OHS Code Explanation Guide

Published Date: July 01, 2009
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Part 36 Mining

Section 603 Riding conveyor belts

Subsection 603(1)

Working areas in underground coal mines are sometimes a great distance from the surface and walking conditions can be poor. In some underground mines, workers ride on specially designed conveyor belt systems to get to and from their respective work areas. In such cases, the entire system must be specifically designed and certified by a professional engineer.

This system includes provisions for getting on and off the moving conveyor and worker training to use the system. The system must also include various fail-safe protective measures to prevent incidents, e.g. if workers cannot get off the belt as anticipated, a method of stopping the belt before the worker is endangered must be incorporated.

Subsection 603(2)

This subsection provides basic design criteria for the professional engineer to use when designing the system. The success and safety of the system relies on proper design, protective features, safe operating procedures and training.

Subsection 603(2)(a)

The gradient of conveyors used to transport workers is limited to a maximum of 15 degrees, while the maximum gradient for conveyors used to carry rock or coal is normally about 17 degrees.

Subsection 603(2)(b)

The head room clearance of 0.9 metres allows a worker to lie comfortably on the belt with head lifted to see disembarking signs ahead. Figure 36.19 illustrates this point. The clearance must also provide enough room for the worker to get on and off the conveyor.

The roof of a mine is generally rock bolted and may be equipped with other attachments to carry a variety of items. As a result, the required clearance must be measured between the belt and any protruding part of rock bolts or other attachments.

Figure 36.19 Head room clearance

Subsection 603(2)(c)

For the safety of workers who get on and get off a moving conveyor, the OHS Code limits the maximum belt speed to 2.65 metres per second (approximately 6 miles/hour). A faster speed could place workers at a greater risk of injury.

Subsection 603(2)(d)

A minimum belt width of 915 millimetres (36 inches) is specified to provide adequate space for a worker. This width is critical to a worker attempting to get on the conveyor. This width provides a reasonable safety factor in case of a trip or misstep when getting onto the moving belt.

Subsection 603(2)(e)

Non-slip surfaces ensure safe mounting onto moving belts. Workers need a solid foothold from which to make the angular step necessary to get on the belt. The length of the non-slip surface must be sufficient to give workers enough time for mounting.

Subsection 603(2)(f)

Properly designed dismounting platforms are a critical safety component of any belt-riding system.

Since the conveyor belt will be moving at a consistent speed of up to 2.65 metres per second (6 miles per hour), the dismounting platform must be large enough, at least 0.6 metres wide, and long enough, at least 15 metres in length, to accommodate the moving worker. To minimize the risk of injury, the platform surface must be treated or be constructed of materials that provide a non-slip surface. A properly fitted handrail provides an additional means of protecting workers.

Recognizing the limitations of space in a typical underground mine, the OHS Code requires that adequate head room clearance be provided at a dismounting platform so that a worker can dismount in an upright position. With adequate overhead clearance, a worker need not be concerned with suspended or protruding objects at roof level. An upright body position provides a worker with a better chance of maintaining balance during dismounting, thus minimizing the potential of a trip or fall.

Subsection 603(2)(g)

Underground lighting is often limited, so proper illumination is critical at mounting and dismounting platforms. Without proper illumination, a worker will have difficulty seeing or judging distances at a mounting location. Further, at an inadequately illuminated dismounting platform, the loss of a miner’s lamp could be disastrous to any worker who was already riding the conveyor belt. As a result, the OHS Code requires that all conveyor mounting and dismounting platforms be electrically illuminated.

Subsection 603(2)(h)

Again, due to the limited availability of fixed lighting in an underground mine, it is important that workers be directed to mounting and dismounting platforms by the use of reflective signage. It is important for workers riding the conveyor belt that reflective signage is installed to indicate that they are approaching a dismounting platform. According to this subsection, those reflective signs must be installed at distances of 30 metres, 20 metres and 10 metres from any dismounting platform. Such advanced notice provides adequate time for a worker to get ready for a safe dismount.

Subsection 603(2)(i)

Since it is possible that a worker will miss the dismount platform or have difficulty in dismounting as planned, a belt-stopping safety device is required by the OHS Code. This safety device must be installed in a location that will stop the belt prior to a worker being transported into a more dangerous situation such as into a chute or hopper.

Subsection 603(2)(j)

Any man-riding conveyor belt must be equipped with brakes that automatically apply to stop and hold the conveyor when a belt-stopping safety device is activated.

Subsection 603(2)(k)

A principal safety hazard with man-riding conveyors is the danger of stepping onto a torn or split belt. This could allow the human rider to contact the rotating rollers underneath, usually resulting in tragic consequences. This is typically addressed in the industry by use of “torn belt” sensors which are interlocked with the drive. Whenever a split in the belting is detected, the belt stops, allowing it to be repaired and preventing any subsequent accident.

Subsections 603(3) and 603(4)

Workers riding conveyor belts must be adequately trained and have access to detailed safe operating procedures for riding conveyor belts. Section 8 of the OHS Regulation requires the procedures to be in writing and available to workers.

Procedures and precautions must be posted in a conspicuous place for easy reference and should include such things as
(a) pre-use inspection of the belt,
(b) prohibited materials that cannot be transported with a worker,
(c) periodic testing of safety dismount devices, and
(d) separation distance between riders on a belt.