Bolt diameter in hull framing

[DocBlake]

In looking through my copy of Goodwin's book  "The Construction and Fitting of the English Man of War ,1650-1850" , I found that late 17th century British ships had a scarf in the framing at the weather deck level and bolts holding the futtocks together.  I plan to replicate that for a build I'm starting.  My question is how big would the bolt head have been?  Goodwin doesn't say, and I couldn't find an answer in Steel's book either. The image is from Goodwin's book.

[druxey]

A later rule of thumb for fastener diameter was 1" for every 100' 0" in length of the vessel. Obviously the bolt head would be slightly larger. This might be roughly correct for you. 

[DocBlake]

Thanks, Druxey!

[Mark P]

Evening Dave;

 

My reply is in two parts:

 

The diameter of the head of the bolt would be at least 2x the diameter of the bolt,  judging from illustrations I have seen of typical bolts.  It needed to be wider to prevent the head pulling through.

 

The largest size bolt I have seen referred to for the period you mention is 1 3/8". The smallest is 3/4" (although I stand to be corrected if necessary)  The exact size depends upon the size of vessel concerned, and the bolt's location.  Assume a bolt head diameter of around 2" and you are unlikely to be far out. At scale sizes,  the difference is unlikely to be noticeable.

 

By the way: before you accept Goodwin's reconstruction as the only one,  I would read the beginning of Franklin's 'Navy Board Ship Models, 1650-1750',  where he discusses some interesting alternative framing possibilities (in the picture you have posted at the beginning here,  there is no means of attaching the second filling frame to the keel,  nor is it attached to the floor/futtocks on either side. Effectively,  it is floating in air,  which cannot be correct)

 

Richard Endsor in his two books on Restoration period vessels shows a lot of detail of framing (his work is greatly superior to Goodwin's in many respects) which I recommend you also get a look at if possible.

 

All the best,

 

Mark P

Edited July 2, 2018 by Mark P

[Baker]

Dave,

 

Bolts, the head of the bolt is indeed about 2x the diameter of the bolt (70 a 100 years earlier Gresham shipwreck)

 

From the same shipwreck :

The filling timbers (green) were here not attached to the futtocks or the keel

 

link : http://www.maritimearchaeology.dk/downloads/Full thesis bates.pdf

[allanyed]

Good information, thanks for sharing.  One oddity is that the dimensions are metric which was not used in shipbuilding at that time.   No issue to convert, but surprising to me.

Allan

[druxey]

Often marine archeological papers give measurements using the metric system. Get used to it, you duodecimal folk!

[DocBlake]

Thanks, guys!

[Baker]

You're welcome

 

I grew up with the metric system. Worked for 2 years at Ford tractor in Antwerp And all dimensions were inch in decimal at Ford (example: diameter 1.2546 inch.)

Every measurement system has its advantages and disadvantages. The system you grow up with is still the easiest to understand

[Dowmer]

Dave,

Pretty much what they said.  All are excellent answers. 

I did find in Steel's 1805 Vade Mecum which is a bit later period from what you are looking for, but he mentions for all the Futtocks Scarfs bolted through with

Iron 1 1/4" - 3/4" bolts depending on the size of ship.  74 Gun to Sloop. 

[Mark P]

Evening gentlemen;

 

Some interesting things posted here.

 

Backer,  the archaeology report is very interesting.  Please note,  though,  that what are referred to here as filling pieces are not the same as filling frames.  The keel is missing,  and would have been somewhere below the bottom of the drawing. Filling pieces were a common practice,  and were inserted between the main frames to fill any gaps between the main timbers.  This was done in the bottom of the hold to prevent water build-up and rot.

 

The joints at the ends of the floors are interesting.  And the construction appears to be repeating single futtocks (navel or naval timbers they are called in early contracts) which are then sandwiched by a sequence of second futtocks whose ends completely fill the spaces between the ends of the first futtocks.  This is similar to the construction shown in many Navy Board ship models,  which is generally believed to be un-representative of full-size practice. 

 

I would be very cautious of accepting the blue shaded areas as part of the third futtock;  they do not seem right for this location EDIT: (I have just noticed that they are listed as firring pieces in the index,  which would mean they were added to increase the vessel's breadth)

 

This is food for thought indeed;  thank you for the post.

 

All the best,

 

Mark P

Edited July 2, 2018 by Mark P