The Magazine for Underwater Professionals
In the fourth of a series of articles on hyperbaric rescue, Brian Redden, director of global hyperbaric rescue services at UK-based JFD, looks at self-propelled hyperbaric lifeboat recovery
In the first three parts of this series of articles I reviewed the general history of the modern commercial diving industry and how hyperbaric rescue has developed to date. Here, in part four, I will look at what is undoubtedly the industry ‘hot topic’ just now, the recovery of a launched self-propelled hyperbaric lifeboat (SPHL).
When SPHLs were introduced they were a major step forward. However, it has always been recognised they have a significant limitation. This is that their design, being a compromise considering hull shape, weight and space limitations, gives most SPHLs a maximum speed of around six knots at best. So if launched, the crew must either try to reach their HEP (hyperbaric evacuation plan) nominated safe haven under their own power or hope that another vessel can rendezvous with them to either take them in tow, or sail alongside providing a shelter lee to help them get to port.
In 2003, the Norwegians introduced a game changer when the MV Stril Poseidon was commissioned into service by Statoil as the first rapid response rescue vessel (RRRV), a ship equipped specifically to recover conventional lifeboats at sea. Modus operandi was rapid transit to the lifeboat(s), take it under tow and winch it up the stern slipway, empty it of people and go rescue the next one. The Stril Poseidon and her successors all have the capacity for taking some 300 persons on board.
That same year, Norsk Hydro introduced the RRRV Havila Troll which also included the capability for the recovery of SPHLs as she was equipped with a LSP (life support package) and a modified slip to avoid damage to a hyperbaric lifeboat’s bottom mating flange.
In 2008, Statoil took into service the RRRV Stril Herkules and in 2011 the RRRV Stril Mercur, both equipped for conventional and hyperbaric lifeboats.
In 2014, Statoil, together with Technip and Subsea 7, performed a first-time-ever full-scale test of recovering an SPHL into an RRRV. They presented their findings at the 2014 IMCA Annual Seminar in London, UK, and described their lessons learned, stating their overall conclusions to be:
While the RRRV approach to SPHL recovery is certainly ‘a good starting point’ and is better than having no recovery options at all, the full-scale test video showed the solution to be very weather dependant.
The other alternative is to physically lift the SPHL out of the sea and this is the solution Thrust Maritime of Australia provides with its stern-mounted Thor A-frame. Thrust put its first system to work in 2013 and commissioned its second system this year for its latest contract offshore Myanmar. This project is interesting because, as the location is so remote, Thrust has installed a portable HRF as well as its Thor A-frame onto the MV Surf Panglima, its HRV (hyperbaric rescue vessel) for the duration of the campaign.
Lifting the SPHL out of the sea is also the solution JFD is introducing with its SPHL recovery (SPHL-R) service, but with very different methodology. With more than 31 years experience of operating submarine rescue systems, we have concluded that an ‘over the side’ launch and recovery system (LARS) is a superior solution to a stern-mounted A-frame, mainly because the vessel itself can be used to create a lee. This makes rendezvousing with the SPHL and handling much easier.
The JFD SPHL-R service also uses a LARS with twin lift points, which means the SPHL can be lifted in higher sea states than if the single central lift point is utilised (because in the majority of SPHLs, this is certified for a maximum of sea state 2).
The LARS is a Caley Ocean Systems, UK, design which has been in service with the Canadian Coastguard since 2005 and is installed on a number of its vessels to handle workboats of up to 18 tonnes.
The SPHL-R LARS design is certified to handle all sizes of hyperbaric lifeboat up to the latest 24-man design (i.e., to 13.5 metres LOA and 24 tonnes for operations in up to sea state 6). Additionally, because the LARS is a two-point lift with constant tension winches that can be operated individually or in tandem and includes hydraulic snubbers which stop the SPHL swinging or rolling, the ride for the occupants is made considerably safer and more comfortable.
Modus operandi for the SPHL-R service is that LARS systems will be held in readiness in bases around the world for rapid mobilisation onto a pre-engineered vessel of opportunity mother ship (MoShip) when JFD is notified of an SPHL launch.
