Exploring different ways of hull construction

[JKC27]

Sorry that I didn't post my last completed build and it's progress, or my latest that I am working on, but they are also great lakes freighters.

 

My 2 builds (Algoma Strongfield - which has a build log on here) and it's fleetmate (Tim S Dool - no build log as mentioned above) were built from scratch at 1:200 and 1:192 scale respectively using basswood for their hulls.  I like working with it as it's easy to shape and readily available, but a little pricey in my area.  These are large ships, thus large models.

 

As I evolve as a modeller, I am always thinking of different ways to make my builds easier, etc.  A model with a solid basswood hull that is almost 48" long is heavy.  For my next/current build I have been working on building the pilot house, accomodations, etc..... actually building an unloading boom too which is turning out good (I will post pics for this build and make a log - I promise!).  I plan to add led lights on the masts, cabins, and maybe deck if all works out.  This has led me to consider doing a hollow hull.  Doing so with basswood or balsa (even if for just the sides) is simple enough, and would the stern as a solid block.  Leaving the solid block would allow for me to shape area where the propeller would attach, and rudders.  However......I thought it be rather simple to do the hull out of styrene sheets, easy to weld together, but......how would I go about that back end area (pic included in this post) with styrene?  I am thinking that wouldn't be possible......maybe somehow attach a carved wood back end to hollow styrene hull?????

 

Thoughts/suggestions???

 

[Javelin]

I wouldn't try to connect styrene to wood. Due to the different expansion coefficients it's likely to crack at the seams. 

 

It's not fully clear to me what the shape of this vessel is from the plan, I'm assuming a twin prop -twin rudder configuration? 

If you want to go full styrene, I guess making styrene strips (=planks) over styrene frames will be the easiest way in such an area. Afterwards you can fill the gaps with filler and sand smooth.

For the stern itself I'd make a false stern/last frame to end the planks on, then level all planks there and put the full stern plate behind that. 

 

 

Although I'm mainly a styrene builder, I must admit for such a size model, I'd prefer wood. Styrene becomes very brittle and if you're making such a large detailed model, it might as well last for a while...

 

Edited April 30 by Javelin

[JKC27]

30 minutes ago, Javelin said:

I wouldn't try to connect styrene to wood. Due to the different expansion coefficients it's likely to crack at the seams. 

 

It's not fully clear to me what the shape of this vessel is from the plan, I'm assuming a twin prop -twin rudder configuration? 

If you want to go full styrene, I guess making styrene strips (=planks) over styrene frames will be the easiest way in such an area. Afterwards you can fill the gaps with filler and sand smooth.

For the stern itself I'd make a false stern/last frame to end the planks on, then level all planks there and put the full stern plate behind that. 

 

 

Although I'm mainly a styrene builder, I must admit for such a size model, I'd prefer wood. Styrene becomes very brittle and if you're making such a large detailed model, it might as well last for a while...

 

It's a single prop, 2 rudders.  here are couple other pics I grabbed from the 'net....  Hard to see, but this is what she looks like.  I really can't see a way of making the rudder/prop area with styrene.

 

 

 

[Javelin]

Here you see what I tried to describe. This one is in wood, but the same method can be applied in styrene. It avoids compound curves, which styrene sheets, like wood, won't handle either. Depending on the curve you can adjust the thickness and size of strips you use. 

I didn't apply filler on this wood hull as it would be covered by fibreglass (RC model), but with styrene, some filler will give good results. 

[Roger Pellett]

Cost:  Ordinary lumberyard pine is an overlooked but perfectly suitable wood for “carved hull models.  Sort through the 1” stock and pick out what you need.  You don’t need top grade quality as you will not be using the whole board as one piece.  You can discard areas with knots.  
 

Weight:  For my current project, the lake freighter Benjamin Noble, the long middle body is an open topped box with a U cross section.  Deck is brass plated craft plywood, but you could plate with paper. Bow and stern sections are solid “plugs”that fit into the ends of the box.  All carved to shape.  Material: 1in lumberyard pine.

 

Roger

[Jaager]

Pine is good.  I use a lot of it.

There is another wood that is worth a look.  Goodreau Sawmill & Woodworking has Yellow Poplar that costs about the same as their White Pine.

If your focus was a couple hundred years earlier - they also have Hard Maple, Black Cherry, Beech.

They also have the usual nutwood species whose grain and open pores do not scale.

 

I would place a bet that you will come to regret  having a large solid wood carved hull.  The rules that Dana Wegner developed for USN museum acquisitions - rules that specify a hollow hull, are probably the result of lessons paid for from disasters reflected by solid hulls.

 

[allanyed]

Hi John,

For the plug, have you considered styrofoam as an alternative to wood then heat and form styrene around the plug?  For the area such as at the stern it may be easier to make that area of the plug out of wood to withstand heavier bending.  MAYBE this video will give you some ideas.  https://www.youtube.com/watch?v=AxP3vtQxVtw for the shaping of the styrene sheets.  There is at least one MSW member that has made beautiful hulls for "steel" ships using alternative materials.  Hope he sees your post and responds.

