GKD safety control systems use precision sensors and hydraulic motion cut technology to automatically restrict machine movement before a hazard zone is breached, keeping operators, workers and equipment safe on site.
Before work begins, the operator defines the safe working limits for height, slew or load directly from the in-cab display. Limits are stored and active for the duration of the shift.
Gravity angle sensors and proximity-based sensors continuously monitor boom angle, slew position and load moment in real time throughout every machine cycle.
As the machine approaches a pre-set limit, the system provides visual and audible warnings to the operator, allowing time to adjust movement before the boundary is reached.
At the pre-set limit, the system releases a hydraulic solenoid valve to cut off the relevant service, stopping boom lift, slew rotation or load movement before the hazard zone is entered.
Movement back into the safe working zone is always permitted. The restriction is directional and the machine can continue operating productively within the defined limits.
All GKD systems are compatible with 12v and 24v hydraulic coils and can be installed by any competent engineer, with simple calibration required on setup.
Excavators operating without height, slew or load controls fitted represent one of the highest risk scenarios on Australian construction, civil and utility maintenance sites. Understanding the risk, the legal obligation and the available engineering control is essential for every PCBU and principal contractor.
WorkSafe Queensland incident alerts confirm that with excavator slewing, workers are at risk from the dipper arm and the bucket as well as the counterweight throughout the full slew arc. A single uncontrolled rotation in a confined space, near a live traffic lane, or adjacent to overhead powerlines can result in fatal or life-altering injury. These are not theoretical scenarios. Regulators across Queensland, New South Wales and Victoria have published incident reports involving workers struck by excavator arms, machines contacting energised conductors, and overload incidents resulting in structural collapse. See the WorkSafe QLD incident alerts for documented case examples.
Under the Work Health and Safety Act 2011, a person conducting a business or undertaking (PCBU) must eliminate or minimise foreseeable risks so far as is reasonably practicable. The Safe Work Australia Code of Practice: Managing Risks of Plant in the Workplace places engineering controls above administrative measures and PPE in the hierarchy of controls. Codes of practice are admissible as evidence in court proceedings under the WHS Act. Where an engineering control was available, was not fitted, and a worker was injured as a result, a PCBU cannot rely on signage, spotters or verbal instructions alone to demonstrate compliance.
A GKD height limiter, slew limiter or load control system is the engineering control. It prevents the machine from physically entering the exclusion zone or exceeding the safe lift capacity. It does not rely on operator awareness, fatigue levels, communication systems, or spotter availability. It works every cycle, every shift, regardless of site conditions. Fitting a GKD system and documenting it in your Safe Work Method Statement as an engineering control is the most effective and most defensible action a PCBU can take to manage the risk of excavator-related incidents on site. See the WorkSafe QLD incident alerts for documented excavator incidents on Australian sites.
WorkSafe Queensland incident alerts confirm that with excavator slewing, workers are at risk from the dipper arm and the bucket as well as the counterweight throughout the full slew arc. A single uncontrolled rotation in a confined space, near a live traffic lane, or adjacent to overhead powerlines can result in fatal or life-altering injury. These are not theoretical scenarios. Regulators across Queensland, New South Wales and Victoria have published incident reports involving workers struck by excavator arms, machines contacting energised conductors, and overload incidents resulting in structural collapse. See the WorkSafe QLD incident alerts for documented case examples.
Under the Work Health and Safety Act 2011, a person conducting a business or undertaking (PCBU) must eliminate or minimise foreseeable risks so far as is reasonably practicable. The Safe Work Australia Code of Practice: Managing Risks of Plant in the Workplace places engineering controls above administrative measures and PPE in the hierarchy of controls. Codes of practice are admissible as evidence in court proceedings under the WHS Act. Where an engineering control was available, was not fitted, and a worker was injured as a result, a PCBU cannot rely on signage, spotters or verbal instructions alone to demonstrate compliance.
A GKD height limiter, slew limiter or load control system is the engineering control. It prevents the machine from physically entering the exclusion zone or exceeding the safe lift capacity. It does not rely on operator awareness, fatigue levels, communication systems, or spotter availability. It works every cycle, every shift, regardless of site conditions. Fitting a GKD system and documenting it in your Safe Work Method Statement as an engineering control is the most effective and most defensible action a PCBU can take. See the WorkSafe QLD incident alerts for documented excavator incidents on Australian sites.
Every machine has different height, slew and load requirements. Book a demo and we'll show you the configuration and telemetry that fits one excavator or your entire fleet.
Book A DemoFrom simple entry-level height and slew limiters through to advanced multi-function control systems, GKD has a solution to meet your site requirements and budget.
Protects workers from overhead danger by restricting boom movement above a pre-set height limit. Simple to install and suitable for excavators, backhoe loaders and telehandlers.
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Restricts excavator slew rotation to a pre-defined safe working sector, preventing machine damage and protecting workers when operating in confined spaces.
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Monitors load moment status in real time and alerts the operator at 50%, 75% and 100% of maximum safe lift capacity, preventing overload on excavators and cranes.
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Next-generation multi-function control with full colour touchscreen, true proportional motion cut, crane mode, telemetry and Network Rail certification for high performance working.
