Flat Top Tower Cranes is the version of foundation anchors. The front jib can be built in sections in the air if required, which is a very useful feature where space is restricted so that the jib cannot be built complete at ground level. Stacking one crane over the other, in multi crane applications, results in lower overall hook heights with flat top cranes. The upper crane which has been completely pre-assembled can be installed with only four auto crane hoists, slewing platform with cabin system, counter jib, jib heel section with hoist and trolley winch gear unit as well as a trolley with lifting crane hooks including reeving ropes and the preassembled jib.
A flat washer has a flat surface used to spread tightening forces over a wider area. Flat washers are used under the head of a bolt or nut to distribute the forces applied when tightening. It is serve as bearing surfaces to prevent bolt heads and nuts from digging into the work surfaces. It is used to increase the clamping surface area. They prevent the smaller bolt head from pulling through the sheet metal or plastic.