Offshore safety gets green light

17 Jun 2002

Lifor Limited, a Scottish optoelectronics company with six employees, has developed a device to help people to escape from fires on oilrigs.

The system, known as TrailLight, is made from a side-emitting fibre-optic cable connected to a battery-powered green laser. Side-emitting fibres are already employed in architectural lighting, but the light source is usually a metal halide lamp, which only lights up the cable for about 20 metres and takes several minutes to warm up. Laser light is better because it is more intense and the angle of entry into the fibre allows it to illuminate up to about 130 metres of the cable.

Lifor developed the 532 nanometre diode-pumped solid-state laser in conjunction with St Andrews University, Scotland. The device needed to be small and require the minimum amount of power. David Stevenson, Lifor's managing director, said that the laser is very efficient and has a small battery that can give up to three hours of emergency lighting.

The human eye is most responsive to green light, so this is the best colour for emergency lighting. The visibility depends on the thickness of the smoke. In a fire, people only need to see as far as the cabling at their feet to find the way out. However, Stevenson says that, when the fibre was stretched out on a golf course, it could be seen from an aircraft at a height of about 10,000 feet.

Fires on oilrigs are rare but, when they do occur, the isolation of a platform makes the consequences very serious. When fire broke out in 1988 on the North Sea's Piper Alpha platform, 167 people died. An expert on health and safety on oilrigs said that the inability of people to find their way out contributed to the number of casualties. He believes that Lifor's system should be beneficial, not just on oil rigs but also for emergency lighting in cinemas, theatres, aircraft and even football grounds. He also points out that the system can be made safer in an explosive environment because the electricity supply is isolated in one place.

The price of the system has not yet been set and will depend on specific installation costs, but Stevenson predicts that it will be about 30 UK pounds per metre. The company will begin extensive trials early next year, with products planned for about May 2000. "Obviously equipment like this has to be utterly reliable and we will work with the existing safety officers within the oil installations," said Stevenson.

SH