Ultimate Strength of the Buoy Structure due to the Loads Arise from the Tanker and Mooring Lines

Murdjito Murdjito; Resy Agatya; Handayanu Handayanu

doi:10.12962/j2580-0914.v1i1.2893

Ultimate Strength of the Buoy Structure due to the Loads Arise from the Tanker and Mooring Lines

Murdjito Murdjito, Resy Agatya, Handayanu Handayanu

Abstract

A study was conducted to evaluate the ultimate strength of a 40 ton buoy induced by the dynamic loads arising from a 120,000 DWT Aframax tanker and mooring lines. The buoy is operated at Bangka Strait offshore oil terminal. The evaluation was commenced by analyzing the motion characteristics of the buoy and tanker due to environmental excitations, both in free floating conditions. This is continued by the simulation and time-domain analysis of connected buoy and tanker to observe the hawsers and mooring line tension intensities. The corresponding results show the largest tension occurs in the in-line configuration with the tanker in ballast condition, where hawsers tension reaches 1282.58 kN with a safety factor of 2.23 and mooring line tension 1974.18 kN with a safety factor of 3.20. The resulting tensions were further applied as input data for structural modeling using FEM to find out the stresses develop on the buoy structure. Results of this modeling reveal the maximum value of stress experienced by the buoy structure is approaching 184.28 MPa, which is below allowable stress of 200 MPa. Following this, the ultimate stress of 450 MPa will be violated by 143% incremental load above the maximum, namely 3,116.67 kN and 4,797.26 kN due to the hawsers and mooring line. This fact suggests that the structure is unlikely to experience ultimate failure if merely operated in the current operational site.

Keywords

buoy; tanker; mooring system; tensions; ultimate stress

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References

Dragani, J. and Kotenev, M.: Deepwater development: what past performance says about the future. The Way Ahead, Vol. 9-1, pp.8-9, 2013

GBI: Offshore drilling industry to 2016 - rapidly rising demand for hydrocarbons expected to boost offshore drilling in ultra-deepwater and harsh-weather environments. Report Code: GBIGE00053MR, GBI Research, Dec. 2011

Chang, Z.Y. et al.: Deployment simulation of mooring buoy system. Applied Mechanics and Materials, Vol. 141, pp. 98-102, 2012

Versluis, J.: Exposed location single buoy mooring. Offshore Technology Conference, Paper: OTC-3805-MS, Houston, TX, 5-8 May 1980

World Maritime News: Leighton Offshore Completes Tanzania Single Point Mooring Project. Retrieved from http://worldmaritimenews.com/archives/69495/ on 12 July 2017 at 15:16

Arda, Djatmiko, E.B. and Murdjito: A study on the effect of semi-submersible drilling rig motions with variation in mooring line pre-tension to the safety of drilling riser. Proc. of the 8th International Conference on Marine Technology MARTEC 2012, Kuala Terengganu, Malaysia, 20 – 22 October 2012

ABS: Rules for Building and Classing Mobile Offshore Drilling Units. American Bureau of Shipping, ABS Plaza, Houston, TX, USA, 2012

API: Design and Analysis of Station Keeping System for Floating Structures, API RP 2 SK. American Petro¬leum Institute, Washington DC, 2005

Prastianto, R.W., Otsuka, K. and Ikeda, Y.: On the multi-mode VIV response of a small-long flexible horizontal cylinder in uniform flows. International Conference on Violent Flows (VF-2007), pp. 429-437, RIAM, Kyushu University, Fukuoka, Japan, 2007

Yuda, I D.G.A.S., Djatmiko, E.B. and Rosyid, D.M.: A study of the dynamic longitudinal hull structural responses and ultimate strength of drillship. Journal of Ocean, Mechanical and Aerospace - Science and Engineering, Vol. 17, pp. 1-8, March, 2015

DOI: http://dx.doi.org/10.12962%2Fj2580-0914.v1i1.2893

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