tank cars

yES

You have to remember that long bits of steel etc expand and contract. Underframes and tanks aren't neccessarily made of the same material and therefore might expand at different rates. I don't know, but a steel underframe and a steel tank full of liquid might well change temperatures at different rates) The simplest way to deal with that problem is to allow the two to move in relation to each other rather than have banana shaped tank wagons!

Greg.P.

Exactly. The frame stays more-or-less at the ambient air temperature while the tank full of liquid takes quite a while to either gain or lose much heat.

Thus at night time the frame cools and shrinks quite rapidly as compared to the tank; and in the morning the reverse occurs.

~Pete

Don't forget that you also donot want to have the stress of the train pppulling and pushing on the frame to be transfered to the tank itself. You could tie one end to the car but then you will have twice as much motion on the other end of the tank to compensate for.

-- Bob May

rmay at nethere.com http: slash /nav.to slash bobmay http: slash /bobmay dot astr>

Go look at modern tank cars.

HTH

No need for that. The first frame-less tank cars date from about 1903

Howard Garner

Thanks, all!

mark

Hi :)

Check out decembers issue of model railroader magazine for a story on tank cars and imformation