Roger Pellett

Computer technology aside, there are engineering reasons why a boat design cannot simply be reduced. Simply put the characteristics that produce a successful design are not linear.  For example, displacement is a cubic function.  If dimensions are halved  displacement decreases by a factor of 8 (the new displacement is 1/8 that of the old).  Transverse stability is an exponent function of the waterplane, and so forth.

Roger

The book Ships’ Boats by Ernest Blocksidge (1920) lists the following proportions for lifeboats.  Dimensions in feet and inches:

Capacity (people).       Length     Beam.    Depth

16.                                  18.            6’-3”.       2’-4 1/2”

18.                                   19.            6’-6”.      2’-6”

Hope that this is useful

Roger

Every year during the SNAME conference there is a dinner for Naval Architecture  alumni of the University of Michigan. While not a SNAME member, I always get invited.  One year the dinner was held at the New York Yacht Club.  Unlike most yacht clubs it’s in the middle of Manhattan, not on the water.  I was able to schedule other business to be in NYC to attend the dinner.  As Allan writes, a visit to the club’s model is an opportunity not to be missed.  The model collection is spectacular and I don’t think that they are about to put them in storage to make room for a more “relevant” display.

I would suspect that Shamrock’s wire rigging would not have been served.  Designers of these yachts were concerned with the aerodynamics of the rig.  They would have tried to minimize the cross sectional area of the standing rigging to cut wind resistance.  

Here again, more research is necessary but I believe that the racing rigs were considering to be “temporary.”  When these challengers crossed the Atlantic to race, if sailed they did so under reduced rig. Later the Cup Rules allowed boats to be towed or shipped on a steamer.  The racing rig was erected upon arrival in the US for competition.  Some of the American J’s were furnished with several masts that could be swapped out during the trials.  In any case,  these boats did not have long lives.

Roger

According to Llewellyn Howland III in his biography of W. Starling Burgess, the first large yacht to utilize solid bar rigging was the 1934 America’s Cup defender Rainbow.  The bars couldn’t be produced in long enough lengths requiring turnbuckles half way up. Shamrock V would, therefore, have been rigged with wire rope.

 Apparently, the J Boats also used wire rope for some running rigging.  Burgess, became marooned atop Enterprise’s mast when he used the main halyard to hoist him up. The wire rope halyard was heavier than he was! 

Roger

America’s Cup competition has always featured boats built with high tech features to gain a competitive edge.  This was as true in the 1930’s as it is today.  Furthermore, the very tall Marconi rigs were highly stressed and rigging was tuned (highly tensioned) to provide optimum performance.  Stretch had to be minimized.  As a minimum the J boats would have been rigged with wire rope.  In later years America’s Cup yachts featured solid rod rigging. More research needs to be done to determined which was used.

Roger

Most of the readily available information about ships’ boats deals with warships.  Since you are building a sailing merchant vessel you are venturing into uncharted territory.

From the drawing that you posted it would appear that the double ended boat is a lifeboat and the other a workboat.

In this context, a “lifeboat” was a specialized craft designed to meet British Board of Trade regulations covering capacity, stability, flotation, and hull strength.  It could have been of either wood or metal construction.  If wooden, it would have been clinker planked.  Capacity, generally began with crew size, allowing 10 cu ft per person.  The regulations then specified  proportions, length, beam, and depth for each range of capacities.  You might begin by trying to look up Board of Trade Regulations on the Internet.  Old shipbuilding handbooks often publish lifeboat drawings.

For the workboat, a square sterned, relatively full lined wooden boat.

Roger

The real question that you need to answer is “what is the market value where I live?”  If people are quoting USA EBay prices, they are based on freight charges to destinations within the USA.  Overseas shipping charges are much higher.

If there is an active market for your kit within New Zealand these EBay prices might be realistic but if you have to ship it overseas you might have to discount it to account for higher shipping costs.

Roger

From what I have read, the Higgins boats use a proprietary compressed air system to launch torpedos.  The Elco boats used the (black powder?) explosive method.

Roger

My technique for turning very small items.

1. My standard material is brass.  A brass belaying pin painted brown looks much better than an over scale wooden one.

2. I use collet chucks to hold brass rod.  I let the unused portion of the rod pass into the hole in the headstock spindle.  Although expensive, I find collet checks to be necessary for the work that we do.

3.  I feed a very short section of rod to be turned from the collet and turn it to the required diameter.  I then turn off the lathe and feed out a little more to be turned to the same diameter.  By turning the rod in very short steps, you are never trying to turn long unsupported lengths of material.

