RAF Pre-Heating vans

Just started reading Desmond Scott’s 1982 book “Typhoon Pilot”.

Looking through the photographs first (as you do) Illustration 11 shows/is captioned “collapsible tubes used to carry hot air from the pre-heating van” (IWM).

Can’t remember seeing such a pic before.

Anyone tell me more about these vehicles? Were they only required for the Typhoon/Sabre combination or did other types need them? Does an example survive?

Roger Smith.