Wind sector dictionary

Being attached to an anchor at every moment you are exposed to a fall: one lanyard leg always clipped on while the other moves.

If the gap between a lightning flash and its thunder is under 30 seconds, the storm is close enough to strike: stop work at height and come down. Go back up only 30 minutes after the last thunder.

A load too long, wide or heavy for normal road rules. It needs permits, often a police escort, and usually travels at night.

How much electricity a turbine or farm is expected to make in a year, in MWh or GWh.

A ring of long steel bolts cast into the foundation. The bottom tower section is bolted onto their tops.

What you clip to. Certified anchors are marked; on older machines they are not always obvious, and this is where access plans go wrong.

Two different jobs with the same letters. An Authorised Person is named in writing to switch high-voltage equipment and issue the safety documents for it. An Appointed Person plans a crane lift and answers for it, from the lift plan to the crew who carry it out.

Worn for switching and any live electrical work. Rated in cal/cm², and it must be the outermost layer.

GWO module for rescuing a casualty from places a basic rescue cannot reach — hub, blade, inside the tower.

EU rules for equipment used where an explosive atmosphere may exist. Affects which tools and torches you may carry.

Putting soil back over the foundation slab. Its weight helps hold the turbine down against tipping over.

The large bearing in the hub that each blade is bolted to, so the blade can be pitched.

A thin layer of lean concrete poured on the bottom of the excavation, so the steel is built on a clean, level, dry surface.

Stretching a bolt with a hydraulic tensioner, then running the nut down by hand. More accurate than torque for large bolts, and several can be tensioned at once.

The crane's long lattice arm, assembled on the ground piece by piece. For a 100 m hub height it is often 140 m or more.

Everything on a wind farm that is not the turbines: cables, substation, roads, foundations.

Looks inside a gearbox or bearing without opening it. Turns a strip-down into a ten-minute check.

The GWO entry-level safety package. Onshore is four modules; offshore adds Sea Survival.

The shortened repeat of BST taken before the two-year certificate expires.

GWO modules covering mechanical, electrical and hydraulic fundamentals. Separate from BST.

Telling a supplier to deliver now. Components are made long before and wait at a factory or port until they are called off.

The up-front cost of building the farm, as opposed to the cost of running it.

A storage area for the whole site. Anything stored there has to be loaded and moved again later, which costs time and crane hours.

Actual output divided by theoretical maximum output. Onshore is typically 25–40%, offshore 45–60%.

A government-backed price guarantee for the electricity a farm sells. Decides whether projects get built.

Vented, with a chin strap. Not a building-site hard hat — a helmet that falls off at 90 m becomes a dropped object.

Vibration and temperature sensors that predict a bearing or gearbox failure before it happens.

GWO module on isolating electrical, mechanical, hydraulic and stored energy before work starts — lock-out/tag-out done properly. More and more employers ask for it alongside BST.

Testing that everything works as designed before the turbine runs for real: every sensor, safety system and setting.

A hub or a blade root is a confined space with its own permit, gas checks and a standby person outside.

The turbine's computer. It turns the nacelle into the wind, sets the blade angle and stops the machine if anything is wrong.

A large crane on tracks instead of wheels. Its lattice boom is built up on site, and it can walk short distances between turbines along a prepared crane path.

Stepping from a moving vessel onto the boat landing while the bow is pushed against it. Timed with the swell, three points of contact.

The fast catamaran that pushes onto the boat landing and puts technicians on the turbine.

Concrete gaining strength chemically over days and weeks. It has to stay damp and above freezing, and the tower only goes on once tests show it is strong enough.

Rated for cut and abrasion. Grip rating matters as much as cut level — wet gloves that slip are their own hazard.

Paying a haulier or ship owner for keeping their truck or vessel waiting beyond the agreed free time.

The ring between your shoulder blades. Fall arrest only. You cannot reach it yourself, which is the point — nothing can unclip it by accident.

