CSCS Mini Digger key terms

Something in the workplace that has the potential to cause harm, such as an open trench, an overhead power line or a swinging machine counterweight. Hazards are identified first, then the risk they create is assessed and controlled.

A careful look at the work to identify hazards, decide who could be hurt and how, and record the sensible steps needed to remove or reduce the risk before work starts.

Equipment worn or held by the worker to protect against a specific risk, such as a hard hat, high-visibility vest, safety boots, gloves or hearing protection. It is a last line of defence, not a substitute for safe working.

A marked area around a working excavator that keeps pedestrians and other workers out of the danger area. It must be wide enough to cover the full slewing circle, the reach of the arm and any risk of ground collapse.

A trained person who guides the machine operator using agreed hand signals or radio, especially when visibility is limited, when reversing or when working close to people, structures or buried services.

Areas around an excavator that the operator cannot see from the cab, even with mirrors fitted. Blind spots are largest at the rear, low down beside the tracks and behind the counterweight as the machine slews.

A short briefing held on site before work starts, covering the specific hazards of the day's task, the method to be used and any changes to the risk assessment. It gives workers the chance to raise concerns.

An unplanned event that did not cause injury or damage but could have done. Near misses must be reported so the cause can be put right before it leads to a real accident.

The basic facilities that must be provided on site: toilets, washing facilities with soap and warm water, drinking water, somewhere to rest and eat, and shelter from bad weather, plus a way to dry wet clothing.

Underground pipes and cables such as gas, water, electricity, telecoms and drainage. Striking them can cause explosion, flooding, electrocution or loss of supply, so their position must be confirmed before digging begins.

The main UK law covering workplace health and safety. It places general duties on employers to protect workers and others affected by their work, and on employees to take reasonable care of themselves and each other.

The Provision and Use of Work Equipment Regulations. They require work equipment such as excavators to be suitable for the job, maintained in a safe condition, inspected where necessary and used only by trained, competent people.

The Lifting Operations and Lifting Equipment Regulations. They cover lifting equipment and lifting operations, requiring proper planning, supervision where needed, and thorough examination of equipment used for lifting loads.

The Construction (Design and Management) Regulations. They set out how construction projects must be managed, including the duties of clients, designers, principal contractors and contractors, and the need for a construction phase plan.

The Reporting of Injuries, Diseases and Dangerous Occurrences Regulations. They require certain serious incidents to be reported to the enforcing authority, including deaths, specified injuries, long absences and dangerous occurrences such as striking a buried cable.

The Control of Substances Hazardous to Health Regulations. They require employers to assess, control and record exposure to hazardous substances such as diesel fumes, hydraulic oil, dust and battery acid.

Guidance approved by the regulator that gives practical advice on how to comply with a specific set of regulations. Following it is normally enough to show the law has been met, unless another method is equally effective.

Someone with the training, knowledge, experience and other qualities needed to carry out a task safely, such as operating an excavator or inspecting equipment. Competence must be checked and evidenced, never assumed.

A formal written authorisation issued before excavation in an area where buried services or other hazards may exist. It records the survey information, the safe digging method and the signatures approving the work.

A competence card issued through the Construction Skills Certification Scheme. It shows the holder has passed the relevant health, safety and environment test and, for a skilled card, holds a recognised qualification for the trade.

A check the operator carries out at the start of each shift before the machine is used. It covers fluid levels, leaks, tracks, pins, guards, cab glass, seat belt, quick hitch, horn and alarms, with faults reported.

A mechanism on the end of the dipper arm that allows buckets and other attachments to be changed quickly. The attachment must be fully engaged and the locking pin or safety device checked before the machine is used.

A lever or switch in the cab that isolates the hydraulic controls. It must be moved to the locked position before the operator gets in or out, so that knocking a control cannot make the machine move unexpectedly.

Roll-over protective structure: a strong frame around the operator's position that protects the operator if the machine tips over. It must not be cut, drilled or modified, and is only effective if the seat belt is worn.

Falling-object protective structure: a reinforced roof or canopy over the cab that protects the operator from material falling from above, such as rocks, bricks or spoil dropped from a higher level.

The restraint fitted to the operator's seat. It must be worn whenever the machine is working or travelling, and works with the roll-over protection to keep the operator inside the protected area if the machine tips.

The heavy mass at the rear of the machine that balances the load at the front and keeps the excavator stable. It swings out behind the tracks and creates a crushing hazard in the tail-swing area.

The arc swept by the rear of the upper structure, including the counterweight, as the machine slews. On many mini diggers it reaches beyond the tracks and can trap or crush anyone standing behind the machine.

The maximum load a machine or attachment is designed to lift safely in a particular configuration, as given in the manufacturer's capacity chart. Lifting at long reach or over the side reduces it sharply.

The ability of the machine to stay upright. It depends on the centre of gravity, the load being carried, arm position, ground condition and slope, and it falls quickly when working over the side or on soft ground.

A push blade fitted to the undercarriage of many mini diggers. It can level material and, when lowered, adds support and balance to the machine while digging, and it should be lowered whenever the machine is parked.

Continuous rubber belts that carry the excavator. They spread the machine's weight over a wide area, grip well and are gentle on finished surfaces, but can be cut or run off the sprocket on sharp debris.

How tightly the track belt is adjusted. Correct tension keeps the track seated on the sprocket and idler, and it is set to the manufacturer's specification and checked as part of routine inspection and maintenance.

A hand-held locator, usually used with a signal generator, that detects buried metal pipes and cables before digging. It adds to, but does not replace, service plans and careful safe digging practice.

The load the ground can carry without settling or collapsing. Soft ground, backfilled trenches, recent rain, voids or excavations nearby reduce it, so the machine may need a different position or track mats.

Recording any fault found on the machine in its log or defect book and telling the supervisor, so the fault is repaired before use. A machine with a safety-critical defect must be taken out of service.

Filling the machine with diesel. The engine must be stopped, no smoking or naked flames allowed, the area ventilated, a funnel or nozzle used to avoid spills, and the cap replaced with any spill cleaned up.

A clearly marked control that cuts the engine or hydraulics immediately in an emergency. The operator must know where it is and how it works, and it should be checked during the pre-use inspection.

Moving the machine over sloping ground. Where possible the tracks should point up or down the slope, the bucket should be kept low, and the machine should not be slewed or turned across a bank where it could tip.

Excavated material stacked beside a trench. It must be placed well back from the edge, because its weight adds surcharge to the ground and can cause the trench sides to collapse onto people working below.