Mechanical engineering
The ocean is both a difficult and unforgiving environment in which to undertake scientific research. Mechanical engineers and technicians are at the forefront of ensuring that the equipment scientists need to undertake observations and measurements is capable of surviving and working despite the many challenges. For the mechanical engineer these challenges include:
- The crushing effects of hydrostatic pressure, arising from the weight of the water between the depth of interest and the surface. For the deepest part of the ocean, the Challenger Deep, this is about equivalent to a fully grown elephant of 5 tonnes standing on the smallest postage stamp of 2cm square.
- The tendency of water under high pressure to find its way into any device. This is a problem of sealing. Synthetic rubber ‘O’ rings are very effective at sealing when under pressure, but even one human hair across the ‘O’ ring surface can lead to a catastrophic leak.
- The corrosive nature of seawater. Unprotected steel rusts quickly in salt water. Even stainless steels can suffer from crevice corrosion that may sap strength or lead to leaks. Aluminium is a good choice, being light, strong and durable, but only if its coating (anodising) remains intact and if more easily corroded ‘sacrificial anodes’ are used. Titanium is these days the metal of choice, as, despite its high cost, over the lifetime of the equipment the reliability proves worthwhile.
- Ensuring that materials do not contaminate the scientific measurements, e.g. if the need is to measure dissolved iron in seawater then any form of steel, even stainless steel, cannot be used.
- Designing to avoid the impact of biofouling. Beginning with organic films, then microorganisms, then larger marine plants and animals, biofouling can be a big problem in well-lit surface waters. Designs must be able to cope with such growth.
Mechanical engineering at the National Oceanography Centre
Mechanical engineering activity at NOC spans the Liverpool and Southampton sites. Skills include expertise in two- and three-dimensional Computer Aided Design (CAD), Computer Aided Manufacture (CAM), Structural and Finite Element Analysis (FEA), machining and tool-making, the outsourcing of manufacture and the construction, assembly and maintenance of oceanographic equipment.
The group has access to well-equipped workshops and assembly areas and test facilities, including pressure testing to over 60MPa.
Engineers from the group work with scientists to design and develop a wide range of equipment, from sub-assemblies for complex autonomous underwater vehicles (AUVs) to simple clamps for attaching instruments onto their deployment frames.
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Mechanical engineers
The Mechanical Engineering Group has staff at Liverpool and Southampton. In broad terms the staff provide engineering design, small-quantity manufacture, assembly and support for operations to other groups at NOC and to others as needed. Read more about our mechanical engineers →
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Testing facilities
We have a number of marine test facilities at Southampton for internal use and also available for hire. Read more about the testing facilities →
