Toisa Pegasus - Diving Support Vessel

The Toisa Pegasus is a diving support and offshore construction vessel built by IHC Merwede for Toisa Ltd of Bermuda (the company has 23 offshore vessels including four saturation diving support vessels).

The Pegasus was built at the Merwede yard in Holland between March 2006, when the contract was won, and November 2007 when the ship was officially launched. After sea trials, the Pegasus is due for delivery in early 2008 and will be managed by Sealion Shipping Ltd, a subsidiary of Toisa. The ship is registered in the UK

SHIP CONSTRUCTION

The ship was designed as a fully dynamically positioned construction-class diving support vessel for worldwide operations. The design is similar to its sister ships Proteus, Polaris and Perseus but features enhanced capability for saturation diving with a state-of-the-art, 18-man twin bell saturation system.

In addition, the Pegasus has a flexible under deck arrangement to allow a broad range of equipment to be installed and also a large clear deck area to accomodate contractor applications. The 1,200m² work deck has a load capacity of five tons per square meter.

The ship has berths for 99 personnel in 64 cabins. There are currently four captain-class cabins, seven officer cabins, 18 single crew cabins and 35 double crew cabins.

The Pegasus has a total length of 131.7m (432ft), a perpendicular length of 117.7m and a moulded breadth of 22m. The main deck depth is 9.5m and the design draught is 6.25m, while the scantling draught is 6.75m. The ship has two self-propelled hyperbaric lifeboats and a maximum operating depth of 300m.

Deadweight at design draught is 8,200t while the deadweight at the scantling draught is 9,440t. The offshore crane has a working load of 400t and a radius of 16.5m. The Pegasus also has a helideck suitable for the operation of Super Puma helicopters. The helideck is also equipped with a fixed foam fire fighting system.

PROPULSION AND POWER

There are two azimuth thrusters at the aft end of the vessel, each with a power rating of 3,000kW (variable speed drive). There are also two tunnel thrusters at the forward end of the vessel with a power rating of 1,335kW each.

There is a retractable azimuth thruster at the forward end of the Pegasus with a rating of 1,200kW (variable speed drive). The ship, which can make 13kt, also has two active Intering stabilising systems. There are four main generator sets running from diesel engine alternators (720rpm) with an output of 2,970kW (2,980kVA) at a voltage of 690V.

In addition, there are two emergency generator sets (one for dive use and the other for normal use) running from diesel alternators.

The emergency dive generator is rated at 968kW (1,138kVA) with an engine speed of 1,800rpm (440V). The second diesel-powered emergency generator has a rating of 232kW (250kVA) at a speed of 1,800rpm (440V).