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Dr PR

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  1. Dr PR's post in Deck planks and more on Joggling sticks was marked as the answer   
    No two planks are the same. The width of the "nib" is 1/2 (or 1/3 on some vessels) the plank width from one side to the center of the plank, and is the same on all planks. But the angle back to the other side of the plank is determined by the angle of the margin board. So every plank has to be fit in situ.
     
    On my current build I planked from the center outward. I cut the nib to 1/2 the plank width. First I marked the center of the end of the plank with a pencil. Then I slid the plank along the already laid inboard plank up to where the end of the new plank came to where the inboard plank met the margin board.
     
    With the new plank in this position I marked the margin board along the end of the new plank, out to the center of the plank. Then I marked the position on the new plank where the outboard edge crossed the margin board. I also marked this position on the margin board. Then I trimmed the new plank back from the center of the end to where it crossed the edge of the margin board.
     
    Then the plank positioned  over the margin board and the outline was drawn on the margin board. Next I cut the nib into the margin board. Now the plank fits into the cutout in the margin board. This was a lot easier than I had imagined it would be, and the nibs came out symmetrical port to starboard!
     
    I have posted photos of the process here:
     
    https://modelshipworld.com/topic/19611-albatros-by-dr-pr-mantua-scale-148-revenue-cutter-kitbash-about-1815/?do=findComment&comment=605072
     
  2. Dr PR's post in Mast Cutting was marked as the answer   
    I find a coarse flat file to be the best tool to use for reducing the top section above the hounds (where the crosstrees fit) of a larger diameter mast. Then for the very top tenon that fits into the cap I use a hobby knife and small fine toothed files. I take measurements often to avoid removing too much wood.
     
    As for making masts from square stock, I had heard others say this was the way to go. I had always chucked dowels into a drill and used sandpaper to slowly grind the piece into shape. But on my last build I decided to start with a square piece and cut it down to size. First I cut the square piece down to the desired taper of the mast. Then I used a small plane to shave off bits of the corners to create the octagonal shape. Then I shaved off the corners of the octagon to get 16 sides. Then I chucked it into a drill and used sandpaper for the final shaping.
     
    This was MUCH faster and easier than trying to reduce the round dowel! MUCH!! Now I understand why all of the experienced modellers use this technique. It worked the first time and was a lot of fun.
     
    I have posted pictures and a description of the process here:
     
    https://modelshipworld.com/topic/19611-albatros-by-dr-pr-mantua-scale-148-revenue-cutter-kitbash-about-1815/?do=findComment&comment=908539
     
    Also note that I kept the mast square under the hounds for the cheeks to fit onto. You can't do this if you start with a round dowel.
     
    Then I shaped the top, including cutting it octagonal just for show.
     
  3. Dr PR's post in Problem adding text below a photo was marked as the answer   
    If you click on the picture you will see options for the position of the picture in the column (left, right or nothing) and to change the size of the picture.
     
    If you put the picture to the left margin the text will wrap around the right side. I just enter Carriage Returns (ENTER key) until the cursor moves below the picture.  Always put a blank line (ENTER) immediately after the picture.
     
    This behavior changed a bit a couple of years ago with an upgrade of the forum software, so some old posts may have  some misplaced text around pictures (they need the extra blank line below the photo).
     
    Always save the post and then look at it. You may have to edit it (click on the three vertical dots at the upper right of the post, and select "Edit") to add an additional blank line or two to get the text to the position you want it.
     
     
  4. Dr PR's post in Topsails rigging for a Gloucester fisherman - help with the plans and instructions understanding needed. was marked as the answer   
    Juraj,
     
    1. The main difference between the fore and main topsails is the main and topmast stays (lines S, T and U in the drawing) and the gaff topping lift. These interfere with the fore topsail. When the ship tacks the sail and it's rigging have to be lifted over these lines. The main topsail does not have this problem with the stays, but must still be lifted over the topping lift.. For this reason many schooners just used a main top staysail that is much smaller than the one shown in your drawing and is positioned above the topping lift.
     
    2. With just the one tack both sails would look the same. The bottom corner (tack) of both sails would blow against the gaffs.
     
    3. The fore topsail would have tack lines running down to the deck. If there are two tack lines one (lee side) would be draped over the fore and fore top stays. The other windward (weather) stay would be pulled tight. Looks like they forgot to show the fore tack line(s) although there is a short curved line running up from the sail tack corner.
     
    4. This is just a guess. The fore topsail may have two sheets attached to the clew corner of the sail, These pull the clew corner out to the end of the gaff, running through a block at the end of the gaff or a sheave in the gaff end. From there the sheet often ran forward to a single block attached to the bottom of the gaff jaws and then down to deck.
     
