24 - Lifting arrangements

Abstract

This chapter focuses on the different lifting devices such as masts and sampson posts, derrick rigs, and shipboard cranes. Masts on a general cargo ship may fulfill a number of functions but their prime use in modern ships is to carry and support the derricks used for cargo handling. Single masts are often fitted, but many ships now have various forms of bipod masts, which are often more suitable for supporting derricks, although some types can restrict the view from the bridge. Sampson posts are often fitted at the ends of houses and may be found at the other hatches also. The chapter discusses that a wide range of standard shipboard general purpose cranes with safe working loads (SWL) from 5 tonnes to 60 tonnes are found on general cargo and reefer ships. The electro-hydraulically powered cranes may have single or twin jibs, and wire or ram luffing arrangements. These cranes may be positioned on the ship's centre line; however, this may require an extremely long jib when the ship's beam is large and a reasonable outreach is desired. Pairs of cranes at one end of the hatch or at opposite corners of the hatch and with an ability to work through 360 degrees can provide a full range of load/discharge options for a ship.