Thread: Tankers: Square vs. Eliptical
03-12-2001, 03:39 PM #1Jim WodrichFirehouse.com Guest
Tankers: Square vs. Eliptical
Any ideas where I can find data on safety. Looking for roll over safety etc. I am writing a spec for our first eliptical tank. Which would you prefer?
03-13-2001, 02:23 AM #2Engine69Firehouse.com Guest
I suppose they put baffles in eliptical tankers now. When I started, I remember the "full or empty" rule with them, meaning you only drove them in one of those two conditions.
My personal feeling is to go with the square design. You can carry more water in a smaller package with a box shape than you can with a tube.
03-15-2001, 05:24 PM #3RJEFirehouse.com Guest
You can get any type of tank you want, with or without baffles. The "baffleless" tanks are typically from reworked commercial tanks. Certain products (like milk) require the tanks to be cleaned or inspected regularly, thus the lack of baffles, so you can get inside.
Most commercial tankers (like 18-wheeler gas tank trucks) are baffled.
Ellipical gives you a lower center of gravity than an equivalent sized round. Likewise, square gives you one that is lower yet. Also, the square can let you carry more water on a shorter wheelbase. Then again, there's a lot of space "under" the curve of an elliptical that can be used for compartments - if that's what you want.
Also keep in mind that wheelbase is an issue with weight. Longer wheelbase may not turn as tight, but spreading the weight over a longer distance can help w/per axle loadings. And a tractor/trailer can be upgraded separately (from single to tandem axle - or to bigger/longer tank).
My old dept. used a refurbed 4000gal Mack tandem axle w/elliptical, baffled tank and under tank compartments.
My company recently donated a used tractor and trailer to be refurbed to a local vollie dept. 5000gal tank trailer and Pete tandem axle tractor. It's harder to drive (articulated, 10 speed manual tranny, etc.) but they like it because its more powerful than typical for its weight, and it turns tighter (like a tiller aerial) than others of comparable length.
03-18-2001, 01:15 PM #4tillerman14Firehouse.com Guest
Eliptical with a commercial chassis,,,,either MACK or Peterbilt
03-18-2001, 04:31 PM #5pwc606Firehouse.com Guest
Jim, you may want to check with the local and federal highway boards on the accidents that they looked into involving these types of vehicles. They should have some sort of report that you can get under the Freedom and Information Act. I would also check with the different manufacturers and see what they are or have repaired in the past from accidents.
As far as what kind of tanker to go with, I personally prefer the pumper/tanker with the standard square poly. This allows you to be able to have, if needed, an attack piece that has lets say 2500 gallons of water. This enables you, for that rare case of no pumper in the station, to be able to respond and not have to worry about hose lay outs and manpower. I know they are big and expensive but you are getting a lot for your money.
Hope this helps. Good luck.
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