    In the rig shown in your drawings, because of the main to fore mast stays, the clew corner must be lifted over the stays when the ship changes course (tacking) to bring the wind to the other side. Two sheets would allow this to be done from the deck, pulling the slack line tight to haul the clew corner of the sail up and over the stays. So the slack sheet would be draped over the stays like the line you point to in the drawing.
     
    With two sheets and two tacks the sail could be shifted from one side, up and over the stays, and then back down on the other side just by hauling and slacking the proper combination of sheet and tack lines.
     
    One of the main advantages of the fore-and-aft rigging like on the schooners is that almost everything could be done from the deck without anyone going aloft. This was very important in the topsail schooners, especially in the over rigged (in British opinion) American schooners. They were very "top heavy" or "tender" and a sudden squall could just blow them over and capsize them. There are several records of this happening. So it was essential that they could shift or drop the topsails very quickly.
  5. Dr PR's post in Stunsail Booms was marked as the answer   
    Dave,
     
    I am not familiar with the Endeavor so I suggest you find whatever you can that was published about the ship.  But here is a guess as to why there were no studding sail booms on the topsail yards.
     
    First, the boom spread the foot or bottom of the sail. The top of the sail was laced to a (relatively) small studding sail yard which was hoisted to the end (yard arm) of the spar above. So if you have booms on the course (lowest) yards they are for studding sails that are raised outboard of the topsail.
     
    The booms stowed on the channels hooked into fittings on the hull or channel, and were used to spread the lower studding sails outboard of the course (lowest sail) and the studding sails were raised on studding sail yards that were hoisted to the yard arms on the course yards.
     
    This arrangement would provide studding sails for the lowest two spars on the mast. I would guess that there were no studding sails for the topgallant or royal, if the ship had these sails. Therefore there would be no studding sail booms on the topsail or topgallant yards.
     
    Mark's comment about changing tack must be spot on. There were enough other lines and sails to be messed with. Raising and lowering studding sails would have added a lot of work. One thing to remember about sailing ships is that nothing happened very fast. Eight to ten knots was a good speed for most ships (but clippers often moved twice as fast). Changing tack took quite a bit of time, especially on merchantmen with small crews. So the studding sails would be used only when the wind was right and the ship would be on the same tack for quite a while. Period paintings often show studding sails rigged only on one side.
     
    For what it is worth, I knew little about sailing ships when I started modelling, and I still know a lot less than some of the "old salts" on this forum. But I am learning, and that is a big part of the enjoyment of model making for me!
  6. Dr PR's post in Why masts are square at the top? was marked as the answer   
    Tommy,
     
    Good question.
     
    First, although there was a general "right way" to build masts that was passed down from generation to generation of ship builders over the centuries (word of mouth - no Internet), ship builders were also artisans who took pride in their work. And whoever commissioned/purchased the ship (merchant or Navy) set limits to the cost (time and materials). Consequently there were a lot of variations on the basic "right way."
     
    One of the problems with wooden masts is that trees could not be found that were tall and straight enough for really tall masts. So they were created in two or three parts, with each part "stepped" as in the Petersson illustration Barkeater posted above. This area where the two masts ran parallel was called the "doubling." They also needed platforms for sailors to stand on while working aloft. So the "top" was created where two masts were joined and the associated rigging attached.
     
    Just below the "top" the mast was round typically, although this is a very oversimplified statement! But at the top some structure was necessary to support the lower part of the upper mast and fasten it in place. The point where the mast changes from round to square is called the "hounds." Please do not ask anyone to explain why!
     
    But at the hounds several pieces of timber were attached to create the foundation for the top. Two fore-and-aft wooden boards (rectangular cross section) or "trestletrees" were attached on either side of the lower mast. Note: In the Petersson illustration forward is to the left for most, but not all, ships. To make the trestletrees fit tightly the mast was carved square. These two trestletrees formed the sides of a pocket the upper mast fit into. You can see these in Petersson's illustration. The square mast section prevented the trestletrees from trying to rotate around the mast.
     
    Two or more "crosstrees" (also rectangular cross section) were attached behind the lower mast top and forward of the upper mast bottom or "foot." You can see these in Petersson's illustration. Again, having these parts of the masts carved square made the cross trees fit tightly. On the higher masts the cross trees were all that were provided. But on lower mast tops of larger ships a platform was sometimes built on top of the crosstrees.
     
    OK, we have described the lower part of the doubling where the two masts ran parallel.  The top of the doubling was the "cap". This is the rectangular wooden piece at the top of the lower mast in Petersson's illustration. The hole for the lower mast was square. This was to ensure that the top couldn't rotate around the  mast. So, with the lower part of the lower mast doubling square to accommodate the trestletrees and crosstrees and the upper part square to fit the cap, it was easiest to just make the entire part of the lower mast doubling square. Of course, it really isn't that simple.
     
