SUSU Antenna Array/Risk Assessment

From SUWS-Wiki

Potential risks

Provisional risk assessment; this will be under continual review for the next few weeks.

Note: "society members" refers to people who are members (full or partial) of the Southampton University Wireless Society.

Risks in general operation

Hazard Potential for harm Mitigation Likelihood Impact Risk
Structural failure due to rust Parts falling off onto people below All metal hardware and components are aluminium or stainless steel to prevent rusting. 0 3 0
Mechanical or electrical failure causing rotator to operate outside designed limits Rotator could fail in such a way that the mast is allowed to freely rotate. Internal failure of rotator will not cause any structural failure. Internal mechanical stops limit rotation in the event of internal breaks failing. 1 0 0
Lightning Strike Potential for serious injury to people operating equipment during the strike; heavy damage to equipment. Potential for fire inside the building. Note: current mast has no mitigation. Lighting bond to be installed on mast attached to building's lightning strap (nearby). Equipment not to be used in person during lightning storm. Static protection will be installed on active antenna elements to provide mitigation without interfering with transmission or reception. 1 3 3
Wind Could cause damage to rotator or structural failure of mast (see consequences for rust above) if wind loading not taken into account properly in design. Perform calculation specified by Yaesu for wind loading of the rotator, and standard wind shear calculations for mast and cross-beam. Do not use rotator during exceptionally strong winds to avoid damage to motor or gears. Have multiple experienced society members evaluate mounting designs to check for standard mounting techniques and best practice. 1 3 3
Trip hazard for cables Can cause people in the room to trip. All cables will be securely routed between equipment cupboard and mast/power supply. Good cabling discipline will be maintained to ensure no cables are permanently trailing out of cupboard without being secured. Make use of existing cable run on the external wall to prevent cables falling externally. 1 2 2
Mounting hardware works loose causing parts to fall See rust above All fastenings will be checked to ensure they are secure after erection is complete. Where possible, Loctite (or similar products) will be used to ensure these fastenings cannot loosen. 1 3 3
Electric shock Electrocution All power cables will be inspected for damage to insulation. No exposed metal will have a dangerously high potential. Equipment in the rack will be tested for compliance with relevant safety requirements. 1 3 3
RF burn High powered radio transmissions can cause RF burns if the antenna or bare metal connected to the antenna is touched. These burns are generally not medically serious, but in extreme cases can cause superficial scarring. The antennas will be physically disconnected from any device capable of transmission at powers high enough to cause harm while antennas are in any situation where they are likely to be handled. Cables to antennas, internal and external, will be insulated. While high power transmissions are ongoing, either the equipment cupboard will be locked preventing access to exposed connectors, or a member of the society will be present to prevent others touching antenna connectors. 2 1 2
Risk of injury to operator due to operator error Potential errors include touching antenna connectors during high power transmission (see RF burns above), receiving an electric shock while attempting to repair or diagnose equipment, and minor physical injury by trapping hands in hinges or connectors. Everyone operating equipment will be a licensed radio amateur, or being actively supervised by one as part of training. They will be required to operate according to their licence conditions appropriate to their level of competence. Everyone who uses the equipment will require a short induction session, which will contain safety-related information such as how to turn off power in an emergency. The society will review the potential for introducing a lone working policy if it would significantly reduce the risk of injury, to prevent more risky activities being performed alone. 2 1 2

Risks during installation

Hazard Potential for harm Mitigation Likelihood Impact Risk
Person falling from cherry picker Very serious injuries or death. Those using the cherry picker will be fully trained, using safety harnesses and following best practices. In order to to ensure compliance, only Estates and Facilities-trained university staff will be allowed on the cherry picker; society members will direct from the ground only. 1 3 3
Parts of the mast being dropped during installation Injury from parts falling on head/etc. Access to the area directly underneath erection will be forbidden. This will necessitate the erection being performed outside of The Stag's opening hours. 1 3 3
Dangerous weather conditions during erection Lightning strike or damage to partially mounted components due to strong winds Erection will be postponed in the event of inclement conditions. 1 3 3