In some cases ship management will be carried out by the shipowner’s own organisation, and in others an independent organisation will be employed under contract.  In either event the functions are basically similar. Ship management includes registration and documentation of the ship as required by national and international authorities; it covers crewing, victualling, stores, spare parts, maintenance and  repairs; it extends to arranging insurance and the handling of claims and recoveries; it includes the appointment of surveyors and a host of other tasks designed to keep the ship running properly.  In short, it is the ship manager’s responsibility to ensure that the ship is “tight, staunch and strong, and in every way fitted for the voyage”. The simplest form of cargo handling equipment used on board a ship is the derrick which was developed from the spars of sailing vessels as a means of lifting and transferring cargo from ship to quay and vice versa.  It is essentially just a mast and a swinging boom which allows a load to be lifted and moved sideways. While there are some improved modern versions of derricks in use they have mainly been replaced by cranes or gantries on modern vessels. There are also some ‘heavy lift’ derricks in general use where a very heavy load capacity is needed. These derricks are permanently rigged at the  hatch. Some of the principal modern derrick designs are: Hallen Derrick: The derrick is labour saving as one man positioned at a control console can operate it. The lifting capacity of the Hallen Derrick may be up to 200 tonnes. Velle Derrick: The design allows very wide slewing angles and because of the arrangement of the topping lifts, they act to aid recovery when the derrick is slewed outboard.  This is particularly useful when handling heavy lifts against an adverse list. It is used for loads in the range 35 to 100 tonnes. Stuelcken Derrick: This is perhaps the best known of all heavy lift derrick types. The derrick is supported by two outboard inclined masts and employs a twin lifting span.  It is operated by four winches and has a very high capacity (in excess of 300 tonnes is not uncommon), and speed of operation.