Ship-shape

The advanced lightweight materials frequently used in the design of small boats and yachts could soon become more attractive to major ship-builders thanks to ground-breaking trials of UK sensing technology.


The advanced lightweight materials frequently used in the design of small boats and yachts could soon become more attractive to major ship-builders thanks to ground-breaking trials of UK sensing technology.


In an EU funded project, fibre-optic sensors developed by Bracknell-based Smart Fibres are being tested on board a composite ship operated by the Swedish navy.


Dr Crispin Doyle, chief engineer at Smart Fibres, explained that while the technology has already been used on the masts of luxury yachts, previous applications have been mostly static. The current trial represents perhaps the largest and most prominent example to date of the technology being used on a vehicle of any type, he claimed.


The company’s technology is based on optical fibre bragg grating sensors. These devices, which can be fitted in large numbers on a single fibre-optic cable, are just 250 microns in diameter and a few millimeters long. The small, strong and flexible sensors can be embedded in structures and used to monitor stresses and strains.


Doyle said the sensors have significant advantages over the large and expensive electrical strain gauges traditionally used for load monitoring on larger ships. Being electrical, such systems require large amounts of cabling and shielding from other electrical machinery. They also require protection from the damp environment in which they operate. Also, conventional systems are only really appropriate for steel structures.


So Doyle argued that the Smart Fibre technology could encourage the use of lighter materials.


‘The boat building industry is still quite conservative in terms of the materials it uses, but a feedback system that tells them how the material is behaving would make them more likely to use advanced materials,’ he said.


The main advantage of the technology, according to Doyle, is that the sensors are completely immune to any kind of electromagnetic interference, and therefore require far less cabling than existing monitoring systems. They are also much smaller than conventional strain gauges, and can therefore be placed in dense concentrations around certain critical locations in highly-loaded parts of ships.


Also, because they are small and self-contained they can be embedded within materials to monitor the internal stresses and strains.


Assuming that the trial goes well, Doyle said that the technology is likely to be commercialised for use on ships by Finnish project partner R Ruvari Oy.


With a small amount of companies operating in this monitoring field — and a huge number of ships that could benefit from the technology — the potential market is huge, he said.


Looking to the future, following further miniaturisation and cost reduction, Doyle anticipates a mass market for the technology in both the automotive and aerospace industries.