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SJSoane

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  1. I checked in on the Tally Ho project. I don't think I will get much work done while I look at all those videos! It is amazing to see in full size what we are doing at a miniature scale... Thanks for the reference to this! Mark
  2. I improved my old beam jig, used years ago for the gun deck beams. It now has a base which runs along the router table surface. Hinged to this is a piece of plywood cut and sanded with the upper and lower deck roundup on each side. The piloting bit on the router table runs against this. an upper piece of plywood clamps down on the beam blank to hold it firmly in place. The hinge allows me to use a digital angle gauge to dial in the correct angle up for the sheer at the beam location. The white screws allow precise adjustment. So I first clamp in for the upper roundup, then switch to the opposite side to do the lower roundup. A spacer behind keeps the beam at its exact moulded depth. 3 done, 24 to go.....
  3. Hi Dave, Thanks so much! His design must have changed over the years, but the concept remained the same. I realize I had one too many pieces I was looking at, and here is how it goes together. Best wishes, Mark
  4. In my enthusiasm for needing some straight metal pieces for another jig, I took apart my old Preac saw taper fixture. Now I am ready to put it back together, I cannot remember for the life of me how this works. Could someone who has one of these post a picture so I can reassemble? Always take a picture before disassembling, I will remind myself in the future....🥴 Best wishes, Mark
  5. Thanks so much druxey and Siggi. I think, I hope, I have finally got it. Using primary sources closest in date to the Bellona, the Dorsetshire section and the Falconer dictionary, here is what I now see: The sweep is one beam astern of the end of the tiller, and the lines run to a sheave in the side, not to a free-hanging block, as in the Dorsetshire: And I will use five wraps on the hub, according to Falconer, which works perfectly with the maximum 2 full turns to each side or 4 turns lock to lock, with a fifth wrap for the nail at the center. This leaves a little bit shorter slot for the rope to traverse back and forth at the quarter deck level: And centering the sheaves in the upper deck framing on the center of each slot, we get: Back to shaping my upper deck beams! Mark
  6. Thanks druxey and Gary. Gary, I see what you mean. Couldn't see it in three dimensions until looking at your stern. So I left the hanging knees out for now, will see how long my horizontal knees come into this space. druxey, fascinating little sketch of the wheel. First, I had the sheaves backwards relative to yours. I switched, and now I have the starboard sheave forward of the one on the port, as above. So I did my own calculations, based on your reasoning. With a barrel diameter of 21", one turn of the wheel pulls in 66" of rope. My tiller can only swing 10'-11" to one side from dead center, because of the gooseneck hitting the beam behind the sweep as discussed before. So I need 1.98 (rounded to 2) turns of the wheel to pull the tiller its maximum distance to one side, or 4 turns lock to lock. So, if I understand how this works, with seven turns around the wheel hub, the rope will move four rope diameters along the hub when turning from dead center to full port, and the same from dead center to full starboard. And turning the wheel itself to port moves the tiller to starboard and the ship to port. In the drawing below, forward is to the right. Assuming I have this right, I located the holes down to the sheaves in the deck so they are about equidistant from the two extremes that the rope on that side will travel. The purple circles are the locations of the holes down to the sheaves. Or would these be slots in the deck down to the sheave, allowing the rope to traverse its full four diameters? I understand HMS Victory had sliding plates allowing the ropes to move without a big slot in the deck; but I am not sure if this had been invented yet in 1760. So many unknowns! Mark
  7. Thanks so much Gary, Mark and Siggi. You caught a mistake, and I was beginning to cut wood for the upper deck! Here is the refined version, thanks to your eagle eyes and research. My athwartship arms of the lodging knees were a trifle too long further forward, and the carlings at the stern were too wide apart. Adjusting for both of these, and the geometry comes out just right. I also fiddled with the geometry of the steering, moving the sweep back one beam, locating the sheaves at the sides according to the Dorsetshire print, and then running the lines to the steering wheel hub location afore the mizen mast. I worked out 7 turns on the hub, which located where the line comes up and then comes down, which are offset fore and aft by the width of the 7 turns. This makes the cross for the sheaves in the deck asymmetrical, as you can see below. Looks funky, but covered in decking eventually, so I guess I don't care! Am I understanding correctly that the port line up is the forward one on the steering wheel hub, i.e., the hub is wound clockwise? So a clockwise turn of the wheel would pull on the port line, which would move the tiller to the port, which would turn the ship to starboard? Hate to get it wrong, and have the helmsman accidentally steer into an obstacle! Mark
  8. Sweet looking gundeck, Alan! I'll be interested to see how far your tiller can swing, assuming the sweep and gooseneck are up in-between the beams as I see in the Dorsetshire plan. It is the gooseneck hitting the side of the aft beam that ultimately limits the rudder swing in the Bellona, not the size of the rudder hole in my case. Mark
  9. A little more digging last night, and I remembered that I was looking at HMS Valiant (1759). I saw this in Brian Lavery's "Building the Wooden Walls: The Design and Construction of the 74-gun Ship Valiant". The Valiant, according to Lavery, was begun the same time as the Bellona, as a substitute at the last minute for a Dublin class 74 that was about to start construction. So this deck plan would have been at least one way of constructing the upper deck of a 74 at the time of the Bellona. Assuming the athwartship arm of a lodging knee reaches from the side to the carling in the middle section of the deck, then these carlings set closer to the side for the remaining 5 beams would either require their knees to be shorter, or for the heads to be cut off, as I have shown above. I will try drawing some shorter knees in this aft section, and see if that looks more shipshape. Mark Detail of Valiant upper deck, from https://collections.rmg.co.uk/collections/objects/384159.html
  10. Hi everyone, Well, this is embarrassing, I can't find the plan I was looking at when I drew my upper deck. I assumed it was the Dorsetshire, but here is the Dorsetshire: I need to keep looking through my various sources. Should have written this down years ago. But if I don't find the source, the drawing Gary showed of the Hector, with the carlings moved in to the heads of the knees does make sense. Thanks for flagging this Siggi! A little more digging to do.... Mark
  11. thanks so much, Gary and Siggi. That makes perfect sense. It is confirmed by the section of HMS Dorsetshire from NMM, below. Here the sweep and gooseneck are clearly in between the beams, and also one beam back as you suggest. This shows what looks like a sheave in a fixture in the side, not a free-hanging block as Lavery shows in the Bellona book.... It doesn't allow any wider swing of the tiller, but it fits constructionally.
