Laurie Crane, North Sea Oil – Saturation Diver and Film Extra
Laurie Crane – Saturation Diver
Saturation diving acquires its name when divers are housed in Steel cylindrical chambers pressurised to the depth at which they are working. The nitrogen in the air they breathe is replaced by helium, this affects the divers larynx & voice, becomes squeaky, his body is saturated by the helium gas, hence the name “Saturation Diving”.
Divers sometimes as many as 18, live, eat, sleep shower & shave in a combination of linked pressurised chambers on board a Dive Vessel (DSV) for up to 28 consecutive days. From here, that they are transported to and from the worksite in a Diving Bell, so called because of its shape.
This bell is pressurised to the same depth as the chambers, a team of 2 or 3 divers enter the bell, which is then detached from the Chamber complex, lowered into the water and descends through the depths to the worksite. A service umbilical, delivers the bells occupant’s vital provisions, such as breathing gas, communications and hot water, which are distributed within the bell and then on to the divers through individual umbilical’s. One diver (bellman) remains in the bell tending his workmates and at hand in case of any emergency.
Divers wear neoprene suits that are plumbed into the hot water; a network of small rubber tubing within the suit sprays the hot water all over the diver’s body, bathing and shielding it from the cold icy waters. The reinforced fibreglass helmet that they don provides gas to breathe, communications to video footage to the Dive control room, a light, illuminates the dark depths. Divers carry a selection of basic tools, as most equipment is supplied from the vessels deck, in workbaskets via the crane. A dedicated team of specialist riggers help ensure that all the equipment is at hand, serviced, working and ready for use at a moments notice
Being the last person at end of an umbilical, the responsibility at times is enormous, all eyes are on the diver, literally, and each and every action is monitored and recorded. Diving has evolved over the last four decades from a cavalier approach with regular incidents, to a modern discipline of “pre planning”, “safety first”, and “take your time” it is with this mind set, that saturation diving in the North Sea, is often preferred to air diving . Of course there’s always a risk, as in all walks of life, with divers, sometimes at depths in excess of 500ft, incidents can have serious consequences, especially when you bear in mind that decompression from say 500ft will take around six days!!.
Saturation Diving is not cheap, far from it; a huge workforce is employed to sustain a Modern DSV. Figuratively from the bottom up, divers are supported by the riggers, overseen by Supervisors (ex-divers) who have an immense responsibility, assuring the diver’s safety and wellbeing as they co-ordinate the dive. The Superintendent is a former supervisor & diver, vastly experienced and chosen as he possesses the ability to co-ordinate the entire workforce, communicate with the client, they have engineers, sub-sea specialists and project co ordinators to assist them, together with the vessels marine crew and captain.
The divers task complete, approximately 7 hours after descending, the bell returns to the saturation chambers back on board the vessel, it is here that the LST’s (life support tech’s) are the external lifeline for all the lads in Sat. Responsibilities include the mixing of gasses, preservation of the chamber living environment and assisted by tenders the preparation of foods, teas, coffees etc supplied to the divers through pressurised locks. They launder the divers work and personal clothing, send their faxes / e-mails, they even flush the diver’s toilets. Divers simply can’t exist without this dedicated team who are in turn aided by the diving technicians whose constant maintenance, servicing and hard work help prolong equipment life in this most hostile of working environments, the cold murky depths of the North Sea.