Cleveland Potash has awarded Qualter Hall a major turnkey contract to renew the headgear at Boulby mine in Cleveland, northeast England. The headgear and associated equipment will be constructed by Qualter Hall on site adjacent to the existing tower during 2012, with the final installation taking place during the mine holiday shutdown in August/September 2013, so as not to interrupt production.

Qualter Hall will be using a highly specialised procedure, involving jacking and then sliding out the existing 2,700 t concrete headgear on polished stainless steel slide paths to an area 50 m from the shaft, where it will then be demolished. Then the new 650 t steel headgear, which will have been prebuilt on slide paths about 20 m from the shaft, will be slid into final position over the shaft for completion and putting into operation, all within the holiday shutdown period. Finally a new concrete outer tower will be built over the new steel headgear.

The scope of Qualter Hall’s turnkey works is extensive and will involve the design, build and installation of the new 50 m high headgear structure along with four 6.2 m diameter headgear pullies, two 23 t capacity skips, skip operating gear, receiving hopper, load out conveyor, gantry, shaft cover, safety systems and all associated electrical equipment inclusive of shaft communications and interlocks. Qualter Hall are also responsible for the civil works and foundations, concrete outer tower, airlock arrangement and demolition of the existing 55 m high concrete headgear structure. The new design will include for future uprating of the system, to allow the two 23 t capacity skips to be increased to two 30 t capacity skips.