On the Ways: Bearn CV

Step 3: Construction - Bow and Stern Frames

With the center framing done, it's easy enough to stick on the front and rear ribs and keels. Pretty straight forward process. Everything went together with minor sanding on one rib to get everything aligned.






Remember the 1/8" thick sub deck? Time to reinforce it to 1/4". Using 1/8" x 1/4" basswood strips, I fitted pieces in between each rib.
Ok, so this is more work than what was probably needed, but I like trying stuff. Heh. Most people would simply use a 1/4" thick subdeck and slot the ribs into it.






The Bearn has casements in the stern. After trimming rib #1, the excess 1/8" thick pieces from the sub deck was used to make the casement steps.






Now it's time to clean up the rough edges. Here is an important tip: using a sanding block, sand an angle into the front bow ribs. This gives the sheeting more area to stick to and keeps it from pulling away from the ribs.




With the sanding block, I sanded an angle into the subdeck and blended it with the ribs.




Cont ...

 

After shaping the subdeck and keels, angling the bow ribs, and leveling off the ribs with the top of the subdeck, the basic ship hull frame is done! This weekend, I'll start filling out the hull.

So far, it's only taken a half day on Sunday and a few hours for 5 weeknights to get this far. Working steady, a builder can have the ship done in a month or even less. In fact, this Bearn must be done and ready for convoy action by June 25th (I'm moving and our household goods gets packed that day). So that leaves around 18 days to go.

 

She's turning out grat Mike! That's why I like this forum, nice and active with people showing off their ship builds and friendly people. I love how much work you're putting into this because you sure are motivating me to make a ship from scratch one of these days.

 

The problem with Mike is that he is making it look to easy. I tried this once and what a disaster, about where he is right now I just chunked it into the garbage can. But Watching Mike build this one, has given me renewed hope that I also will be able to do this one day.

Mike what can I say, another great job.

 

Mike
Great job on the build, and the how-to article.
She is coming along nicely, and others will stand a better chance of being able
to build a ship from scratch.
I will see about putting together a Treaty battle the first weekend in August.
Mikey

 

Mike you make this seem way too easy. I will have to read this much more in depth than I have and it may make for a great point for me to restart the mold for a certain Japanese ship I am wanting to build down the road.

 

Thanks for the compliments everyone. I'm hoping that this build will show that building a wood hulled ship isn't magic or something.

 

Step 3: Construction - Hull Bottom (part 1)

So far the hull construction has been straight forward other than me using a thinner sub deck than normal. Most types of wood construction follows the rib/keel (or flat plate keel)/subdeck frame method. From here on though, construction changes depending on how the builder decides to make the hull bottom.

One method is to use wood strips to plank over the hull frame. It's impressive to see a person who can plank a hull and keep tight joints. I'm not that good though.

So the method I use is to fill in between the ribs, sand to shape, then fiberglass the hull bottom. Various materials can be used between the ribs such as foam or wood. Even though foam is way easier to sand and work than wood, I do not like adding that much flotation to a ship and possibly make the ship tippy later on. I'm sure foam works great, but it's not for me.

So I went with balsa wood. For the Bearn, I used 1/4" thick sheet medium hard balsa. In my first wood ship, the Richelieu, I used 5/8" thick balsa to bring the ship's interior bottom even with the top of the water channel. I'm going to try something different with the Bearn, so for now it's 1/4" balsa.

First things first: marking the waterline. I plan on using the scale waterline location on the Bearn. For the MWC Nats, the ship is going to be at it's standard weight so it should float at it's scale waterline. By the way, I think Big Gun requires the waterline to be at the scale location as shown on the ship plans.

Once the waterline is marked on a rib fore and aft, measure 1" below that and make another mark. This is the lower edge of the penetrable area (window). I used a straight edge to mark the penetrable window on each rib. Now I know how far up to sheet between the ribs.







In the aft portion of the ship, the curve of the hull wouldn't let me use 1" below the waterline. In that case, the bottom of the penetrable window curves around the bottom of the ship for 45 degrees. You'll see it better in later photos.


At this point, it may be a good idea to mark out and test fit your prop shafts. I made a simple template from scrap balsa with the outline of the prop radius on it. Using the template, I measured where the prop end of the prop shaft had to be.


Next I marked out a horizontal line across the keel. I also marked the distance from the keel on each rib. Where the horizontal line intersected a rib is where a hole will be drilled in the rib.








Looks pretty good so far. The Bearn's deep hull and high stern lets the prop shafts run level.

Next up for tomorrow; sheeting the hull bottom.

 

Mike,

Looking great! What type of glue are you using?

 

I'm using a medium viscosity CA to stick it all together. The Richelieu used the same CA and it's still holding together.