A sweep for anything that could fall from height before and after work — including things a previous crew left.

Operates the lower-voltage network that smaller onshore farms connect into.

Copper conductors buried around the foundation and bonded to the turbine. Lightning and electrical faults are led safely into the ground through them.

GWO module that builds on BST First Aid: looking after a casualty for longer when help is far away, as on a remote site or offshore.

The function that owns risk assessments, incident reporting and site rules.

Connecting a turbine to the live network for the first time, following a written switching programme under an Authorised Person.

A contract where one company designs, buys and builds the whole project.

Testing a component at the factory before it ships, so faults are found on the ground.

The moment a project is committed to. Before FID, nothing is certain; after it, hiring starts.

The client accepts the whole wind farm: every turbine taken over, every snag closed and every document handed over.

The thick steel ring at each end of a tower section. Two flanges are bolted together with a hundred or more large bolts.

The check you do at the work face, on the day, on top of the written risk assessment.

Worn under the hi-vis or over it, it spreads arrest forces across thighs, chest and shoulders and holds you upright afterwards. Everything else clips to it.

Bearing greasing is most of scheduled service. The grade is specified per bearing — mixing greases can destroy one.

The device that rides the ladder safety rail and locks if you fall. Attaches to your sternal ring, and it must be the one matched to that rail.

A short burst of wind well above the average. Gusts, not the average, are what make a hanging load swing, so lift limits look at both.

The industry body whose training standards most wind employers require. Not a training provider itself.

A flat, compacted stone platform beside the turbine where the main crane stands. It has to carry the crane, its counterweights and the load without settling — often well over 1,000 tonnes.

The highest predictable tide level. Platform and boat-landing heights are set from it.

The UK regulator. Also used loosely to mean the health-and-safety function generally.

The cast-iron centre the blades bolt to. It houses the pitch system that turns each blade.

How high the centre of the hub is above the ground. Wind is stronger up there, so wind limits for lifts are measured at hub height, not at the ground.

Above 1000 V AC. Requires specific authorisation and switching procedures — never assume access.

For the large flange bolts in the tower and hub. Works in a defined sequence and pattern; the sequence matters as much as the number.

The cable running turbine to turbine in a string, and on to the substation. 33 kV on farms built up to about 2016, 66 kV on almost everything since — 66 kV carries roughly twice the power per string, so a big-turbine fleet needs far fewer cables.

Offshore only. Keeps you afloat and slows heat loss in the water. You are trained in one during Sea Survival.

The UK body behind Managing Safely, a short course for supervisors on spotting hazards and running work safely. A common first step towards a supervisor role.

Trains and certifies MEWP operators. Category 3a covers scissor lifts, 3b boom lifts (cherry pickers). The PAL card is valid for five years.

The rope-access qualification used for blade repair and external tower work.

A vessel that lowers legs to the seabed and lifts itself clear of the water to install turbines.

The rail or steel cable fixed along a tower ladder that a guided fall arrester runs on. Makers such as Hailo supply ladder and rail together; installing one needs their training.

The chart datum most offshore water depths are quoted from.

The ground beside each turbine where components are set down after delivery, planned so the crane can reach them in the order they go up.

Lifetime cost divided by lifetime output. The number used to compare wind against everything else.

A penalty agreed in the contract in advance: a fixed amount per day for each turbine handed over late. The reason a build schedule is watched so closely.

The front edge of a blade. The tip moves at up to about 300 km/h, so rain and dust slowly wear it away — hence leading edge protection (LEP).

Tape or coating on the blade edge that takes rain and sand erosion instead of the laminate.

Worn for every offshore transfer, usually with a personal locator beacon fitted.

The written plan for a lift: the load, the crane and its set-up, the rigging, the wind limits and who does what. Prepared or approved by the Appointed Person.

Receptors near the blade tips and a down-conductor inside each blade lead lightning through the turbine to earth. Turbines are struck often.

