Not an answer to your question, but what we ended up with was an old chemical shuttle (they are made of sturdy plastic) mounted on a pallet with a gas engine trash pump mounted and a hose with fire type valve/nozzle on the end of the hose. Think it was a one inch hose but don't remember for sure.

Was made to size to slide into the back of a Polaris Ranger UTV.

We used that back when we burned wheat fields stubble for double crop beans. That along with a couple of hand held 3 gallon pump up sprayers. If we needed more water we used our sprayer tender trailer with a lot of water supply on it. It had a pump to fill the fire rig on the Ranger.

It is surprising how much the little hand pump up sprayers will do for controlling back fires and such as long as the flames are small. That is what did 90% of the work in a controlled fire, while flames only a foot or so high. Only had to use the fire hose when things started getting out of control.