Rock Breaking & Ripping SWMS

Rock breaking and ripping is mechanical breaking of rock and mass concrete by hydraulic hammer and ripping by dozer or excavator tyne. It is high risk construction work under the WHS Regulation because it is carried out in excavations and cut faces deeper than 1.5 m and is dominated by the movement of heavy powered mobile plant — excavators with hydraulic hammers, dozers and rippers (s291), so a SWMS is mandatory (s299). This is mechanical breaking: no explosives are used; AS 2187.2 is referenced only for its structural ground-vibration limits as the recognised benchmark. The dominant safety hazard is flyrock — rock fragments ejected at high velocity by the hammer, and ricochet off the face or oversize material — which can strike workers and the public well beyond the immediate work area. The dominant health hazard is respirable crystalline silica from breaking siliceous rock, with the dust plume drifting to adjacent workers and occupancies. A further dominant hazard to third parties is ground vibration transmitted to adjacent structures, buried services and sensitive equipment, causing cracking or damage. Around these sit hammer/plant strike on workers, plant rollover on benches and soft ground, service strikes, and excavation-face instability. The SWMS controls flyrock exclusion, silica suppression, vibration monitoring, plant separation and face stability. It supports the earthworks design and does not replace the geotechnical assessment. It is supplied in eight jurisdiction editions, each citing its own Act, Regulation and regulator.

Hazards identified

8 hazards covered, sorted by priority.

Control measures

Hierarchy-of-controls order: elimination → substitution → isolation → engineering → administrative → PPE.

1. 1Elimination — Use non-percussive methods (chemical/expansive burster, sawing) near structures and services so flyrock and vibration are avoided where practicable
2. 2Substitution — Substitute ripping for hammering where the rock allows to reduce flyrock and vibration, and remote/GPS machine control for close-in work
3. 3Engineering — Flyrock exclusion zone sized to the hammer energy and geometry, with protective screening/blast mats where structures or public are nearby
4. 4Engineering — Water suppression at the breaking point to control silica, and vibration monitoring against the AS 2187.2 structural limits with trigger levels
5. 5Engineering — Plant-pedestrian exclusion zones and stable, benched faces designed by a competent person
6. 6Administrative — Services location before breaking, a dilapidation survey of adjacent structures, and vibration limits with a stop-work trigger
7. 7Administrative — Silica exposure monitoring and health monitoring for exposed workers, and RIIMPO plant competency
8. 8Administrative — Spotter controls for the hammer and a face-inspection regime after rain
9. 9PPE — Eye/face protection against flyrock, fit-tested P2/P3 respiratory protection and Class 5 hearing protection
10. 10PPE — Type 1 hard hat and Type R day/night high-visibility for all ground personnel

Applicable Codes of Practice

High-Risk Construction Work triggered

Worked example

At 7:00 am an earthworks crew from Bedrock Civil begins breaking a siliceous rock shelf with an excavator-mounted hydraulic hammer next to an occupied building. Although no explosives are used, the supervisor treats flyrock and vibration as the defining risks: a flyrock exclusion zone sized to the hammer energy is set, screening is placed toward the building, and no one is allowed inside the zone while the hammer works. A dilapidation survey was done beforehand, and vibration is monitored against the AS 2187.2 structural limits with a stop-work trigger — when a reading approaches the limit, breaking pauses and the method is adjusted. Water suppression runs at the breaking point because the rock is silica-bearing, and the exposed crew are in fit-tested respirators and on health monitoring. Services were located, so the operator knows where not to break through. The face is benched to the geotechnical design and re-checked after rain. A spotter keeps the ground crew clear of the hammer and the plant. The shelf is broken to level with the building undamaged and the exclusion maintained throughout.

Related legislation

• WHS Act 2011 (model)
• WHS Regulation 2025
• Working with Silica and Silica Containing Products Code of Practice
• Excavation Work Code of Practice

Frequently asked questions