Tailing deck beams

[allanyed]

In reading  a contract for two of the 130 foot group 50 gun ships (British) of the late 17th century there is the following description:  

Every Beame of the Deck shall be Tayled into the Clamps .     I would really appreciate seeing a sketch of exactly what tailing means in his instance.  I can envision the clamp being scored, or the beam end being scored or perhaps a dovetail of some sort, but not sure if one or none of these is what is meant by tailing.  Thanks in advance!!

Allan

[druxey]

Dovetail, I believe, Allan. See French style builds for this treatment of deck beams and clamps.

[Mark P]

Good Evening Allan;

 

It does indeed refer to dovetailing, as Druxey says. The beams were normally dovetailed on the end, and the dovetail was let down around 1" into the top of the clamp.

 

I'm not sure if the dovetail was worked through the full height of the beam, or merely the part which was set down in the mortice in the clamp. Sources seem to vary on this.

 

All the best,

 

Mark 

[allanyed]

Thanks Druxey and Mark.  Seems to be a never ending (thankfully) learning curve to be contended with these model building endeavors of ours.

Edited October 21, 2019 by allanyed

[druxey]

But ain't that the interesting part?

[paulsutcliffe]

I always thought for some reason dovetail ended beams was a French thing whereas the English just let the beam down into the clamp ???

[allanyed]

So did I Paul.   But, with the contract, I learned this as something new as well.   Going through this contract, I have found a lot of major differences with ships from the 1719 Establishment and beyond.  A lot had to do with timber supplies.  Some examples, the keel for the 50 gun ship is stated to be made of no more than 3 pieces.  From the 1719 Establishment it is given as 5 pieces. There are fewer futtocks for the frames, and the list goes on.  I made a spread sheet of scantlings comparing dimensions and descriptions from the contract to those of the 1719 Establishment and there are many more differences than I would have guessed.

Allan

[Jaager]

What may have been going on =

The number of trees that are suited for warship construction is finite,  especially on an island that is not all that large to begin with.  In the zeal the build a large navy, all of the large old growth Oak was cut.  They had to sacrifice their standards to match what they could obtain.   

 

Unless the project is a cross section,  in a model,  it is a detail difficult to see.  A close, but easier technique; have the clamp stop at the bottom of the beam and fit a short piece of the same wood  between the beams that is the depth of the dovetail.  Done well, the glue joint may appear to be wood grain.

Edited October 21, 2019 by Jaager

[allanyed]

Thanks Jaager,

I really have no issues with dovetailing the ends of the beams if that is what is called for.  I am mainly interested in getting into the details and matching actual construction whenever possible.   There are limits of course, and I probably have more than many others here, but if it can be done accurately I usually like to at least give it a try if only for my own satisfaction.   The more I look at the situation here though, the more I wonder if the answer is a dove tail in the French manner of construction or a variation as Mark mentioned in his reply.  Frolich shows it very clearly in The Art of Ship Modeling as well as in a few build logs here that I recall seeing, but they are all French vessels.   I have not yet seen anything remotely close to a dove tail type of construction in any contemporary or "modern" books on English shipbuilding    Seems the more years I study, the more questions arise, and many, so far, without answers.    Still having fun though :>)

Allan 

[druxey]

I tend to think that the dovetail was only the depth of the let-down on the clamp, as Mark suggests.

[allanyed]

Thanks Druxey, but a shame they would never be seen.   These would certainly strengthen the tie of the beam to the clamp.  I am sure it will take a little bit of extra time, but great practice using my chisels.   

Allan

[druxey]

Yes, too bad that detail will be hidden. However, a photo record before you assemble the parts....

[allanyed]

Photo record for sure Druxey.  I am a LONG way from that point.  In recently receiving the contemporary information from a contract for sister ships to Lichfield as mentioned above, I have had to edit many of the drawings, including every frame, and edit the scantlings folios as well.  It remains a labor of love so I have found no hardship in doing any of it. To the contrary, is has been great practice as well as an enjoyable voyage so far.

 

Edited October 29, 2019 by allanyed

[Mark P]

Good Evening Allan;

 

I hope you are enjoying your labours. I understand what you mean about doing it for love.

 

Another item of interest with deck beams, which no-one will expect you to replicate, not even yourself, is this: alternating beams were laid 'top and butt'. This was the practice of having the root end of the trunk from which the beam was sawn laid alternately to port and starboard. This was because the root end was tougher and more resistant to rot, and meant that, all other things being equal, there would not be a weakness caused by a run of beam ends rotting at the same time.

 

A further precaution was to drill a horizontal hole into the heart of the beam's ends, and then insert a red-hot iron in the hole, charring the wood, which also helped prevent rot. In addition, a further hole could be bored upwards from the underside of the beam, to intersect with this horizontal hole, thus allowing the circulation of air to help dry out any damp in the beam end.

 

All the best,

 

Mark P

[allanyed]

Thanks Mark.   I was aware of a vertical score being made on the ends of the beams which I have done in the past, but not the horizontal and vertical intersecting borings.  And you are correct, unless I was going to make beams from saplings, I will forego the practice of making sure the root end of the beam is alternating port and starboard. :>)  

Allan 

[druxey]

The practice of alternating beam ends and 'mouthing' or the boring of air holes is described and illustrated in The Fully Framed Model, HMN Swan Class Sloops 1767-1780, Volume I, pages 256 and 262.

Edited October 30, 2019 by druxey

[Doug McKenzie]

Allan et. al.

 

In reference to where dovetailing the deck beams ends into the clamp was used,  Norway is another place.  The 1880 DNV classification rules even make it sound as if dovetailing can be used instead of knees  (seems pretty unlikely, but who knows!)- "All deck beams to be securely fastened to the sides of the vessel by knees, either hanging or lodging, OR [emphasis is mine] by being dovetailed or doweled into a shelf; the inner overlaying stringer and waterway being let into the beam."

 

I'm not clear on what it all means, but it seemed interesting.

 

Doug

Edited October 31, 2019 by Doug McKenzie

[Mark P]

Good Evening Doug;

 

Thank you for your post. If the knee was seen more as a method of fastening the beam securely to the ship's side, then its substitution by a dovetailed joint would seem reasonable enough. 

 

Thank you also Druxey, for mentioning the Swan volume. David Antscherl's books are indeed a valuable source for any modeller, and well worth obtaining.

 

All the best,

 

Mark P