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Background And Project Problems Engineering Essay

Jurong Shipyard Private Limited is a entirely owned subordinate of the Sembcorp Marine Ltd and its services include the undermentioned: Ship fix, Ship edifice, Ship Conversion, Rig edifice and Offshore technology. Given its diverse scope of services offered, the corporate profile of JSPL sees a sum of 8 sections under its organizational construction. The 8 sections ranges from, commercial, offshore, production, undertaking direction, quality confidence and quality control, safety, Personal computer or PD to technology. For my fond regard, I was assigned to work in the 3D Design division of the Engineering Department, which specialises in the country of clang trials, 3D modeling and simulation, it is indispensable to be proficient in assorted signifiers of Computer-Aided Design ( CAD ) package.

What the product/system/process is for the survey?

With the increasing demand of energy, semi-sub has moved to run in farther and deeper environment with much harsher conditions. The surveies of hydrodynamic forces on platforms become really of import, and it is worthwhile to discourse their hydrodynamic behaviour in moving ridges, to forestall big gestures which could impact the operations of semi-submersibles. Heave is considered to be the chief gesture to consequence boring rigs, and excessively much heave gesture will blow drilling clip and addition costs. Therefore my undertaking will concentrate on surveies of heave gestures and response of semi-sub in moving ridges.

The chief aim of my undertaking is to optimise the form and dimensions of a semi-submersible. This is achieved by analysing the effects of different hull and column geometries on the heaving gesture and response of semi-submersibles under the conditions of given warhead and changeless supplanting.

This is the undertaking attack, the first thing is to make the literature reappraisal, based on the reappraisals, to transport on the preliminary design of semi-sub, Environment Investigation, choice wave spectrum and sea province for analysis.

For the preliminary design portion, introduce an bing existent semi-submersible construction ATWOOD to be the design mention. The chief intent is to supply an attack to cipher the dimension and weight ratios for three chief constituents of the semi-submersible ( upper deck, column and pontoon ) , so that each constituent can be determined in a more realistic attack.

With the given warhead, I will find the supplanting through arrested development analysis based on informations of bing semi-subs. And so gauge rule dimensions such as ( bombast ) & A ; acirc ; ˆ¦and will cipher GML and GMT.

What the feature of the product/system/process are:

The design includes three different types of semi-submersibles:

1 ) Twin rectangular hulled semi-submersible with square columns

2 ) Twin rectangular hulled semi-submersible with round columns

3 ) Twin round hulled semi-submersible with round columns

What the current jobs are:

The ship & A ; acirc ; ˆ™s critical bill of exchange ( ship becomes unstable ) .

Transverse metacentric tallness.

Some compartment partially-filled with liquid.

Decrease in GM.

What the exact focal point of the undertaking is ( i.e. the demand to hold this undertaking )

Undertaking Introduction -A undertaking was designed to cipher and analyse the heave gestures of semisubmersibles.

It is constructed utilizing Visual Basic for Application linguistic communication in Excel spreadsheet, which can be used to:

Calculate the heaving force ( head sea and beam sea conditions )

Calculate the important response amplitude ( in sea province 6 )

Allow for fluctuations in pontoon length

Allow for fluctuations in sectional geometry of pontoons

Allow for fluctuations in sectional geometry of columns

Expected Results

The expected results for the undertaking is completed successfully and the undermentioned parts were made:

a ) Supply a survey in analysing the effects of different hull and column geometries have on heave response of semi-submersibles under the conditions of changeless warhead and selected sea conditions.

B ) Develop a plan utilizing Visual Basic Application in Excel sheet. By inputting design parametric quantities, the plan will cipher the GM, heave force, RAO and important response amplitude. The plan is potentially utile for farther design surveies.

Expected Benefits

The steel weight signifiers the major portion of the entire design construct and is greatly influenced by the dimensions involved specially to run into other design parametric quantities, such as warhead, platform stableness, perkiness heave response etc. Therefore, the steel weight will be considered as another factor for taking the optimal design of the semi-submersible.

