10.1 Selecting the crane
Matters to be considered in the selection of mobile cranes are outlined in AS 2550.5 : Cranes, hoists and winches - Safe use - Mobile cranes (non-Queensland Government link).
Select the type and number of mobile cranes to suit the particular needs of a workplace. If crane characteristics do not match job requirements, then unsafe conditions are created before any work is done.
When selecting a mobile crane for a job, the size and characteristics of the crane should be assessed against the following criteria:
- the weights, dimensions and lift radii of the heaviest and largest loads to be lifted;
- the maximum lift height and radius, and the weight of the loads to be handled at these points;
- the number and frequency of lifts to be made;
- how long the crane will be required at the workplace;
- the type of lifting to be done (e.g. precise placement of loads);
- the type of carrier required—this depends on ground conditions and machine capacity in its various operating quadrants;
- whether loads are to be walked or carried;
- whether loads are to be suspended for lengthy periods of time; and
- the workplace conditions, including the ground on which the crane is to be set up, access roads and ramps it must travel on, space for erection, and any obstacles that may impede access or operation.
There are basically four types of mobile cranes operating in Queensland—hydraulic slewing cranes (see figure 1), lattice boom cranes (including crawler cranes), hydraulic pick-and-carry cranes and vehicle-loading cranes. Each of the basic mobile crane types has advantages and disadvantages, and the best crane type should be selected for the job to be undertaken.
Figure 1 – Hydraulic slewing mobile crane
Last updated June 9, 2006