 thumb|right|platform supply vessela platform supply vessel (often abbreviated as psv) is a ship specially designed to supply offshore oil platforms. these ships range from 20 to 100 meters in length and accomplish a variety of tasks. the primary function for most of these vessels is transportation of goods and personnel to and from offshore oil platforms and other offshore structures. in the recent years a new generation of platform supply vessel entered the market, usually equipped with class 1 or class 2 dynamic positioning system. ==capabilities== ===cargo=== thumb|deck cargo a primary function of a platform supply vessel is to transport supplies to the oil platform and return other cargoes to shore. cargo tanks for drilling mud, pulverized cement, diesel fuel, potable and non-potable water, and chemicals used in the drilling process comprise the bulk of the cargo spaces. fuel, water, and chemicals are almost always required by oil platforms. certain other chemicals must be returned to shore for proper recycling or disposal, however, crude oil product from the rig is usually not a supply vessel cargo.. ===support=== common and specialty tools are carried on the large decks of these vessels. most carry a combination of deck cargoes and bulk cargo in tanks below deck. many ships are constructed (or re-fitted) to accomplish a particular job. some of these vessels are equipped with a firefighting capability and fire monitors for fighting platform fires. some vessels are equipped with oil containment and recovery equipment to assist in the cleanup of a spill at sea. other vessels are equipped with tools, chemicals and personnel to "work-over" existing oil wells for the purpose of increasing the wells' production. ==vessel crews==  crews on the these ships can number up to 20 crewmembers, but it is usual to run the vessels on minimum manning level to save money. ===daily operations=== crews sign on to work and live aboard the ship an extended period of time (3 â 6 weeks and often more). this is followed by an extended period of time off, often 2â4 weeks depending on the ship owner / operator the number of weeks or months aboard. work details on platform supply vessels, like many ships, are organized into shifts of up to 12 hours. living aboard the ship, each crew member and worker will have a shift, lasting some portion of a 24-hour day. most supply vessels are provided with a "bridge" area for navigating and operating the ship, machinery spaces, living quarters, and an area for cooking and eating. some have built in work areas, and common areas for entertainment. the large main deck area is sometimes utilized for portable housing. living quarters consist of a bunk area, lockers, and spaces for storing personal items
Oil_platforms Petroleum_production Ship_types