300 meters deep and 30 hours at a stretch — no problem for Trident.
Trident™ is the name of the new insulation system for diving bells, based on glass-syntactic PU foam technology from BASF ZEROHg™.
It's cold, dark and dangerous down here. Everything depends on the strength and ingenious technology of the diving bell. And on the experience and concentration of the team at the surface who are responsible for the fortunes of the diving bell's crew. Saturation diving is a key task in the subsea industry. This is why engineers are constantly developing systems to upgrade working and living conditions, reduce pressure, and optimize safety and health.
Huge progress has been made in many important areas, e.g. breathing gases, comfort and medical monitoring. And now breakthroughs in foam technology are making a new contribution to improvements in operating and working conditions.
Trident, the new insulation system for diving bells, has been developed in a strategic alliance with BASF Polyurethane Solutions as the latest generation of glass-syntactic PU for the insulation of subsea equipment.
The co-initiator of this innovation is Trelleborg Offshore Houston, which develops special components for diving bell manufacturer Unique System LLC to improve safety, technical operation, and working conditions at extreme depths.
Ringing the changes for diving bells.
The performance of previous insulation systems was more difficult to predict. They were also susceptible to damage and water ingress, which could affect the thermal and buoyancy properties. In contrast, the Trelleborg polyurethane-based elastomer has high-impact resistance and is totally impervious to water ingress under pressure. It is designed to eliminate any requirement for maintenance in order to minimize life-cycle costs. For the crews of diving bells, Trident is also a big step forward.
The heliox breathing mixture (helium/oxygen) for the atmosphere in the diving bell is imported through an umbilical from the support ship. As heliox has a higher thermal conductivity than air, absolutely reliable and effective thermal insulation is critical to the divers' comfort. Since dive times within the bell can often vary from 10 to12 hours and the divers stay under saturation conditions for up to 30 hours, their well-being is of central importance for the success of each mission.
The new Trident is a real boon to the environment as well.
A general problem with conventional waterproof PU is the use of mercury-containing catalysts. Reducing mercury in the marine environment and in the food chain has therefore been a priority goal for many decades. With Trident, a big step has been taken in this direction
Furthermore, the new system delivers outstanding temperature resistance compared to conventional elastomers of waterproof quality, withstanding constant working temperatures of 110°C (230°F) at depth. Suitable for a multitude of applications, it ensures undiminished performance over long periods under thermal stress.
True quality from a single pour.
One of the keys to the success of the Trident elastomer in the diving bell is the way it was applied to the bell's metal shell. Despite the bell's size, shape and construction with its openings and protrusions, it was of huge importance that the foam could be poured in a single lift. This one-pour method was necessary to eliminate discontinuities and interface joints in the elastomer structure and prevent water intrusion into the foam when under pressure at depth. Penetrating water could significantly affect the elastomers' thermal properties and its characteristics as the outer coating of the diving bell.
Trident and its sophisticated construction now give the bell its inner and outer strength. And this is the best assurance of the safe transfer of divers, equipment and diving gear while providing simultaneous protection from pressure and temperature changes and the effects of currents and storms.