Dave wrote:
I have just been watching them and a thought crossed my mind.

How do they stop the diesel from going solid in the tanks and pipes?

Dave

Use "winter" diesel that includes an 'anti-freeze' additive, just as they
use in this country during the winter months - along with heated tanks,
pumps and filter housings to keep things moving and probably a bit of pipe
lagging (to keep the subject On Topic)!