Water blasts between the concrete and the blades.
The mixer truck is reversed into the workshop with the aid of a banksman.
The telescopic boom is inserted.
The drum rotates at a 1rpm charge rate. The jet oscillates as the boom retreats along the length of the drum.
This is a simplified animation. The operator can chose to pivot the torpedo section so that the jet is closer to the skin of the drum.
The concrete drops away
The hardened concrete
How Do We Manage The Noise Level?
Readyjet Services have invested strongly in the facility at Heathrow. One of the byproducts of an excellent performance is a very high noise level. The noise of the water hitting the skin of the drum is equivalent to the sound of an airplane jet engine. A noise survey identified peak levels of 120dBA. Through consulting with the workers, contractors and an acoustic engineer a 500mm thick treatment has been applied that reduces the noise level outside the workshop to that of a normal conversation - 67dBA.