Fairey Fisherman 27 Motor Sailer

[Chris FellowsParticipant @chrisfellows72943]

I’ve had another look at the keel position and found the Centre of Lateral Resistance by cutting out the below waterline shape of hull and hull keel and finding its point of balance, which is a little to the rear of the rearmost edge of the keel fin.

This position is also back from the hull centre-point on the waterline. So I’m happy with its positioning. It might not look right because the mast is set quite a way forward? I seem to remember reading when doing my initial research that with low speed craft positioning of the keel and mast wasn’t critical and seem to think that with the Fisherman the mast was positioned more with accommodation in mind rather than performance, particularly as the sail area isn’t that great with it being a motor sailer rather than a full-on yacht. And as I said I’m only going to sail this in light winds so hopefully it will be Ok.

Chris

[Chris FellowsParticipant @chrisfellows72943]

Right or wrong no going back now (or forwards!) as I’ve cut out a section of keel to accommodate the sleeve and the other doubler has been glued in place. Doublers are also being fitted where the turns are a bit tight for the keel stringer. I need to drill out for the prop shaft but I think I need a longer drill!

The plan has been fixed to the baseboard with spray adhesive in readiness for fitting the frames.

Chris

 

 

[Ray Wood 3Participant @raywood3]

Hi Chris

Good job 🙂

Also a good idea putting the front and rear bulkheads in on the splay, It saves a lot of chamfering , which to be honest I do very little of, I’m a bit rough with stuff like, that but fast 🙂

Regards Ray

[Chris FellowsParticipant @chrisfellows72943]

Thanks Ray. Yes, it was the amount of chamferring that prompted me to put the frames on the splay in the first place. Also it helped with the hull shape I hope!

Chris

[Richard SimpsonParticipant @richardsimpson88330]

Interesting method Chris.  At first I thought you might be compromising on strength but, the more I think about it, the line of force should be through the frame if perpendicular to the skin, which should actually be stronger than at an angle to the skin.  As long as the joint to the keel is strong as I guess the weakness would now be at that end but I suspect that would be negligible in a small structure such as this.

As Ray says it saves chamfering, which is a pain, so there are a number of advantages.

[Chris FellowsParticipant @chrisfellows72943]

Yes, I’m going to put some strips on the keel for positioning and to provide additional gluing area so hopefully it will all be alright! Ideally it would be good to mill/cut grooves out in the keel but I don’t have the tools to do that and the strips won’t be seen anyway.

As Tim says, once the rest of the structure and planking is in place the whole structure should be strong and as you say the forces shouldn’t be that great anyway.

Chris

[Tim RoweParticipant @timrowe83142]

Strong Chris?  It will be indestructible!

Tim

[Chris FellowsParticipant @chrisfellows72943]

You’re probably right there Tim!

Bit more progress today. Tidied up the keel doublers and then drilled out for the prop shaft tube. Thought I might need doublers there as well but it was Ok and once the tube is glued in will be strong. Made a cut-out so I could access the lower bearing for lubrication and for getting glue in. Funny how many modifications you have to make along the way!

I then cut the legs off the P-Bracket and drilled a hole for the bearing which will be glued in later.

Next job is to make a mounting board for the motor and fit along with the coupling so that I can cut the prop shaft tube to length.

Chris

[Chris FellowsParticipant @chrisfellows72943]

Didn’t do a lot yesterday, just made and fitted a base for the motor mount so that I can cut the prop shaft to length. Can’t do that at the moment as I’m waiting for a longer 4mm drill to arrive.

So, knowing there’s going to be times like this e.g. I need to order the balsa sheet for planking and stock up on other timber then I’m returning to form and starting another build!

This is the Fairey Faun which I was going to build first to get some practice with planking. Just getting the drawings ready for printing and I can make a start.

Chris

[Chris FellowsParticipant @chrisfellows72943]

Ray, you asked about the sails earlier. I’d forgotten I’d got these which show the two types.

The mizzen set-up isn’t showing the staysail though. As I said I’m using the sloop version as the other looks a bit silly and isn’t very good for sailing and is really only for assisting the motor, steadying and to get you home if you have engine problems.

I don’t think they sold many with the mizzen option.

Chris

[Colin BishopModerator @colinbishop34627]

A very nice and well specified boat Chris. I wouldn’t have minded one of those as during my sailing days we seemed to spend as much time under motor as under sail cruising around the Solent and west as far as Poole and up to Wareham.

This advert highlights the plus points of the design.

http://www.fairey-boat-sales.com/brokerage.php?doc=79

My Jaguar 25 was a somewhat reduced version but still featured two V berths forward, a separate WC compartment, spacious saloon with dropping table for conversion at night plus a long single berth under the cockpit. Normally I only sailed with one other but we had three on occasion. The photos show how comfy and practical this small yacht is for coastal cruising.

Colin

[Ray Wood 3Participant @raywood3]

Hi Colin,

Jaguar Yachts produced some great boats on Canvey Island, I had to go there to buy a new pulpit rail for my 21 as it had been ripped off and sunk in the 87 gale, when I was there they were producing Spring 25’s a boat I always wanted but couldn’t afford, now I could as they are knocking on a bit and cheaper !! but I’m sticking with the models, no marina fee’s 🙂

Regards Ray

[Chris FellowsParticipant @chrisfellows72943]

Thanks for the link Colin. I downloaded a number of photos when I first decided on the build but that is a nice example with plenty of useful details. It was also useful as it mentions teak. I want to use some different timber in this and the Faun build and was wondering what to use.

Chris

[Chris FellowsParticipant @chrisfellows72943]

With the Faun on hold now until planking materials and prop shaft are requisitioned in the new year I’ve spent a bit of time over the last couple of days back on this build.

