Roger Pellett

There are rules of thumb that are easy to remember if used often; 3-4-5 triangle for 90 degrees, rule of .7 for laying out an octagon, Pi can be approximated by 3, etc.  Water levels are easy to construct if they had some sort of translucent flexible tubing ( animal intestines ?) and of course chalk lines. Calculations could be made with an abacus.

Congratulations!!

In my opinion your model is Museum Quality for several reasons.

It is a unique subject that required research by you.

Stern wheel steamboats  working in the Great Lakes watershed are practically unknown.

Workmanship looks outstanding.

Marine museums used to be collection of models that people wanted to get rid of.  Our local museum supposedly devoted to Great Lakes Whaleback Ships includes a plastic Titanic.  Today, museums are creating “mission statements” and their collections are being focused on their missions.  The Wisconsin Maritime Museum is “in your backyard” and your model fits right in with their mission.  I’m sure that they would be interested in looking at your model.

Roger

There were many types of scuppers; slots in the bulwarks, possibly lead lined, and sometimes actual pipes, so it’s impossible to answer this question without a description of your model.

Roger 

Wrought iron rivets driven by hand were used for most of the in and out shell plating. The interesting photo that you posted appears to be riveting of the sheer strake, another highly stressed area requiring steel rivets.  An irony of the Titanic sinking is that iceberg damage occurred in an area where lower strength wrought iron rivets  driven by hand were used for plating seams.

Roger

We moved to Marietta Ohio in 1970 to start my career after leaving the Navy.  That was only a couple of years after the collapse of the Silver Bridge downstream at Galipolis Ohio (Moth Man etc).  There was a bridge upstream at Newport, Ohio of identical construction that was immediately closed and demolished.  This was temporarily replaced by a small ferry consisting of a flat top barge and very small tow boat.  The tow boat was attached to the side of the barge by a pivot.  When the ferry approached the opposite shore, the pilot had the skill to kick the tow boat around the pivot so to be pointing in the right direction for the return trip. 

Roger

I don’t know how  long PVA glue will last, but I have a POF model made using PVA glue and completed in 1982 that shows no sign of glue failure.

Roger

Nice work, Eric.

People who have never lived near one of these great rivers probably don’t realize how far apart bridges are.  In days when road travel happened at maybe 6-8 mph getting across the river involved a major trip, possibly requiring several days.  These small river boats were were essential transportation for many people, probably more so than their more glamorous big sisters.

Roger

Remarkable!!

I also enjoyed your Tom Hill ultralight canoe.  It appears to be just like the one that I built from his plans approximately 30 years ago. Instead of the recommended Ocumme (sp?) plywood I used cheap Laun floor underlayment.  My son and I took it up to the Boundary Waters only to discover the hard way that it would not float the two of us plus gear.  Fortunately we were going with a friend who had space for our gear in his canoe.  After that trip I set it up for double paddling for one person and enjoyed paddling it around the Duluth Harbor.

Roger

The shape of hulls built without closely spaced pre-erected frames is determined by the bending characteristics of the planking.  Without going into the math, this shape is governed  by what’s called a cubic function.  A flexible wooden strip called a spline bent around brads tacked into a sheet of plywood or held down with weights will produce this shape.  This shape shape would occur with  boats built without drawings by Mexican boat builders.

Roger

A portable hydraulic riveting machine.  Photo from Practical Shipbuilding, 1914

Jon,

Interesting project!  I don’t remember too much about it but a while ago an article about the development of lightships was published in the Nautical Research Journal.  It did include some drawings.  You should be able to find it on the Guild’s online index of Journal articles.

Roger

Craig,  

Just amazing work and as I posted earlier a beautiful subject.

I am interested in your sand casting.  As a kid I often tried to cast toy soldiers to replace broken ones.  My father took a dim view of this.  He was concerned about steam- hot lead explosions.  I later did cast a set of ducks like yours in a crude sand mold.  What kind of sand did you use?  I believe foundries use special sand that allows the pattern to be removed without collapsing the mold.

Roger

Richard,  

I don’t know when your Tugboat was built, but If it was any time during the 20th Century, I believe that USCG regulations required at least one lifeboat on engine powered vessels to be of metal construction.  If your goal is a realistic model, the vacuum formed plastic shells would be a better choice than building wood hull ones.

Roger

Clinker Bottom Plating and Joggled Frames:

Results of my research on this subject-

Of course all seams in Titanic’s shell plating were riveted.  Specifications for White Star’s Olympic Class vessels, which included Titanic, required that steel rivets be used in selected high stress areas.  One of these areas was her bottom plating. Wrought iron rivets were used elsewhere.  Unlike wrought iron rivets steel rivets were  susceptible to “hot shorting” if if heated above “cherry red” temperature so they were heated to a lower temperature than wrought iron ones and driven quickly before they lost their ductility.  

While wrought iron rivets were driven by hand, steel rivets had to be driven with mechanical riveting machines to ensure that the heated rivet would completely fill the hole in the plate before cooling and losing ductility.  For steel rivets Harland and Wolff used hydraulic riveters.  These were very large machines, each weighing several tons.  Shaped like giant C-Clamps they would squeeze the hot rivet from both ends.  They were powered by hydraulic fluid, probably water, pressurized at a central plant.  They, therefore, had to be attached to a network of piping.  The, other choice was pneumatic riveting, used in American shipyards.  Pneumatic riveting machines only weighed about 24 lbs but British shipbuilders considered these to be inadequate for high quality work.

