The latest daughter craft and rescue boats feature robust designs and enhanced launch and recovery systems
The harsh conditions in the North Sea dictated the design of the davits selected by Esvagt to enable the launch and recovery of daughter craft for three of its upcoming service operations vessels (SOVs).
The trio of vessels are being developed by Havyard Design & Solution and constructed by Havyard Ship Technology, with delivery scheduled for 2020-2021.
Each vessel will be fitted with a PAP-16000 workboat davit with emergency launch capabilities, a PLRH-5000 SOLAS davit, two L-3500 life raft davits and a telescopic painter boom.
The PAP-16000 is a single point davit with a safe working load of 16,000 kg that uses a docking head to fix the boat into position during lifting and lowering. It has been designed to handle Esvagt’s large STB12 safe transfer workboat, with capacity for eight technicians and one tonne of cargo, fully equipped. It has a lifting speed of 45 m per minute and is fitted with shock absorbers and a constant tension system, with additional support coming from the long-outreach telescopic painter boom that can provide adjustable tension on the painter line via its winch.
The PLRH-5000 davit, meanwhile, is SOLAS-approved and will be used to launch and recover Esvagt’s STB7 safe transfer boat, with capacity for up to five passengers with hand-carry cargo. It can achieve lifting speeds up to 60 m per minute and is equipped with shock absorbers, a constant tension system and hydraulic guiding arms.
Nexans’ flagship cable layer Nexans Aurora will be fitted with an innovative system of hydraulic cradles from Vestdavit to handle launch and recovery of its daughter craft.
Instead of using overhead cranes, the vessel will use Vestdavit’s MissionEase multi-boat handling system. MissionEase works on a system of hydraulic cradles that move boats from stowage positions to maintenance, preparation and launch areas.
The system order includes Telescopic TDB-5000 davits installed either side of the mission-bay, deck-mounted transfer rails and a cradle mechanism. It will handle several workboats and tug boats for launch and recovery on either side of the ship. A single operator can use a remote control to launch and recover the mission boat, along with all on-deck handling.
Vestdavit’s system is suited for installation in boat hangars as well as on open decks.
In addition to the MissionEase system, Vestdavit will deliver two H-9000 davits, which can handle twin Fassmer SLT 8.5 life/tender boats.
Nexans Aurora was designed by Ålesund-based Skipsteknisk and will be constructed by nearby Ulstein Verft. It will measure 149.9 m in length by 31 m in width and have capacity to accommodate 90 people. Its duties will include power cable laying and cable-system protection and trenching.
The FRC Mk 3's carbon-fibre construction gives durability at a low structural weight
Denmark’s Tuco Marine Group (TMG) is a manufacturer of compact, lightweight, robust workboats and daughter craft that it says offer significant advantages over traditional materials.
The company’s ProZero construction method utilises carbon fibre materials that provide very high levels of strength and durability at a very low structural weight. These comprise a combination of glass and carbon fibre in a sandwich construction with PVC as a core material. TMG has carried out drop tests that have shown its materials have better energy absorption capacity than aluminium. Another advantage is that the ProZero panels act as a closed cell, meaning that in the event of damage to the vessel’s outer skin, water intake is confined and obstructed. In comparison, an aluminium panel would suffer full penetration.
“The sandwich construction removes the need for internal stiffeners, thereby increasing useable space”
Part-funded by the EU’s Horizon 2020 research and innovation programme for small- and medium-size enterprises, the ProZero project uses these lightweight construction materials to reduce weight, resulting in reduced fuel consumption and CO2 and NOx emissions. This gives these vessels a larger operational range and the ability to travel at faster speeds.
The use of PVC as a core material acts as a natural buoyancy reserve, as it is lightweight and does not absorb water. The sandwich construction, meanwhile, removes the need for internal stiffeners, thereby increasing useable space.
TMG recently announced a super-compact 8 m vessel design, aimed at the service, subsea operations and diving markets.
The design can carry up to six passengers along with a helmsmen, protected from the elements by a full cabin. Sturdy railings and bow access form an integral part of the deck layout, and the raised aft deck functions as a full-beam work platform. Light projectors are mounted on the aft deck to provide optimal illumination when operating in dark conditions.
TMG’s design has been developed with daughter craft functionality in mind and it is equipped for single-point lifting. It can serve as an extension of its mothership to allow operations to be carried out in close proximity to offshore installations. As standard, the vessel is equipped with a single inboard diesel engine and z-drive propulsion unit.
The company has also launched a subsea survey boat, boasting some innovative design features.
