Definition(s)
Freeboard Deck
Freeboard deck.
(a) The freeboard deck is normally the uppermost complete deck exposed to weather and sea, which has permanent means of closing all openings in the weather part thereof, and below which all openings in the sides of the ship are fitted with permanent means of watertight closing.
(b) Lower deck as a freeboard deck
At the option of the owner and subject to the approval of the Administration, a lower deck may be designated as the freeboard deck provided it is a complete and permanent deck continuous in a fore and aft direction at least between the machinery space and peak bulkheads and continuous athwartships.
(i) When this lower deck is stepped the lowest line of the deck and the continuation of that line parallel to the upper part of the deck is taken as the freeboard deck.
(ii) When a lower deck is designated as the freeboard deck, that part of the hull which extends above the freeboard deck is treated as a superstructure so far as concerns the application of the conditions of assignment and the calculation of freeboard. It is from this deck that the freeboard is calculated.
(iii) When a lower deck is designated as the freeboard deck, such deck as a minimum shall consist of suitably framed stringers at the ship sides and transversely at each watertight bulkhead which extends to the upper deck, within cargo spaces. The width of these stringers shall not be less than can be conveniently fitted having regard to the structure and the operation of the ship. Any arrangement of stringers shall be such that structural requirement can also be met.
(c) Discontinuous freeboard deck, stepped freeboard deck.
(i) Where a recess in the freeboard deck extends to the sides of the ship and is in excess of one metre in length, the lowest line of the exposed deck and the continuation of that line parallel to the upper part of the deck is taken as the freeboard deck (see figure 3.3).
(ii) Where a recess in the freeboard deck does not extend to the sides of the ship, the upper part of the deck is taken as the freeboard deck.
(iii) Recesses not extending from side to side in a deck below the exposed deck, designated as the freeboard deck, may be disregarded, provided all openings in the weather deck are fitted with weathertight closing appliances.
(iv) Due regard shall be given to the drainage of exposed recesses and to free surface effects on stability.
(v) Provisions of subparagraphs (i) through (iv) are not intended to apply to dredgers, hopper barges or other similar types of ships with large open holds, where each case requires individual consideration.
<Chapter I, regulation 3>.
Source: IMO Resolution MSC.143(77), amendments to Annex B to the 1988 Load Lines Protocol, 5 June 2003, International Maritime Organization. Legislation
Freeboard Deck
Freeboard deck is the deck as defined in the International Convention on Load Lines in force. <Chapter II-1, regulation 2>.
Source: IMO Resolution MSC.216(82), amendments to the International Convention for the Safety of Life at Sea, 1974, as amended, 8 December 2006, International Maritime Organization. Legislation
Freeboard Deck
The freeboard deck is normally the uppermost complete deck exposed to weather and sea, which has permanent means of closing all openings in the weather part, and below which all openings in the sides of the unit are fitted with permanent means of watertight closing. For semisubmersible units, see also 5.2.4.
Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 4, Steel Unit Structures, June 2013, Lloyd’s Register, Global Standards