2.15 Temporary Safety Barriers and/or Warning Signs Purpose This instruction sets out the minimum requirements for the installation and erection of temporary safety barriers and/or warning signs to: Protect Horizon Power employees and contractors from a potential hazard. Protect the general public from a potential hazard. Prevent the general public from entering a Horizon Power worksite. This instruction does not cover the erection of gantries and scaffolding. Safety Before commencement of work, a risk assessment must be carried out using the Risk Analysis Procedure (OSH-3.6-1-02), to identify and document the hazards and risks associated with the task and ensure appropriate control measures are implemented. It is important that, appropriate control measures must be identified, documented and implemented to lessen or control the identified hazards. Instruction The following are examples of where the public may be exposed to hazards: Pedestrian and vehicular traffic through worksites. Reinstatement of walkways, footpaths and nature reserves. Cables protruding from the ground. Excavation work (holes and trenches). Stringing conductors across roadways, un-sealed roads and bush tracks. Access/entry to electrical apparatus. Substation s gates that cannot be locked. Substation s relay room doors that are left open for ventilation, etc. Plant and equipment left unattended e.g. pole top switches, cable drums and transformers, cable poles, generators, cable drum trailers etc. The public must be notified when the erection of temporary safety barriers and/or warning signs restricts them from entering or exiting their property. For planned tasks, a minimum 3 days notice must be given using the Horizon Power - Planned Power Interruption card. For unplanned tasks the property owners/occupiers must be advised of the restricted areas prior to commencing the task. The need for temporary safety barriers and/or warning signs must be established by undertaking an onsite risk assessment with all members of the work crew prior to commencing any task and before leaving a worksite. CS10 # 2225729 FI 2.15 Temporary Safety Barriers and/or Warning Signs Page 1 of 5
Where practicable temporary safety barriers and/or warning signs must be erected around the hazard where the risk assessment identifies a hazard that would put the public at risk of injury or harm. Where this is not practicable, a safety observer must be appointed to prevent the general public from entering the immediate worksite. Where practicable safe access ways through the immediate worksite must be installed to allow the public to enter or exit their properties. Where this is not practicable, members of the public must be escorted through the immediate worksite. Where temporary safety barriers and/or warning signs are used around excavations, they must be placed at a distance, which prevents persons, plant, the temporary safety barriers and/or warning signs or other materials from falling into the excavated area. Installation and Erection The following are examples of the type of temporary safety barriers that may be installed and/or erected: High Visibility Mesh. High Visibility Rope and Flag. Road Safety Barriers. Temporary Fencing. High Visibility Road Traffic Management Cones and Bollards. An appropriate warning/advisory sign(s) may be required to be erected in conjunction with these types of barriers. Walls, fences or other impassable permanent barriers can be used as part of the temporary safety barrier. Where star pickets are used to support temporary barriers or warning sings, they must be driven into the ground firmly to a maximum depth of 600 mm. Care must be taken to avoid driving the star pickets into underground services. The top of the star pickets must be covered to prevent injury. High Visibility Barrier Mesh High visibility barrier mesh is typically used around excavations, live exposed cables etc, to exclude members of the public from entering a hazardous worksite. High visibility barrier mesh must be a minimum height of 900 mm. High visibility barrier mesh must be attached to star pickets, ground screws, freestanding bollards or a suitable permanent support using one of the following methods: Weaving the star picket through the barrier mesh and made secure using a suitable fastener; or Directly against the selected support using a suitable fastener. CS10 # 2225729 FI 2.15 Temporary Safety Barriers and/or Warning Signs Page 2 of 5
