Wednesday 20 January 2010

Post and Wire Fencing

This article aims to highlight the safe working practices to be carried out when erecting or dismantling post and wire fences only, not wooden fences.

Post and wire fences tend to be used to enclose large areas where a wooden fence would be too expensive, time consuming or too weak. These fences may have ordinary wire, barbed wire or wire mesh, depending on what the fence is intended to keep in or out.

Materials

Line wire can be made of mild steel, high tensile steel or spring steel, barbed wire and woven mesh is normally mild steel or high tensile steel, welded and hexagonal netting is usually only made of mild steel.

Spring steel is the strongest followed by high tensile steel and the weakest is mild steel. Spring and high tensile steel cannot normally be strained to breaking point manually. Mild steel stretches before it breaks. Any kinks, twists and surface damage will cause a reduction in the strength of all types of steel.

High tensile and spring steel will recoil more dangerously than mild steel when cut, broken or just released.

Personal Protective Equipment

The following PPE must be used to comply with HSE rules:
• Gloves to protect against barbed wire, splinters, cuts and scratches.
• Non-snag outer clothing appropriate for the prevailing weather conditions, in certain cases it is recommended that high visibility clothing is used.
• Protective boots with a sole giving good grip, ankle support and must comply to EN 345-1. Although not mandatory thought should be given to using boots that have a puncture proof midsole and are also waterproof.
• Eye protection safety glasses to EN 166 because of the danger of flying debris when dismantling old fences and also if there is an incidence of wire recoil.
• If using power tools then use ear protection, visors and anti vibration gloves.
• If handling preservatives or preservative treated timber where the preservative has not dried, chemical resistant gloves should be used, and depending on the product respiratory masks should be used if the safety instructions on the product specify it.
• Each person should carry a first-aid kit including a large wound dressing.
• Hand cleaning material such as waterless skin cleanser or soap water and paper towels should be available.

Many of these items appear on the Granite Workwear site under the following headings; Gloves, Safety Glasses, Respiratory Masks, Safety Boots, Forestry Clothing, and Ear Protection.

Tools and Equipment

The tools and equipment required will vary depending on the type of fencing being erected or dismantled. However the basic rules are the same whenever tools are being used, they should be appropriate to the task and they must be checked to ensure that they are serviceable.
All cutting edges should be sharp and also guarded when not in use, do not place hand tools on top of fence posts or on the ground, use an appropriate tool belt like the Dickies Deluxe Tool Belt on the Granite Workwear site.

Manual Handling

Always follow the best practices for manual handling, a very useful leaflet is INDG145 'Watch your Back', this is available from the Health and Safety Executive.

Do not try and carry too heavy or awkward unbalanced loads, it is better to make more journeys, also take into account the conditions under foot i.e. uneven, wet, or steep slopes.
Always lift heavy items using the arm and leg muscles with your back held straight.

Organise the delivery of the materials and equipment to be as close to the site where they are needed, wherever possible use mechanised unloading or ensure that there are enough members of the team to help.

Wherever possible use an All Terrain Vehicle or Quad Bike to carry meaterials to the required area.

Preparation

Before starting check the proposed fence line for any underground hazards and services i.e. pipes, cables and any major obstructions.

If you are dismantling old fences look carefully at any vegetation growth that may make the wire or net unpredictable when cutting it.

If you are using a trailer to carry your materials look for a flat surface, if you cannot find one then always ensure that you unload from the top side or the rear if on a side slope.

Sawing

Make sure that the material you are cutting is secured, if you are notch cutting ensure you keep your free hand clear of the saw teeth.

If you are using a chainsaw then you must take all the safety precautions that were mentioned in our article on Using a Rear Handled Chainsaw published 11th November 2009.

Manual Stake Driving

Do not support the stake by hand, you must use a stake holder, also do not adjust or test the stake by using your hand whilst the driving tool is in use.

Always make sure you have sound footing and that your legs and feet are clear of the driving tool.

When you are using a maul ensure that all other people are well away from where you are swinging the maul.

Mechanical Post drivers

Please note that this is always a one person operation, if the post driver is mounted to a tractor by a three point linkage, the tractor must be big enough to remain stable during operation.

The machine must be properly parked and the brakes applied before commencing operations. It must be fitted with a gripping device to hold the post during the operation - never use your hands or a stake holder.

There is a big risk of flying debris so ensure a suitable visor is worn to protect your whole face.

Handling the wire

Always use a dispenser when unrolling the line wires, this avoids kinking and twisting which will have a negative effect on the strength of the wire. Always ensure that the wire is kept firmly in place on the dispenser.

Ensure that one end of the line wire is attached securely to the strainer post before applying any tension.

Knots can only be used on mild steel wire, on other types suitable connectors must be used.
If you are using ratchets make sure that wire has at least two full turns on the barrel.
Ensure wire strainers are properly attached and anchored before tensioning. Never stand astride the wire whilst it is being tensioned.

Never over-tension high tensile or spring steel wire by using extra leverage or more than one person on the strainer and never use a vehicle to tension.

When cutting always make sure that the exposed ends of the wire are secured, always ensure that high tension and spring steel wire is secured on each side of the cut. Make sure that you do not spike your hands or arms on any loose ends.

Always use protective gloves when handling barbed wire and ensure that when it is being dispensed it is kept taut. Always be aware of potential breakage and recoil.
Make sure that all pieces of wire have been removed from the area and that it is disposed of safely.

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