    

Allan

 

 

Edited May 1 by allanyed

[JKC27]

5 hours ago, allanyed said:

Hi John,

For the plug, have you considered styrofoam as an alternative to wood then heat and form styrene around the plug?  For the area such as at the stern it may be easier to make that area of the plug out of wood to withstand heavier bending.  MAYBE this video will give you some ideas.  https://www.youtube.com/watch?v=AxP3vtQxVtw for the shaping of the styrene sheets.  There is at least one MSW member that has made beautiful hulls for "steel" ships using alternative materials.  Hope he sees your post and responds.

    

Allan

 

 

I actually picked up a couple bricks of hard styrofoam (XPS expanded polystyrene) from a local Michael's - called CraftFOM  https://www.floracraft.com/products/floracraft-foam-xps/

 

really light weight, looks easy to carve/shape - not sure how you'd adhere styrene or cardstock to it without it melting though.  I haven't played around with these yet.  The only reason I haven't is the concept of trying to make it a smooth surface to look like a steel hull......adhering styrene sheets to it with the proper glue would melt it (I am pretty sure at least).

[allanyed]

From surfing the net it appear that styrene softens at 212F or a bit higher.   Styrofoam is about the same so does not sound like it would work based on this information.   A wooden plug made of poplar, pine or balsa that would be removed after the hull is formed may be best.   I look forward to seeing the final answer to this one.

Allan

[Roger Pellett]

Great Lakes vessels in bulk cargo trades  are long, narrow, and shallow draft. Designers, therefore, are hard pressed to provide adequate structure to stiffen the hulls.  Even so some ships flex uncomfortably in rough water.

 

The model that John wants to build will exhibit the same problems without internal structure.  A light plastic shell without such reinforcement will behave like a wet noodle.

 

The simplest approach is a wooden hull.  Since these Seaway sized vessels are 90% parallel mid body this can be a hollow open topped box with deck beams and deck added to the carved hull later.  The bow and stern can be laminated and designed to fit the ends of the box.  The bilge radius is easily shaped with a router and the bow and stern shaped by conventional carving techniques.

 

These ships are built with all butt welded seams.  Plating is flush with perhaps 1/8” external reinforcement of welded seams (about .01” at 1:96 scale).  Lapped plates or heavy weld lines are therefore incorrect on a model.  Proper finishing to eliminate wood grain will produce a true to scale model.

 

Roger

 

 

Edited May 2 by Roger Pellett

[JKC27]

16 hours ago, Roger Pellett said:

Great Lakes vessels in bulk cargo trades  are long, narrow, and shallow draft. Designers, therefore, are hard pressed to provide adequate structure to stiffen the hulls.  Even so some ships flex uncomfortably in rough water.

 

The model that John wants to build will exhibit the same problems without internal structure.  A light plastic shell without such reinforcement will behave like a wet noodle.

 

The simplest approach is a wooden hull.  Since these Seaway sized vessels are 90% parallel mid body this can be a hollow open topped box with deck beams and deck added to the carved hull later.  The bow and stern can be laminated and designed to fit the ends of the box.  The bilge radius is easily shaped with a router and the bow and stern shaped by conventional carving techniques.

 

These ships are built with all butt welded seams.  Plating is flush with perhaps 1/8” external reinforcement of welded seams (about .01” at 1:96 scale).  Lapped plates or heavy weld lines are therefore incorrect on a model.  Proper finishing to eliminate wood grain will produce a true to scale model.

 

Roger

 

 

That was another concern I thought about.  I thought of maybe adding some stabilizing framing (which would not be seen in the model).  I like to toss new ideas around, and push myself to the next level.  Unfortunately I do not have cross sections or lines drawings with the drawings that I am using for this build.

 

Looks like it will be a hollow wood hull with mostly solid bow and stern shaped to the correct shapes.  Going hollow will allow for the addition of deck lighting and running the wiring for the lights fore and aft.  Hopefully my local wood shop that I got my basswood from before, still carries it (new owners), otherwise will have to find another option.

 

As you said Roger, modern lake freighters are basically just a hollow rectangle for most of their length.

[druxey]

You will have as many opinions as there are model-makers! If longevity is not a concern, then.... anything goes. For stability, hollow wood is a better choice. either hollow lifts, or plank on bulkhead. Other than the species already mentioned, another possibility is yellow cedar, if you can get it in your area. It is a nice stable wood easy to work with a pleasant odour when cut.

[JKC27]

I will ask about yellow cedar as well, when I hit my local wood shop.  This shop's old owners stocked basswood blocks, but the new owners only carried really rough cut 1x6, which is fine to stack together anyway.  Basswood cuts with such fine dust it is quite messy, but easy to work with.

 

It seems like I will stick with the wood hulls going forward, especially considering the size of my models (1/192 scale of a 740 ft ship is a large model).  Plus, my woodworking skills will improve along with my shipbuilding.