Symmetrical Group

Policies and Procedures

OHS&E\SAFETY PROCEDURES

SG-PR-33-02 Safe Working at Heights

1. introduction

Because working at heights presents a greater risk of injury due to falls, only competent persons shall work at height.  A responsible officer shall be nominated to control the work.  Anyone with a fear of heights shall notify his or her manager and shall not partake in working at heights.

The risk of personnel falling from, through or into any place or structure shall be eliminated and every precaution shall be taken to prevent the fall of equipment.

This guide manual shall be read in conjunction with:

• WORKSAFE WA Code of Practice - Prevention of Falls at Workplaces,
• Occupational Safety and Health Regulations 1996 – Part 3, Division 5 - Prevention of Falls at Workplaces.

References to heights (e.g. above 2 metres, above 3 metres etc.) are applicable as measured from normal ground level, OR from the level where substantial protection would prevent a secondary fall.

For advice regarding safety at height procedures other than that detailed in this document, consult the Worksafe WA Code of Practice for the Prevention of Falls at Workplaces or the OS&H Dept.

2. General safety rules

Working at heights of less than 2 metres can also present a fall hazard.

When working at heights, the following general safety rules apply:

• Only competent persons shall work at heights.( See Definitions)
• Safety harness shall be full-body type, such as parachute harness.
• Any person working at height (that is, at 2 metres and above), where a guard rail is not fitted, and there is a risk of falling, shall:

-        wear an approved full body safety harness,

-        attach the free end of the harness to a safe anchorage point.

• The anchor point shall be sited above the attachment point of the harness.
• Any person who needs to go on the roof of a building shall also obtain:

-        a clearance certificate, and,

-        a special permit.

• A person working at a height of more than 3 metres shall be supervised.
• A person working at a height of 2 metres or more, outside of safety rails, shall be attached from his/her harness to a safety line or fall arrest device at all times.
• When it is a requirement to work at heights of 3 metres or more without permanent or temporary barriers a Job Safety Analysis must be undertaken and a Special Permit obtained from the Responsible Officer (see DEFINITIONS -section 6.1)
• Fall Protection Systems shall be protected from damage due to processes such as welding, cutting, grinding or hot/cold process pipework.

3. precautions

3.1        general precautions

The following precautions shall be observed when working at heights:

• Guard rails, which comply with AS1657 Fixed Platforms, Walkways, Stairways and Ladders - Design Construction and Installation or AS 1576.1 Scaffolding - general requirements as appropriate, shall be installed where:

-        a person could fall 2 metres or more,

-        a trip hazard exists at roof level,

-        a person could fall onto a sharp protruding object or into the path of a vehicle.

• Wherever possible, all personnel working at heights shall be positioned behind permanent or temporary barriers.
• If necessary, work procedures shall be reassessed to permit personnel to work behind barriers at all times.
• Other acceptable alternatives to physical protection against falling include:

-        full body safety harness and lanyard, or inertia reel as appropriate,

-        crane, or fork-lift personnel cages,

-        light duty suspended stage (e.g. swing stage, cradle)

-        elevating work platforms.

• All harnesses shall be fitted and used in accordance with the manufacturers’ instructions.
• Safety equipment, such as safety harness and inertia reel shall be inspected before use.  Only equipment clearly free from defects shall be used.

3.2 Anchorage points for fall protection systems

The following shall be observed when selecting anchorage points:

• Anchor points shall be inspected by a competent person to ensure good order and condition before and after use. (as a minimum, 6 monthly inspections should be conducted)
• Any repairs are to be inspected by a competent person.
• Points shall be strong enough, and as close to vertical as possible above the place of work, to reduce the liability of swing (see also Pendulum Effect, Section 5.3).
• Points shall be capable of taking the force of a fall (15 kN).
• Structural members with sharp edges shall not be used unless protected by a sleeve or sling.
• The amount of slack in the safety line between the anchor point and the person shall be kept to a minimum to reduce the free-fall to less than 2 metres.
• A mobile anchorage shall be used where there is a risk of the pendulum effect or swing back (see Figure 1 and Figure 2, taken from the Code of Practice: Prevention of Falls at the Workplace).
• The anchorage point for an inertia reel shall be as high as the equipment permits.
• Safety lines shall be thicker than 12 mm diameter.

