18.4 Tunnelling, Water Environments, Bulk Mixing Plant, Material Hoists and Explosive Actuated Devices

18.4 Tunnelling, Water Environments, Bulk Mixing Plant, Material Hoists and Explosive Actuated Devices

[!NOTE] SACPCMP Blueprint Context: These are the Construction Regulations that appear least often in training material and therefore most often catch candidates out. Each is short, each is specific, and each carries at least one memorable number that examiners use.

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1. Tunnelling (Construction Regulation 15)

Tunnelling work carries a distinctive combination of hazards: ground instability, restricted egress, atmospheric hazards, water ingress, plant in confined space, and dust in an enclosed volume where respirable crystalline silica concentrations climb rapidly.

The number every candidate should be able to quote is the height restriction:

CR 15 — "No person may enter a tunnel, which has a height dimension of less than 800 millimetres."

Tunnelling work also engages the confined-space precautions of the General Safety Regulations, ventilation and atmospheric monitoring, illumination, emergency egress and rescue planning, and — where excavation forms part of the works — the excavation duties in CR 13, including the CR 13(2)(h) inspection triggers and the CR 13(2)(j) requirement that confined-space precautions be complied with by any person entering any excavation.

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2. Water Environments (Construction Regulation 26)

Regulation 26 is brief and absolute:

CR 26(1) — a contractor must ensure that where construction work is done over or in close proximity to water, provision is made for (a) preventing persons from falling into water; and (b) the rescuing of persons in danger of drowning. CR 26(2) — where a person is exposed to the risk of drowning by falling into the water, the person must be provided with and wear a lifejacket.

Three points of professional emphasis:

1. The regulation requires both prevention and rescue provision — a rescue boat does not discharge the duty to prevent the fall, and edge protection does not discharge the duty to be able to rescue.
2. The trigger is over or in close proximity to water, which captures bridge works, river crossings, marine works, dam and reservoir works, and work adjacent to settling ponds and flooded excavations.
3. CR 26(2) is a "provided with and wears" duty — issue alone is not compliance. It is one of the few places in the Construction Regulations where the regulation itself addresses use rather than provision.

Rescue provision in practice means trained personnel, a means of reaching a person in the water quickly, throwing lines and buoyant aids at intervals along the work front, communication, and — for tidal or flowing water — an assessment of current and recovery point.

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3. Bulk Mixing Plant (Construction Regulation 20)

Bulk mixing plant on a construction site — batching plants and their silos, conveyors and feed systems — combines mechanical entanglement, engulfment in stored material, dust and traffic hazards.

Two provisions to know:

• Construction Regulation 20(7) requires that the precautionary measures stipulated for confined spaces in the General Safety Regulations, 2003 are complied with when entering any silo. Silo entry is engulfment territory and the leading cause of bulk-material fatalities worldwide.
• Construction Regulation 20(8) requires the contractor to ensure that a record is kept of all repairs or maintenance to a bulk mixing plant and that the record is available on site to an inspector, the client, the client's agent or any employee.

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4. Material Hoists (Construction Regulation 19)

Material hoists move material, not people, and Regulation 19 is emphatic about that distinction. The specific figures are examinable:

The tower must be erected on firm foundations and secured to the structure or braced by steel wire guy ropes (CR 19(2)(a)); the platform must be designed so that it safely contains the loads and so that the combined mass of platform and load does not exceed the designed lifting capacity (CR 19(3)(a)); the hoisting rope of a hoist with a remote winch must be protected from external damage between the winch and the tower (CR 19(3)(b)); and every material hoist must have an efficient brake capable of holding the platform with its maximum load in any position when power is not supplied (CR 19(3)(c)). Trucks, barrows and material may not be conveyed unless secured or contained so that displacement cannot occur during movement (CR 19(4)).

[!WARNING] CR 19(7) is absolute: no contractor may require or permit any person to ride on a material hoist. There is no exception for a short lift, for a supervisor, or for an emergency. Where people must be moved vertically, the equipment required is a passenger or goods-passenger hoist certified for that purpose — and note that under DMR 18(8) no user may require or permit any person to be moved or supported by means of a lifting machine unless it is fitted with a man-cage designed and manufactured to an approved SANS standard approved by an inspector, after a risk assessment has been done.

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5. Explosive Actuated Fastening Devices (Construction Regulation 21)

Cartridge-operated nail guns are among the most commonly misused tools on South African sites, and Regulation 21 is precise.

CR 21(1) — no contractor may use, or permit any person to use, an explosive actuated fastening device unless:

• the user is provided with and uses suitable protective equipment;
• the user is trained in the operation, maintenance and use of such a device;
• the device is provided with a protective guard around the muzzle end which effectively confines any flying fragments or particles; and
• the firing mechanism is designed so that the device will not function unless it is held against the surface with a force of at least twice its weight, and the angle of inclination of the barrel to the work surface is not more than 15 degrees from a right angle.

CR 21(2) — the contractor must further ensure that only cartridges suited to the relevant device and the work are used, and that the device is cleaned and examined daily before use, and as often as may be necessary for its safe operation, by a competent person appointed in writing for that purpose.

The two numbers to carry into the examination are twice its weight and 15 degrees from a right angle.