Swallow Yachts Association

Swallow Yachts Forum => Technical => Topic started by: Julian Swindell on 19 Oct 2009, 09:53

Title: Rear Cabins
Post by: Julian Swindell on 19 Oct 2009, 09:53
I think this deserves a new thread. I would love to see others ideas on a rear cabin and I shall spend the winter sketching out my own.
For a start, I think a better rig for a rear cabin might be like Nigel Irens Romilly. Then you could have a huge cockpit with the mizzen stuck on the rear end of the cabin.
http://www.nigelirens.com/FRAMEcruising.htm
If you want to have a look at some really eccentric stuff, including a rear cabin and fantasy sailing companions for old sailors, have a look here
http://www.yrvind.com/index.html
Matt must love it when we experts start telling him how to design boats
Title: Re: Rear Cabins
Post by: Michael Rogers on 02 Nov 2009, 23:51
Julian, I am an old fogey, but could we possibly have 'stern' or 'after" cabins? I think it's a sad day when boats have rear ends. Am I starboard or am I port (as a nautical BFG might have said)?
Title: Re: Rear Cabins
Post by: Julian Swindell on 03 Nov 2009, 10:51
:-[
I stand (or sit to be honest) corrected! Can I still call the cabin roof the poop deck, even if there isn't headroom to sit on it?
Title: Re: Rear Cabins
Post by: Michael Rogers on 03 Nov 2009, 11:44
Please  feel free. I think a poop deck is brilliant, and highly nautical. Even if you can't sit on it, let alone stride across it au Hornblower/Aubrey, would there be room for a small brass cannon, for firing appropriate salutes while lying hove to and watching the sailing world go by? I'm sure the Commodores of all Yacht Clubs in the vicinity would be highly gratified. Do Classic Marine do cannons?
Title: Re: Rear Cabins
Post by: Craic on 03 Nov 2009, 13:14
A stern cabin with a walkable roofdeck above it would probably be very nautical and scenic, but not be very clever.

Because the key benefit of a stern cabin would be that it could have a much lighter roof, because it would not have to be walked on. Unlike any forward cabin which needs a strong roof in order to support the main mast or to work on the mast or to walk to the bow across it to work the bow and anchor.

This is how the stern cabin idea came about: Old rowing lifeboats and modern Atlantic crossing rowboats use rather than a ballast keel a forward cabin plus a stern cabin for self-righting from a capsize. These chambers have so much buoyancy protruding above cockpit deck level, that a boat rolls back from a capsize even without having a ballast keel as such. The added benefit is that the crew sits quite protected in a central cockpit. Pretty or not, form follows function.
Title: Re: Rear Cabins
Post by: Tony on 03 Nov 2009, 16:18
More on stern cabins....
The first diagram shows a BayRaider hull with a stern cabin superimposed. Note relatively large volume of cabin possible without reducing the size of the cockpit. Have to hang the outboard off the stern (ugh) or use some kind of electric drive. Forward position of the centreboard, or dagger board, (more usual with Junk-rigged sampans), would be balanced by a larger rudder than the usual high aspect ratio model fitted to BayRaiders.
With the main mast so well forward, to suit a balanced lug or junk rig, there would be no problem fitting a sprayhood to shelter the crew when making to windward. Minimal protection when you consider a major disadvantage of  stern cabins – as shown in the shot of Andreu Mateu s boat. In a storm, the cabins  windage holds the boat head to wind – no bad thing - but the hatch opens to windward!
Sean Moriarty s boat has a forward cabin, too,  which gives protection and bouyancy without increasing the windage too much. Incidentally, his boat has adjustable water ballast...see http://www.kerryrows.net/pages/boat.php
Title: Re: Rear Cabins
Post by: Craic on 04 Nov 2009, 05:11
Here is another photo, of the standard RNLI self-righting lifeboat. 

Full story of her renovation with a photo of her with two masts up at http://www.polperro.org/lifeboat.html .

BTW, in the Swallowboats BayRaider is already another feature originally developed in the 30ties for lifeboats, the asymmetric capsize buoyancy.
Title: Re: Rear Cabins
Post by: Tony on 09 Nov 2009, 01:54
Yet more on stern cabins;
This is GRATIS, a steam powered, aft cabin design found in an obscure corner of the Wooden Boats web site while looking for info on junk rigs...

http://www.woodenboat.com/forum/showthread.php?t=71730

.....not quite to my taste but Ive seen uglier boats.
Title: Re: Rear Cabins
Post by: Julian Swindell on 09 Nov 2009, 09:43
So... You stand with the steering wheel behind you?
Apart from that, I think it has potential, but as Claus said, the forward facing cabin door is a problem.
Title: Re: Rear Cabins
Post by: Craic on 09 Nov 2009, 16:54
Quote from: Julian Swindell on 09 Nov 2009, 09:43
... as Claus said, the forward facing cabin door is a problem.