Physically locking an energy source off and tagging it with your name, so no one can energise it while you are inside.

You put your own lock on the isolation and your own name on the tag. Nobody can re-energise it while your lock is on.

Up to 1000 V AC. Still lethal — most electrical incidents in service work happen at LV.

Everything is installed, bolted to its final values and cabled. The turbine is ready to be energised and commissioned.

Measures insulation resistance. Used after isolation to prove a circuit is healthy — and dead — before work starts.

A powered platform that lifts people to work at height: scissor lifts, and boom lifts known as cherry pickers. Operators need IPAF training, and on a boom lift you still clip in.

Bringing people, machines and cabins to site and getting them ready to work. Demobilisation is the reverse, at the end of the job.

The single large steel tube driven into the seabed that carries most offshore turbines in the region.

The average sea level, used as a reference height for structures.

The voltage a turbine sends its power out at: usually 33 to 35 kV on onshore farms, 66 kV on offshore farms built since about 2017. Only authorised people work on it.

The housing on top of the tower that holds the drive train: main bearing, gearbox or direct drive, generator, brakes, cooling and often the converter.

The region this platform focuses on: the Nordics, the Baltics, Germany, the Netherlands, Belgium, Poland, the UK and Ireland.

Inspecting a weld, bolt or blade for cracks without damaging it — ultrasonic, dye penetrant, thermography.

Something that could have hurt someone but did not. It is reported so that it never happens for real — reporting one is a good thing.

Its International General Certificate is the standard qualification for HSE advisers and a common requirement for site and construction managers.

The phase after construction, and where most technician jobs are.

The company that built the turbine — Vestas, Siemens Gamesa, Nordex, Enercon, GE.

A smaller mobile crane that lifts components off the trucks and sets them down in the laydown area.

The ongoing cost of running the farm: service, spares, vessels, crew.

Proving that the turbine shuts down safely if the rotor turns too fast.

Written authorisation to start a task, issued only once the isolations are proven. No permit, no work — including for you.

Turning each blade about its own length to catch more or less wind. Turning the blades fully out of the wind is how a modern turbine brakes.

Worn on the lifejacket; transmits your position if you end up in the water.

The check you make at the work face on the day, on top of the written RAMS, because conditions on site are never quite the paperwork.

A long contract to sell the farm's electricity at an agreed price.

Helmet, glasses, gloves, boots, hi-vis, harness and lanyards — the last line of defence, never the first.

Doing as much work as possible on the ground before a part is lifted — quicker, safer and cheaper than doing it at 100 m.

A widely used project-management method with its own certificates. Common among the project managers who run wind farm builds.

The written authorisation to start a specific task, issued after the isolations are proven.

The document pair saying what could go wrong and exactly how the job will be done.

Steel bars tied together inside the concrete. Concrete is strong when squeezed but weak when pulled; the steel takes the pulling. A turbine foundation holds tens of tonnes of it.

The turbine runs on its own for an agreed time — often 240 hours — to prove it works before the client takes it over.

Lowers a casualty or yourself at a controlled speed. You will practise on it in GWO Working at Heights and hope never to use it.

The liquid plastic used to repair composite blades. It only cures properly when it is warm and dry, which is why blade repair stops in cold or wet weather.

A self-retracting lifeline that pays out as you move and locks under a sudden load. Shorter fall distance than a lanyard, so it suits low clearance.

How your time is structured: 14/14 and 2/2 offshore, 5/2 with call-out for many onshore service teams.

Steel pins that lock the rotor mechanically so it cannot turn. Nobody enters the hub until the rotor lock is in.

Toe cap, midsole plate, ankle support. Ladders are climbed on the arch, so a rigid sole is what stops your feet aching by the third tower.

A hard-wired loop of emergency stops and sensors. Break it anywhere and the turbine stops, whatever the controller thinks.

