Interpreting plans

I am still preparing to build my first wooden hull and have a basic question about plans. I have a set for the HMS Sverige, Swedish coastal defense ship. (I saw one that was built from these plans and She ran well, although low in the water.

The plans were copied and the ribs cut out already. My question is; these hull ribs were cut out to the shape of the hull, but as I have looked at all the different ship building threads here, the ribs have a small area at the top which goes into the upper deck slot and is secured by an adhesive. In this fashion, the top of the rib is even all along the lenght of the ship.

If my rib pattern has been cut out, and I see most plans just have the hull rib to the top of the ships deck, but lacks the piece that goes into the slotted area of the upper deck, how do I add this?

I hope this makes sense and I can clarify it if needed. Thanks.

 

Yeah, I think it makes sense.

The rib sections shown in plans show where the outer edge of the hull should be, all the way up to the main deck. You need to allow for:

1. Thickness of skin. The rib itself should be reduced by the thickness of your outer skin, so that the outer surface of the skin ends up being where the line is drawn.

2. Thickness of main deck PLUS thickness of the caprail (subdeck). The caprail/subdeck is like a "horizontal rib" that goes all the way around the ship to help hold it together. Usually, but not necessarily, it gets built from the same material as the ribs. If the ribs butt up against the bottom of the caprail, then the thickness of the caprail & main deck need to be cut off the tops of the ribs. An alternative is to cut notches into the caprail and/or the ribs so that they fit together like a fingerlap (or dovetail) joint, in which case only the deck thickness needs to be removed from the tops of the ribs.

Probably the easiest way to make a caprail is to make a copy of your plans, cut out the "Plan" (overhead) view, spray the back with adhesive, & stick it to some plywood as a pattern. Be aware, though, that sometimes plans have inconsistencies from side to side, & there's no guarantee that the sides are the same unless you measure yourself. Also, there may be discrepancies between rib Sections & Plan views. For instance, at Rib D, the Section may indicated 3-1/4" from center to gunwale, but the Plan shows 3-3/8" at that point. In such cases, you'll have to make an "Executive Decision" how to proceed.

I've also made caprails (& main decks, too) by plotting points & "connecting the dots". The points plotted would be where ribs meet deck. Draw a center line on your plywood & set a point for the bow. Measure back from that point to where the 1st rib goes, & draw a perpendicular line. Measure from the center to gunwale for each rib line & mark there on both sides.

You also need to consider whether or not your club allows "extra depth" for the ship, & if so whether or not you're going to take advantage of it. Generally, it's a good idea to take whatever extra space your rules might allow, although a scale purist might not want to.

There's also the matter of tolerances. Most clubs allow a certain amount of "slop" to allow for different levels of building skill. It's a really good idea to get input from a club Technical Officer before you get too far committed to a project. Once parts are glued together, it can be a lot harder to make adjustments.

JM

 

John, thanks for the reply. I have been studying some BDE plans for the Scharnhorst and Renown pattern sets and some Geroge Goff plans. I have built caprails and decks with fiberglass ships before but never had experience cutting the 'dovetail' joints for the hull ribs. Any special glue to use or just wood glue??

With the Sverige plans, I was going to use 3/8th for the keel and 1/4 for the ribs and capral?? I say this as the other plans indicate this for their construction. And I noted that some builders use a homemade jig to hold the ribs in place while curing. Should a jig be used in most builds of this type or only for larger ships?

Also, some plans I have seen have a smaller number of ribs then others. Does the number of hull ribs make the ship sturier or stronger or give it better lines? Just wondering as some of the plans I have been looking at have different combinations.

Example is the BDE Renown which shows "X" number of hull ribs which make the cutout windows smaller and/or larger along her sides. To comply with our club rules, should I add extra ribs to compensate for the area allowed?

Not having really done this before, (tried once but it came out like a deformed tinker toy kit), I want to do it right this time. (haaaa) Hence all the questions.

But once I see and do for myself, I usually can get it right after that. I really appreciacte all the advise and support that you and the other members have given me on these issues!

Thanks, Steve

 

I wouldn't go so far as an actual dovetail, but I wouldn't be surprised if there are people out there who would. What I use is more like a fingerlap. Rib extends upward to the level of the top of the caprail, & caprail extends outward to the edge of the rib. Each has a corresponding notch cut out, so that they fit together snugly:



As for glue, pretty much anything that's good for bonding wood (or whatever your materials are) that won't dissolve in water after it's set is good. I use Bondo Marine Epoxy for frame bonding, as well as plenty of other uses including painting a coat over the finished frame to seal it.

I only use a jig where I want the parts to align in some particular way (which, basically, is all the time!). A jig doesn't have to be anything complicated. It can be as simple as a piece of plywood nailed, glued, or screwed onto a piece of 1x2, etc. at a right angle. Clamp the jig & 1 piece (or partially-completed assembly) to your workbench. Clamp the part to be glued to the jig. Align them to each other the way you want them & clamp down fully. Then apply your adhesive & let it set.

It's very rare to find plans that were drawn specifically for combat ships, with ribs spaced as per rule for penetration. The plans were drawn with non-combat model shipbuilders in mind. The sections in the plans are grouped together where there's the greatest amount of change in the hull form, & spaced farther apart where there's less change. You may very well find a large portion of your hull amidships where 1 section in the plans can be used for many identical ribs (especially for cargo ships, which are often boxy). The plans may place more ribs near the bow or stern than what you want to use, & fewer in the middle of the ship. When that happens (which is almost always) you need to interpolate where the ribs in between the sections should be, based on the best information that you have. I described my process for doing this in a document that I uploaded to the site:

Visit this site

I got a set of HMS Vanguard plans from White Ensign Models that

 

Thanks John........your advise and experience is appreciated! And I will try my hand at the rib creation with Corel! I am off to buy some wood!

Thanks again.

Steve

 

Best of luck Wind...... oh, i see you have an Andrea Doria..how was she? i almost bought her, buy i bought a Graf Spee instead.

 

Boomer, the Andrea Doria was my second ship and an easy ship to build, besides being fun to battle with. (Sidemounts!!!) She is 26 seconds and isn't as manuverable due to the one rudder as some. However, I really liked the way she handled and she has beautiful lines. I am sure that the Graf Spee will be fun to battle with. Is she already to rumble?

Ciao,

Steve

 

I was thinking about doing an AD, but i found a cheap, but high quality graf spee hull, and i had to pounce on it. No, actually, i just started the build. I can only work on it every other weekend, but after one, i already have all the windows cut out, a shipyard built for it, and this weekend im planning on sanding up the windows, cutting out the subdeck, and maybe the deck. The deck will be made out of plexiglass.

 

I like the Andrea Doria too. Maybe in 2009?

 

Any news here, I'd love to see any progress. Pictures especially

 

Windrider has been working on a fiberglass Littorio hull for use in the WWCC. He ran it at the last maneuvering event, and I think I have a couple pictures, but I need to dig them up.

 

Ive seen the Littorio, its listed in the Ship List--Our Ships thing. I meant the HMS Sverige Swedish coastal defense ship.