JFD will ensure that in each operating region, enough platform supply vessels will be identified and pre-engineered, so as to ensure that there is a large enough ‘pot of MoShips’ from which to choose in the event of an SPHL launch. All the potential MoShips will be monitored constantly by the ‘SubRescue Ops team’ in Govan, Glasgow, Scotland, via the internet, so that we know where every vessel is every hour of every day, in exactly the same way the team keeps tabs on their submarine rescue ‘MoShip fleet’.
The JFD SPHL-R service will meet the performance criteria in OGP 478. The key capability measure of SPHL-R will be to achieve a time-to-first-rescue (TTFR) of 32 hours in all cases (TTFR is a key measure in JFD submarine rescue, so has also been adopted for SPHL-R). In order to achieve this, the service will bring together a variety of elements, as illustrated in Figure 1.
Each SPHL-R base will be equipped with LARS with hydrulic power unit, life support package, spares/workshop container and offshore generator.
For the North Sea SPHL-R service, the call-out timeline is shown in Figure 2.
JFD plans to have the first SPHL-R service operating in the North Sea region in early 2017.
In the next issue of UCi, I will look at the practical and physiological issues the divers and operating crew would face in an SPHL launch and the priorities for the medical team once the hyperbaric lifeboat has docked to its HRF.
It was May 1974 in the Ekofisk oilfield offshore Norway and I had been one of the divers in a team living on board the jack-up rig Gulf Tide for about six months working four weeks on and one week off. People working offshore nowadays don’t know how good they have got it. They usually look at me as if I am telling porkies when I tell them that that rota was the norm in those days. Even worse, we didn’t get paid for the week off and because we crew changed both ways by supply boat, if like me you lived in the UK, you usually only got three days at home. No wonder a high proportion of us got divorced.
We were carrying out various installation jobs in the Ekofisk oilfield, which was still under construction. The first platforms had been put in about two years before and it would be another few years before the whole complex was commissioned. To get cash flow, the operator Phillips Petroleum had had the Gulf Tide on station acting as a temporary production platform since 1971, but it wasn’t until April 1974 that production platform 2/4 Ekofisk Alpha started to lift oil from its well no. 13. The crude went from the well up to the platform where water and gas were separated out, then was pumped into the pipeline to a loading bouy where the tanker Elizabeth Fernstrom took the ‘Texas tea’ cargo on board.
We were living on the rig but were transferred down by crane basket to the supply boat MV Imkenturm which had an air dive system on board, to do whatever job was on each day. For the first few months we had been diving below and around the rig connecting pipelines and various flexible flowlines.
The dive team was the usual eclectic bunch and as we were quite weather dependant and had many days when we could not dive, we all got to know each other quite well. We were usually eight divers and a supervisor, with a mix of nationalities and backgrounds.
The supervisor was a tough as a nut five-foot, one-inch ex-Royal Navy clearance diver from deepest Norfolk whose favourite saying was “larf ee say, oi larfed sow much oi peed oiself n made oi leg go rusty”!
One of the divers was about six-foot, six inches, an ex-Royal Navy submariner who used to make his model trains offshore. He had come on board with his small bag of tools and paints, some parts he had turned on his lathe at home, a collection of wheels and axles and a few sheets of tin plate and by the end of each trip he had have made and painted a beautiful engine or rolling stock for his train set layout at home.
Another was an ex-SBS diver who was intensely proud of his wedding tackle and at the merest mention of male competition he would lob his pride and joy out to show it off.
We also had an American diver who said he was an ex-Seal, although nobody believed him. He was totally fixated on Princess Caroline of Monaco. When he opened up his briefcase, unlike every other diver who had a selection of the stickers from every dive company they had worked for (and a few they said they had worked for, but hadn’t), he had around 20 pictures of Princess Caroline in bathing costumes and ball gowns stuck on the inside of the lid. He bragged that he and she were pen pals, but that was another thing nobody believed.
Anyway, to get to the point of the story, or points plural because two things I distinctly remember happened on this one trip.