Tony said that, I would say differently.
All houses, sheds and ships on this planet have doors to windward, at least part time. Not a real problem.

The good thing about a boat is you can change course a bit to avoid the door is facing windward when you want to use it. And when lying at anchor, hey, why not spread a cover between sprayhood and stern cabin? Super simple with a stern cabin and gives a huge dry space underneath.
Title: Re: Rear Cabins
Post by: Tony on 10 Nov 2009, 23:30
(Julian)... as Claus said, the forward facing cabin door is a problem.

(Claus) .... Tony said that, I would say differently.
Quote

Not guilty!
I dont think a forward facing hatch is a problem either. You just need to be a bit careful opening it when making to windward. Most of the time it would simply be a welcome source of fresh air...especially during a Greek August.

I like the idea of a temporary hard top for expeditions....especially if you could whip it off and use it as a tender. A bit difficult to retro-fit something like that, perhaps, but a reluctance to have a permanent cabin on a small boat is understandable if you mostly daysail.....and dont have small, easily chilled kids with you. We could do worse than look at 19th Century pleasure boats. They had all sorts of hints and tricks such as lifting roof, folding sides, etc. All done with wood and canvas, too.
Title: Re: Rear Cabins
Post by: Julian Swindell on 11 Nov 2009, 10:52
I should be working, but this is far more interesting. One problem with an aft cabin would be getting at the mizzen. The best solution to a problem is always to get rid of the problem. Rather than a yawl or ketch rig, how about a schooner? The mainmast could be stepped at the fore end of the cabin, maybe with a main sheet track across the cabin top. The smaller foremast could be stepped well forward in the cockpit. You could get at the luff of the main sail easily then, as well as any reefing lines. You may not need a jib at all. Would not look remotely like a current Swallow Boat, but could look very good. You should see Nigel Irens' gorgeous, now lost schooner Maggie B
http://schoonermaggieb.net/
Her replacement M2 should be even better. She has just been turned upright at the boatyard
http://www.youtube.com/watch?v=Kvh8U6ofBqI
This is what she will look like, gorgeous:
Title: Re: Rear Cabins
Post by: Michael Rogers on 11 Nov 2009, 12:38
Good, logical thinking, Julian, and clearly an opportunity to use modern Junk rig.
Title: Re: Rear Cabins
Post by: Craic on 11 Nov 2009, 21:43
Guys,
the world is so small.
Matt and I were at the Enkhuizen Klassieke Schepen Show last week and up came this guy with a truly amazing small waterballasted popup stern cabin sailer.
Have a look yourself, cannot a stern cabin look sweet? Best solution I have seen in a long time.
Title: Re: Rear Cabins
Post by: Craic on 14 Nov 2009, 04:31
Quote from: Tony on 09 Nov 2009, 01:54
Yet more on stern cabins;
This is GRATIS, a steam powered, aft cabin design found in an obscure corner of the Wooden Boats web site while looking for info on junk rigs...

http://www.woodenboat.com/forum/showthread.php?t=71730

.....not quite to my taste but Ive seen uglier boats.

Dear Tony,
well done digging up little GRATIS, thanks. As small as she is, the stern cabin looks fine on her.
Title: Re: Rear Cabins
Post by: Tony on 14 Nov 2009, 14:26
Hi, Claus,
I like the centre cockpit ketch you posted the other day. The more I think about it the better I like the idea.  My idea of the "perfect" small boat is:
easily trailed long distances on unbraked trailer with family car
sea worthy enough for exposed coastal cruising – no fear of F6 gusting F8 (common enough conditions to be normal these days)
living space and facilities for weeks of cruising and marina-free anchoring in relative comfort
These are conflicting requirements, of  course!

- Pop-up headroom in harbour and low windage when sailing could be an excellent combination, if implemented well. The lowered roof should be bomb-proof and solid.
-The well sheltered centre cockpit is safe for rough weather – so long as it is self draining - and the fore and aft cabins are designed not to flood with a rogue wave or a knockdown.
-Not so keen on the exposed outboard...but my "ideal" boat would be diesel electric with a (yet to be developed) briefcase-sized diesel generator, super efficient solar cells, perrhaps,  or a cheap, mass produced fuel cell (again, yet to be developed!).

