Diesel isn't so bad, but gasoline it is quite an issue - grounding.
Those 18 wheelers will be using grounded fuel hose, and also a ground strap in most areas of the country to unload. One most likely will buy the cheaper ungrounded hose without thinking.....
Using a rubber innertube as he is, there are several grounding issues, from the tank to the vehicle, from the tank to earth, and even from the vehicle to earth - as well as if an electric fuel pump is being used. As fuel flows, it creates a weak static charge - ignoring any other discharge sources. Due to the size of his tank, he needs to cover his behind on this issue. Again, diesel is not much of an issue on this (gasoline always has the right evaporated fuel mix _somewhere_ around the tank when transfering, up here in MN a few fires are caused by the static electricity from touching the car & getting a little static spark in the dry air of winter...), but local & distributor rules on this should be considered. Sounds like he checked that out tho....
The fuel supplier will have grounded hose, so filling should be covered, and he likely will not unload more than 20 gallons at a time so the static will not build up a whole lot. But grounded hose on his tank would be a better idea, and/or a ground clamp when he unloads. Even if it is an 'issue', it only will cause a problem one in many thousand cases so one of those things we all ignore....
As the other person said, I'm not against the project, just some things to consider for the size of his project. Hate for him to find surprises after the fact. /forums/images/graemlins/smile.gif Officials will become concered about how much volume of fuel can be transfered at one time (creating a bigger static charge) and if the hoses involved are grounded type.
--->Paul