Section 9 Marine Operation

901. General

1. General

The effects which may be induced in the structure during the marine operations required for the transportation and installation of the structure and equipment are to be considered. The emphasis of this Chapter is the influence which these operations may have on the safety and integrity of the structure.

2. Application

(1) In this Rules, the followings may be included in marine operations in general;

(A) Lifting and mooring operation

(B) Load-out

(C) Construction afloat

(D) Towing

(E) Launching and uprighting

(F) Submergence

(G) Pile installation

(H) Final field erection

(I) Removal operation

(2) For all marine operations except towing, the skilled supervision is being provided and the oper- ations are being executed with satisfaction of the Surveyor. During a tow, the towage master is

to assure that proper procedures are followed. The Operator may also optionally request that a Surveyor be present during a tow.

902. Documentation

1. General

The extent of documentation and analysis(see 903.) of marine operations is to be commensurate with the size and type of structure involved, the particular operation being considered, the extent of past experience with similar operations, and the severity of the expected environmental conditions.

2. Report

(1) A report on the marine operations planned to transport and install the structure is to be devel- oped and submitted for use in association with the review of the analyses required in 903.

(2) For structures requiring a significant amount of construction while afloat(e.g., large concrete

gravity structures), documentation of the operations involved is to be included in this report.

(3) The purpose of this report is to demonstrate that the strength and integrity of the structure are not reduced or otherwise jeopardized by the marine operations. Generally, this report is to con- tain the following information.

(A) Description of the marine operations to be performed and the procedures to be employed.

(B) For operations which do not govern design of the structure, a description of the engineering logic, experience or preliminary calculations supporting this conclusion.

(C) For operations which govern design of the structure, the assumptions, calculations and results of the analyses required in 903.

(D) For structures to be uprighted or submerged by selective ballasting, a detailed description of

the mechanical, electrical and control systems to be employed, the ballasting schedule and supporting calculations.

903. Analysis

1. Loads

(1) Analyses are to be performed to determine the type and magnitude of the loads and load com- binations to which the structure will be exposed during the performance of marine operations.

(2) Particular attention is to be given to inertial, impact, and local loads which are likely to occur

during marine operations.

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(3) Where significant fatigue damage occurs during marine operations, it shall be included in calcu- lating the total fatigue lives.

2. Stress

(1) Where temporary attachments or appurtenances(tie-downs, skid beams, etc.) are utilized, analyses are to be performed to ensure that these items and their supporting structure have sufficient strength to withstand the type and magnitude of loads with the appropriate factor of safety re- quired in Par 1.

(2) The strength criteria of Sec 5 and 6 for steel structures and concrete structures, respectively, are to be employed in this determination.

3. Stability

(1) Analyses are to be performed to ensure that the structure, or its means of support where such exist, has sufficient hydrostatic stability and reserve buoyancy to allow for successful execution of marine operations.

(2) For large or unusual structures, an experimental determination of the center of gravity of the structure and its means of support, where such exist, is to be performed.

904. Fitness to Tow Certificate

1. General

(1) Upon request by the Operator and where authorized to do so, this Society will undertake the services required for the issuance of a fitness to tow certificate.

(2) The adequacy of the towlines, attachments and towing vessels will not be reviewed Society.

by this

(3) Review by this Society solely for purposes of classification is not to be considered a replace-

ment for the review commonly required for the issuance of a towage certificate.

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