New project

[Chris FellowsParticipant @chrisfellows72943]

Whilst I've got enough on my plate building Fairey sports boats (when time permits) I'm feeling the need to do some more drawing for another project.

Sticking with Fairey, but wanting to do something a little different and with some sail, for a little while I've had my eye on the 27 foot motor sailer, which like the other boats, I want to build to a scale of 1:12.

This boat is based on a lifeboat hull and as such has a few more curves than the sports boats. I'm assuming this will have to be plank on frame and as such would welcome any advice on methods, type and thickness of material etc. and pointing in the direction of any builds showing the process etc.

Being more complicated (well for me!), what with sails etc., this is going to be a longer term project and likely to go beyond the other builds. Looking forward to getting started on it though.

Chris

[Chris FellowsParticipant @chrisfellows72943]

[Ray Wood 3Participant @raywood3]

Hi Chris,

If you have a look in my Album Rays Boats, there are a few similar plank on frame models, if you get hold of a drawing with hull lines & sections it's a good starting point, Jim Pottinger has produced hundreds over the years.

The Fisherman 27 would need a fin keel and lead bulb to achieve a decent sailing performance , my YM Wild Duck plan published last year  has a removable keel for static display

Regards Ray

Edited By Ray Wood 2 on 23/06/2018 06:43:55

Edited By Ray Wood 2 on 23/06/2018 06:47:22

[Chris FellowsParticipant @chrisfellows72943]

Thanks Ray, I'll have a look at your album and thanks for the tip on the keel.

I'm sure there will be plenty more questions as I progress this one.

Chris

[neil hpParticipant @neilhp]

if its based on a lifeboat hull, then try with 1/32 birch faced ply, a double diagonal planked hull as old RNLI lifeboat hulls were made……the thin ply is both water resistant and as ls very pliable at that thickness.

[Chris FellowsParticipant @chrisfellows72943]

Thanks Neil, that sounds just the job.

Looks like I will have to get myself a small table top saw for cutting the strips?

Chris

[Dave MilbournParticipant @davemilbourn48782]

There's nothing like a new project as an excuse for more shiny new toys. Insertion of the word "small" won't justify the price – or fool Helen. Believe me, Chris, I've tried every trick in the book – including having the bloke in the shop put a lower price-ticket on the item. Do it, but don't forget to feel guilty about it…or at least feign remorse…
DM

[Chris FellowsParticipant @chrisfellows72943]

Thanks Dave. I've got a motorcycle or two (another hobby) in the garage and many a part has been transported into the garage under the cover of darkness!!

At least while I'm still working part-time (for a few more months) I can at least say whilst I'm still working we can afford it!

A drill stand would be useful (no essential!) as well.

Trouble is with online banking Helen can see what I'm spending!

To be honest she's pretty good and allows me to indulge from time to time without too many moans though there has been the odd moment when I've announced I've bought a new car!

Chris

[Ray Wood 3Participant @raywood3]

Hi Chris,

She is too small and pretty to have been a double diagonal planked life boat of the RNLI, maybe a cconverted ships boat but I doubt it, anyway cutting 1/32" ply really only needs a steel rule & a Stanley knife, but buy the saw anyway

Regards Ray

[Chris FellowsParticipant @chrisfellows72943]

Hi Ray

The hull was built by Fairey, using their hot moulding technique and was designed as a ship's life boat.

Unfortunately it wasn't financially competitive but rather than waste the hull plug it was decided to use it for the Fisherman 27 motor sailer.

In the light of yours and Dave's comments I feel duty bound to purchase a table saw now!

Chris

[Ray Wood 3Participant @raywood3]

Hi Chris,

Mr Google images, has a drawing for you, no sections but it's a good start

Regards Ray

[Chris FellowsParticipant @chrisfellows72943]

Thanks for looking Ray.

I've got the original Fairey drawings which those pretty much are.

As you say no cross-sections or bottom of the hull but with the addition of photographs and life boat builds to refer to I should be able to draw something up.

