frank shurick

research
Futtocks - Setting the Split Lines at their Heads

I am doing research so that I can draft a set of plans for an American Privateer Schooner (1812 era), the Snap-Dragon.

 

I have reviewed 7 schooner designs, using plans obtained from the Smithsonian and Greenwich Maritime Museum

and others printed in Chapelle's books. These ships are all about 100 feet in length with 25 wide at the mid-section.

 

For most of the scantlings, I can make a credible determination using similarity or other means.

However, one item, a rule to set height of the futtock heads is elusive. I have been unable to decipher a

consistent rule, formula or standard.

 

My observations, so far,

0 the length of the floor timber may be related to the moulded half breadth dimension. But my measurements

range from 50 to 67%. Maybe, there is a better figure of merit?

 

0 My structural engineering background suggests that the overlapping futtock joints should align

with deck intersections and the locations of the thick stuff where the punch loads from the decks into the timbers are best resisted.

However, this does not seem to be an absolute rule. Other considerations are influencing the designer.

 

0 Is there a standard length for the overlap?

 

Any thoughts?

 

Take care,

Snapdragon

  

 

 

mtaylor likes this

Share this post


Link to post
Share on other sites

Uncertain how American practice may have varied from British.  For British, you might find something in Rees or Steel.  For US, possibly in Humphreys notebook.

 

mtaylor likes this

Share this post


Link to post
Share on other sites

Chapelle discusses this topic briefly in the Search For Speed Under Sail.  He believes that these small schooners were built by erecting widely spaced doubled frames and then adding filler frames where floors and futtocks were not necessarily joined together.  While this does not help modellers trying to build accurately framed models it does make sense.  Framing a vessel with British style closely spaced preassembled frames requires the ability to loft requiring skilled people, a large flat surface, and some way to communicate the required information such as a table of offsets.

 

To date, I have seen no credible research describing actual building practices for small vessels in the Revolutionary- 1812 US.  Until we learn more about the technology available to build them, I don't believe that we can accurately model hull structure.

 

Several vessels have been found and excavated on Lake Ontario.  These were built by New York area shipbuilders but they were built as warships, and shortcuts were taken to speed up construction neverless, you might look into this.  This research is summarized in the recently published book Coffins of the Brave.

 

Roger

Eddie, trippwj and mtaylor like this

Share this post


Link to post
Share on other sites

Thank you Wayne and Roger for the replies.

 

I agree that the British style of framing is not suitable. The American builders were very competitive. Speed and cost were king.

 

The British scantlings describe a tighter frame spacing as did the American schooners built in the later stages of the war. A lighter ship would be the faster design.

 

A tigher spacing would be more suitable for warlike activities. Chapelle's Search for Speed Under Sail documents that the Snap-Dragon was one of the fastest ships of the era.

 

I have read 2 books that describe the adventures of the Snap-Dragon. They give some insight to the design of the ship.  It was built in Baltimore prior

 

to the war and served as a merchantman.  The books mention that it was lightly framed. This makes sense as it was a very fast sailor.

 

After looking at admiralty drafts of a number of captured schooners. I think that the best representation may be the Flying Fly. The Fish was also built in Baltimore

 

in 1806. Possibly by the same builder but, that I can not be certain of.  I ordered admiralty plans of the Fish and should get them in a few weeks. I will take your advice and try to get

 

a copy of the Coffins of the build.  After that I plan to give it my best shot and consruct a 3D CAD model.

 

I hope to document my findings on this site along with results.

 

Thank you,

Frank 

mtaylor and trippwj like this

Share this post


Link to post
Share on other sites

I once was interested in Snap Dragon.
Mostly because at that time the anual vacation was
taken near Beaufort NC, the area that Otway Burns
and Snap Dragon sailed from.

The data:
70 feet 'overall'
crew 100
147 ton schooner (Baltimore Clipper)
original name Levere
cost $8,000
narrow with low bulwarks
 Two different listings for armement:

US Naval Inst. Proceedings
V. 42 No. 163  pp. 873-911   1916

4-5 6 lb on open gun deck
1 long 9 lb pivoted midship
2nd voyage  1 long 12 lb

The Commonwealth of Onslow  A History
Jos Parsons Brown
Owen G Dunn Co
New Burn NC  1971
pp  43-46

5  12 lb
50 muskets
4 blunderbuss

Rig  -
quotes from USNIP article

" Burns caused yards to be fitted to her formast
 (and possibly Main) which could be sent on deck
at short notice when the schooner was beating against the wind
or could quickly be replaced when running before a gale
by this means the Snap Gragon combined the advantages of a
fore-and -aft schooner and the square rig of a brig."

"the wind held so fresh as to carry away the Snap Dragon
jibbom and two topmast stays."

"furl topgallant sails, single reef topsails and take a bonnet out
of the fore sail."

"flying jib"

"her fore topsail was loosed"

"main topmast"


Scantlings

Lacking contempoary data for the actual vessel, I would
use Steel
Brigantine 10 guns  201 tons  is as close as listed

R&S  2' 0"
27 floor timbers
sided 10"
length midships  18' 8"
moulded at keelson  10"
     "         at head         8"

1st futtock
sided  mid    9.5"
 moulded        head     7"
scarph on 2nd futtock   5'

( this means that  the 1st futtock is  9' 4" + 5'  or  14' 4" long )

2nd futtock  
sided mid  9"
moulded at head  6"
scarph on 3rd futtock  5'   ( 10' long)

Top timber
sided at heel  9"
sided at top   7"

 

I would probably use the scantlings - or a touch lighter

but for R&S  use paired frames - but a wider space.

Not 20" space - more like 12-14".

 

Rather than butting the heels of the 1st futtock at the keel,

I like the French practice of using a half floor or cross piece with

the 1st futtock  so instead of a 14' 4" timber, the half frame would

take up 4.5' of it.

allanyed likes this

Share this post


Link to post
Share on other sites

THANK YOU JAAGER,

 

I appreciate your input. I added the rigging information to my design notes

and the timber scantling dimensions to an EXCEL spreadsheet which has data from a number of 

ships.

 

FYI, your brigantine data matches well with the other data. I am getting more confident that the

end product will be reasonable. I'll post my spreadsheet next month and I receive 3 more ship plans

from the Smithsonian.

 

If you would like to read more about the Snap

I recommend two books - "The Cruise of the Snap-Dragon" by Ruth Balbour and

"Captain Otway Burns", by Walter Francis Burns.

 

The books are available online.

 

Thank you,

 

mtaylor and trippwj like this

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.