Section 3 Miscellany of model barge construction.

 

Contents

 

Building methods

 

Building the hull

  The building board

   Setting up the frames

  The balsa inner skin

  The outer skin

 

How to fix things down

 

Hard points

 

The deck

 

Rails

 

Lettering and scroll work

 

The fin and bulb

 

The rudder

 

The deck hatches

 

Deck houses

 

Winches and windlasses

 

The crab winches

 

 

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Building methods

I find it to be very difficult to offer constructional methods for model barges because most modellers use a limited range of equipment and tools and I have a comprehensive workshop. I do not need to trawl the shops for a plastic cap to press into service or to look for gears, it is quicker for me to make them and they are then the right size and shape. I have seen lots of examples of modelling Thames barges and it seems to me that modelling with limited equipment is a skill in its own right. I recall Eric Piggott who was a very competent sailor of model barges. He had two models and both of them were made in very simple ways. If you just looked at his deck winches they said quite clearly “ I am a deck winch” yet a closer look showed that they were very simply made, much more easily than I make them. This extended to all his model and I was very impressed. It is a skill that is not given to everyone.

 

The skill in drawing that I acquired when training as a draughtsman is of enormous value for drawing hull frames, fin sections and so on and that when this skill is used with a computing program like Mathcad it becomes powerful tool for designing hulls. People from all walks of life want to build barges and, often, must do so without these skills. They find their own ways round every problem.

 

Nevertheless there are some aspects of modelling that are universal especially those that depend on hand work and not machining and I want to look for these in particular.

 

There are other aspects of modelling that have come my way and, where they might be useful, I have included them. This has ended up as a mix of odds and ends that might be useful to builders of model barges. I shall split the text into the hull and the rig if only to split up the figures.

 

Building the hull

The impression that I have is that most modellers think that building a hull is too difficult to contemplate. This might be true if, before the hull can be built, it has to be designed. However, if it is a hull for a scale model of a barge that is needed, then the shapes of the frames for a plank on frame hull are available for some model barges.

 

In figure 1.1 I have shown a photo of the hull structure for my bowsprit barge ready for planking. The building board is made from 6mm MDF and is stiffened by more 6mm MDF set in from the edge so that the barge can be tipped on its side during construction. The frames are made from 1/8² birch ply that were fixed to the building board with triangular balsa blocks.

 

Figure 1.2a is of the shadows (outlines) for the hull as I received them. All I have done is scanned one half of the forward shadows and created a mirror image and joined them together to give complete shadows of the outside of the hull.

 

The shadows for the bow  are not much use without the  shadows for the stern . These are given in figure 1.2b.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The skin thickness of my barge was 1/8² made up of one layer of 3/32² balsa and one layer of 1/32² bass wood. In figure 1.3 all the bow shadows but one have been reduced by 1/8² all round. I made copies of this sheet. Then the same was done for the aft sections.

 

The odd frame is the one where it is necessary to make an additional allowance of 1/16² on the mid section to accept a 1/16² doubler to join the balsa planks for the inner skin. See figure 1.4. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 1.5 is a copy of the drawing for frame 4 of my model. All the other frame lines were blanked out with correcting fluid ready to draw up for cutting. First an extension to attach the frame to the building board  was carefully added to the top so that the overall height was a fixed distance from the bottom of the keel for all frames. An arc of 36² radius was drawn across the top between A and A of the frame allowing 1/16² for the deck. This is to be cut with a fret saw to leave only two small widths to be cut away after construction is complete. Then the centre to be cut out is drawn (use a coin to draw the corner radii.) and the notches for the keel, the inwales and the chine strips marked. It makes sense to cut the deck “beam” for the sides of the holds at this stage. I cut these middles out very carefully with a fine piercing saw and save them. They come in useful to be incorparated in servo mounts and the like and then stuck back in place. All this can be seen in figure 1.6 where the frame is shown with balsa fixing blocks added to it.`

The key to getting a hull free from bumps and hollows is to get the top line of the extension at the correct distance from the bottom of the keel and straight and square.