First job was to drill through the hull keel for the prop shaft itself using the longer drill I’d been waiting for previously. Bit nerve wracking as not much room for error and indeed I had a minor breakthrough when drilling from the prop end. Bit annoying as I’d managed the bigger diameter hole for the prop shaft tube Ok. Not much of a problem though as it’s on the junction of the planking and a bit more filling using sawdust should hide it as it’s going to be varnished. Shaft was a bit tight to turn but filing along the hole sorted that.

The prop shaft and motor was then assembled to determine where the tube and shaft needed to be cut and is now ready for gluing in place. The motor mount base needs to be thicker (better than thinner!) to align properly and that will be done later. For a change I’ve gone for Raboesch props for both these builds. I didn’t fit the prop shafts at this stage with my other builds but I had more wriggle room with them and as we know with these type (and size with the Faun) access is more awkward. With three bearings on this one the assembly only has to be under the slightest of side pressure and the shaft is harder to turn.

Well that’s it for now until after the festivities and the first beer will soon be cracked open. Merry Christmas and Happy New Year to my fellow modelers.

Cheers, Chris

[Chris FellowsParticipant @chrisfellows72943]

Doubled the thickness of the motor mount base with another piece of ply glued to it. Then put a splint on the coupling to line up the motor and prop shaft. The position of the mount holes were then marked and drilled and the mount bolted down. The prop tube was then glued into position with 20 minute epoxy.

Chris

[Chris FellowsParticipant @chrisfellows72943]

More done to the keel so that it can be assembled with the frames. Today I started fixing the frames to the baseboard. This is a job in itself and complicated by the angled frames. Once completed and the keel glued in place and the stringers fitted it will be ready for planking.

Chris

[Chris FellowsParticipant @chrisfellows72943]

Taking shape now. Glad I stuck with the angled frames as they are working out well. No doubt like most things, they have been done before?

I’ve got to remake the No. 1 frames though as for some reason they are too short from top to bottom. I think I know why but will have a look at my drawings and revise.

Faun and Fisherman for comparison at the same scale!

[Colin BishopModerator @colinbishop34627]

Angled frames are new to me, look quite ingenious. I have always assumed full hull width frames in the conventional way which usually work well enough but I can see the potential advantages of angling them each side.

You learn something new every day!

Colin

[Chris FellowsParticipant @chrisfellows72943]

Thanks Colin. Probably wouldn’t make sense or work at full size due to the forces and their directions involved but in a model, with in this case, a substantial keel and the general over-engineering of models anyway, it works. Once planked, as we know with models, they are very strong.

Well it’s working so far! We will see!

[Tim RoweParticipant @timrowe83142]

Cant frames are widely used in full sized shipbuilding and have been so going right back to wooden ships.  The hydrostatic and wave motion forces on a ship’s shell plating or planking act normal to to the surface so from a structural point of view having a stiffener on the other side also normal to the surfaces is efficient.

The other reason is practical. As the bow and stern sweep around to the centreline, the frame has an open side and a closed side in relation to the shell.  The open side is an obtuse angle and in the case of riveting it is easy to open up an angle bar and get access for riveting.  On the closed side the angle forming is much more difficult and it could be impossible to get access to work the rivets.

The same applies for welding if it is required on both sides.  It is easy to weld on the open side but impossible to get a full penetration weld on the closed side.

On tradition shipbuilding it saved making big bevels which was wasteful of material and labour.  The lofting was a bit more difficult but they were clever at that and Chris is too.

Tim

[Chris FellowsParticipant @chrisfellows72943]

Thanks for that Tim, that’s interesting. Thought you’d be the man to know!

In my case it was also to avoid big bevels and also because I found it easier to visualize the curves of the hull at right-angles to the frames.

Found the problem with Frame 1, as I suspected this frame is where the bow curves up and I hadn’t used the point at which the angled frame meets the keel which is below where it would be if the frames were at 90 degrees. Doh!

Chris

[Colin BishopModerator @colinbishop34627]

Modellers usually just sidestep the issue by chamfering the frame edges.

Colin

[Richard SimpsonParticipant @richardsimpson88330]

The downside of a canted frame is that the frame doesn’t then transmit transverse forces perpendicular into the keel.  Consequently what you are benefitting by having a perpendicular joint at the hull is partly offset by the fact that you have to accommodate angled forces at the keel joint.  This might be additional brackets or partly let into the keel.

Not an issue at modelling scales of course but it does have to be accommodated in full size shipbuilding.

[Colin BishopModerator @colinbishop34627]

I had never thought about this before and find it quite interesting (nerd me!). Like so many things it is a compromise.

I am currently re reading D K Brown’s book on the Grand Fleet which offers an insight into many constructional issues of the time as do his subsequent books on the construction of Royal Navy warships. Many ships suffered from design weaknesses and had to be subsequently reinforced.

Rather off topic and best continued in a new one if people are interested.

Colin

[Chris FellowsParticipant @chrisfellows72943]

Richard – as you say not a problem with models as the materials are usually way over scale and the forces small. Especially when you have a substantial mahogany keel like I do! With “normal” frames as well as some of the force being transmitted at 90 deg to the keel it is also resisted by that part of the frame on the other side of the keel. With canted frames some of the forces are transmitted along the line of the keel so the resting forces don’t need to be that great. As we’ve said before, once the hull is planked it acts as a whole anyway and transmitted forces will be pretty much non-existent unless another model smacks you on the side!

Colin – feel free to continue on here or start a new topic. I’ve never studied full size building practice and will find it interesting. Probably a new topic is best though as more folks will read it and hopefully contribute and easier to find in the future.

Chris

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