3.3 roofs

The following precautions shall be observed when working on roofs:

• Authorisation shall be obtained before accessing any roof.
• Standard procedures, such as roof ladders and scaffold planks, shall be used for all roof work.
• Tank top surfaces shall be tested for strength before stepping onto them.

3.4 Holes and openings

The following precautions shall be observed when working near holes and openings:

• Any hole or opening (other than a lift shaft or stairwell) with dimensions of more than 200 mm x 200 mm, but less than 2 m x 2 m, shall be covered with material strong enough to prevent persons or things entering or falling through the hole.  The cover shall be securely fixed to the floor and clearly marked with legible lettering not less than 75 mm in height with the words “Danger - Hole Beneath”.
• Where work is to be done in such holes or openings and covers are to be removed, approved safety signs with the words “Danger - Hole” in lettering not less than 75 mm, shall be placed where access is possible.  The area shall be further secured completely with bunting or danger tape before the covers are removed.  Only persons involved in the work may enter the area.

4. training

Training in the prevention of falls shall include:

• Safe work practices to prevent a fall, including electrical safety and working on brittle roofs as appropriate.
• Correct use, fitting, care, maintenance and storage of fall arrest systems and devices, tools, equipment and personal protective equipment to be used.
• Procedures in the event of an emergency such as rescue, accident or injury, and the reporting of hazards and incidents and accidents.

5. Certification or accreditation

There may be occasions when a person is required to obtain some formal accreditation or certificate, for example, scaffolder’s, rigger’s or dogger’s ticket.

Managers shall ensure that any necessary accreditation or certification is valid and current.

Managers shall also ensure that personnel who are being trained to obtain accreditation or certification are supervised during that training.

6. definitions

6.1. responsible officer

A responsible officer is an employee, competent in the work area, nominated to supervise and control work at heights.

6.2. competent person

A competent person is one who has, through a combination of training, education and experience, acquired knowledge and skills enabling that person to perform work at heights correctly.

6.3. pendulum effect

This is a potential hazard with the use of individual fall arrest systems.

The Pendulum Effect requires consideration, prior to the setting of anchorage points.

To eliminate the pendulum effect, place the anchorage point perpendicular to the position of the line at the perimeter edge.  A mobile anchorage helps here.  The use of second anchorages and belay devices is another way of minimising this effect.

6.3.1 Swing Down

Can occur if an inertia reel or work positioning device is extended diagonally so that the line makes an extreme angle with the perimeter edge of the structure.  In this situation, the forces generated in an arrested fall over the edge will cause the line to rotate back along the perimeter edge until it reaches a position directly in line with the anchorage point of the inertia reel and at right angles with the perimeter edge.

As the line moves back in this way its unsupported section lengthens, thus dropping the attached worker further than the original (arrested) fall distance.  If the length of the unsupported line equals the height of the building then the worker will hit the ground.

Figure 1  Swing Down

6.3.2 Swing Back

In an arrested outward fall, particularly from a perpendicular edge, a person will swing back into the building structure and collide with any obstructions in the path of the swing.  If this situation can arise, the use of an individual fall arrest system should be re-assessed.

Figure 2  Swing Back

6.3.3 Drop Lines

Drop lines should be of a minimum knotted strength of 22kN (2.2 tonne) and be of a nominal diameter of 11 to 12mm.  They should have a fixed eye at one end for attachment to an anchor point or static line, and be knotted at the other end to stop a rope grab device from becoming detached.  A drop line should be of kernmantle or 3 strand construction.

Secondary Safety Line

Vertical Lifeline (droplines) shall be used in connection with work from a boatswain chair or ladder.  Only one person should be attached to any one lifeline.

6.3.4 Ladder And Tower Safety Systems

Temporary systems such as ladder and tower safety systems should comply with the requirements of drop lines.  However, the locking devices should not be capable of damaging the line in case of fall.

Date published: 25/07/2013

* -25/07/2013 12:27:06 PM