 

Filling in between the ribs is pretty easy. I just place the wood sheet under the hull between two ribs, mark and cut the piece, then sand to fit.


The hardest part of the hull tends to be the stern sections. The wood has to angle in odd directions to fit between the ribs. Patience is needed to sand the wood pieces to fit.


Since the prop shafts are already trial fitted, it's easy to mark out the stern sheeting to cut out slots for the shafts.











The center of the hull is much easier to do. Notice I haven't done the water channel yet. The plan is to fill the channel after the rest of the wood is in place to add some ridgity to the hull frame. Also, the side pieces only go up to the penetrable window marks we did earlier.






The hull looks rough right now, but that'll change once the sanding starts.

Tonight, I'll post the water channel sheeting and putting on the bow and stern.

 

Wow, so many pictures! How do you like the sanded balsa bottom? Would you consider wrapping it with 1/32" plywood instead of fiberglassing it? Also, what sort of modifications would it take to convert the hull from the Bearn aircraft carrier to the Normandie dreadnought? Lastly, what tools did you use to notch the subdeck and ribs, was it anything special or just a bandsaw?

This is looking like a very cool build so far. I might want to try some of these techniques in my next project.

 

I like the sanded balsa bottom because of it's thickness, durability, and workability. It can be sanded to match scale outlines, especially bulges like the Jean Bart's.

I forgot about the plywood method ... it was mentioned someplace else on these forums. Personally, I wouldn't want to try to bend plywood, even 1/32", around multiple curves like the back half of the Bearn or some of the more oddly shaped bulged hulls out there.

Unfortunately, I don't have any plans or outline for the Normandie so wouldn't know the exact changes between the two ships. The full size Bearn was build on the Normandie's hull. And yes, I have thought about making a second deck and superstructure for the Normandie to swap on this Bearn's hull. Being able to change ships with a superstructure swap is one of the major reasons I'm going with a removable hanger deck on the Bearn model.
As a Normandie for Big Gun or Treaty, this ship would be deadly. Slow ... but deadly because it should turn on a dime like a PE or NC.

The subdeck, ribs, and keels were notched on a scroll saw. A bandsaw would work well also. Frankly, notching could be done with a handsaw too.

 

Mike
You picked a great ship for this project.
It is arguably the best convoyship is some of the formats out there. So
if someone wants to build an un-armed convoyship, then here it is. She is slow, but pretty manouverable, and has lots of survivability.
And at a later time, they can always decide to arm her. And for that, she has lots of room, and weight to play with.
A very forgiving first build for sure. But a really good ship over-all, as well.
Mikey

 

Yeah, it's really too bad the Normandie is not legal in MWC or IRCWCC. It would make a very nice beginner 4 or 5 unit ship.

 

Mike
That is way too funny.
If you think about it.
Can anyone tell me why the IRCWCC, and MWC do not allow the Normandie to be built??
Mikey

 

Here is a quick photoshop comparison I did between the Bearn and Normandie:
http://i65.photobucket.com/albums/h237/kotori87/normandiebearncomparison.jpg
As you can see, while the bow is correct, the Normandie has a stepped deck in the stern that the Bearn does not have. Still, it's worth asking your TO if you can still do a Normandie conversion without the stepped deck.

I remember several years ago looking up in either MWC or IRCWWCC rules, that IF the Normandie had been completed, it would be 5 units. Don't quote me on that though, look it up yourselves.

 

Step 3: Construction - Water Channel bottom and Sanding the Hull

Before putting in the 1/8" hard balsa water channel bottom, first some of the ribs were removed. Only a few were kept to tie the hull bottom together and act as a guide for the 1/8" balsa.



1/4" balsa was used for the last two rib bays in the water channel. This is where the keel starts to form on the bottom of the hull, so the thicker balsa gave some material to blend the hull into the rear keel.



1/8" balsa was used for the rest of the water channel.







Ok! It's time to sand this thing into a nice pleasing shape! I used 60 grit sandpaper on a sanding block to rough out the basic hull shape using the ribs as guides. Change out the sandpaper often! I changed it three times which helped get this part done in less than one hour. Finish sand with progressively higher grit paper. I finished sanded this hull with a folded piece of 220 grit sandpaper.








Up next; bow and stern blocks

 

Nice job! Maybe I'll have to build another hull with a stepped deck for the Normandie.

Based on displacement, the Normandie would be a class 5 ship in MWC. MWC rules state that the ship must have been launched and completed. Unfortunately, the Normandies were never completed with the exception of the Bearn as a carrier. It's really too bad ... the Normandie would have made a very nice beginner ship.

 

Wow!!! That sanded hull looks absolutely AWESOME! It's almost a shame to cover it up![^]