Railway Pressure Vessel Cars
Railway Pressure Vessel Cars
(OP)
Does anyone know why railway pressure vessels cars (propane, ethylene, etc.) are wasp-waisted at the top, in the middle, right where the top manway is?
I was just noticing this on the weekend and couldn't get a good answer from anyone.
Thanks
I was just noticing this on the weekend and couldn't get a good answer from anyone.
Thanks





RE: Railway Pressure Vessel Cars
RE: Railway Pressure Vessel Cars
Could the wasp-waisting be something to just lower the manway for clearance or better access? Or maybe to exempt people from fall-protection requirements?
RE: Railway Pressure Vessel Cars
I can't imagine this being for drainage and I can't figure out any structural advantage to this design.
RE: Railway Pressure Vessel Cars
All I can find is reference to cars where the whole car (top and bottom surface) slopes down to the center. And that is so the product can drain out better. Are you SURE that the bottoms of the cars you're seeing are straight?
I find this called a "funnel flow" design by the way, and not limited to pressurized cars.
Quote 1:
"The silhouette of some modern tank cars depart from the strictly barrel-like horizontal cylinder by the ends turning upward somewhat and the middle sagging slightly downward. This shape allows better drainage of the contents and may help to accommodate sloshing when in motion."
Quote 2:
"An interesting variant is the "Funnel Flow" tanker which is slightly sloped toward the middle from each end, giving it a bent appearance, but allowing it to be drained by gravity."
Note that these quotes are from people dealing with models, not from carmakers, so are not necessarily authoritative.
RE: Railway Pressure Vessel Cars
I see those tanks every day and observing the foll:
there are no external supports for the load and what that tells you,
that huge tank will a little.
GB
RE: Railway Pressure Vessel Cars