Chapman Water Hoy 1768 by DocBlake - 1:48 scale

[DocBlake]

Chapman Hoy Scratch Build 1:48 scale

This will be my log for a 1:48 scale (actually 1:50 scale as all the plans are metric) scratch build of a Chapman Water Hoy. A hoy is a small vessel, designed to move cargo and supplies to and from ships and the shore. These included provisions, munitions, fresh water etc. Hoys were sloop-rigged, with a mainsail on a gaff, but loose-footed (no boom). Fifty tons burthen was typical for size. This hoy had a large beam and draft for her length to maximize carrying capacity. The Chapman Water Hoy was designed by Fredrik Henrik af Chapman, a Swedish ship designer in 1768. This is an odd little ship but very interesting and with a simple rig. She was built for a life of hard work. The photos show three drawings of the vessel and a model photo i found on the internet.

Another reason I chose her to build is to spare the world another "Victory" or "Syren" build log! LOL!!

 

 

 

[Landlubber Mike]

Looking forward to this one Dave!

[BANYAN]

I was wondering where/what you would look to next Dave.  Great choice, this should make into a lovely model.  It seems you have quite a bit of info to get a good level of detail.

 

cheers

 

Pat

[Dr PR]

Howard Chapelle would approve!

 

Would this be the hoy Delay mentioned in Shakespeare's "Comedy of Errors" Act 4, Scene 3?

[DocBlake]

Thanks for your interest, guys!

 

There are a lot of real challenges involved in building this little ship…not the least of which is the extended hatch to the cargo hold.  The framing for than long hatch curves across the beam to match the deck camber, but also fore and aft to match the deck sheer.  I plan to also change the wooden slats which cover the hatch opening from flat to curved.  Lots of solid geometry to contend with.  I suspect that part of the build may take a month to complete, with multiple trial and error attempts.  Challenging and fun!

[Roger Pellett]

A great subject.  The Victory’s and Syren’s could not have functioned without these small vessels.

[DocBlake]

I happened to have a copy of the March, 1993 issue of Model Boats magazine which had an article by Peter Danks about building this small coasting vessel. It included a full set of plans, which I had digitized so I could copy selected parts of the plans as needed. The model is about 13” long without the sprit, so enlarging the plans to 1:32 results in a model that is still reasonable for the average house! I abandoned my usual preference for larger scales and decided to build at 1:48 for a change of pace!

The construction technique in the original plans was weird. It employed a strange jig that was INSIDE the model, and the model was built upside down, with extensions glued to the jig like a Hahn style POF. The model was then cut from the jig after planking the exterior. I decided to go a different way. I converted the skeleton to a typical POB model, with a central false keel and bulkheads. This was challenging because the plans don’t include a water line or bearding line and the station lines, which form the basis of the bulkhead, are poorly drawn.

I made up foam board mockups of the bulkheads and false keel before I made the final versions in basswood. The first photo (on page 2 of Danks’ article) shows the odd construction plans and the weird up-side-down inside out jig. There is even (un-necessary) deadwood! The second photo shows the profile and the station lines which I used to draw the false keel and plan the bulkhead locations. The third photo shows the sheer line of the deck drawn in, which defines the top of the false keel as well as the slots for locating the bulkheads.

 

 

 

[yvesvidal]

An unusual subject. I am all for it.

 

Yves

[DocBlake]

The bulwark extensions on the bulkheads would be harder to fair if made of plywood, but if basswood were used, they would be very fragile and likely to break. I solved the problem by making up a blank for each bulkhead. These were two 1/8" thick squares of basswood glued togther. I glued them so the grain of each was at 90 degrees from the other. This prevented breakage of the bulwark extensions. I also ploughed dadoes into each bulkhead so I could fit basswood stringers to stiffen the frame. Easier than blocking each frame. The final bulkheads are ¼” thick.  You can see the two layers in the second photo.  The third photo shows the layout of the profile former before cutting and the last photo is of all the bulkheads ready to be glued up! 

 

Note the tumblehome of the fore and aft bulkhead extensions.  That may be a problem a little later! 

 

 

 

 

Edited May 29, 2022 by DocBlake

[BANYAN]

That's a great solution to the problem Dave, those recessed/flush stringers should do the trick nicely.

 

cheers

 

Pat

[DocBlake]

Thanks, Pat.

 

After drawing in a bearding line and the rabbet, I tapered the lower edge of the false keel to proper size and glued the frame together.   

 

 

 

[BANYAN]

That skeleton came together very nicely Dave.

 

cheers

 

Pat

[DocBlake]

The subdeck is difficult to fit because of the bulwark tumblehome at the bow and the stern.  I’ll make it in two pieces.  I blocked in the space between bulkheads #6 and  #7 to provide a gluing surface for the edges of the two pieces.  I then made the stringers and glued them in the rabbets.  When dry, I trimmed them and sanded the whole framework top.  Next is to install the subdeck.   

 

You can see the bearding line drawn in on the middle photo.

 

 

 

Edited June 4, 2022 by DocBlake

[DocBlake]

 

As mentioned, the sub deck is made in two pieces.  I used 1/32” plywood because it bends easily and you can cut it with a pair of scissors!  Since there is a second final layer of decking, I wasn’t too concerned about how tight the tolerances were for the notches that accommodate the bulwark extensions.  I framed in the mast step on the profile former, drew a centerline on both pieces of subdeck, drilled the mast hole and then glued down the sub deck using 30 minute epoxy and those little yellow nails that come with every model ship kit!  When the glue dried I removed the nails.  The next task is bow and stern filler blocks.  There is a bluff bow and the stern is pretty rounded also.  

 

 

[DocBlake]

I fitted the bow and stern filler blocks.  They are balsa wood so they shaped easily.     The filler blocks and the frames were then faired.  No problem with any of the bulkhead extensions breaking due to the double thickness of cross-grained basswood making up the bulkhead blanks. 

 

 

 

[BANYAN]

That hull looks very nicely faired Dave; will you be sealing the balsa first?

 

cheers

 

Pat

[DocBlake]

Hi Pat!  Not really necessary to seal the balsa.

 

The next task was to thin the bulkhead extensions.  They were left thick to allow fairing of the outside of the hull.  The inside surfaces then need thinning.  I use X-Acto blades and a Proxxon detail sander with 60 grit adhesive backed sandpaper.  Worked well.  No broken extensions because of the two thicknesses of basswood ninety degrees to each other.   

 

 

 

[the learner]

Oh my this looked like it was going to be a fantastic build, very unusual one