Collected By : Vikramjit Kakati , Dibrugarh , Assam
They are safe
.....
They have been rescued.
And they are out of danger.
As soon as these messages had gone to the extremely anxious family members of the six divers, who were stuck in the gas decompression unit of the accident hit Samudra Suraksha, there was a great sigh of relief. Quite understandably, after spending long hours in the challenging circumstances when these six divers came back unhurt, ONGCs rescue ability had once again been revalidated.
Deep Sea Saturation Diving is a procedure followed, wherein saturation divers carry out prolonged underwater tasks in depths of water deeper than 25 metres, or so. Saturation diving requires divers to be pressurized in steel chambers, in an atmosphere made up of Helium and Oxygen (Heliox), to pressures equivalent to the pressure that would be experienced at their working depths. Once under pressure, they cannot be de-pressurised (brought up to the surface / de-compressed), in a short duration, since their body tissues are saturated with the Heliox gas atmosphere. A coarse analogy of this situation would be similar to the opening of a bottle of Pepsi / Coke and the spontaneous release of bubbles. This explains briefly, why the pressure could not be released in the chambers in which these six divers were housed. They were basically trapped. Prior to the accident, the Samudra Suraksha was engaged in a routine subsea Inspection, Maintenance and Repair (IMR) assignment at the N-7 Platform, and was carrying out saturation diving. Two saturation divers had returned to the diving system, at around 1500hrs, after a bell run (saturation dive), and were relaxing, with their buddies, in their living chamber. Upon impact of the vessel with the BHN platform, the initial assessment indicated challenging consequences, with imminent possibilities that the vessel would be lost (sunk). The Diving Superintendent, who was on the vessels main deck, at the time, immediately headed for the Saturation Chamber Control Room, and gave instructions for emergency procedures to be initiated. By this time, the off shift Life Support Technicians had already reached the control room, to assist the on shift personnel, with the emergency. The emergency procedures included pressurizing the chambers, in which the six divers were housed, to a pressure equivalent of 85 metres of sea water (approx. 9.5 Kgs/cm2). This was done with the intention of preventing an ingress of water into the chambers, due to the imminent danger of the vessel sinking. In parallel, the divers were also provided with emergency life support supplies. Within a span of no more than 10 to 15 minutes, the situation on board had deteriorated. That is where these divers showed unusual grit and determination. The six divers were in continuous discussion with themselves, utilizing their years of experience, putting forth their ideas, views and suggestions. By this time, they could feel the heat on the starboard bulkhead (wall), of the chamber that they were in. The chamber was on the starboard side of the vessel. They then decided to move across to the interconnected chamber, on the port side of the vessel. Like how ships are provided with Life Boats and Life rafts for evacuation of onboard personnel. On similar lines, Saturation diving systems are provided with a life boat, called a Hyperbaric Rescue Lifeboat (HRL), within which is housed a chamber, inter connected with the living chambers. Due to the emergency, the divers had commenced transferring, along with additional life support material, to the HRL. Just as the last two divers were going to transfer, the divers who were already in the HRL felt excessive heat in the chamber, and they immediately started returning to the main chamber, through the interconnecting manway (approx. 6 mtrs. Long, and 0.6 mtrs. in dia.). Just before leaving the HRL chamber, the divers noticed the fire outside, through the view port, and actually saw that the outer surface of the viewport (acrylic material), was melting. The divers expedited their transfer, through the manway, where some of them sustained minor injuries. The hatch at the end of the manway was shut immediately, as the last diver came through. By this time, the Samudra Prabha was directed to fight the fire raging on the vessel. Life support personnel were immediately mobilized from the Samudra Prabha, to take charge of the divers, and their further safe management. They consoled with the divers, and conveyed appreciation of their bravery and calm composure, during their last 10 anxious hours. The divers were provided with drinking water, fruits and biscuits. The chamber atmosphere was continually flushed with fresh Heliox to replace foul gases that had built up with in the chamber atmosphere during the past hours of crisis. Decompression of the divers was commenced.The divers were confident that they were now safe. Parallel efforts were made by base teams positioned at ONGCLs and the Subtecs office to transfer the Samudra Surakshas Diving Superintendent, Supervisors and some key Life Support personnel to the vessel, from the OSVs that had rescued them. By 0700hrs, the local hyperbaric medical consultant was mobilized at the ONGCs Juhu helibase, for transportation to the Samudra Prabha. He was appraised of the situation with respect to the divers. At this time, smoke was still emanating from the vessels accommodation and bridge, though it was stable and the fire was under control. The divers were therefore given a hold as there had been too rapid a change in pressure in the last few hours. The condition onboard deteriorated during the night and the life support technician reported smoke in the saturation control at about 0400hrs. Dr. Kulkarni the local hyperbaric medical consultant embarked Samudra Suraksha once again at about 0700hrs., and after a quick assessment of situation, conveyed to both the Diving Superintendents, his decision to abort the saturation. Decompression was stopped at 0720hrs., and the divers were informed of the doctors decision and the system was put on hold. An abort decompression was commenced at 0800hrs and completed at 0825hrs. All six divers reported that they were all right. Divers were transported to Samudra Prabha in a Zodiac and recompressed for a proper standard saturation decompression. The decompression was completed successfully. Following are the names of six divers in Saturation at the time of the accident : 1. Gyan Chand Yadav 2. Surender Singh 3. Raj Prakash Sharma 4. Rati Ram Phogat 5. Subhash Chander 6. Ranjit Singh By about 0230hrs (28th July), the Samudra Prabha had controlled the fire where the Diving Supt. and a couple of members from the Prabha dive team could board the vessel, to check on the status of the divers. Some metal to metal sound signals were passed, which received spontaneous responses. A brief peep through chambers view port confirmed that the divers were alive. Communication through a sound powered phone was carried out between the Diving Superintendent and the divers, to confirm that all was well. Fortunately, in a skillfully executed operation, the fire had been controlled before it reached the chamber area and by providence the oxygen gas quads which were stowed on the vessels deck, narrowly escaped the wrath of the fire. The six divers are part of the 31 man dive team onboard the vessel, and work for an international diving company, M/s Subtec Middle East Ltd., which is a subsidiary of M/s Global Diving Industries, USA. M/s Subtec provides the diving support to the Shipping Corporation of India. Owing to stiff underwater conditions these divers work only for six months a year said one of the senior executive of M/s Subtec Middle East Ltd., It was indeed a big relief for their families when it was known that they are safe. Thanks to ONGC he added.
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