A company with roots in St Andrews University has developed an LED-based system for marking dive umbilicals for North Sea divers that has already been credited as making a significant contribution to their safety.
Known as Lightpath, it has been developed in co-operation with several leading subsea contractors and the Underwater Centre at Fort William.
The firm, PhotoSynergy, has achieved this with a side emitting 5mm diameter fibre that carries no electrical power, only light up to 150m in length. The fibre is spirally wound into the dive umbilical thereby creating a flexible continuous line of light from a low-power LED light source which can be either steady state or flashing.
The initial testing and evaluation took place at The Underwater Centre, which ran an open day to bring the system to the offshore industry’s attention.
PSL, which was founded in 2002 as a joint venture between St Andrews University and Ferranti Photonics, secured collaboration, support and advice from Bibby Offshore, Helix Well Ops UK and Boskalis Offshore Subsea Services operating in both saturation and wet bell systems.
Feedback has been positive and supports Lightpath as an “innovation that helps de-risk diving operations; a major industry concern”.
Steve Ham, general manager at the UWC said: “We were delighted to be able to provide PSL with the opportunity to test its illuminated rope in the controlled environment of our pier, using divers in training.
“Our onshore tank, which has viewing panels on all sides, also provided the perfect location for a demonstration of how the light rope works, to potential clients.
“It’s a very important piece of new technology, which we can see has significant benefits to commercial divers, and ROV pilot technicians when working offshore or in poor light.
Helix Well Ops reported that, in low visibility situations, having illumination of this kind is a “real safety bonus” when the divers can, at a glance, see the direction their umbilicals are going.
“We are continuously doing SIMOPS (simulated operations) with work-class ROVs and the ROV pilots have commented on how much easier it is to manoeuvre around the divers’ umbilicals now that they are (the umbilicals) illuminated,” said a spokesman.
“The umbilical really did light up really well; with the divers able to follow the umbilical all the way back to the bell. We believe this is a real step forward in the ability for better diver umbilical management and safety.
“What is really noticeable is the way the umbilical stands out when an ROV is moving around. This has got to be a major safety feature. If it wasn’t for the light string, you wouldn’t know the umbilical was there.”
Nigel Kenrick, of Bibby Offshore, said that, on its dive support vessels, different colours were used for each diver to avoid confusion when they were working close together in poor light conditions.
“The main benefit is that the divers can readily identify where their umbilicals are at any time, preventing potential problems with unseen snagging hazards,” said Kenrick.
“The ROV can also quickly check the divers’ umbilcals are completely clear before landing large items on the seabed.
“The divers themselves started requesting umbilical lighting quickly following the early offshore trials. This, in itself, speaks volumes,” added Kenrick, who is diving & dive systems operations manager at the company.
Boskalis described Lightpath as a “very nice system” though it could be a bit brighter.
According to PSL, its technology offers the potential to enhance safety for all parties operating in the subsea environment.
The firm says this has been proven for the individual diver, his colleagues in the water and the bell-man.
Moreover, ROV pilots are aware of the route of the umbilical which minimises the risk of collision and helps detect cases of dive umbilicals snagging on structures.
The system can be used to identify the individual diver through choice of light output colour . . . green, blue and white.
Green operates near the peak eye response, the optimum wavelength for the human eye, and provides extraordinary output from minimum power, typically less than seven watts.
Subsea professionals have identified various further applications of PSL’s technology, including the lighting of tool boxes, tether lines and restraint systems including the so-called “golden gate”.
ROV pilots highlighted the lighting of manifold valves, control panels and docking or garage guidance systems.
Salvage divers identified guide routes into wrecks utilising a continuous line of light and marine archaeologists are looking at controlled site access and “grid location”.
For non-submerged operation PSL has developed a fourth colour system . . . red.
Marine applications to enhance operational safety on deck include guard rails, open hatches, temporary work areas and below deck identifying egress routes.
Offshore wind safety applications identified include turbine tower access and lighting and ship personnel transfer systems. To that end, PSL is working with the SE Offshore Wind Expert Support programme and BVG Associates.