The first was a diving incident. The Imkenturm was moored up to the flare jacket 2/4, weather was virtually flat calm and my job was to do an air SurDO2 dive in a KMB8 to fit an anode onto a platform horizontal cross member at the -140-foot level. I left surface at 20.00hrs (diving in the dark again!) and slid down the downline to the jobsite where I arrived OK a couple of minutes later. We had already fitted a bunch of these one-tonne anodes, so had the routine off pat. The anode was lowered down by the platform crane and had a hinged flange which was tied open with rope. I had the eight bolts and nuts and two ring spanners in a canvas bag carabinered to my harness. The job went well, I had positioned the anode, cut the rope to let the flange close around the cross-member, got all the bolts in and nuts on and was just hand tightening the last of them when I started to feel queasy/nauseous and my head started to pound.
I had had surface slack off on the crane wire, taken the two strop shackles off the anode lift eyes and refitted their pins and just told surface the crane wire was clear to lift away, when I reported feeling unwell to the supervisor. He asked a couple of questions and I think by the tone of my voice deduced that all was not well and told me to ensure I was free to leave the jobsite (we usually carried a short rope strop and sometimes tied ourselves to the jacket if there was a tide running) and start up the downline. I told surface “left bottom – up on my umbilical” (even though the actual seabed was some 100 feet below) and the last thing I remember was the supervisor repeating back to me “roger that, you’ve left bottom. Your bottom time was 58 minutes”.
I woke up with somebody saying to me “OK, take big breaths, come on – breathe easy”. I realised that I was on the surface, had been undressed (my Viking dry suit removed) and was in the DDC (deck decompression chamber) lying on a bunk in my woolly bear (undersuit) breathing oxygen from a BIBS (built-in breathing system) mask strapped to my face. Apparently, I had blacked out and when the supervisor got no response from me he had had my tender continue to haul me up by my umbilical while he jumped the standby diver to come and get me. On the surface they had quickly undressed me and the three of us (me, standby diver and diver medic) had been chucked into the DDC and re-compressed to 60 feet and started on a US Navy Treatment Table 5 decompression schedule. Although I had a headache initially, that cleared by the time we were near surface in the pot and I had no other ill effects.
It transpired that with the weather being so calm, the ship’s exhaust fumes had not been taken away by the wind as they usually would have been, but had swirled about and been sucked into the diving LP air compressor intake. So I had been poisoned by carbon monoxide (CO), made worse by breathing the CO at a higher partial pressure because of my depth. The supervisor and medic suspected this could have been the cause when they got me on deck and took off my bandmask and saw that my lips were cherry-red. A couple of the guys on deck had also complained of feeling mildly nauseous, with headaches and dizziness.
Once I was safely into the DDC and on oxygen a test was done on my umbilical breathing air and this confirmed there was a high concentration of carbon monoxide in it. Luckily, the standby diver had not been affected because his umbilical air supply was from a different source to mine (an HP air bank and through a regulator panel).
The second memorable aspect of that trip offshore was a weather incident. We had got out of the DDC after treatment and been lifted up onto the Gulf Tide when the weather started to deteriorate quickly. By midnight the wind was blowing so hard it was forbidden to go out of the accommodation/bridge areas and the captain had jacked up the rig to try to get it out of the waves. However, green water waves were washing over us and every man on board wore his survival suit and lifevest for the next 48 hours or so.
We couldn’t see much of what was going on outside, but in that two-day period, 100 feet plus waves were recorded going through the Ekofisk platforms twice – and that was only supposed to happen once every 100 years! The waves took away all of the platform’s boat landings, a lot of the platform’s near surface cross-members and all the walkways, causing a colossal amount of damage.
I did once see a photograph taken from a ship of one of the 100-foot waves as it went through the Ekofisk platform 2/4/D southern flare stack and all you could see was the top 15 feet or so of the flare stack with the green water wave just curling its way through. If anyone has this photo, I would love to get a copy for my scrapbook.
So that was a week in the life of this diver in May 1974 – and one that saw another one of my nine lives gone!
Brian G. Redden