 

It is important to plan for the keel fittings. Whatever your facilities may be it is necessary to find a way of attaching the keel to the hull in a way that permits it to be removed for transport and storage. Most arrangements will involve making a hole in the keel and the keel must have doublers on both sides to restore its strength. If the keel is to be fitted using a carbon tube it will also require a locating peg so the doublers will need to be 5² or 6² long fitted about the 40% point between stem and transom. Notch the relevant frames to suit. Mine can be seen in figure 1.

 

The building board

One tends to regard a building board as any old thing that can be pressed into service. I think that it is worth spending some time on the board. I have said that I use 6mm MDF and I start with a piece that if 48² long and 12² wide cut from one side of the board so that I can use the machine-cut edge as a datum edge to use to draw a centre line for the hull and to use with a try square to locate frames accurately and squarely.

 

Suitable dimensions are given in figure 1.7. With this construction the board will then stand on edge at a suitable angle to fit the side planks and indeed for sanding and painting.

 

Setting up the frames

Lay out the centre line of the hull at 6² from the datum edge, mark off the positions of the frames and draw lines across the board using a try square.

 

Triangular balsa stock is readily available. Cut two 1.5² lengths for each frame and stick them carefully to the top edge of the extension as shown in figure 6. I usually set them with white glue on the extension and align them with a glass cube that was sold for a pound or so as an ornament. It is better than a vee block because it is easier to clean. When the glue for the blocks has set, glue the frames upside down to the board making sure that the centre line of each frame is on the centreline of the hull and that one face of each frame lines up with the cross lines on the board.

 

Join the keel and stem and fit it to the frames checking that every frame is square to the board. It might be necessary to make a hole in the board to clear the stem, do not make the stem too short. It has to stand proud not of the deck but of the rails. It should then look like figure 1.1 without the 1/4² by 1/4² balsa strips round the deck edge and at the chine. Fit those strips. I usually use two strips each 1/4² by 1/8² one on top of the other because two strips are easier to bend than one. The first three and the last three frames really need to have their edges chamfered to match the curve of the planks. In my view it is worth cutting some cross grain 1/32² balsa strips 1/8² wide and sticking them to the sides of the frames with superglue and then dressing them off with sandpaper to the correct angle. This can be seen in figure 1.8 on the forward frames.

 

The first plank has to butt up to the keel and a fixing is needed. Fit 1/8² by 1/4² strips on edge to the keel between the frames and dress them off to have the angle of the frames. The pieces near to the stem and sternpost have to have a twisted surface as can be seen in figure 1.1.

 

The balsa inner skin

There is no requirement to have this skin made to look like the planking of a real barge but it does present an opportunity to size up a way of working in the planks for the final skin. Figure 1.9 shows the planking at the bow of a real barge and figure 1.10 the planking on my boom sail barge.

 

Between them we can see that the planks are set into a rebate in the stem that runs out as it goes round the forefoot, that the plank next to the keel twists and lays against the stem, and that the planks from the sides and from the bottom taper so that each set occupies about a half of the length of the stem. So planks that start off with uniform width at the middle end up much narrower but of uniform width at the stem.

 

Working the planks into the stern is rather easier than working planks into the stem because the planks lay flat on the transom but there is a reverse curve to deal with. Here planks that butt on the outside do not touch in the inside.

 

Figure 1.11 shows my hull as it came off the building board. All the planks run out to the transom. The gaps between the planks as they go over the reverse curve are visible but these were filled with the coat of polyester resin.

 

Note also the frames bottom right that were cut back ready for the hold when the frames were drawn.

 

Start with  the doubler. Cut 1/16² hard balsa to fit between the two frames on either side of the one that is cut back to take the doubler. Glue it in so that the end of the 3/32² strips can be glued to it to act as a joint. The strips will be shaped to fit round the bow or stern as the case may be The strips have to be tapered off to fit into the reducing space at say the bow. I stick them using penetrating superglue but I do work out of doors. It is simply too unhealthy to work indoors with superglue and its hardener that is in an aerosol or spray can.