  12. Hi everyone, While waiting for the upper deck beam glue joints to dry before shaping their roundup, I worked some more on the tiller and its tackle. In a post to Alan (AON)'s site, Gary (garyshipwright) pointed out the need for directing the wheel ropes up through the deck forward of the mizen mast. I started working on this and discovered a few things. First, according to Brian Lavery's Arming and Fitting of English Ships, pp. 18-20, at the 1760 date of the Bellona, the Royal Navy was holding up the fore end of the tiller with a gooseneck running along a curved sweep track, just under the upper deck beams. A rope ran from the end of the tiller to a block on either side of the ship, back to a central block and up to the steering wheel. A problem with this method was that the tiller rope did not equally tighten and slack on each side of the tiller, causing sloppiness and some accidents. The solution was found in 1771, when Pollard, a Master Boatbuilder at Portsmouth devised a way to run the tiller rope along rollers within the track itself, keeping equal tension. But this was 20 years after the Bellona, so I will have to model the earlier, cruder method. And here it gets interesting. the original Bellona draft shows the tiller very tight up against the upper deck beams. We are seeing below the tiller at midships, but the beams at the sides. When the beams are shown at the center location, their bottom surface is only an inch or so from the top of the tiller surface. How does the gooseneck and the sweep fit? Here we see close up that the gooseneck and sweep cannot fit under the main beam. Both have to fit up into the space between the beams. There is more clearance at the small intermediate beam shown in orange. but eventually as the tiller sweeps to the side the gooseneck (shown in dotted orange) it hits the next big beam aft. (this drawing is not accurate for the position up and down, since the tiller sweeps downward as it sweeps to the side, following the roundup of the deck beam. But the space between tiller and beam will remain the same through the sweep, so this is just showing that eventually the gooseneck hits the beam.) In plan, this means that the tiller can only swing as far as the location shown in purple. The green location is a 33 degree angle David Antscherl discovered as the ideal angle in a study of helm angles in the eighteenth century, and described in The Fully Framed Model, vol. II, pp. 47-8. The Bellona geometry only allows a 26.7 degree sweep. However, the contemporary study David quotes also notes that some ships in the period only swept 28 degrees. So maybe this is close enough. There really isn't any lee-way, given the restricted space between beams 23 and 24, into which the gooseneck and sweep have to fit if the tiller really is as tight to the beams as the original Bellona section shows. Even with this, the sweep will have to be pared down at its outer ends to fay onto the underside of beam 24. Mark
  13. Gary, thanks for the note regarding how to handle the tiller ropes. I would have been in some difficulty getting around a central carling a few months down the road. Isn't it great to share ideas on this website! Mark
  14. I realized that other day that summer is coming to an end, and cold weather will be upon us before we know it. That means I need to plan ahead for anything needing the use of the router table in the garage before it is too late. So, I temporarily put aside spirketting, to concentrate on making the beams for the remaining decks. I used a router jig for the gundeck beams, and plan on the same idea for the rest of them. First, the upper deck beams. Much as I admire the tabled joints done by our great craftsmen including Gary (garyshipwright) and Ed Tosti, I remind myself that my design goal is to emulate the Admiralty style models I can see close up including the two Bellona models and also the Princess Royal model in Rob Napier's book. My hull framing is thus stylized, and so should the deck beams as seen here in my photo of the first Bellona model. The two beam halves are a simple scarphed joint. I did this on the gun deck, and so will continue onto the upper deck. The higher decks are one piece beams. So, I measured the angle needed to form the correct length of the scarph, and used angle gauges of 3.5 degrees to set up the table saw for an angled cut: I then slid this angled plywood piece under the angle table on the Sherline mill, to set the correct angle of taper. On top of this I bolted a simple holding jig, into which I can slide beam blanks, clamp them down, and then run the cutter across to form the angle. The brass bolt was used for fine tuning of the angle after I ran some tests for the correct length. I have 27 beams in the upper deck, times two halves, times 3 passes for controlling the depth of cut, equalling 162 passes of the cutter. A happy five hours! Here are the blanks awaiting their turn at the mill... Next, gluing up and shaping the roundup on the router table. Mark

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