Sliding into place: support vessels gain mothership capability

Lars Joergen Tveit of Vestdavit explained that rather than using overhead cranes, MissionEase utilises a series of sliding racks which hold their loads securely either on deck or in the hangar. Given a signal, these individual racks are hydraulically propelled forward, at the end of their run the arms retract, placing the daughter craft neatly onto a cradle waiting beneath. This then slides towards the hangar doors on its own track, where its load is picked up and swung outboard on single point or dual point davits.

Tveit said: “You can position lots of different kinds of equipment on the deck this way, it’s a very flexible system and it can be used for a two tonne davit as well as for much heavier daughter craft – in fact it can be configured to take anything up to 42 tonnes.”

The kit can also be used to deploy multiple loads at once, from different sides of the deck or through opposing hangar doors. The system is fast, efficient and it can be used for retrieval even in dynamic seas as the storage bays, without swinging loads, are inherently much safer to deal with than crane-type systems.

The MissionEase already has a future on polar expedition vessels which often deploy a number of smaller surface or underwater vessels, and there are signs it will find a take up onboard larger workboats.

To this end, Vestdavit is offering a version tailored for offshore support vessels as it can hold a combination of two or more daughter craft and standard size containers: the same kit allows containers to be let down or picked up from the quay while in harbour, simplifying loading operations.

This system could prove itself very useful, given the wind industry’s future further offshore, as it would raise the capability of both walk-to-work vessels as well as allowing a range of larger support craft to be used as mother ships.