Chris

[Chris FellowsParticipant @chrisfellows72943]

I'm progressing quite well with the drawings for the hull (strained the brain cells a bit though!) and am pretty happy that after tweaking and retweaking more than once (and will probably do so again!) I've come up with a shape for the hull that is about right. Of course the only true test is building it.

I'll post up some drawings when I've done a bit more work – probably after the weekend if the weather forecast is to be believed.

Ray – how did you attach the removable keel on Wild Duck? As shown in the drawings you posted up for the Fisherman the sail area isn't that great relative to the hull, unlike a yacht, so the keel shouldn't need to be too heavy or deep. First thought is to get one as used on my Dragonforce 65 type yacht and modify the fixing.

Cheers, Chris

Edited By Chris Fellows on 06/09/2018 13:38:14

[Ray Wood 3Participant @raywood3]

Hi Chris,

Wild Duck is only 22" long but has big rig comparatively, the fin is 1/8" x 2" dural 7 1/2" deep to the lead bulb which weights in at 1lb 8oz. The fin extends up a further 6" into a slot/opening in the keel with ply doublers each side, which needs to be sealed with varnish before aassembly to form a dagger board approach as on a sailing dinghy.

Your Fairy is a motor sailor and will sail a lot better with the fin keel, or did she have a centre plate which was dropped for sailing? The df65 keel is 12" to the bulb so is long enough to do the job but you will have to cross drill it to put a retaining pin through it, it's a super section but will take some packing to make good fit in a slot.

Regards Ray

[Boiler BriParticipant @boilerbri]

Hi Chris, are you drawing it up on CAD or paper?

Bri

[Chris FellowsParticipant @chrisfellows72943]

Ray – thanks for that, really useful. I'm asking now so that I can incorporate in the drawings. I thought it might be along those lines. Another method I was thinking about was say building a brass block into the bottom of the hull and bolting a keel to it. Probably over complicating it and a source of water ingress – yes, thinking more about it, definitely so!

On the full size boat a cast iron keel is used running the full length of the boat. I'll post a picture up. Not very practical in a model though!

Brian – I'm drawing it up on the PC but it's not a proper CAD program, it's a 2D drawing program called Microsoft Visio. I have years of experience as an architectural draughtsman using a drawing board but I have to say this project has filled me with admiration for the boat/ship designers of the past who could only work on paper. I'm used to thinking in 3D and drawing in 2D but buildings are easier as most are a series of boxes though there are exceptions with some of the fancy CAD designs that we see nowadays.

I'm sure I could have done it on the drawing board, but it would have taken me longer. At least with a drawing program or CAD you can alter, redraw and move things around a lot easier.

Be interesting to find out what the processes were for designing boats and ships in the past. I'm guessing a mixture of drawing and modelling before producing the construction drawings?

[Chris FellowsParticipant @chrisfellows72943]

Couple of shots of the keel. A real maintenance problem!

[Chris FellowsParticipant @chrisfellows72943]

After a bit more tweaking I'm happy with the drawings for the hull. Just got to decide on the method for securing the bulb keel (Ray's way is favourite) and incorporate them in the design and I'll be ready to start building. Well once I've ordered yet more timber from SLEC!

That won't happen until well into October though as I've got a couple of trips coming up over the next few weeks.

Glad I've got to where I am though.

Couple of pictures attached but apologies for the quality if viewing on a small screen.

Chris

[Chris FellowsParticipant @chrisfellows72943]

It's funny how many times solutions or flashes of inspiration come to me (usually for work) when having a shower etc. but this morning was one of them.

Despites its benefits the trouble with the dagger board approach for this model, it being a motor sailer, is that the dagger board assembly is going to be bang in the middle of the boat and will be just where the battery needs to go.

The Fisherman has a small external keel, which I could deepen a bit, and I could bolt the bulb keel to that. I'm going to use mahogany for the keel (even though its painted) to work with something other than ply and for additional strength some brass strip could be fixed either side.

A brass channel could then be fixed to the top of the fin and then bolted to the boats keel. The sail area isn't that great and I shall only use it occasionally in light winds so the forces between the hull and keel won't be that great and will be transmitted to the hull's keel which will be the strongest part of the boat.

