Storm Arwen leaves in its wake extremely dangerous trees
Storm Arwen has produced a myriad of new areas of storm damaged and extremely dangerous trees. Working in these conditions the operator needs to be trained and competent (with experience working in windblow). To deal with windblow situations, use mechanical assistance whenever possible. Mechanised systems should be considered as a safer alternative to chainsaw work. Now the initial phase of access route clearance is complete, many farmers and landowners are now reviewing the wider damage. This work needs to be carefully planned and risk assessed. Services and damaged buildings increase the risk and may slow or prevent the work being undertaken until appropriate measures can be taken. Planning should aim to use mechanised systems whenever possible; if chainsaw work is undertaken, the operator must be competent. During works safe access and egress for the operator is crucial, the area around the work is a risk zone and must be kept clear to limit the risk of additional falling timber and debris.
Engaging competent contractors is vital. Farmers and landowners may be renown for turning their hand to a multitude of tasks; BUT NOT THIS, tackling extremely dangerous trees should not be one of them! Clearing storm damage should only be undertaken by those competent to work on such dangerous material, leave the saw in the shed and call in a professional. Gauging the competency of a contractor will include training, suitable past experience, use of equipment fit for purpose and wearing of relevant protective PPE. The clear up will take time.
Sites with several storm damaged areas may require access to be either limited or even excluded until made safe. Networks now re-energised have the risk of hanging and blown trees in proximity to live power lines. Everyone must assume that all overhead and underground electrical equipment is energised unless it has been confirmed by the Network Operator that it has been de-energised (isolated and earthed). This will be arranged by the Network Operator issuing a Permit to Work, or similar document, to an authorised permit holder. Work requires the necessary discussions with the Network Operator and an authorised system of works, which needs to be arranged WELL BEFORE WORK STARTS where tree felling/harvesting operations are to be carried out within 2 tree lengths plus the vicinity zone of the OHPL or close to underground cables. If tree-felling work is required within one tree length plus the vicinity zone or within 10m of the line (the Red Zone) while energised, then this will only be carried out by staff engaged directly by the Network Operator.
New areas of storm damaged trees include windblow, potentially weakened standing and snapped trees, and unstable debris overhead. Access routes may also still be affected. Farms and landowners in the worst hit regions have suffered extensive damage, temporary measures will be required, as the clear up operation will take time to ensure that it can be done safely. For those that outwinter cattle many have lost vital shelter belts (cattle needing to be moved or housed), temporary electric fencing often required to secure fences damaged/lifted by tree root plates, flattened water troughs needing replaced by temporary provision - the feed pipe if located can be tapped off and plumbed to a temporary trough. Spring will see the turnout of livestock from winter housing, with fencing repairs needed before turnout. Windblown boundary trees in the fence line are extremely dangerous, often with large root plates increasing the risk. A competent contractor will work with an agreed system of work, using supporting mechanisation/winching; some trees will require additional anchor of the root plate.
Tree Shear and grapple saw are some of the mechanised equipment in use after the storms. Newly released FISA 608 Tree Shear & Grapple Saw Safety Guide (free to download on the ww.ukfisa.com website) provides guidance on the safe working practices to be followed when operating this equipment.
 The vicinity zones around an OHPL are the areas in which there is the danger of electricity flashover if someone enters, this distance increases as the voltage increases.