Quick questions on Crane engineering case studies: HSC Engineering Studies Lifting Devices

Capacity is given as a load chart: maximum load at minimum and maximum radius. A typical city tower crane lifts 1.5 tonnes at 60 m radius and 12 tonnes at 13 m radius. The capacity falls with radius because the moment about the slewing ring is the constraint.

A mobile crane has a wheeled or tracked carrier with a telescoping or lattice boom. Categories:

Port Botany and the Port of Melbourne use ship-to-shore cranes that gantry along the wharf on rails. Key engineering features:

:::worked Worked example A 65-tonne ship-to-shore crane lifts a TEU container at 90 m/min hoist speed. Hoist power required (assuming 100 percent efficiency):

Tower cranes are visible on most Sydney CBD and Parramatta high-rise sites. Operators are licensed by SafeWork NSW (CN class). Operators do not stand on the load; they sit in a cab 80 to 150 m above the street and communicate by radio to dogmen on the deck.

Tower cranes weather-vane in high winds (the jib is left free to rotate so wind does not impose a moment). Ship-to-shore cranes have tie-downs to the wharf rails to prevent overturning in cyclonic winds.

All-terrain cranes road-travel; crawlers do not. Truck-mounted cranes are different again. Capacities span two orders of magnitude.

NESA expects named Australian sites. Use Crown Sydney (tower crane), Port Botany (ship-to-shore), Sydney Metro (mobile crane in tunnelling). :::