| An important part of hauling water is being efficient at the process. Tankers that gravity dump are effected by the head pressure of the water in the tank. When the tank is full, the head pressure is greatest, thus water rushes out very fast when the dump is first opened. As the water level drops, so does head pressure and the result is a lower off-load rate.
So, a 3000-gallon tanker may off-load 2000 gallons of water in the first 90 seconds but to get the rest of the water off requires almost another 2 minutes. It would be more efficient to simple stop dumping at the 90-second mark (critical dump time) and head for another load of water.
Remember, that when hauling water in a shuttle, efficiency is about time and GPM delivered. That 3,000-gal tanker dumped 2,000 gallons in 90-seconds (1,333 gpm) - why would you wait another 2-minutes to offload the remainng 1000 gallons (500 gpm).
Thus - you have to know when to cut and run!
For more info about Critical Dump Times and tanker offload testing - see the Tanker Offload Tests from 2009 in DeKalb County, Alabama that is posted in the Data Section of our website. |