Clinker plating was installed one row at a time, like shingles on a roof, so the hydraulic riveting machine never had to reach over more than one strake of plating to get to the seam being riveted.  On the other hand, when using the “in and out” plating system, shipyard practice was to first install all of the “in” strakes then the “out” strakes. (The geometry of the in and out method requires that two in strakes must be installed before the overlapping out strake between them.  The backing strips between the adjacent in strakes and frames were driven into the gap between them and held in place by friction.  Holes were punched in the backing strips matching those in the frame and the out strakes.)

If the in and out system had been used to plate Titanic’s bottom plating, the heavy, unwieldy, hydraulic riveting machines would have had to reach over at least two strakes of plating to close the outboard  seam of each out plate.  The plating for these strakes could be 8’ wide so the machine would have to have a reach of at least 16ft vs 8ft with the clinker system.

in short the reason for the clinker plating- Shipyard fabrication capabilities.

Once the decision was made to use the clinker plating system for Titanic’s bottom plating, joggling the frames followed.  This eliminated the cost of the expensive tapered liner plates.

Roger

References:

Holmes, A. Campbell,  Practical Shipbuilding, 1916

Garzke & Woodward, Titanic Ships, Titanic Disasters, 2002

McCarty & Foecke, What Really Sank The Titanic, 2008*

* Forensic and metallurgical analysis of Titanic’s rivets

Look on used book websites for the book Whale Ships and Whaling by Church.  Copies are usually inexpensive.  In the early 1900’s when sailing warships were still sailing, the author gave cameras to whale ship captains.  The book is a wonderful collection of whalers working at sea.

Roger

Every time I look at this beautiful model, I am astonished by how “long” it is.  Logically, of course this should not be surprising as she existed to provide a runway for aircraft.  Never less photos in the WWII Navy books in my library,  were usually at sea taken at sea level so her length relative to her breadth and depth is not apparent.  The model shows off her hull shape nicely.

Roger

Kelp,  

See my post # 53, previous page.  Fig #11 of the posted drawing shows clinker plating with tapered packing strip.

Without further study it’s just a guess but I suspect that the clinker plating and joggled frames made it easier to replace damaged individual plates in the event of a grounding.

Roger

Rik,  A challenging project, beautifully executed. Superb workmanship!

Roger

The overall displacement theory makes little sense.  The metric that Naval Architects usually try to minimize is Tonnage.  Since vessel registers and shipping reporters describe ships as “the 10,000 ton SS Rust bucket,” those not familiar with shipping terminology assume that 10,000 tons is the vessel’s displacement which is equal to its weight.  In fact in this case, tons is a measure of the vessel’s internal volume.  The term dates way back to Henry VIII when wine was shipped in large casks called TUNS and Import duties were assessed on the number of Tuns that the vessel was carrying.  Since then, vessel’s are measured to determine their internal volume called tonnage.  This number is used to assess docking, harbor, and pilotage fees as well Canal Tolls.  The idea is to maximize the amount of cargo that can be carried while minimizing the Tonnage.

The clinker plating would not affect cargo carrying capacity.  Cargo was not stowed in the double bottom, and while it might have saved some weight, that would be insignificant in the overall scheme.  In the case of a grounding, it would make the ship’s bottom easier to repair.

Roger

This comes under the “you learn something new every day category!”  Titanic did have joggled frames and clinker plating.  I stand corrected.  The joggled Frames, of course would have eliminated the need for those pesky backing strips between the, frame and plating.  I dig out some references from my library and found a midships section drawing for Titanic.  It appears that the shell her double bottom was clinker plated with joggled frames up through the turn of her bilge with in and out plating (Frames without jiggling) up the sides. I wonder if this was standard practice with Harland and Wolfe built ships?  

Roger

Deliberately wetting wood to raise the grain and then sanding is an old gunsmith’s trick when finishing gunstocks.

Years ago, master ship model builder Eric Ronnberg built several models of early steam trawlers.  The models are now in Mystic Seaport’s model collection. These were steel hulled vessels of riveted construction; overlapping steel plates.  He made extensive use of acrylic matt medium to hide the grain.

Roger

Not pear or cherry.  There are many woods called mahogany.  The bottom piece in your photo looks like The species known as Laun.

Roger

A beautiful and successful design and a gorgeous model!

Roger

This is the tension that always exists between two aspects of Ship design; Naval Architecture (hull design) and Marine Engineering (propulsive power).  The resistance of the hull to the water through which it travels is usually separated into two factors; drag caused by fluid resistance and waves generated by movement of the hull.  Unfortunately, these scale differently.  Drag is proportional to immersed surface area and the square of velocity.  Wave making is proportional to velocity and the square root of waterline length.  Note that in conventional vessels neither of these factors are directly related to weight.  A heavily loaded Great Lakes 1000 ft ore carrier generates little wave making resistance doe to it’s low speed and long length.  Likewise, while drag is increased by the larger immersed  hull area, drag, the squared factor is minimized by the vessel’s low  speed.  This is why waterbourne shipping is so economical.

I would, however, argue that oared vessels are subject to a factor that is directly affected by weight: inertia.  Oared vessel’s are propelled by short bursts of power.  This is especially noticeable with very light rowing shells.  When racing, these boats noticeably accelerate with each stroke.

So how does all of this affect your model?  Put your Marine Engineering hat on and provide more power.  First, your model may work much better with the second bank of oars.  If not try increasing the rate of the stroke, and finally make the oar blades larger.

You have an advantage over the ancients; relatively unlimited power.  The trick is to connect it to the water.

Roger

I personally would not stain a ship model with any kind of wipe on oil or resin based product intended for full sized objects.  I believe that like everything else involving models the coating thickness needs to be to scale.  Heavy buildups of wipe on oils is undesirable.  If you use classic ship model woods to scratch build Dockyard type models staining should not be required.  Most woods supplied with kits are better painted.

Roger