Thanks Mike. The steel framed sprayer trailer will have dirty muddy tyres and they will be located on wet mud in the field.

And the tractor tyres may be filled with water as ballast!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

It seems to me, in essence, you would almost have to make a deliberate determined attempt to cause a decent chance  of a real world danger

So?

So, it appears that only direct contact with H.V. overhead lines may cause an electrocution.

Farmer ordered to pay £18,000 after man electrocuted to death - FarmingUK News

Z.

And another case where a tipper trailer came into contact with overhead H.V. lines.

“I was literally stuck to the spot,” he said. “It was about three or four minutes after that when the front tyre of the tractor caught fire. Even though the power hadn’t killed me, if I hadn’t managed to break free then the fire would have.”

'11,000 volts shot through my body': Farmer tells story about dangers of power lines - FarmingUK News

Z.

Advice in case a farm vehicle  comes into contact with over head electric lines.

To be read in an American accent obviously.

NASD - Agriculture Electrocutions in the United States (nasdonline.org)

Z.

There was a guy locally who sold storage silos for farms, he used to take one of them to local agricultural shows on the back of a tipping wagonas a display, he would drive onto the showground and part tip the wagon, then reverse and slam the brakes on allowing the silo to slide off the back and stand itself up.

Which worked well until the day he did it under HV power lines then climbed out of his wagon.

aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaand? Did he then slip over on a cow pat?

Z/

So, it appears that only direct contact with H.V. overhead lines may cause an electrocution.

I wouldn't go that far - other risks will still be there even if the probabilities are lower. As that American document points out you can get a hazardous voltage gradient over the ground in some circumstances (Equipment touching the line, line down or a vanilla earth fault on the HV system) - so certainly still possible to be electrocuted without direct contact. I like the 'shuffle' idea (I'd only come across 'bunny hops' suggested before).

Also note the US HV lines are generally more hazardous than ours - because they distribute a HV PEN conductor they have no means of detecting Earth faults - so their lines are almost always remain live under many fault conditions. This side of the pond HV connections are all L-L so earth faults currents can be distinguished from load current and most supplies will disconnect. Not 100% reliable as fault currents too low to cause disconnection can still easily kill, and not every HV circuit might have the disconnection equipment, but still far fewer dead bodies overall than with the American system.

   - Andy.