Section 2 Special surveys – Hull requirements
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Construction and Classification of Floating Docks and Dock Gates, July 2022 - Part 1 Regulations - Chapter 3 Periodical Survey Regulations - Section 2 Special surveys – Hull requirements

Section 2 Special surveys – Hull requirements

2.1 General

2.1.1 The full requirements of the annual and underwater surveys are to be complied with together with the following:

The spaces between the safety and top working decks are to be cleared and cleaned as necessary and examined; lining and pipe casings are to be removed as required.

2.1.2 The Surveyor may require the gauging of the thickness of the materials of any portion of the structure by means of ultrasonic testing, where signs of wastage are evident or wastage is normally found. Any parts of the structure which are found defective or materially reduced in scantlings are to be made good by materials of the approved scantlings and quality.

2.1.3 Where the inner surface of the bottom plating is covered with cement, asphalt or other composition, the removal of this covering may be dispensed with, provided it be inspected, tested by beating or chipping, and found sound and adhering satisfactorily to the steel.

2.1.4 Pontoon and side wall tanks are to be cleaned and examined internally and tested by a head sufficient to give the maximum pressure that can be experienced in service.

2.1.5 Wood deck sheathing is to be examined, if decay or rot is found, or the wood is excessively worn, it is to be renewed. Attention is to be given to the condition of the plating under the sheathing or other deck covering. If it is found that such coverings are broken or not adhering closely to the plating, sections are to be removed as necessary to ascertain the condition of the plating.

2.1.6 The Surveyor is to satisfy himself as to the efficient condition of the following:

Means of escape from:

  1. Machinery spaces.

  2. Crew spaces.

  3. Spaces in which crew are normally employed.

Means of communication between control position and machinery spaces.

2.1.7 For floating docks not more than 15 years old, fuel oil tanks forming part of the main structure need not be examined internally. When examining tanks internally, the Surveyor is to satisfy himself as to the condition of the pump suctions.

2.1.8 At the first Special Survey held after the floating dock or dock gate is 25 years old and at every 10 years thereafter or at the next Special Survey after the expiration of the latter period, the full requirements of Pt 1, Ch 3, 2.1 General 2.1.1 to Pt 1, Ch 3, 2.1 General 2.1.7 together with Pt 1, Ch 3, 2.1 General 2.1.9 and Pt 1, Ch 3, 2.1 General 2.1.10 are to be complied with.

2.1.9 In addition to the thickness measurement to ascertain local wastage, the outside plating of the walls and pontoons are to be gauged by ultrasonic testing to determine the amount of any general diminution in thickness. The gauging is to be done in at least two places in each strake of plating on each side within the amidship half-length.

2.1.10 Measured thicknesses are to be reported. Where gauged plates are renewed, the thickness of adjacent plates in the same strake are to be reported.


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