All we need is a few million Euro spent on R&D for the mechanical/technical hardware and the fast, light weight, long distance cruiser could become a reality. 
Why my friends spend a fortune on 30 foot white plastic clones with unimaginative rigs and poor performance beats me. Especially as they spend most of the time growing weed in a marina. There are cheaper ways of  having  a week end cottage by the sea.  Don't get me wrong. I love ditch crawling off the Essex coast but wouldn't it be nice if you could tow the boat to Italy for a week or so?
Title: Rear cabins
Post by: Craic on 15 Nov 2009, 17:51
[Original post deleted by a spammer.  Their replacement post removed by a moderator]
Title: Re: Rear Cabins
Post by: Tony on 16 Nov 2009, 01:25
Claus
Yes, you're right, of course.  I'm just suggesting that any progress is necessarily preceeded by a flight of fancy, then realised by competent design/engineering and enabled by a well heeled sponsor or two.  Any Lottery winners out there listening? How about that cheap, mass produced fuel cell, then!

A minimal cruiser? (Hmm.. I sense a new thread coming up.)
I need no convincing.....you've seen the Four Sisters! 
Using a  GRP BayRaider hull "off the shelf" would make an excellent platform. Bolting on a low cabin top – or even an extended flush fore deck - would give ample dry storage and sleepingbag room for two without mucking up the sailing...and a deep spray hood would give sitting headroom for ...er...sitting.
Is this the kind of thing you're thinking of?
How much modification to the present BayRaider would be needed, do you imagine?
Would it be possible to retro-fit a stern cabin on a standard boat?
Title: Re: Rear Cabins
Post by: Craic on 16 Nov 2009, 16:15
Thanks Tony,
MINIMALIST CRUISER would be a good headline.
Top safety staying as top priority, lightweight trailering next, good sailing performance then. Basic comfort, sure, allowing two people to cook and eat their meals sitting upright and have enough dry area to sleep aboard for a week and dry their clothing a bit. Looks? Rather like GRATIS than like a Drascombe Coaster.   

Best cost efficiency comes from re-using and re-arranging proven modules.

The BayRaider GRP hull is there ready, it is fully tested and proven, and being almost mass-produced it is available in quantity. Same applies to rudder, centreplate, rig and sails.

The first idea would be a hardtop retrofittable to the open BR. This could be something in the shape of the sprayhood, but a bit longer and with a (canvas or rigid) door. But then one realises that such a hardtop behind the mast would make working the mast very awkward, and would prohibit the mast from being lowered in the tabernacle hinge.

Putting the tabernacle onto the hardtop roof to overcome that would result in the rig and sail having to be shortened, and the hardtop requiring a compression post underneath, etc.. Complications and costs there, and new RCD/CE testing.

On the other side, putting a hardtop over the stern would not require structural changes. The mizzen mast is a spear type and  in two parts anyway, so  one could make it longer for very little money.

That stern hardtop could also be in two parts, telescopic lenghtwise. To fit two basic berths underneath will be tricky, but not impossible. The tiller/rudder could be connected to a yoke again, like in the SeaRaider, works very well, and the engine could be left petrol, or exchanged for an electric one. A table can be clipped onto the tiller. In connection with the foldable sprayhood and a basic cover between sprayhood and stern cabin there would be a very large dry central cockpit and space underneath. Costs: for that stern hardtop only, no structural changes are required to boat, rig, sails. Especially, if the stern hardtop was made out of a lightweight foam sandwich material,  I would see it would rather aid  the uprighting properties of the boat further, so no major difficulties with CE testing must be feared.

Any other ideas out there how to turn the BR into a minimalist cruiser?
Title: Re: Rear Cabins
Post by: Tony on 18 Nov 2009, 21:36
Hi, Claus.
If you really wanted to keep a fore cabin on the Minimal BayCruiser, Whisper Boats have an idea. Cut away the central part of the cabin top all the way to the mast,  but instead of a sliding hatch (which would be limited in travel by the mast) they have a sheet of heavy canvas which rolls away.  Something built like an old fashioned fabric car sunroof might be an improvement and could be quite tough and water proof.

http://www.youtube.com/watch?v=1BPBDyaEvZE