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March/April 2009
SAFETY STANDBY VESSELS CONTINUE RAPID EVOLUTION
DESIGN AND CONSTRUCTION OF SAFETY STANDBY VESSELS, OR EMERGENCY RESPONSE VESSELS (ERRV's) HAS EVOLVED RAPIDLY AND CONTINUES TO DO SO WITH NEW TYPES, NEW TECHNOLOGY AND NEW ROLES COMING TO THE FORE, ALTHOUGH A NUMBER OF CHALLENGES REMAIN
Speaking at the Annual OSJ Conference 2009, David Kenwright, Chairman of the Emergency Rescue Response Vessel Association (ERRVA), provided an overview of what he sees as some of the key issues facing this industry sector, which has evolved rapidly in the last four or five years. At the same time, Michael Cowlam, Technical Director of Seacroft Marine Consultants provided an overview of the latest technical advances.
'Many of these challenges are very similar to those facing the whole marine industry, namely recruiting and retaining competent well-trained crew, securing gainful employment for vessels and, more recently, addressing the problems associated with access to funding, at a time when the banking industry is in turmoil', Mr Kenwright told the conference.
'The one area where there is a major difference is that the supply and demand for ERRVs has remained stable, and has not been the focus of major speculative investment by shipowners from other market sectors'.
'The present low oil price, coupled with worldwide financial instability will, if sustained, inevitably lead to a reduction in exploration and development activity in the short-term, and may also lead to a postponement in exploitation of known accumulations. Any consequent reduction in the demand for ERRVs could therefore come at a difficult time for the industry, which has invested heavily in new tonnage as part of a fleet renewal process.'
'However', Mr Kenwright said, 'most importantly, the need to exploit oil while the existing, ageing North Sea pipeline and platform infrastructure is operational will remain, especially as North Sea oil and gas production has reached a plateau and is in decline.'
As he noted, the weakening of Sterling against both the Euro and the Dollar, in an industry where revenue and costs are invariably in Sterling, has resulted in foreign seafarers seeing their income being eroded, and which if compensated for, inevitably leads to spiralling operating costs for shipowners.
Nevertheless, Mr Kenwright told delegates, 'even considering all these factors, an ongoing need for investment will still be needed if the average age of the ERRV fleet is to be maintained at the present level, and if the inventory of vessels is to be maintained at an adequate number to meet not only present but future demand.'
'The industry challenge is how these factors can be accommodated, while at the same time maintaining traditionally high standards, and meeting the needs of our clients,' Mr Kenwright concluded.
The fast pace of ERRV development has been addressed before in OSJ, at the Annual OSJ Conference 2009 in London during February, Michael Cowlam, Technical Director at Seacroft Marine Consultants, provided a new take and a fresh perspective on changes taking place in the sector. His interesting paper looked at vessel evolution and at offshore rescue and recovery as a whole.
As is well known, not that long ago, most ERRVs were converted fishing vessels and hence of relatively low specification and performance, with relatively poor manoeuvrability. They had minimal modifications to suit them to their new role, limited space and facilities for crew and survivors, also limited rescue equipment. Moreover, launch and recovery arrangements were not always ideal and there was little or no additional training of seafarers, who, although well qualified in their own field, had little or no experience of resuce operations.
The most important milestone in offshore rescue and recovery was, of course, those changes implemented following the Piper Alpha disaster, the world's worst offshore accident. The findings of Lord Cullen's inquiry led to widespread new thinking.
These and subsequent changes have been described previously in OSJ but in his presentation Mr Cowlam moved right up to the present day with a discussion of the latest types of multi-role ERRVs, the first generation of which combined the role of a safety standby vessel with those of a PSV, providing supply and infield cargo operations. More recently, such multi-role ERRVs have also begun to be used as platforms for ROV work and potentially many other roles too, such as emergency towing and tanker assist, emergency dive support and providing offshore accommodation and access to platforms.
One interesting example highlighted by Mr Cowlam is Grampian Frontier, one of the earliest vessels used for ROV support; it first undertook ROV operations in the early development phase of the Foinaven and Schiehallion fields West of Shetland. The ROV function of Grampian Frontier has now been removed, but the vessel has since become involved in another auxiliary role; it is equipped with an emergency diver decompression chamber to support diving operations within the turret of the Schiehallion FPSO. This unique requirement came about when it became clear that there were no alternatives if the installation needed to evacuate personnel in the event of an emergency.
