Leo,
I find your answer interesting, as all the steel and aluminum tanks we
produce for hauling asphalt (truck tanks) require surge plates, bolsters, and
external rings for each tank. Perhaps the gauge of the railroad tank steel
is thicker? (we use 10 gauge grade 50 tank steel). With this gauge, the
barrel is not strong enough to support itself without the surge plates
(completely welded internally) in addition to the heads. Our tanks are 8,000
to 13,000 gallons. We are just building a 13,000 gallon chemical tank
(without external rings) that requires 11 surge plates and a bulkhead.
Perhaps it has something to do with the need for quicker stopping with a
truck tank.
I was talking to one of the old drivers and he said that if the tanks were
completely topped off that the "surge" wasn't so great. If they were not
topped off, the surge would rebound back and forth and could actually move
the truck forward.
Next time I see a model layout operator going too fast while spotting a tank
car, I will yell at him!
Rich
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