Quick answer: hire a knuckle (articulating) boom when the work point is somewhere a scissor lift cannot stand underneath: behind an awning, over a garden bed, past a parapet or among plant on the ground. The boom can rise, bend over the obstacle and reach down to the work. Whether a particular job is in reach depends on that model’s working envelope, so send the measurements first.
We hire two 34ft class articulating booms: the Genie Z-34/22 and the LGMG AR11J. Their reach figures are in the table below, read from the machine records.
| Machine | Working height | Horizontal outreach | Width | Platform capacity | Power |
|---|---|---|---|---|---|
| Zoomlion ZA10RJE Electric Articulating Boom Lift | 11.6 m | 6.9 m | 1.19 m | 230 kg | Electric |
| Genie Z-34/22 Articulating Boom Lift | 12.6 m | 6.8 m | 1.85 m | 227 kg | Diesel |
| LGMG AR11J Articulating Boom Lift | 12.8 m | 6.8 m | 1.85 m | 270 kg | Diesel |
| Genie Z-40/23N RJ Articulating Boom Lift | 14.3 m | 6.9 m | 1.5 m | 227 kg | Electric |
| Skyjack SJ45 AJ+ Articulating Boom Lift | 15.5 m | 6.9 m | 2.29 m | 300 kg | Diesel |
| Skyjack SJ46 AJ Articulating Boom Lift | 15.9 m | 7.5 m | 2.29 m | 227 kg | Diesel |
| Skyjack SJ51 AJ Articulating Boom Lift | 17.6 m | 9 m | 2.29 m | 227 kg | Diesel |
| Sinoboom AB18J Articulating Boom Lift | 20.3 m | 12.2 m | 2.28 m | 250 kg | Diesel |
Figures are read from the manufacturer specification held on each machine record. Fleet data last updated 23 October 2026.
Two geometry examples
Over an awning. A shop sign sits 1.5 m above a 2.5 m deep awning. The machine stands at the kerb edge of the footpath. The boom has to rise above the awning’s top edge, then reach 2.5 m back plus the distance from the kerb to the shopfront. On the Genie Z-34/22 the up and over clearance is 4.57 m; if the awning top is higher than that, the boom cannot bend over it from ground level, whatever the headline working height says.
Past a garden bed. A render repair sits 6 m up a wall behind a 3 m garden bed. The machine stands on the driveway beside the bed. The work point is 6 m high and about 3.5 m out from the turntable: plot that point on the model’s reach chart and check it sits inside the envelope with margin. See how to read a boom lift reach chart.
Jobs a knuckle boom suits
- Facade and render work over garden beds or footpaths, from hardstand
- Signage above or behind awnings
- Awning and canopy work on top of the obstruction itself, where a scissor cannot get above it; a telescopic boom or a scissor on the far side can also suit some canopies, depending on access
- Gutters and rooflines behind landscaping, fences or parked cars
- Lighting and services around plant such as car park lights and loading dock services
- Over-parapet access just past a roof edge, from ground level
- Tree work only where the machine rating, ground and any arborist and powerline requirements are confirmed
When it is the wrong machine
Straight-up work with clear, firm ground below usually costs less with a scissor lift, which also gives a bigger deck. Long horizontal reach with nothing to bend over can suit a telescopic boom, which we do not currently hire; we will say so rather than send the wrong machine. Compare in scissor lift vs boom lift and articulating vs telescopic boom lifts.
The licence note
In NSW a boom-type platform with a boom length of 11 m or more needs an operator with a WP class high risk work licence. Boom length is not working height, so check the figure for the exact model and your site’s requirements in the EWP licence guide. We hire the machine only; the operator is supplied by you.
Need a boom for this job? Get a hire quote with the work height, the distance from where the machine can stand and the obstacle height, or use help me choose. Call 0472 721 234.