Armstrong Crane & Rigging Corp, based in Minneapolis, Minnesota, US, has taken delivery of the first Grove 450t (550 USt) capacity GMK7450 all-terrain (GMK7550 in the US) produced through local Grove dealer Hayden-Murphy Equipment.
Earlier this year the company fitted the crane with Grove’s MEGA-WING LIFT attachment to further increase capacity. MEGA-WING LIFT is designed to offer greater lifting capabilities throughout by stabilising the main boom, and allowing the addition of more counterweight.
One job said to have demonstrated the benefits of MEGA-WING LIFT saw Armstrong place a pair of 8.2t (18,000lb) chillers on the roof of a high-rise building in Minneapolis.
The job required the air conditioning equipment to be placed 15m inwards on top of the 96m tall building. The best position to set-up the crane was 30m from the building giving a total radius for the lift of 45m.
To handle the lift, Armstrong configured the Grove with 55m of main boom and fitted a total of 67m of luffing jib at a 22 degree offset.
Grove said: “Maximum capacity for a standard GMK7450 in this situation is 5t (11,200lb), but with the addition of MEGA-WING LIFT that rises to 12t (26,400lb). MEGA-WING LIFT also allows up to 160t (352,000 lb) of counterweight to be accommodated, but on this lift only 99 t (220,000lb) was required.
The lifts were completed in less than four hours.
