Vertical Scarf Joints on Keels

[tmj]

  I keep seeing scarf joints shown on keels, as depicted in the photo below. This rectangular box with an 'X' in it confuses me. Does this symbol mean that the scarf joint could go in either direction, from stem to stern, or vice versa at the builder's discretion? An explanation of what that symbol actually means would be greatly appreciated!

 

Edited October 31, 2023 by tmj

[druxey]

In contemporary plans, often the vertical joint line nearer the viewer (starboard side) is a solid line and the other is a dashed (hidden) line.

[allanyed]

The below may help showing aft section of keel with starboard side view and top view.  Note the dashed line as Druxey mentions on the port side of the side view.

 

The drawing you posted brings up a new one for me.  I always saw the false keel joint as a single angled mating so it can slide off the one aft each other without damaging the keel should the ship run aground and snag the bottom (false keel)

Allan

Edited November 1, 2023 by allanyed

[tmj]

1 hour ago, druxey said:

In contemporary plans, often the vertical joint line nearer the viewer (starboard side) is a solid line and the other is a dashed (hidden) line.

I understand hidden lines. I just don't know what an 'X' inside of a rectangle means.

[tmj]

2 minutes ago, allanyed said:

The below may help showing aft section of keel with starboard side view and top view.

Allan

Allan,

'That' answers the question! Thank you for the plan view and an elevation view! It makes sense now. I've never seen any hidden lines in the drawings that I have looked at. I only see a solid rectangle with an 'X' going from corner to corner. That 'X' does not belong in a mechanical drawing depicting a joint like this, not for true construction. This tells me that the rectangle with an 'X' 'is' just a symbol! I also now understand why such a joint is called a 'vertical' scarf joint! Thank you!

Would this joint have been tree-nailed, bolted, or bolted like a sandwich with metal plates being on the port and starboard sides of the joint?    

 

[tmj]

I just took a peek at a plan view showing the top of the keel, just to make sure that I did not miss anything. No joints at all are shown on the top/plan view of 'that' drawing of the keel. "It's amazing the stories that can be told with more than one view and the understanding of a 'symbol'! 🙂

[Jaager]

I have it in mind that the English keel scarphs would be a vertical line seen from the side and a elongated "Z" seen from the top.

The French method was 90 degrees different - a horizontal line seen from the top and the elongated "Z" seen from the side.

To me, that means that the scarph on an English can be faked with a simple butt joint - the false keel would hide the "Z".

 

If I have it correct, then the rectangle with the "X"  indicates two things:  where the scarph is  and how long it is.

 

I guess that North American practice could be either one - I see heavy Frog influence here as well as English.  My bet is that which ever method was more efficient and less labor intensive was preferred at each step.

Edited November 1, 2023 by Jaager

[allanyed]

9 hours ago, tmj said:

Would this joint have been tree-nailed, bolted, or bolted like a sandwich with metal plates being on the port and starboard sides of the joint?    

Actually, the joints were far more complex with tabling, hooking, and/or using coaks.     For our purposes, this would not be seen, unless you used a hook joint and looked at the bottom of the model to see the bottom of the keel.   Page 6 of Goodwin's The Construction and Fitting book shows variations.   

 

Metal bolts let into the keel.  Goodwin, page 7 gives the bolt diameter of a first rate as keel depth/16, for a 2nd rate divided by 15 and other diameters for other ships' sizes.  This is not the head diameter so what will be seen on the model would be larger. If iron bolts, I like to use copper wire of the appropriate diameter then blacken it with diluted liver of sulfur once in place as it is instantaneous and does not stain the wood.  But for the period after about 1783 copper bolts (and probably much earlier)  were most common.  Again from Goodwin, page 7 FYI if this is for your Victory, there were likely eight bolts for each joint.  The length of the joint for a first rate would be (Keel depth X3.5)/12   This varied a bit for other rates.    

Allan

Edited November 1, 2023 by allanyed