Mobile crane hire: how to choose the tonnage and boom length for your lift in South Africa

You need the mobile crane whose load chart shows enough capacity for your load at your working radius and boom length. The headline tonnage applies only at the shortest radius: one manufacturer's chart for a 50 t crane gives 50 t at 3 m, and only over the rear.^[9]

In South Africa, regulation 18(1)(b) of the Driven Machinery Regulations, 2015 requires the load chart: where the safe working load varies with the conditions of use, "a table showing the safe working load with regard to every variable condition" must be posted where the operator can see it.^[1]

The hook block counts as load: the remarks to that manufacturer's chart say it "is part of the load" and must be deducted from the chart figures. The slings and shackles below it are lifting tackle, gear "used to attach a load to a lifting machine".^[9][1]

Working radius is measured from the crane's slewing centre to the hook, and it matters at both the pick-up and the set-down point.^[9]

Height sets the boom length, and a longer boom costs capacity: at 6 m radius the same 50 t crane lifts 22.7 t on a 22 m boom but 7.5 t on its full 38 m boom.^[9]

Wind limits bulky loads: the same chart assumes a wind speed of at least 9 m/s and 1 m² of sail area per tonne, and the permitted wind speed has to be reduced for loads with a larger sail area.^[9]

In South Africa, a mobile crane needs a thorough examination and performance test "by a lifting machinery inspector of a lifting machinery entity" before first use, after being re-erected and "at intervals not exceeding 12 months" (Driven Machinery Regulations, regulation 18(5)(a)). Regulation 18(5)(c) excludes mobile cranes from the performance test "after each re-deployment within the 12-month period".^[1]

The inspector must be registered with the Engineering Council of South Africa and work for an entity the chief inspector has approved and registered, which "shall on request produce a certificate of registration" (regulations 1 and 19(4)).^[1]

Ropes, hooks, sheaves, brakes and safety devices need a thorough examination by a competent person at least every six months (regulation 18(6)), and slings and other lifting tackle at least every three months by a competent person appointed in writing (regulation 18(10)(e)).^[1]

A power-driven lifting machine with a lifting capacity greater than 5,000 kg may not be used without "a load indicator" showing the mass being lifted "and/or" "a load-limiting device" that stops the drive above the safe working load "at that particular radius" (regulation 18(9)).^[1]

For a hired machine, regulation 18(7)(b) makes the user keep on its own premises "the latest applicable performance test and service records not older than 12 months".^[1]

On a construction site, the lift falls under the risk assessment that a competent person, appointed in writing, must do before work starts (Construction Regulation 9(1)). Neither the Driven Machinery Regulations nor the Construction Regulations use the words "lift plan" for a mobile crane.^[1][3]

SANS 12480-1:2006, reaffirmed in 2017, is the South African standard for the safe use of cranes: it covers planning, selection and operation, and the selection of drivers, slingers and signallers.^[8]

Near overhead power lines, no person may encroach "in person or with objects" on the minimum safety clearances "except by permission of the supplier, employer or user operating the power line" (Electrical Machinery Regulations, 2011, regulation 19(5)).^[5]

The client carries duties too: the Occupational Health and Safety Act makes the "user" of machinery whoever uses it for their own benefit "or who has the right of control over the use" of it, and excludes the lessor (section 1).^[4]

Section 37(1) presumes that an employer or user did what its employee did, unless it proves the conditions listed there. Section 37(2) says this "shall mutatis mutandis apply in the case of a mandatary of any employer or user, except if the parties have agreed in writing to the arrangements and procedures between them to ensure compliance by the mandatary with the provisions of this Act". A mandatary includes "a contractor or a subcontractor for work" (section 1), so write those arrangements into the hire agreement: who supervises the lift, who rigs the load and who checks the ground.^[4]

1. The load: what it is, its mass in tonnes from the nameplate, drawing or delivery note, its dimensions and its lifting points.^[9][1]
2. The working radius at the pick-up and the set-down point, measured from where the crane can stand, and the height the load must reach or clear.^[9]
3. The ground where the crane will stand (paving, compacted fill or a slab), any trenches or buried services nearby, and the space available to set up.^[10]
4. Overhead power lines near the lift or the access route, and who operates them.^[5]
5. The date, the number of lifts and the route into site, with any width or height limits.^[6]
6. The load chart for the proposed boom and radius, and the crane's latest performance test certificate from a lifting machinery entity approved and registered by the chief inspector, not older than 12 months.^[1]
7. The operator's licence, showing the code for this crane class (C33 for a hydraulic mobile crane up to 50 t, for example) and an expiry date still ahead.^[2]
8. On a construction site: the operator's medical certificate of fitness and written authorisation, and who does the risk assessment.^[3]
9. Who supplies the rigger, signaller and slings, and the slings' examination record, no older than three months.^[1][8]