What is Iolair?

The Iolair (Gaelic for eagle) is a semi-submersible vessel that served as an Emergency Support Vessel (ESV). She was built by Scott Lithgows in Port Glasgow for BP to assist oil platforms in the field. The Iolair is a self-propelled, twin hull, semi-submersible type vessel and operates as a dynamically positioned (DP) construction support vessel.

MSV

This unique vessel did not start as an ESV, but rather as the concept of a Maintenance and Support Vessel (MSV). It was proposed for the Forties oil field, operated by BP Petroleum Development Company Ltd in the North Sea. A particular feature of the design by the Naval Architects was that there was no cross-bracing between the pontoons. Instead, the platform was given extra strength by a box-girder construction and diagonal bracing was arranged from the centre of the platform to the pontoons. This arrangement remained virtually unchanged to the build completion and offered exceptional speed when the vessel was de-ballasted on the surface. The intention was to achieve a rapid response to emergencies, wherever they might be experienced in the North Sea.

As an MSV, the vessel was always conceived to provide accommodation for about 220 persons, saturation diving facilities, a large workshop, craneage, and helicopter landing area with hangar and re-fuelling. All were still featured in the eventual design but had been enhanced with other features and sophistication much of which was to support the emergency role. There is no question that ESV incorporated novelty and ideas that were years ahead of their time. Indeed, part of the brief was that she should still be modern ten years after entering service!

Industry firsts

Among the many firsts were:

• Heave/swell compensation in the diving tube to enable operation in rougher weather.
• A Citadel area to which people could retire and survive if the vessel was engulfed in gas.
• A drenching system to cool exterior surfaces if the vessel was close to a burning platform.
• The largest capacity and longest range firefighting monitors ever at sea.
• Fixed water-cannon on the after columns to cool the underside of production platforms.

Iolair is assured of its place in history by being the subject of a 28p commemorative stamp issued by Post Office Ltd on 25 May 1983. This was one of a series of three stamps celebrating British Engineering Achievements.

History

In her early years, she was positioned in the BP Forties Oilfield. In 1995, she was sold to U.S. drilling company Reading & Bates. She was to be converted to a workover/well intervention vessel and was stationed West of Shetland. The modifications included removal of some of the top structures, removal of the fire-fighting systems, closing of the dive tube and wave surge tank. However the intended conversion was never carried out and she was heavily involved in the installation of subsea production equipment using Remote Operated Vehicles. She was also heavily involved in the commissioning of the Foinaven and Schiehallion floating production vessels. In 2000 she left the UK oilfields and went to the Bay of Campeche, Mexico, working in the Canterell Field. There she carries out construction and platform support work. She was sold in 2001 by Transocean, who had taken over Reading and Bates, and is now registered in the Marshall Islands, a long way from her original registered port of Dundee in Scotland.

Particulars

The Iolair can operate up to a water depth of 488 metres (1,601 ft), is 102 metres (335 ft) long and 51 metres (167 ft) wide, and has 207 beds with single and double occupancy.