The system that monitors and controls the whole farm remotely, and logs every fault code.

The big aluminium hook on a lanyard tail, wide enough to take a structural member. The gate must close and lock on its own.

The small lift inside the tower. When it is out of service you climb the ladder, so the job needs fitness too. Installing and running one needs the maker's training.

Written before you leave the turbine. Fault codes, what you found, what you changed and what you left open — the next crew reads this.

The pack that tears progressively in a fall to keep the arrest force under 6 kN. Once deployed it is scrap — never repack it, never reuse it.

The rings on your hips. Positioning only — they hold you leaning back with both hands free. Arresting a fall on them would fold you at the waist.

The person who attaches the load to the crane hook and guides the crane operator by hand signals or radio. GWO now has a training standard for the role.

Carries power and signals from the fixed nacelle into the rotating hub. A common source of pitch-system faults.

The design condition for normal operation — deflection and vibration stay within tolerance.

A list of faults found during checks. Category A must be fixed before the next step; category B can wait a little, but not forever.

A vessel technicians live on for weeks, with a motion-compensated gangway to the turbine.

The rounded cover over the hub. It keeps the weather out and smooths the airflow.

A remote-controlled trailer with dozens of individually steered wheels, for moving very heavy loads such as nacelles and transformers over short distances.

Paid time when conditions stop the work. How it is paid varies by contract, which is worth checking before you sign one.

Chest attachment, used for ladder systems and for rescue. Also fall arrest.

A threaded rod without a head. Studs are fitted into the blade root and pass through the blade bearing, with the nuts on the hub side.

Where the farm's power is collected and stepped up to grid voltage: the wind farm's connection to the outside world.

Cabinets with circuit breakers that connect the turbine to the cable network or cut it off — a very large, very serious fuse box.

A rope tied to a hanging load and held from the ground to stop it spinning or swinging. You steer the load with it — you never take its weight and never wrap it round your hand.

A second, smaller crane that holds the bottom of a long part while the main crane lifts the top, so a tower section turns from lying down to hanging upright.

The short briefing before the shift where the day's specific hazards are agreed out loud.

Making a cable end ready to connect: stripping it, fitting a lug or plug and sealing it so it carries high voltage safely.

The document in which the client accepts a turbine (the Taking-Over Certificate in FIDIC contracts). From then on it is theirs, and the payment for it is released.

Every tool taken above ground level is tied to you or to the structure. A dropped 1 kg spanner from a nacelle is lethal.

The short briefing at the start of the shift where the day's specific hazards are said out loud, not just written down.

Twisting force. A bolt is tightened to an exact torque so it stretches by just the right amount and clamps the joint.

Bolt tension is a design value, not a feel. Every torque tool has a calibration date, and using one out of date invalidates the work.

The yellow section between the monopile and the tower, carrying the platform, ladder and boat landing.

Operates the high-voltage grid. Sets the rules a farm must meet to stay connected.

A motor that slowly turns the hub during installation, so each empty blade bearing can face the crane in turn when blades are fitted one at a time.

Two legs from one shock pack so one hook is always attached while the other moves past an obstacle. This is what 100% tie-off means in practice.

The design condition for survival — the extreme load the structure must not fail under.

Turning a tower section from lying on the ground to standing upright, with the main crane and a tail crane working together.

NDT method using sound to find cracks inside steel or a blade bond line.

Wind speed, wave height and visibility limits that decide whether you climb or transfer at all. The limits are set by the task, not by how you feel.

Typical limits are roughly 12–15 m/s to climb and lower still for lifting or blade work — the site rules are the authority.

Where every GWO certificate is registered. Employers check your training there with your WINDA ID, so keep the number to hand and check your record after each course.

The formal name for a single turbine. You will see it on every drawing and work order.

A purpose-built jack-up that carries and erects turbine components offshore.

Not an acronym, but always capitalised on drawings: the drive that turns the nacelle into the wind.