On July 27 2005 the Dive Support Vessel Samudra Suraksha contacted gas risers attached to the Mumbai High North (MHN) Platform and the resulting fire destroyed the platform, the ship and a jack-up which happened to be drilling on the wellhead platform. There were 11 recorded deaths and 11 people were posted as missing. The Oil and Natural Gas Corporation of India carried out an investigation with the assistance at the time of the UK HSE. As far as can be ascertained the report into the investigation has never been published.
THE VESSELS INVOLVED.
The dive support vessel Samudra Suraksha was built at Kleven Maritime in 1982 and was a UT707. It was 100 metres (328 feet) long. It had 15500 bhp available which drove a single main propeller with two azimuthing thrusters aft, and two tunnel thruster forward. The ship was provided with DPII and could also be manoeuvred using a joystick, a collective control. It had individual throttle, rudder and thruster controls. It was also possible to operate the thrusters by push buttons, known as the “emergency control”. The ship was provided with a saturation diving system which allowed divers to be housed in a high pressure environment, so that they could be deployed in the diving bell and recovered and rested without any change in pressure. This is known as being “in sat”. A sister ship the “Seagair” which had been owned and operated by BP had been constructed in UK in 1983.
The Mumbai High complex consisted of four bridge linked platforms, NA, MHF, MHN, MHW. It was located about 100 kilometres west of Mumbai in 73 metres (239 feet) of water. It had an oil processing capacity of 180,000 bpd. The MHN platform was an eight legged steel jacket with a three deck topsides, and had been built as the processing platform in 1981. The NA platform was a small wellhead platform which was constructed in 1976, and was the first offshore well in India. The MHW was a recently added additional process platform. The MHF was the accommodation platform.
The Noble Charlie Yester was a LeTourneau 116C jack-up rig built in Singapore in 1980. It was capable of drilling to 25,000 feet (7620 metres) and could operate in water depths of up to 300 feet (91 metres).
PREAMBLE.
On the day of the accident the Samudra Suraksha was carrying out diving operations in the field. There were 84 people on the ship, including six divers in sat.
The Noble Charlie Yester had its cantilever deployed over the NA platform and was carrying out various downhole tasks on behalf of its charterer the Oil and Natural Gas Corporation of India. There were 73 people on board.
The Mumbai High Field was, in general, following its normal day to day activities, involving the processing of hydrocarbons, the maintenance of equipment and the provision of hotel services. The only unusual circumstance was that there was a helicopter shut down on the helideck of the MHN platform due to the monsoon weather which prevailed at the time. There were 227 people on board the platform complex.
On the day of the event monsoon condition were being experienced in the field, with wind speeds of about 20-25 knots, and wave heights of four to five metres (15 feet).
THE SEQUENCE OF EVENTS.
July 27 2005.
1400. The Cook on the Samudra Suraksha cuts off the ends of two of his fingers. The Captain orders the recall of the divers to the bell, and the recovery of the bell. The ONGC rep on the ship requests the medical evacuation of the Cook by helicopter.
1445 approx. The OIM in the MHN platform receives a request for the transfer of the Cook, however the helicopter which is parked on the MHN is not allowed to fly due to weather conditions. The Samudra Suraksha’s Captain requests permission to basket transfer the Cook, but is told to wait because the platform is busy with an OSV.
Medical assistance is requested from, probably, the MHF platform but this is refused.
The Captain calls the jack-up Aban 5 and requests permission to transfer the Cook for medical attention, but this is refused due to the inability of the rig to accommodate the injured man overnight.
1530. The OIM of the MHN agrees to allow a basket transfer using the south crane which is to windward. The lee side crane is unavailable due to mechanical problems. The ship makes its way to the MHN platform and the starboard azimuthing thruster is seen to be sluggish. The master decides to operate the thrusters in emergency mode.
1605. The Cook is successfully transferred by basket, and the ship is attempting to move away when a heavy swell displaces it towards the platform and the helideck hits the southwest corner, severing one or more gas export risers.
1610. There is fire at the southwest corner of the MHN platform and on board the Samudra Suraksha. A number of explosions take place on the Mumbai High North and a Mayday is sent out. The ships in the area converge on the location of the accident. A total of 15 vessels are involved in the rescue. 362 of the 384 people are rescued, leaving 22 dead and missing.
