SSCV Hermod is a semi-submersible

Semi-submersible

A semi-submersible is a specialised marine vessel with good stability and seakeeping characteristics. The semi-submersible vessel design is commonly used in a number of specific offshore roles such as for offshore drilling rigs, safety vessels, oil production platforms and heavy lift cranes.The...

 crane vessel

Crane vessel

A crane vessel, crane ship or floating crane is a ship with a crane specialized in lifting heavy loads. The largest crane vessels are used for offshore construction. Conventional monohulls are used, but the largest crane vessels are often catamaran or semi-submersible types as they have increased...

 operated by Heerema Marine Contractors

Heerema Marine Contractors

Heerema Marine Contractors is a contractor most notable for operation of three of the largest crane vessels in the offshore industry.-History:...

.

History

Semi submersible crane vessel (SSCV) Hermod was constructed in 1979 by Mitsui Engineering & Shipbuilding Co., Ltd.

Mitsui

is one of the largest corporate conglomerates in Japan and one of the largest publicly traded companies in the world.-History:Founded by Mitsui Takatoshi , who was the fourth son of a shopkeeper in Matsusaka, in what is now today's Mie prefecture...

. Hermod and sister vessel, Balder

DCV Balder

DCV Balder is a Deepwater Construction Vessel operated by Heerema Marine Contractors.-History:The Balder was constructed in 1978 as semi-submersible crane vessel by Mitsui Engineering & Shipbuilding Co., Ltd.. Balder and sister vessel, Hermod were the world's first semi-submersible crane vessels...

 were the world's first semi-submersible crane vessels. In the early 1980s these vessels set several lift records while operating in the North Sea.

Design

The hull consists of two floaters with three columns each. The transit draught of 12 meters is normally ballasted down to 25 meters for lifting operations, with the floaters (with a draught of 12 meters) are well-submerged, reducing the effect of waves and swell.

Propulsion is by two controllable pitch propellers and two forward, retractable, controllable pitch thruster. The helicopter deck will sustain a Sikorsky 61-N

Sikorsky S-61

The Sikorsky S-61L and S-61N are civil variants of the successful SH-3 Sea King helicopter. They are two of the most widely used airliner and oil rig support helicopters built.-Design and development:...

. Up to 336 people can be supported in the air conditioned living quarters.

Cranes

The Hermod has two cranes at the stern. Originally the starboard-side crane was rated at 3000 short ton

Short ton

The short ton is a unit of mass equal to . In the United States it is often called simply ton without distinguishing it from the metric ton or the long ton ; rather, the other two are specifically noted. There are, however, some U.S...

 and the port-side at 2000 short ton. In 1984, the lifting capacities were upgraded to 5000 and 4000 short ton respectively. The main hoist can lift 92 m (301.8 ft) above the work deck. The auxiliary hoists can lower to a depth of 3,000 m (10,000 ft) below the work deck. A tandem lift using the main hoists can lift 9,000 short ton at 39 m (128 ft) radius.