So my department has a 4500 gallon tri-axle monster of a tanker that we have given the nickname "the whale." I want to know if anyone has anything bigger. I dont know how to upload a photo from a differant computer but if you check out my page there is a pix of it somewhere. You will notice it (the big white truck) LOL
Our largest tanker is a 2000 gallon olyptical tanker on a Sterling Chassis with a 500hp Detroit diesel and a 500gpm pump. The rear has three manual dumps, and an automatic porta tank rack on the officer side. The truck was manufactured by US Tanker in Wissconson. It is the first one in our area (ST.Louis) Manufactured by US Tanker. The truck has been in service since 2005 and has been a very good piece of equipment. I think if you get much larger than a 2500 gallon unit you will be hurting any tanker turn around evelotion you may establish. A neighboring District not to far from us has a Tractor Trailer unit with an 8000 gallon tank. It is know as the "Super Tanker" however it doesn't get used much around us but the District that owns it usses it regularly.
We have a 2005 E-ONE 3000 gallon Pumper/Tanker with a 1250 gpm midship top mount pump and an 8 man cab. We use it as our first due engine or as a tanker for mutual aid calls. It has 2 150' 1.75" cross lays, 1 150' 2.5" cross lay, a 100' 1.75" trash line, 1 300' 1.75' rear preconnect, 1 300' 3" rear preconnect, 1000' of 4" LDH, a 1000gpm deck gun, and a 10" rear dump. We call this our "Attack Tanker".
We have a 4200 gallon tanker, sits on an 1981 peterbilt chassis. We just call it the big 'un. I've seen one a few districts over that was 5500 gallons, but they could only fill it to 3500, as it would compress the asphalt roads.