July 29 2005.
0400 Approx. The six divers who have been in sat are rescued from the burning hull of the Samudra Suraksha.
August 1 2005.
The Samudra Suraksha, which has been towed out of the field, sinks.
Within hours of the initial event the MHN and MHF platforms had been burnt down and the jack-up Noble Charlie Yesterseverely affected by radiation. The rapid spread of the fire inhibited the launch of most of the lifeboats on all installations with only two of the eight complex lifeboats being launched and one of the ten liferafts. Only half of the Noble Charlie Yester lifeboats were launched.
Although none of the available information tells us, it appeared from a statement made in the Indian Parliament by the Minister of Petroleum and Natural Gas that the Mumbai Marine Emergency Communications Centre was completely out of action due to a power outage in the monsoon conditions, and that all the 12 commercial helicopters used in the area were grounded due to the weather.
THE INFORMATION IN THE PUBLIC DOMAIN.
Lacking any formal report, a number of organisations have made presentations to interested bodies and to the media, and this narrative also contains some details from a paper written by a student from Faculty of Engineering and Applied Sciences at St John’s University. A certain amount of information has also been available in the Indian newspapers.
In general the presentations have agreed on the sequence of events, although not all have featured the extraordinary lack of assistance offered to the Captain of the ship by the various facilities in the field. The UK HSE have been particularly keen to ensure that such an event would be unlikely to occur in the UK sector of the North Sea, and subsequent to the disaster the Indian government set up the “Oil Industry Safety Directorate” in 2006. Later this organisation was to ask for assistance from the American offshore regulators, and a Memorandum of Understanding was signed in 2006, although the safety record in the Gulf of Mexico has been nothing to write home about.
All those who have written about the incident have provided their own views of the shortcomings which resulted in the accident and the actions that might be taken to improve the situation. No-one has picked up on the lack of help the Captain received, but all have suggested that there should be an improvement in the procedures in place to provide guidance for the OIM of the installation, and they have suggested that in the prevailing conditions he should not have allowed the Samudra Suraksha to come alongside, no matter what. We can then consider the maintenance of the ship, which may have been less than adequate if one of the thrusters was not working properly. And one of the presentations suggests that the Chief Engineer had asked for time to fix the thruster, but instead the Captain had chosen to use the Emergency System.
The Canadian paper suggests that had a proper risk assessment process been in place then the vulnerability of the gas risers would have been identified and the HSE presentation points out this failing, framed in the hope that such an accident could not occur in the UK sector of the North Sea. There were other suggestions about the possibility of improved training for shiphandlers.
COMMENT.
Something that seems to eluded those commenting on the event has been the fact that the lee crane was down, the weather was extremely unpleasant, and the windward crane of the MHN was still working. After all, the diving ship was not allowed to come alongside because the crane was working another ship! Here-in lies a basic offshore problem. There is a tendency for those on board offshore installations to see getting the job done as the top priority, and the easiest way of dealing with support vessel is just to ask them whether they will be okay to carry on working, or going to work. In this they have avoided making the decision about ship work altogether. But the other half of the problem is that the shipmasters will feel that in order to fulfil the charterer’s wishes they should do their upmost to go to work, and will therefore be prepared to take risks. In general the size of ships has increased over the years so that if things go wrong they pose a danger to the installations they are serving, regardless of whether there are risers on the outsides of the jackets. It should therefore be up to the OIM to decide whether it is a good idea for a ship to go to work, or on the other hand the operator could make some rules.
And then we have the risers cobbled on to the outside of the jacket. Well, when it comes to installing the pipework after the platform has been put in place, it is obviously easier to attach them to the outside of the jacket rather than the inside. And this problem is not unique to India. There was, and maybe still is at least one platform which has the risers running up the side of the jacket directly under one of the cranes in the UK sector of the North Sea.
Since the report on the investigation has not been released we do not actually know how the evacuation process went, but probably not very well. And finally the MHN platform completely burnt down to a metal stub sticking out of the water in two hours. Were there no means on board to prevent the fire spreading?