One advantage of this approach of course it that the keel can be moved forwards and backwards easily to find the optimum position.

Probably not a new idea for seasoned modellers but it is for me!

Chris

Edited By Chris Fellows on 09/09/2018 11:19:11

[Malcolm FraryParticipant @malcolmfrary95515]

If the keel and whatever it is fixed to can live through the stresses that a fin and bulb will impose, great. Remember that all of the force provided by the sail is passed through everything on its way to the fin, any weak point is where damage will occur, and a row of bolts across the line of transmission of the force becomes a fulcrum, and if lacking enough support each side, becomes the weak link in the chain.

A lot of sailboats that were converted to auxiliary motor had their prop shaft offset to avoid weakening the keel by drilling a big hole through it.

[Chris FellowsParticipant @chrisfellows72943]

Thanks for the advice Malcolm..

I'm going to take the mast all the way down to the keel so it will only be a short distance from where the forces provided by the sails will be transmitted to the fin. I tend to over-engineer things anyway and will make sure that everything is good and strong.

I shall enjoy all the little challenges of building this one.

Chris

[Ray Wood 3Participant @raywood3]

Hi Chris,

Your bolts and channel will just break of the strip of keel due to stress of the moment the rig excerts on fin & bulb, to reduce this stress the fin forces need to be taken up to deck level. The idea of moving the fin to find the right position is not required and not trial & error and is not in the centre of the boat, the leading edge of the needs to be about an inch behind the mast position. All yachts with a Bermuda rig use the same basic formula, to make them sail.

Hope this helps ? These keels have 6mm stainless steel studding to deck level

Regards Ray

[Malcolm FraryParticipant @malcolmfrary95515]

Posted by Chris Fellows on 09/09/2018 19:09:52:

Thanks for the advice Malcolm..

I'm going to take the mast all the way down to the keel so it will only be a short distance from where the forces provided by the sails will be transmitted to the fin. I tend to over-engineer things anyway and will make sure that everything is good and strong.

I shall enjoy all the little challenges of building this one.

Chris

Even if the mast goes down to the keel, there is still the butt join which is the weak point. Most yachts using a fin have either the top of the fin in a box or its stiffener in a tube go up to the deck. If it parallels the mast it makes for a good overlapped join. If the fin box/tub is fixed to the mast tube, even better. A quick goggle for "bono yacht fastnet drum" illustrates what happens should the design not be quite good enough.

If this gets in the way of a single central battery, consider a split pack. If the original had a dagger board, it was probably out of the way of the engine due to the engine being nearer the stern than is easily possible on a model.

[Chris FellowsParticipant @chrisfellows72943]

Ray and Malcolm

Thank you for the further advice and observations. Not as easy as I thought!

Maybe I'll just run it with the sails furled! Only joking!

In the full sized boat there is a cast iron keel (see photos in earlier posts) and indeed the engine is nearer the stern. I'm going to use a similar position as the shaft angle is fine and it's only a slow speed craft so no concerns about the bow being forced down under power.

Had thought about splitting the batteries but ideally want to keep them central.

Thinking cap back on!

Thanks, Chris

[Chris FellowsParticipant @chrisfellows72943]

For some reason my wife isn't too keen on me using my Dremel this evening whilst she is watching the television in the room below so I've returned to drawing.

I was still thinking that a bulb keel could be bolted to the keel and having had an interesting conversation with a chap on one of the club stands at the recent International Model Boat Show who has done that successfully on a similarly sized boat with a timber keel, albeit by clamping rather than bolting, I'm absolutely determined to go down that route.

What I'm going to do is make the centre section of the keel out of solid brass and mortice it to the rest of the keel which I'm building in mahogany. The mast will be located on the top of the brass keel and also restrained where it passes through the cabin roof. The keel will then have a couple of holes drilled through it to attach the bulb keel.

What is nice is that the brass keel will have echoes of the cast iron keel on the full sized boat and will provide some of the required ballast.

Really looking forward to doing some metalwork, last time I did anything much was at school!

Edited By Chris Fellows on 20/11/2018 21:14:00

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