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Erecting a Lattice Jib.

Erecting large jibs is one of the hazard points of assembly. At the point of lifting the jib from horizontal the loading on the machine is at its lifting maximum, this is often very close to the full loading capacity of the machine.

The counter weights, outriggers and alignment must all be in correct place before this is attempted.
It can also be seen also from the image right the amount of space that is required for this operation.

Image right - Lifting a Colossus 5000 boom

click for larger image

click for larger image

The instructions below for Erecting the jib of a 1958 Ranger 25 ton Crane were taken from a Coles leaflet of the time but apply to any strut jib crane. On the larger cranes the moving of the jib sections and counter weights is usually handled by a smaller assembly crane brought in for the purpose.

Image left - Cover of instruction manual
The gantry is quickly and easily erected and a conventional sling attached to the lower section of the jib. Using the power of the derrick motion the crane lifts and accurately positions the jib extensions at ground level.

When all the extensions are joined by inserting the joint pins, the crane superstructure is slewed over the rear of the chassis and the jib lower section lowered until its upper fixing points register with those of the jib extension.

The joint pins are inserted and the and the jib carefully "derricked in" to rase it from ground level until the lower fixing points register. This allows the insertion of the lower joint pins.

The jib in put into working order by removing the front gantry leg, attaching the derrick tie ropes to the jib head and lifting mast and reeving the hoist rope. The jib can the be raised from the horizontal position.

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