Accommodation/service rigs have traditionally been used wherever there is a need for additional accommodation, engineering, construction or storage capacity offshore. Typically, these rigs will be employed for installing and commissioning new facilities, upgrading or maintaining existing installations, hooking-up satellite fields to existing infrastructure, and removing installations. The rigs are positioned alongside the host installation and are connected by means of a telescopic gangway, or personnel can be transported to and from the unit by boat or helicopter. These rigs boast substantial accommodation capacity, with berths for 245-812 people, have high quality welfare and catering facilities, medical services, storage, workshops and offices, deck cranes, and the necessary equipment and systems for ensuring the safety of the personnel living on board.