Roger

When you shorten your guns, and I certainly hope that you do, I suggest that you take a look at the two current series of posts for scratch builds of these gunboats.  The elaborate moldings on the muzzles of the kit supplied guns that you are using look wrong for Civil War era guns.

Roger

Rob,  Nice Job!!

Did you make the figures or were you able to find 1:96 scale figures?

Roger

Sherline equipment is modular.  The head which includes the motor, speed control, and spindle is the same for both the lathe and milling machine.  The head can be easily interchanged between the lathe and Mill by removing one set screw.  Rigidity is a key to accurate work, and the design of the joint between the head and column or lathe bed provides rigidity.  If you use a Mill often, but a lathe seldom, you could buy a mill and later just the lathe bed.  

Although pricy, Sherline offers a huge selection of accessories to complement the machines themselves.  IMHO, the skill in machining is often the setup to hold the parts accurately and rigidly, and that’s where accessories are needed.  I recently bought a rotary table to allow me to drill a series of equally spaced holes around the periphery of a disc.  In addition to the table, I was able to buy a fixture that accurately mounts in its center to hold a collet chuck (the same collets that fit the lathe).

Located in California, Sherline is easy to contact and they back up their products with excellent customer service.

Roger

I have read that an old (British?) Naval expression says,  “A Ship is judged by the condition of her boats” and your boat is very nice.  I also suspect that at this small scale your Mark 1 Eyeball did a better job of arranging the planking than you would have done by marking them out on the plug.

Roger

The model that I used it on was rigged with line from my stash of “Cuttyhunk Hard Twisted Linen” line.  I used both cotton thread and unknown composition fly tying thread for serving, seizing, etc.  

The stuff that I have does not have a strong odor.

Roger

I have posted this before but here it goes again-   Old fashioned clear nail polish; not the acrylic kind but the varnish kind that comes in the little bottle with the brush in the top.  Sold in cosmetic sections of pharmacies, it’s cheap, dries very quickly and convenient.  No need to clean anything up since when you screw the lid on the brush gets dunked back into the liquid.

Roger

Very Nice!

If a drydock, floating or otherwise, was unavailable damage to underwater areas of the stern was sometimes repaired by ballasting forward sections to raise the stern.  A bomb explosion at the stern would probably require realigning of propeller shafting.

Roger

Very nice work!

IMHO, for World War II oil fired ships manned by crack crews smoke is best avoided.  While modelers might think that it adds atmosphere, in reality it was a dead giveaway for the ship’s position.  Boiler tenders were responsible for balancing the combustion air-fuel mix to prevent clouds of smoke.

Roger

Another lines drawing trick that I have found useful is to draw lines at twice the anticipated model scale.  Lines for a 1:48 scale model would be drawn at 1:24.  After tracing the drawing in ink on Mylar I then have half size contact prints made by an architectural printing company.  This makes closely spaced lines easier to draw and any inaccuracies are cut in half.

Roger

A nice looking model and. An interesting subject.

Here’s mine.  I cast them in a homemade sand mold in 1965.  I still use them as I do not use CAD.  Splines are ripped from straight grained spruce left over from wood canvas canoe restoration projects.

Roger

I believe that the difficulties building the Ohios had more to do with commercial problems that existed between the US Navy and General Dynamics Electric Boat shipyard than with actual construction of the submarines.

I am in the process of rereading October Fury by Peter A. Huchthausen.  The title refers to the events at sea during the Cuban Missile Crisis.  This is a great book about Cold War Russian Submarine operations.  Huchthausen was a very junior officer aboard one of the destroyers enforcing the blockade.  He later was  a Naval Attache’ in Moscow and came to know several of the Russian Submarine officers involved.

Roger

A well equipped shop needs inventory; a stock of commonly used raw materials.  Ready access to these allows the modeler to solve problems like the warped bulkhead without having to visit the local hardware/ hobby shop.  Otherwise there is always the temptation to muddle through with poor results.  An essential material that I keep in stock is thin craft plywood.  This is available in several fractional sizes from 1/64 to 1/4in.  I use this material for patterns,  mockups, repairs, reinforcing joints, etc.

If you don’t want to fabricate a new bulkhead, I would cut it in half as posted above and laminate it to two pieces of thin craft plywood; one on each side.

Roger

We often get requests to help with research, some of which are open ended.  Since I too have amassed a notable library over my adult lifetime I used to direct the questioner to the relevant books in my library resulting in complaints about telling others to spend money, limited budgets, and the cost of books.

If you don’t already have a library, this is your opportunity to start one!  Almost any book on this list would be worth adding to a ship modeling library.  The prices including shipping is less than a visit to your favorite fast food joint or premium coffee shop.

Roger

Contact Mystic Seaport