The vessel’s hull is designed for efficient surveying, with minimal interference to sensitive measuring equipment. Ths design accommodates workspace for two subsea specialists along with a helmsman.
This is achieved through recessing sonar equipment into the hull structure itself to protect it from adverse conditions. The hull profile has been designed to reduce cavitation bubbles and the sweep-down of bubbles from the bow that could cause interference with the survey equipment. TMG enlisted Copenhagen-based Hauschildt Marine to carry out computational analyses to identify the best hull design prior to the vessel entering production
A third-generation iteration of TMG’s ProZero fast rescue boat design has now been launched. Measuring 7.7 m in length with a beam of 2.86 m and a draft at full load of 2.36 m, the new design features a large deck area with capacity for up to 16 people and a maximum load of 1,310 kg. TMG has also incorporated new bow and fender configurations to improve safety during transfer operations. The standard propulsion setup is a single water jet option, but a twin installation is also available.
ERRVs move to Caribbean in support of BP
VOS Gorgeous and sister vessels VOS Fabulous and VOS Grace will relocate to the Caribbean in support of BP
Vroon Offshore Services (VOS) Aberdeen has signed a multi-year, multi-million-pound contract with BP Trinidad and Tobago, to supply emergency response and rescue vessel (ERRV) services for BP’s operations in Trinidad and Tobago.
The North Sea’s largest operator of ERRVs, VOS – part of the Netherlands-based Vroon Group – will relocate three vessels, VOS Fabulous, VOS Gorgeous and VOS Grace, to the Caribbean to support the contract.
VOS Aberdeen managing director Craig Harvie said the contract will allow the company to build on a partnership it established last year, with an agreement to supply multiple ERRVs in the North Sea and west of Shetland for BP Exploration Operating Company Ltd.
“The new contract and repositioning of three offshore-support vessels also signals a strategic move into the Caribbean and South American market for Vroon Offshore Services, as we continue to assess further opportunities in the region,” said Mr Harvie.
In terms of survivor recovery equipment, the three vessels have slightly different loadouts. VOS Gorgeous carries one Delta 15-person daughter craft launched from a Macgregor HMD G80 davit with an 8-tonne safe working load (SWL) and one Kossen 15-person fast rescue craft launched from a MacGregor HMD G40 davit with a 4-tonne SWL. Additional rescue and recovery facilities come in the form of a Dacon Scoop mechanical recovery system, two 5 m overside rescue zones, an emergency helicopter winching area, a six-person rescue basket, two searchlights and a self-drenching capacity.
VOS Fabulous has the same configuration, with capacity for additional rescue craft to be fitted on request; VOS Grace carries the same configuration but has helicopter winching areas forward and aft, and mounts four searchlights, two forward and two aft.
With an overall length of 50 m, VOS Fabulous has seats for 66 and bunks for 26 survivors and is fitted with rescue and daughter craft. Both VOS Gorgeous and VOS Grace have similar capacities for survivors but are slightly longer, at 60 m each, and have dynamic positioning class 2 capability.
New UK Workboat Code
The National Workboat Association (NWA) has launched Edition 2 of The Workboat Code, a document that defines working practices and standards for workboat operators.
It is 20 years since the first edition of the code was published in 1998. Like the first edition, the second edition was developed by a working group led by NWA in close co-operation with the Maritime and Coastguard Agency (MCA) and other partners, including class societies Bureau Veritas, DNV GL and Lloyd’s Register.
The new code is mandatory for use on new workboats and pilot boats, with keels laid or in a similar state of construction on or after the publication date of 31 December 2018; it can also be used on pre-existing workboats and pilot boats.
Existing workboats that choose to comply with the new code must do so as described by the code itself and in full and cannot meet a combination of second-edition standards and those of earlier codes or standards. When an existing vessel has new equipment installed or undergoes modifications, the standards of the code are to be applied as far as is practicable.
It applies to small workboats operating to sea and all pilot boats carrying cargo or not more than 12 passengers or industrial personnel. Small workboats are defined as vessels being less than 24 m in load line length, or for vessels with keels laid prior to 21 July 1968, with a gross registered tonnage of less than 150. The code applies on UK-flagged vessels meeting this description regardless of location, and to non-UK-flagged vessels meeting this description in UK waters or operating from UK ports.
Revisions and additions to the code reflect changes in workboat operations in the 20 years since the first edition was published. New areas covered include updates to guidance on stability for modern designs, vessels engaged in towing, and workboat applications such as offshore wind crew and equipment transfer, along with carriage and transfer of hazardous materials.
The full code can be downloaded from MCA’s website.