To maintain the minimum height of 900mm (to prevent the barrier mesh from falling over), star pickets, ground screws or freestanding bollards must be positioned up to a maximum distance of 2.0 metres apart. High Visibility Flag Rope Barriers High visibility flag rope is typically used to safely guide members of the public through or around a hazardous worksite. High visibility flag rope must be tied to star pickets, ground screws, freestanding bollards or suitable permanent supports or attached to the selected support using a suitable fastener. High visibility flag rope barriers must be positioned between 900mm and 1200mm above the ground. Star pickets, ground screws or freestanding bollards must be positioned up to a maximum distance of 3.0 metres apart to prevent the flag rope from sagging below 900mm. Road Safety Barriers (Concrete) Road Safety Barriers are designed to provide a physical barrier between the travelled way and the work area to inhibit the penetration by an out of control vehicle and will preferably have some vehicle redirecting properties. They are typically used between traffic and a severe hazard such as deep longitudinal excavations for the protection of workers and pedestrians. Road Safety Barriers must be installed where the: Length of excavation is greater than 10m. Duration of exposure is more than 1 day. Depth exceeds 500mm; and The distances from the roadway are less than those shown in Table 1 below. Table 1 Speed (kmh) Distance from Roadway (m) < 60 2.5 70 5.5 > 80 6.0 The Road Safety Barriers must be offset from the nearest edge of the traffic lane and have a safety space between the Road Safety Barriers and the closest edge of the excavation as shown in Table 2. Table 2 Speed (kmh) Offset (m) Safety Space (m) 40 0.3 50-60 0.5 70-80 1.0 80 2.0 1.8 CS10 # 2225729 FI 2.15 Temporary Safety Barriers and/or Warning Signs Page 3 of 5
Note: Where the nearest edge of the traffic lane is clearly delineated by an edge line, lane line or kerb, the safety space can be taken from the edge line, lane line or kerb. Field Instruction 6.4 Excavation Work and Directional Drilling must be complied with where the Road Safety Barriers are placed in the collapsible area at excavation sites. Plastic Barriers may be used to redirect pedestrian traffic away from a worksite. They must not be installed to provide a physical barrier between the travelled way and the work area. Temporary Fencing Temporary Fencing is used to prevent unauthorised entry to worksites. When installed Temporary Fencing must be at a distance that will not present an additional hazard to the general public. Temporary Fencing must be installed where enclosures are required to prevent unauthorised entry to electrical apparatus, plant and equipment. Temporary fencing must be constructed to a minimum height of 1800 mm, with the panel sections consisting of either: Steel Mesh. Chain Wire. Metal Hoarding. Where access/exit gates have been fitted, they must have suitable provision for locking. Barbed wire extensions may be attached to the top of the temporary fencing for increased security Temporary fencing may be used in conjunction with road safety barriers to protect workers from flying debris in the event of an accident. When used, the fencing must be placed beyond the likely deflection limits of the safety barrier if struck by a vehicle. Warning Signs Temporary warning/advisory signs may be required to be erected in conjunction with temporary safety barriers. The following are examples of warning/advisory signs that may be used on Horizon Power worksites: Power Line Work in Progress. Pedestrians This Way. Do Not Enter. Caution Excavation Work In Progress. Danger High Voltage. Warning/advisory signs must be positioned where they are clearly visible and do not obstruct pedestrians and/or vehicular traffic. All warning/advisory signs must be legible and in good condition. CS10 # 2225729 FI 2.15 Temporary Safety Barriers and/or Warning Signs Page 4 of 5
Reference Occupational Safety & Heath Act 1984 Occupational Safety & Health Regulations 1996 SHMS OSH-3.6-1-02 Job Risk Analysis (JRA) Procedure SHMS OSH-3.6-1-26 Personal Protective Equipment Field Instruction 6.4 Excavation Work and Directional Drilling Field Instruction 2.6 Worksite Clothing / Personal Protective Equipment Requirements Field Instruction 2.15: Temporary Safety Barriers and Warning Signs Field Instruction 2.17 Safe Approach Distances Field Instruction 2.23 Job Hazard and Risk management (JRA) Section 4.6 of Code of Practice for Excavation Barriers and warning signs Utilities Providers Code of Practice for Western Australia Works near Horizon Power Underground and Overhead Networks CS10 # 2225729 FI 2.15 Temporary Safety Barriers and/or Warning Signs Page 5 of 5