for them to put half the charge at one spot to cut the rail and the other half spread out along 5 to 10 feet of the same rail to bend it inward.  Guaranteed derailment.

Jim
Title: Re: proof that track in real life is more forgiving than in scale
Post by: jward on August 29, 2011, 11:51:35 PM
had they done these experiments on a curve i think the results wound have been much different. as a matter of fact, the results we had when i worked with the railroad were quite different. we were running 14000 ton coal trains on 80 year old 100 lb rail. when that brittle rail snapped we usually piled them up. we had derailments every couple of months, because the ownership of the track was in question nobody wanted to take responsibility for it. so we pounded it into the dirt, and only patch repairs were made.

jim, what you described is exactly what happened in nevada in 1939. somebody unbolted a rail joint, and moved the rail inward. the city of san francisco hit it at speed resulting in numerous fatalities. the way the train was travelling, the end of the rail was bent inward so the wheels dropped on the ties and the rail forced them over the bank with enough force to take down a nearby truss bridge.