Single and dual lift analyses of offshore structures

Conference · Wed Feb 01 04:00:00 EST 1984 · Soc. Pet. Eng. AIME, Pap.; (United States)

OSTI ID:5957531

Sekita, K; Kimura, H

At offshore job sites today, decks are lifted onto jacket structures in relatively large, heavy sections. Since lifting operations are greatly affected by the motions of the derrick barge or the crane ship, it is necessary to evaluate the sling system in consideration of vessel motions in order to regulate lifting operations at the job site. This paper proposes a static analysis method for designing sling systems and describes the application of this method to dual-lift operations carried out by two derrick crane barges in Southeast Asian waters. This paper also presents the methods of analyzing the motions of a hoisted load caused by wave-induced vessel motions and resulting dynamic sling tensions in single- and dual-lift operations. Single-lift, unified analysis -- a method that considers the interaction between the barge and the hoisted load -- is discussed, and calculated results are compared with 1/75-scale model test results to clarify the conditions necessary for unified analysis. Finally, the results of transient motion analysis for a barge crawling while lifting a load are compared with model test results.

• Research Organization: Nippon Steel Corporation Sagamihara R and E Center
• OSTI ID: 5957531
• Report Number(s): CONF-8402115-
• Conference Information: Journal Name: Soc. Pet. Eng. AIME, Pap.; (United States) Journal Volume: SPE 12419
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
03 NATURAL GAS
030300 -- Natural Gas-- Drilling
Production
& Processing
BARGES
CRANES
DYNAMIC LOADS
EQUIPMENT
HOISTING
MATERIALS HANDLING
MATERIALS HANDLING EQUIPMENT
MOTION
OFFSHORE PLATFORMS
PERFORMANCE TESTING
SCALE MODELS
SHIPS
STRUCTURAL MODELS
TESTING
WAVE FORCES