BP's Jigsaw project has, of course, seen signficant changes, with 24 hour rescue cover provided by a combination of Search & Rescue (SAR) and helicopters (except for overside work). For normal operations, a multi-role Regional Support Vessel (RSV) acts as host for rescue craft, and this deploys its rescue craft as required; these take the form of two 18.8m Autonomous Recovery & Rescue Craft (FRCs) to provide additional cover for overside work. The deployment of resources for Jigsaw is actively managed by an onshore co-ordinator.
The other key element of the Jigsaw concept is, of course, not a vessel or rescue craft at all, but a helicopter - actually two AS332 L2 Super Puma SAR helicopters with a speed of more than 140 knots plus, capacity for at least 21 survivors. Such designs have a host of features including a forward looking infrared (FLIR) camera; a high-powered searchlight; a fixed electric hoist plus a fixed back-up hydraulic hoist; the ability to drop life rafts; direction finding equipment for personal locator beacons (PLBs), a loud hailer and stretchers.
The BP RSV is, of course, a unique vessel type, based on the IMT992 design. At 94m length overall and with a beam of 22m and draught of 8.5m, it has twin azimuth propulsors, a maximum speed of 16 knots, a deadweight of 4,600 tonnes, and a crew of 26 (including 12 ARRC crew).
The IMT 992 RSV has capacity for 300 survivors, is designated as a place of safety; can act as an on scene co-ordinator and has a 760 sq m clear deck and deck tanks for all bulk supplies and products. The ARRCs are based on design from Delta Power Services and have a length of 18.8m, speed of 34 knots, range of 400 nautical miles and capacity for 24 survivors and 6 crew (in an emergency it can cope with 84). Like the RSV, the ARRCs are approved at a place of safety in the UK HSE and MCA to SCVC Category 1, have a qualified medic and treatment area, can be launched in 7m seas, and can be recovered in 5m seas.
As previously highlighted in OSJ, a multi-role function undertaken more recently has seen BP's pioneering Walk to Work concept tested on board the Multi-Role Access Vessel (MRAV) Highland Spirit. The Walk to Work concept sees the MRAV combine the role of an accommodation ship and providing an access gangway to offshore platforms. The package trialled by BP utilised a Class 2 dynamic positioning system, deck-mounted acccommodation structures, and a heave-compensated offshore access sytem (OAS) that provides access from the ship to installations that are normally unmanned.
In another interesting advance, the first ERRVs with the Ulstien X-Box hullform have been ordered. These are ships which will have a number of innovative design features, in addtion to the X-Bow, such as a stern ramp for the ship's FRC, an ARRC casualty rescue ramp, the use of a new generation of PLBs and rescue craft that are fitted with Royal National Lifeboat Institution (RNLI) style crew seats.
The potential merits of the X-Bow have, of course, been described on numerous occasions in OSJ, but they include; reduced slamming; higher speeds in poorer sea states (17 knots in 2m seas); reduced movement for launch and recovery of FRCs and daughter craft; excellent visability forward of the bow for casulaty approach; better crew comfort and a more stable working platform; and a higher volume of accommodation for additional facilities.
The new X-Bow ships will be owned and operated by Esvagt, which has introduced a number of innovations recently, including the company's own FRC design. An evolved version of an earlier Esvagt craft, this latest design differs from its forebear in a number of respects, not least that the earlier twin outboard diesel engines have been replaced with twin inboard engines and propeller out-drives (or Z or leg drives as they are sometimes known).
Inboard diesel engines coupled to waterjet propulsion are not uncommon in rescue craft, but what is unusual about the 15 man Esvagt FRC is that it has twin inboard engines, which is rare on this size of craft. This feature gives the apparent benefits of reliability and fuel economy whilst maintaining 100 per cent redundancy with dual propulsion, fuel and electrical systems. Another new feature is extensive sound-proofing from engine noise, which has been reported as being "sufficiently quiet that a conversation with the adjacent person at full speed is possible".
Historically, crew seats on FRCs have been marinised versions of seats from earth moving machinery, but on the ARRCs deployed from the BP Jigsaw vessels, the seats were specifically designed for the RNLI, for its new Tamar class lifeboat. Seats of this type were acquired and modified by BP for the ARRCs, and are said to reduce the amplitude of slamming from 20g to 7g, thus protecting the crew from potential injury. OSJ