Same engines that we used to have on the infamous "Snow-blo". We would sit between a pair of the cantankerous old blasters, mounted on the front of a fuel bowser (a concept taken to its extreme by NASA's Shuttle) and try to maintain the fine balance between blowing away the snow and melting the runway. Most of us weren't very good at it, which explains the current condition of Waddington's runway - several subsequent resurfacing projects have failed to patch up the damage.
I often wondered, while sitting there with my trousers on fire, why an engine that hot couldn't push a Vampire supersonic.