View ProductCommon questions from site managers, safety officers and plant operators about GKD height, slew and load control systems supplied by SmartTech Australia.
The GKD Series 1 range covers entry-level single-function systems designed for straightforward installation and reliable performance. The Series 1H controls height only, the Series 1S controls slew only, and the Series 1L monitors load moment. All three use a simple LED display with integrated key switch and are suitable for self-installation by a competent engineer.
The GKD Series 2 Evo is a next-generation multi-function system controlling height, slew and load on a single platform with a full colour IP65 touchscreen display. It adds true proportional motion cut for smooth stopping, crane mode for load swing reduction, up to 36 pre-defined lifting zones, multipoint virtual walls, dig mode, telemetry via the GKD Insights Platform, and Network Rail certification for high performance working. If your site requires control of more than one function or demands advanced data logging and compliance reporting, the Series 2 Evo is the appropriate choice.
For working near overhead powerlines where boom height must be restricted, the GKD Series 1H Height Limiter is the entry-level solution. It uses a gravity referenced angle sensor on the boom and cuts hydraulic motion on the lift circuit when the pre-set height is exceeded. Because the sensor references gravity rather than the machine body, height limits remain accurate even when the machine is working on an incline.
For working in confined spaces where the machine must be restricted from slewing into an exclusion zone, the GKD Series 1S Slew Limiter is the correct system. The operator sets left and right slew limits from the cab and the system cuts the relevant hydraulic slew service when the boundary is reached. Slew movement back into the safe zone remains permitted at all times.
If your site requires both height and slew restriction simultaneously, the GKD Series 2 Evo provides combined control of height, slew and load on a single platform. Contact SmartTech Australia to confirm the right system for your specific site conditions.
GKD height limiters, slew limiters and load monitors are not universally mandated by a single national standard in Australia, however the Work Health and Safety Act 2011 requires PCBUs to eliminate or minimise foreseeable risks so far as is reasonably practicable. Where an excavator is operating near overhead powerlines, in a confined space with workers present, or performing lifts close to rated capacity, engineering controls such as motion limiters are the appropriate risk control measure under the hierarchy of controls.
The Safe Work Australia Code of Practice: Managing Risks of Plant in the Workplace places engineering controls above administrative measures and PPE. Codes of practice are admissible as evidence in court proceedings under the WHS Act. Courts may rely on them to determine what was reasonably practicable in the circumstances. Where a worker is injured in a situation where an engineering control was available and not fitted, a PCBU cannot rely on signage, spotters or verbal instructions alone to demonstrate compliance. Regulator investigations routinely cite the absence of engineering controls as an aggravating factor in determining penalties.
WorkSafe Queensland incident alerts confirm that workers are at risk from the dipper arm, bucket and counterweight throughout the full slew arc of an excavator, and identify engineering controls as the appropriate response. See the WorkSafe QLD incident alerts for documented excavator incidents on Australian sites. Many Tier 1 civil contractors and principal contractors across Queensland, New South Wales, Victoria and Western Australia now specify height and slew restriction as a mandatory site requirement for excavators in high-risk zones. Contact SmartTech Australia for guidance specific to your state and site conditions.
All GKD Series 1 systems are designed for self-installation by any competent engineer and do not require specialist tools or programming equipment. The Series 1H requires mounting the gravity angle sensor on the primary boom, running a cable to the in-cab display, and connecting the relay output to the relevant hydraulic solenoid valve. The Series 1S requires fitting proximity switches to the slew ring and connecting to the two-bank motion cut valve. Both systems are compatible with 12v and 24v hydraulic coils.
A straightforward installation on a standard excavator typically takes between two and four hours. Calibration is simple: for the 1H, the operator sets the desired height limit from the cab; for the 1S, a rotational calibration learns the tooth count on the machine and the operator then sets left and right limits. SmartTech Australia can supply systems with full installation documentation and provide technical support throughout the process.
GKD Series 1 systems are competitively priced as entry-level safety control solutions. The total installed cost will depend on the specific system selected, the machine type, hydraulic valve requirements, and whether installation is self-performed or carried out by a SmartTech Australia technician. As a guide, the Series 1 range represents a significantly lower investment than the advanced Series 2 Evo, which includes a full colour touchscreen, proportional control, telemetry and multi-function capability.
When evaluating cost, it is worth considering the full picture: a single incident involving an excavator contacting an overhead powerline or swinging into a confined space can result in serious injury, project delays, regulatory investigation and significant financial liability. A GKD system is a one-time capital investment that actively prevents these outcomes. Contact SmartTech Australia for a current price and supply quote specific to your machine and requirements.
SmartTech Australia is the authorised distributor of GKD Technologies safety control systems across Australia, with offices and technical support available in Brisbane, Townsville, Sydney, Melbourne and Perth. We supply and support the full GKD range including the Series 1H Height Limiter, Series 1S Slew Limiter, Series 1L Load Monitor and the advanced Series 2 Evo.
All systems are supplied with full installation documentation and technical support. SmartTech Australia can arrange delivery nationally and provide on-site installation and commissioning where required. To discuss your requirements, request a quote, or confirm the right system for your machine, contact SmartTech Australia directly via the enquiry form on this page or call 1800 655 860.