Beginning of Information and Key Words

I will utilize the below beginnings to happen the information:




Academic supervisor ( Dr.Ke Xing )

Industry supervisor ( Mr.Shen Zhao Zhi )

I will mean to carry on my probe and seek to supply every bit much as possible of the grounds ( facts and figures ) that I collect as a consequence and evaluated on my undertaking. Consequently, I besides will split my stuff into assorted chapters and do my chapters flow good from one chapter to another chapter.

An Example Mention

*P.W.Penny.M.Sc, CEng, Associate Member, Preliminary Design of Semi-Submersibles, 8th Octorber 1984. University of Newcastle.R.M.RIISER, B.Sc, M.Sv, Associate Member, VO offshore Ltd.

Undertaking Planing

The undermentioned type of procedures can do my study flow good from one chapter to another chapter:

Gantt chart will be provide to pull off the activities smooth complete of the undertaking.

To run into the mark of the undertaking, I will execute the clip frame to maintain path of the activities.


Beginning day of the month

Expected Completion Date

*Review on moving ridge forces and ensuing dynamic gesture.

10 Jan 2011

18 Jan 2011

*Review on cardinal constructs in Semi-submersible computation.

19 Jan 2011

08 Feb 2011

*Review on spectral computation.

10 Feb 2011

08 Mar 2011

*Select preliminary design conditional.

16 Mar 2011

03 Apr 2011

*Analyze the influential of different geometries on stableness and heaving response with a changeless warhead.

15 Apr 2011

15 May 2011

*Develop a plan utilizing VBA in excel to execute the heaving gesture computations, to optimise the Semi-submersible.

20 May 2011

30 Jun 2011

*Validate the plan consequences with bing experimental informations or other numerical informations.

01 Jul 2011

09 Sep 2011

*Compilation of study.


09 Sep 2011


To plan a boring platform, many facets need to be considered, such as vas map, working country, demands sing variable burden capacities, gesture response, theodolite velocity, etc. ( P.W.Penny. 1984 )

For the pontoons ( lower hull ) how to supply sufficient supplanting to back up the lightship weight and supplies during theodolite?

For the columns level how to supply sufficient waterplane country for stableness and support for the deck?

The pontoon length is related to the needed longitudinal column spacing, the breath to depth ration will act upon the added mass and gesture.

For the figure of columns will non consequence BM, provided the 2nd minute of the country and the waterplane country is keep invariable. A lessening in the figure of columns may act upon the deck weight and bring on less satisfactory damaged stableness characacteristis.

The moving ridge excitement forces experienced by the pontoons are reduced because of the exponential decay of wave gesture with deepness. Where moving ridges have a length comparable to the beam it is besides possible to work the stage differences of the forces on detached submerged members to cut down the frequence response at a design frequence.


An of import characteristic of a semi-submersible is its good gesture response features. To optimise the gesture response is hence an highly of import portion of the design process.

The survey is limited to vass holding four columns and twins round hulls, but the tendencies are believed to be every bit applicable to vessels holding more figure of columns.

I will develop a plan. By input the certain parametric quantities i.e.payload, etc, it will make all the computations and polish the hull shapes for lower limit heave gestures.


The chief things of this undertaking are the undermentioned:

To analyze the design constructs of Semi-Submersible

To cipher heave gesture and heave response of different geometries on Semi-submersible

To develop a plan to execute the computation based on given warhead.

To optimise the hull dimensions and form sizes based on consequences.

The plan is non intended to replace the advanced interior decorator, but to enable a scope of parametric options to be quickly assessed.


Costing subdivision is non portion of my undertaking. Higher direction ( i.e. senior director and subdivision director ) will to the full in-charges the costing subdivision. The plan will be validated by comparing consequences with bing experimental informations and besides good for future surveies and development.


I need to prove the undermentioned resources:

Calculate the heaving force ( head sea and beam sea conditions )

Calculate the important response amplitude

Allow for fluctuations in pontoon length

Allow for fluctuations in sectional geometry of pontoons

Allow for fluctuations in sectional geometry of columns

The testing will be conducted by following application:

Choose the semi-submersible`s design type

Input the rule dimensions consequently

( the plan uses SI units system )

The estimated values of KG, BML, BMT, GML, GMT

The entire heaving force moving on the constructions in the caput sea and beam sea conditions

The heaving response in caput sea and beam sea conditions

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