Section 2 Definitions
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 2 Rules for construction - Chapter 1 Structures – Floating Docks - Section 2 Definitions

Section 2 Definitions

Parent topic: Chapter 1 Structures – Floating Docks

2.1 General

2.1.1 The lifting capacity of the dock, , in tonnes, is equal to the displacement of the heaviest ship that the dock is designed to lift in normal service. LR reserves the right, however, to reduce the lifting capacity if the sinkage trials show that insufficient freeboard is available at the pontoon deck when the lifting capacity is added to the light displacement of the dock see Pt 2, Ch 1, 1.8 Stability.

2.1.2 The light displacement includes the structural weight of the dock complete with all machinery, crane(s), equipment, fresh water, fuel oil for the use of the dock, compensating ballast water (if required), and rest-water.

2.1.3 The length, L D, in metres, is the length of the bottom caisson or the distance from the aft end of the aftermost pontoon to the fore end of the forward pontoon, excluding non-integral end platforms or swing bridges.

2.1.4 Amidships is to be taken as the middle of the length L D.

2.1.5 The breadth, B D, is the moulded breadth, in metres.

2.1.6 The depth, D D, in metres, is the vertical distance from the lowest point of the bottom framing to the lower surface of the uppermost deck plating.

2.1.7 The length, Ls, is the length between perpendiculars of the shortest ship whose displacement is equal to the lifting capacity of the dock, in metres. The length Ls, is in general not to be taken as greater than 0,8LD. For docks exceeding 40000 tonnes lifting capacity, Ls is not to be taken greater than that obtained from Table 1.2.1 Ship to dock length ratio per lifting capacity.

Table 1.2.1 Ship to dock length ratio per lifting capacity

Displacement, Δs, in tonnes Ship to dock length ratio, Ls/LD
40 000 0,800
45 000 0,826
50 000 0,850
55 000 0,870
60 000 0,888
70 000 and above 0,920

Note Intermediate values may be obtained by linear interpolation.

2.1.8 The safety deck is a watertight deck arranged at such a distance below the upper deck as to determine the maximum submergence draught of the dock whilst ensuring an air draught to the upper deck of at least 1 m. Alternative arrangements will be specially considered.

2.1.9 The rest-water is the ballast water in the tanks which the pumps cannot discharge.

2.1.10 Compensating ballast water is ballast water which may be used to limit the deflection of the dock by counteracting the ship-induced longitudinal bending moment. Rest-water should not be included in compensating ballast water.

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