Stern Deck Height

[Danny1234]

Hello there

I'm in the process of designing/specifying a wide beam canal boat.

For now I have the stern deck at 1000mm above the base plate. Normally then the draft would be about 450mm, maybe 500 max.

I've been told that there should be a minimum of 400mm from the waterline to the deck (is that correct?).

The there is a small 'lip' where the doorway to the stern deck will be (there will be a barrier/steel wall) around the stern deck

I might get rid of this 'lip' as it could be a trip hazard.

Question is then, is 1000mm enough?

Even if it is enough for the canals, would this be enough for the Thames? I don't intend on being on the Thames that much. Only really in transit from West to East London (River Lee over to Paddington/Slough, and maybe the Kennet & Avon)

I'm trying to keep the height of the deck down so that the steps in to the cabin area. The higher the steps, the more steps needed so the more the 'staircase' will encroach in to the cabin

Regards

Danny

[RobinJ]

Hello there

I'm in the process of designing/specifying a wide beam canal boat.

For now I have the stern deck at 1000mm above the base plate. Normally then the draft would be about 450mm, maybe 500 max.

I've been told that there should be a minimum of 400mm from the waterline to the deck (is that correct?).

The there is a small 'lip' where the doorway to the stern deck will be (there will be a barrier/steel wall) around the stern deck

I might get rid of this 'lip' as it could be a trip hazard.

Question is then, is 1000mm enough?

Even if it is enough for the canals, would this be enough for the Thames? I don't intend on being on the Thames that much. Only really in transit from West to East London (River Lee over to Paddington/Slough, and maybe the Kennet & Avon)

I'm trying to keep the height of the deck down so that the steps in to the cabin area. The higher the steps, the more steps needed so the more the 'staircase' will encroach in to the cabin

There may be some confusion here? I would say that deck height is related to cabin height, since you will need to be able to see over the top!

Freeboard is the crucial measurement, the distance from the water to the top of the gunnel, and that will determine suitability for rivers etc.

If you are planning to go on lumpy stuff then you will need some sort of 'protection' to prevent water entering the cabin, the reason a lip is normally fitted!

[Keeping Up]

Remember that some or all of the deck can be below gunwale height. On our cruiser-stern narrow boat for example, just over one foot each side is at gunwale height making it safe and easy to step on, but these are lockers so you are standing on their lids. The space in between is then at a lower level, just high enough to clear the engine, so that there are less steps into the cabin. This would be even easier on a widebeam. You just have to ensure that there is suitable drainage (and not into the cabin).

[David Schweizer]

There are recommended minimum free board distances for sink waste outlets and hull mounted engine exhaust, so your gunwale freeboard would need to be able to accomodate them. I cannot remember exactly what they are, but a surveyor would be able to advise you, or someone on here may have a note of them.

[ditchcrawler]

I would suggest if you are going into that much detail designing your boat and not just buying the builders standard hull you need a working knowlage of the RCD.

[WotEver]

There are recommended minimum free board distances for sink waste outlets and hull mounted engine exhaust...

I'm pretty sure it's only 10" or 250mm.

 

Tony

Edited April 30, 2012 by WotEver

[steelaway]

I'm pretty sure it's only 10" or 250mm.

 

Tony

 

 

 

I would agree.

10"' deck - 2'6" draft - 4' air draft leading to a 6'+ head hight inside cabin.

 

Alex

[RLWP]

I would suggest if you are going into that much detail designing your boat and not just buying the builders standard hull you need a working knowlage of the RCD.

 

Me too

 

Richard

[ChrisPy]

when I did my RCD stability and downflooding calculations for the RCD on a widebeam, I recall that the openings have to be 250mm above the waterline when the hull is heeled over by the persons on board, etc.; in my case 400mm was safe.

the biggest issue was the engine room vents that are louvres on each side above the rubbing strake on a Liverpool hull.

needs to be recalculated for a narrowboat.

critical factor for stability is the number of persons on the builder's plate.

Edited April 30, 2012 by ChrisPy