Challenge
Our customer had been contracted to supply a pre-piling template to ensure the accurate installation of piles for an offshore wind farm project. This type of work is within their core business of marine foundation solutions and piling equipment for nearshore / offshore.
Their customer had requested the inclusion of an air bubble curtain as a noise mitigation measure. This is an environmental consideration to dampen and absorb the sound of underwater construction to prevent hearing loss and noise harassment of marine mammals.
In addition, we were asked to include control of the water jetting system which is used to enable suction release of the mud mats when the rig is being lifted and moved.
Engagement
We collaborated with our customer to outline the concept, then to design and develop a bespoke solution. Investing a great deal of engineering time, we were able to simplify the design overall to reduce build complexity and potential for failure as the system had to work first time. There was no opportunity for ongoing development or prototype testing, once it was put into the sea, there was no turning back.
We worked with the customer to provide validation of their air requirements and produced a full set of 3D models for their approval.
Solution
The solution delivered was a complex electro-pneumatic system consisting of a series of actuators and a control system mounted into subsea pressure vessels with a subsea distribution manifold for the air. There were also a number of control panels and a touchscreen interface for installation into the control cabin.
PSI brought together the skills and capability of a number of component manufacturers, along with our own engineering expertise to create a system that was fit for purpose in one of the most demanding environments that exists, the sea.
Subsea Actuator Pressure Vessels, each containing an IP67 electrical actuator controlled ball valve. (Vessels manufactured by Omega)
Subsea Control System, housed in a specialised subsea stainless steel vessel (Vessel manufactured by Greenaway Marine – not shown in photo)
Subsea Distribution Manifold
Compressor emergency shut down and exhaust system with flow monitor, consisting of a control panel (shown), pneumatically actuated stainless steel ball valve and stainless steel pipework supplied. The flow meter head placed inside the panel for protection.
On board ship PLC Control Cabinet, and Pump Control Cabinet. The cabinets were integrated into the control cabin being manufactured by another sub-contractor. The control cabin was responsible for the launch & recovery system.
HMI which was the control interface for the end users.
A Success Story
To design, build, test and supply a complete subsea control system was a tremendous up-taking, and a challenge we were keen to meet. By working very closely with our customer, we were able to provide ‘a right first time’ control system – essential due to the location of the project.
The installation and commissioning of the system and the coastline went smoothly. The equipment worked well with no issues, failures or water ingress into the subsea components throughout the duration of the wind farm construction project.
The success was such that it was generally considered to be a blue print for subsequent windfarm installation projects.
