The Magazine for Underwater Professionals
Sonardyne Inc. in Houston, USA, reports it has supplied acoustically-aided inertial navigation technology to offshore engineering, procurement, construction and installation company McDermott International, USA, for its lay vessel 108 (LV 108).
The Ranger 2 Pro DP-INS system, the highest specification available from Sonardyne, is being used to support touchdown monitoring surveys of submarine cables, umbilicals and pipelines and as an independent position reference for the LV 108’s Kongsberg, Norway, dynamic positioning system.
McDermott’s LV 108 entered service in 2015 and is currently on contract in the Ichthys field, Western Australia. Designed as a fast-transit, dynamically positioned (DP2) vessel for subsea constructions support across a wide variety of water depths, the LV 108 has 21,528 square feet (2000 square metres) of deck space and can accommodate a crew of 129.
“Dynamically positioned construction and installation vessels such as the LV 108 conventionally rely on ultra-short baseline acoustics and the Global Navigation Satellite System as their primary sources of position reference data,” said a Sonardyne spokesman. “However, a vessel’s station-keeping capability can be compromised in the event the USBL is affected by thruster aeration and noise and the GNSS signal is simultaneously interrupted. The latter is particularly common around equatorial regions and during periods of high solar radiation.
“The Ranger 2 Pro DP-INS system addresses this vulnerability. It aids vessel positioning by exploiting the long-term accuracy of Sonardyne’s Wideband 2 acoustic signal technology with high-integrity, high-update rate inertial measurements. The resulting navigation output has the ability to ride-through short-term acoustic disruptions and is completely independent from GNSS.”
UK-headquartered Global Marine Systems (GMS) has announced it has been awarded the renewal of the Atlantic Cable Maintenance Agreement (ACMA), alongside its Atlantic partner for maintenance services, France-based Orange Marine. The new contract runs for five years, through to December 2021.
ACMA is a non-profit cooperative subsea maintenance agreement consisting of 60-plus members. ACMA members are companies responsible for the operations and maintenance of undersea communications and power cables, as well as oil and gas platform operators, in the Atlantic, North Sea and South Eastern Pacific Ocean. GMS has delivered maintenance services across the Atlantic since the first cable was laid in the 19th century and has been a key supporter of ACMA since its inception in 1965. GMS currently delivers maintenance support in three of the six zone agreements globally.
GMS’s dedicated maintenance vessels, the Wave Sentinel and Pacific Guardian, will be servicing ACMA17 from their respective bases in Portland, UK, and Curacao in the Netherlands Antilles. Both vessels are fitted with powerful remotely operated vehicles, the Atlas and ST200 series respectively, which are used for monitoring, cutting and burying cable.
Aberdeenshire, UK-based survey and positioning services provider iSURVEY Offshore Ltd reports the award of a non-exclusive call-off contract with Shell UK Ltd, Shell NAM, Norske Shell and Shell E&P Ireland for the provision of rig positioning and surveying services.
The three-year contract, which has the option of up to two one-year extensions, will see the company provide non-exclusive rig and surface positioning services, subsurface positioning and dimensional control and platform surveys to Shell’s mobile offshore drilling units.
Andrew McMurtrie, managing director of iSURVEY Offshore, said: “This is a significant win for iSURVEY in what has been a challenging time for the entire market. We are pleased that our capabilities and service offering have been recognised by Shell, proving our reputation in offshore positioning within the European markets, and is testament to our highly skilled and experienced team.
“We look forward to supporting Shell’s operations, and intend to use this positive development as a springboard for growth throughout 2017 and beyond.”
Lowestoft, UK-based CMS-Geotech reports its multipurpose vessel MV FlatHolm has completed a successful charter with James Fisher Marine Services, UK, undertaking a variety of service activities in connection with the UK’s Galloper offshore wind farm.
Currently being constructed 30 kilometres off the coast of Suffolk, the Galloper offshore wind farm project is scheduled to be fully operational in 2018, generating enough power for up to 336,000 homes. The project has recently been busy with turbine foundation preparation.
“MV FlatHolm provided daily cover, making sure the site was clear and checking for hazards and obstructions which might have hindered operations with the scour protection rock placement work,” said CMS-Geotech. “Being based locally in Lowestoft, MV FlatHolm was able to be on standby for any situation which might require immediate deployment, offering efficient and cost effective support whenever needed.”
The 24-metre vessel also completed operations with the deployment of two Triaxis waverider buoys before the charter conclusion, the firm added.