British Marine Code of Practice for the construction of Inland waterways craft
3.
FREEBOARD. All vessels should have a minimum
freeboard to deck edge or gunwale of 250mm around the periphery of the vessel in the most onerous loading condition. For open vessels this requirement should be increased to 400mm if they are unable to pass the swamp test as detailed in Section 1.3.
Simplified MCA MGN 280 Stability and freeboard test:
A vessel should be tested in the fully loaded conditions. For the purposes of this code a person is taken to weigh 82.5 Kg. As in Workboat 3 code.
The vessel will be judged to have an acceptable standard of stability if the test shows that:
a. b.
c.
The angle of heel does not exceed 7 degrees; and
In the case of a vessel with a watertight weather deck extending from stem to stern, the freeboard to deck is not less than 75mm at any point; or
If unable to meet the criteria in b. The angle of heel may exceed 7 degrees, but should not exceed 10 degrees, if the freeboard in the heeled condition is in accordance with that required by Section 5 in the upright condition.
a.
In the case of a vessel with a continuous watertight weather deck which is neither stepped or recessed or raised, it should have a freeboard measured down from the lowest point of the weather deck of not less than 300 mm for vessels of 7 metres in length or under and not less than 750 mm for vessels of 18 metres in length or over. For a vessel of intermediate length, the freeboard should be determined by linear interpolation.
b.
In the case of a vessel with a continuous watertight
weather deck which may be stepped, recessed, or raised, it should have a freeboard measured down from the lowest point of the weather deck, of not less than 200mm for vessels of 7 metres in length or under and not less than 400mm for vessels of 18 metres in length or over. For a vessel of intermediate length, the freeboard should be determined by linear
interpolation. The raised portion(s) of the watertight weather deck should extend across the full breadth of the vessel and the average freeboard over the length of the vessel should comply with section 5 above for a vessel with a continuous watertight weather deck.
c.
In the case of an open boat, it should have a clear height of side (i.e. the distance between the waterline and the lowest point of the gunwale1) of not less than 400mm for vessels of 7 metres in length or under and not less than 800mm for vessels of 18 metres in length or over. For a vessel of intermediate length, the clear height should be determined by linear interpolation.
The Boat Safety Scheme (BSS)
Examples of inland waterway guidance where freeboard requirements are stated are given below. - All hull openings need to be watertight above the normal laden waterline to at least 10" (250 mm).
- Self-draining cockpits do not need to meet the 250 mm requirement, provided a bulkhead (or sill) of 150 mm (6") is fitted or the deck drains include non-return valves.
- For such as sinks, as long as the waste pipework is secure (not push-fit), then it is the top of the sink that is the watertight level.
- Weedhatches need to be watertight to at least 6" (150 mm) above the normal laden waterline.
- Hull intakes need to be a seacock directly fitted to the hull fitting with the seacock readily accessible.
Therefore, we now have some measurements to work with: The lowest category waters are A which require 250mm.
The next lowest category waters are B which require 400mm.
A vessel with a continuous watertight weather deck:
In Category C waters the requirement for 7m -18m length is between 360mm - 630 mm.
In Category D waters the requirement for 7m -18m length is between 600mm - 1050mm.
Or without freeing ports: Category C for waters the requirement for 7m -18m length is between 7-18 m length 120 mm-240 mm.
Category D for waters the requirement for 7m -18m length is between 200mm- 400mm.
In the case of an open boat, it should have a clear height of side. Category C for waters the requirement for 7m -18m length is between 240mm- 400mm.
Category D for waters the requirement for 7m -18m length is between 400mm- 800mm.
The freeboard to deck edge should, in general, be not less than 50% of the required freeboard to downflooding.
During assessment above for MCA / AINA Inland Waters Small Passenger Boat Code each person may be represented by a weight of 75kg, or for the purposes of the British Marine Inland Waterways Small Passenger Boat Code below a person is taken to weigh 82.5 Kg.
When testing:
In the case of a vessel with a watertight weather deck extending from stem to stern, the freeboard to downflooding is not less than: MCA Category A waters - 100 mm. MCA Category B waters - 175mm. MCA Category C waters - 75mm.
The angle of heel may exceed 7 degrees but should not exceed 10 degrees. The vessel will be judged to have an acceptable standard of stability if the test shows that:
a. b.
The angle of heel does not exceed 7 degrees; and
In the case of a vessel with a watertight weather deck extending from stem to stern, the freeboard to deck is not less than 75mm at any point.
British Marine Code of Practice for the construction of Inland waterways craft
All vessels should have a minimum freeboard to deck edge or gunwale of 250mm.
For open vessels this requirement should be increased to 400mm.
a.
In the case of a vessel with a continuous watertight weather deck which is neither stepped or recessed or raised:
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