    The hole in the cap where the upper mast fit was round  and the upper mast tapered above the cap. Below the cap it was typically cylindrical, or maybe octagonal, but slightly smaller diameter than the hole in the cap. The bottom or "foot" of the mast was square and sized to fit into the pocket formed by the trestletrees and crosstrees. This was so the upper mast could be lowered and raised through the hole in the cap and the pocket between the trestletrees and crosstrees. The whole thing was designed to be taken apart and rebuilt at sea!  And that is a long story!
     
    Then you must add to this the variations in design that resulted from cost conscious jobs and the very elaborate variations where elegance was more important than cost. In other words, on fancy ships the upper part of the lower mast and lower part of the upper mast were often carved octagonal, or square with octagonal sections, etc. "Tricked out" in modern terminology.
     
    If you really want to know how masts were assembled and repaired get one or both of these two references. They explain how ships were built and operated in the age of sail - from the horses mouth!:
     
    "The Young Sea Officer's Sheet Anchor" by Darcy Lever (1808) and updated for the US Navy by George Blunt in 1858. Everything you ever wanted to know and a lot more!
     
    "The Art of Rigging" by George Biddlecombe (1925), a republication of David Steele's "The elements and Practice of Rigging and Seamanship" (1794).
     
    You can also find Steele's original work on line in PDF form.
     
    For mast plans and a LOT more look at James Lees' "The Masting and Rigging of English Ships of War 1625-1860", Naval Institute Press, 1984. But it is specific for British ships (a strong influence on American practice), and says little about smaller rigs, especially fore and aft rigs of schooners, cutters and such.
     
    A very good general reference (get this if you don't get anything else) is Wolfram zu Mondfeldt's "Historic Ship Models", Sterling Publishing Co., New York, 1989. Again, everything you wanted to know and a lot more. He explains the historical development of a lot of the parts of sailing ships.
     
    Harold Underhill's "Masting and Rigging of the Clipper Ship & Ocean Carrier", Brown, Son and Ferguson, Ltd., Glasgow, 1972 (mentioned above) is the best written and most useful reference I have sound for sailing ships, especially for understanding the arcane terminology. However, he describes ships of the late 1800s and early 1900s, so it is of less usefulness for earlier ships.
     
    If this isn't enough just ask and we can supply references to a dozen or more other useful books!
  7. Dr PR's post in What are the rules for determining the thicknesses of rope for standing and running rigging? was marked as the answer   
    Marcus,
     
    zu Mondfeld's "Standing rigging sizes" table on page 272 and "Running rigging sizes" table on page 308 have an error. This had me scratching my head for a while. They say
     
    "The figures given refer to the thickness of the main stay, 0.166% of the diameter of the mainmast at the deck (100%)."
     
    The actual number is mast diameter x 0.166,  or 16.6% of the mast diameter.
     
    The resulting number is the circumference of the rope, not the diameter. Divide the circumference by Pi (3.14159) to get the diameter of the rope.
     
    ****
     
    Before I figured this out I was getting really strange rope sizes. For example, 0.166% = 0.0016. If a model's mast was 0.375 inch diameter I thought the rope diameter was 0.0016 x 0.375 = 0.0006 inch!  That is about 1/5 the thickness of a sheet of 24# printer paper! That is way too small and obviously incorrect.
     
    So I tried 0.375 inch times 16.6% = 0.375 x 0.166 = 0.062 inch, or about 1/16 inch. But 1/16 inch diameter seemed much too large.
     
    Then I realized it meant a 1/16 inch circumference, or 0.0625/3.14159 = 0.019894 or 0.02 inch diameter rope for the main stay.
     
    All other rigging circumferences are based upon the main stay circumference.
     
    ****
     
    In my schooner rigging spreadsheet I used Lees' formulas for English square rigged ships. But mast diameters are smaller on schooners that on full rigged ships. So reducing the mast diameter for schooners also reduced the size of the ropes used for the rigging.
     
    However, the rigging size section of the spreadsheet is not linked to the masting part. There is a separate cell (BH9) for the rigging calculations where you enter the model's mast diameter. So for any ship type just enter the mast diameter and the spreadsheet will use Lees' rules and calculate all the rigging sizes. However, I only include the rigging used on a schooner (and not all of that it turns out - I am learning). But the spreadsheet is not locked so you can modify it however you please.
     
    CAUTION: The spreadsheet uses Lees' English unit formulas and some calculations contain English feet to inch conversions, so entering metric values for the mast diameter will result in some meaningless Metlish measurements! If you want metric values enter the mast diameter in inches and then add a column to the calculations to convert the English units to metric units. Or just rewrite the spreadsheet.
    Mast spar and rigging calculations.xlsx
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