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Matrim

More Rising Wood

The Rising Wood is turning into the bane of my plans. I must have done something to correct it last time but since I did not record what that is have utterly forgotten.

 

Anyway if you look at the bearding line on the plans it matches the traced cant frames stern/bow exactly so appears to be correct (drawn by offsetting a vertical line on the body plan)

 

All's well. But the curve it creates on the square frames drops very low indeed so much so that midships there is only 0.9 mm (at 1:48 scale) thickness. This must be wrong.

 

I have rechecked old research posts and the plan sets I possess and not managed to resolve this.

 

The Naiad plans appear to follow the bearding line from the rear of the ship but the bearding line is visibly lower at the front of the ship (in relation to the rising wood) so it is not being used the entire length. The other plan sets (Swan,Euryalus) seem to match.

 

Therefore am I correct in making the assumption that  the rising wood follow a set height (Swan appears to say 7 inches) for the majority of the square frames and should rise to join the rear bearding line using a curve?

 

My second assumption is that the notches are higher still than the height of the rising wood and not notched into the rising wood.

 

Anyway this is obviously an abject lesson to track this sort of details to avoid this brain freeze..

 

 

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The rising wood runs along the length of the square frames. Its height is governed by the rise in floors, which will vary depending on the form of the vessel. At its termination fore and aft, the deadwood commences. This is higher at the junction with the rising wood by the depth of the first cant frame. An example is seen below.

post-635-0-45941300-1483908412_thumb.jpg

Mahuna, allanyed, Matrim and 1 other like this

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Oddly, or so it seems to me, the top of the rising wood reflects a particular buttock line.  Here is how.

 

Draw the buttock line that is in the vertical plane of the side of the keel.  This buttock line will almost touch the top of the keel for much of the area of the square frames, but in fact it will probably not touch the top of the keel at all.  Amidships this buttock line will probably be in the order of less than a tenth of an inch above the top of the keel (real world).  This line will rise at the bow and stern as the floors rise.  It represents the level of the bottom of the floor timbers.  Now draw a line above this buttock line offset by six inches (the depth of the score into the floor timbers).  This second line is the line of the top of the rising wood.

 

If we remember that the floors rest on the rising wood, then our purpose is to determine the height of the floors (the first buttock line) or of the scores set into the floors (the offset line).  Thus I suggest the above process.

 

The bearding lines fore and aft are taken from a different buttock line.  The bearding lines show the line upon which the cant frames are set.  Since the cants rest on a shelf of 1 1/2 to 2 1/2 inches, the bearding lines are the buttock line set the width of the shelf from the side of the keel.  

 

If you look at the framing plan for Euryalus you will see that the bottom of the frames are not drawn as if resting on the keel (as is the conventional practice).  This is because the frames in fact do no rest on the keel at all, they rest on the rising wood.  

 

Just my take on things.

 

Wayne

Matrim, druxey, mtaylor and 1 other like this

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Cool, and thanks as always both of you..

 

I ran that line across the sheer (and at its lowest it came in at 0.14 inches) and then for a test threw up a line 6 inches above at three points - the rear square frame, the forward square frame and the (0) frame midships.

 

For everyone utter confusion here is what it looked like (the lower yellow line is the curved buttock line, the straight yellow line is a line 6 inches above using the station line as the horizontal lock (just to pick a random point)

 

I have left in my (orange) rising wood based on the bearding line as comparison

 

So the rear

 

post-387-0-22320500-1483988903.png

 

Here it matches the (orange) bearding line rising wood quite well (which matches the plans I have seen)

 

Towards the bow

 

post-387-0-51651000-1483988925.png

 

If I am correct this is tying in with the lower apron..

 

 

and the centerpoint

 

post-387-0-59641100-1483988955.png

 

Nothing much visual to see except that if the lower yellow line is 0.14 inches then you can see why I was suddenly concerned that the line of the rising wood was much too low...

 

 

Phew, I think I can generate a line I will be happy with from that and I haven't lost too much hair. (must remember to record this in the log nicely as well...

mtaylor likes this

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I should have observed that my above comments assume the station lines were drawn correctly at the heel (keel rabbet).  That is, the station lines when draughted terminate at the inner point of the rabbet "triangle," but when lofted terminate at a point tangent to (to the "back" of) the upper arc of the rabbet.

 

I think I understand your drawing.  Are you agreeing that the top of the rising wood needs to be significantly higher than you have it?

 

I would divorce the line of the rising wood from the fore and aft bearding lines entirely for the reason already mentioned.

 

Wayne

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Wayne: Certainly the bearding line (or stepping line) reflects a buttock line about 1 1/2" or so lateral to the side of the keel, as does the outer edge of the rising wood once it is faired to the frames.

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