The Naiad Voyages

Mark Austen

2016.10.23 - Continuing With the Stowage II

After a leisurely lunch I continued with the port side stowage with the intention of completing it by the end of the day. More templates and fiddly bits but in the end I managed to get it all done.

The port bunk slats needed to be trimmed since the book case now reaches down that the level of the stringer.

This, after much messing about with templates, is the stowage before it is fitted. A thin batten is already screwed to the cabin side.

And this is the stowage fitted. It is only screwed in place for the moment, there should not be any heavy items stowed here and there is the possibility that I'd want to modify it, so screws for now and maybe glue later once I've had a chance to use it.

The stowage is quite capacious, I expect that it will soon fill up with odds and ends.

This is the aft-most one which is a little shorter than the rest.

Making it shorter is deliberate since the Boat Safety Scheme required fixes ventilation. The aft end of the cabin will go across the bridge deck but will not reach up as far as the side deck leaving a gap about 2" high by 6" wide. This will give a fixed ventilation on both sides of the cabin as well as the gap in the cockpit above the centreboard case and the holes that I will make in the washboards.

This is what the BSS has to say about ventilation taken from "BSS Examination Checking Procedures for Privately Owned and Managed Vessels" Appendix K - Ventilation p78:


The formula used to calculate the fixed ventilation requirement is derived from BS 5482‐3 Annex B (Code of practice for domestic butane and propane gas‐burning installations — Part 3: Installations in boats, yachts and other vessels), but as extended by BS8511 Annex A (Code of practice for the installation of solid fuel heating and cooking appliances in small craft) to address solid fuel stoves and other appliances.

The formula for calculating the fixed ventilation requirement ( in mm2 ) is as follows:

= [2200xU] + [650xP] + [550xH] + [440xF], where:

U = input rating for all un-flued appliances (inc. cookers) (in kW)

P = number of persons for which the accommodation space is designed
H = nominal output rating of all open‐flued solid fuel appliances (in kW)
F = input rating for all open‐flued appliances (in kW)

For Naiad U is 2, P is 2, H is 3 (if I fit the heater) and F is 0. So the required minimum fixed ventilation needed is:

(2200 x 2) + (650 x 2) + (550 x 3) or 4400 + 1300 + 1650 or 3390 mm2. That's 5 1/4 square inches. Not a lot really, but I'll be providing about three times that to be safe.