Access to an offshore structure, for example an offshore wind turbine, may be gained by climbing a ladder attached to a transition piece such as the monopile of a wind turbine. Both the ladder and the transition piece are frequently used by offshore workers to access, service and maintain said offshore structure.
A growing problem in offshore structures is the build-up of bird droppings (guano). Birds roost and loaf on fixed structures at sea, including offshore wind turbines. If the guano is left to accumulate, they can harden and adhere to the surfaces of the offshore structure.
Turbine Transition Piece with observed roost locations labelled, picture kindly provided by John Vernon, Ørsted.
This is a particular issue on the parts used for access by offshore workers. Excessive amounts of bird guano pose health and safety issues as well as impacting the morale of offshore workers. That is, the bird guano will cause the affected areas to become extremely slippery, creating additional hazards when using the ladders, moving around the transition piece or accessing other platforms such as helipads. Furthermore, the bird guano produces an unpleasant sight and smell, is unhygienic and may carry disease. Finally, in areas such as ladders and helipads, markings may be obscured, which can lead to dangerous landing conditions.
The figure shows an example of a water delivery apparatus and an offshore structure, when the water delivery apparatus is in a ready mode and a pump of the water delivery apparatus is in an off state
The apparatus comprises a hose 102 comprising a water inlet 120 towards a first end of the hose 102; a pump 140 located along the hose 102 and configured to be switched between an on state and an off state; a plurality of nozzles 150 distributed along the hose 102 for delivering high pressure water; and a controller 180 configured to switch the water delivery apparatus 100 between a standby mode and a ready mode. When the water delivery apparatus 100 is in the ready mode, the controller 180 is controllable to control the pump 140 to switch between the on state and the off state. When the water delivery apparatus 100 is in standby mode, the controller 180 is controllable to control the pump 140 to switch to the off state. Wherein in the on state, the pump 140 is configured to draw water through the water inlet 120 to deliver said water to the plurality of nozzles 150 and wherein the plurality of nozzles 150 are positioned such that the delivered water cleans at least part of said offshore structure 10.
A water delivery apparatus is provided with improved cleaning ability of an offshore structure. The apparatus is capable of automatically cleaning key areas of an offshore structure without the need for manual cleaning. The apparatus also prevents the build-up of bird guano by being activatable at various times of day and night, every day of the year. The apparatus is also minimally invasive to birds, pollution free and helps to alleviate interruptions to operations. The apparatus will function regardless of sea conditions, thus lack of access due to rough seas is not a problem. The apparatus requires minimal maintenance and is cheaper to run than existing systems. By reducing the build-up of bird guano, the working conditions for offshore technicians are dramatically improved and more easily maintained.
In addition, because the offshore structure access points will stay clear of bird guano, more immediate access can be granted to crews, without having to send in a cleaning crew first. This reduces downtime of the offshore structure (for example a wind turbine) and therefore allows for increased energy production. Finally, costly hiring of cleaning crews and designated vessels is no longer required.
The apparatus may be permanently installed on offshore structures, drawing water from the sea and cleaning walkways and ladders on access areas of said structures. Therefore, birds are deterred from landing on said structures, and excess bird guano is cleaned on a regular basis.
The apparatus may comprise further features, such as a temperature sensor 190, a float switch 160, an indicator 200 and a one-way valve 148. The water inlet 120 may comprise a cleaning device 132 – the cleaning device 132 may advantageously cleans the water inlet 120 without the need for external access, power, or replacement. The buoyant cleaning device 132 uses the movement of the waves and tide to ensure that the water inlet 120 remains clean and in working order.
Jonathan Foster
Lead IP Specialist