 

When the inner planking is complete sand off any serious protruberences and give the balsa a coat of sanding sealer. Lightly sand it to get rid of fluff from the grain of the wood. Now look at it carefully to see whether the curves are true and smooth. If there are any hollows fill them with lightwaeight filler Look at figure 1.12 when the outer skin was partly fitted. Note the black filler on the inner skin. It is Leak Fix from the Plasic Padding range. If you go carefully it can be feathered off by sanding to give a smooth surface ready for the outer skin. Whatever you use be careful because the filler might be much harder than the balsa. If it is, cross hatch the wood with a blue or black felt tipped pen so that you can see where the sanding block is cutting wood away. Keep cross hatching as you sand. Sand the hull to get a smooth surface free from bumps and hollows. Get it right and refill if necessary. Give the balsa another coat of sanding sealer or for “belt and braces” a coat of polyester resin. This gives a base to which the final skin can be stuck.

 

 

 

The outer skin

The second skin is 1/32² bass wood. Midwest sell this in 24² lengths so, as in the full size, there will be butt joints between planks. These joints have to be spread about the hull to avoid weakening it. This gives planks that are short enough for slow setting cyanoacrylate to be used. The slow setting is only relative to the penetrating cyano and is really very fast compared with, say, white glue. But it does give time to coat a plank liberally and place it into position and just keep smoothing it down until it sets. But the planks must be shaped first.

 

It makes sense to mark off the inner skin to give a planking guide for the outer skin as you can see in figures 1.12 and 1.13. This means dividing the curved distance between the chine and the deck and across the bottom into equal intervals. My boom sail barge has 8 planks on the side and 9 across the half bottom. The sprit sail barge has one fewer in each case. The usual way to make the division is shown in figure 14. Set up a vertical line of a suitable length that is longer than the maximum half width of the hull and easy to divide into say 9 equal lengths. Divide it and join each point to a single other point such as P in figure 1.14. Draw reference lines parallel to the first line to use as guide lines. Take a strip of paper about a half inch wide and lay it on a line across the hull and mark its two ends on the paper strip. Lay the strip on the diagram so that the marks coincide with lines with the required number of spaces between them with  the strip parallel with one of the reference lines. Mark the intervals on the strip and transfer them to the hull. Do this as many times as permits the shaping of the planks. I use a felt tipped pen.

 

Start by sanding the planks lightly and giving them a coat of sanding sealer on the finish side and rub down again.

 

Start fitting the planks from the keel. I usually lay a piece of the bass wood sheet on the hull where it is to go and pick off widths from the marks on the hull using springbow dividers shown on the board in figure 1.13. If these marks are sensibly close together along the strip a steel rule and a scalpel can be used to cut straight lines between marks. When the plank has been sanded lightly to a smooth curve it can be fitted. Bass wood can be twisted and bent into a desired shape before it is fitted, it is very amenable stuff. Run a bead of cyano along the keel, coat the plank and fit it. Smooth it with a piece of kitchen roll until it sets. It is not the speediest job but there again it is fun watching the surface develop.

 

When the skin is finished it can be sanded lightly. As you can see I sand as I go. We want the planking to show so it is not a totally smooth surface that we are looking for. Fit the two chines and the wales that are 12² wide to scale round the deck edge. Paint the hull now or leave it for later.

 

The hull is ready to remove from the building board. Just split the balsa blocks using a chisel and lift it off. The extensions can now be removed by sawing through the short solid pieces of ply and dressing the frame. If it is not a clean cut it is not important as it will be covered by the deck. Sand the deck edge to give a clean surface for the deck.

 

How to fix things down

Inevitably things will have to be fixed to the deck and servos and pulleys inside the hull. I think that the best way is to use machine screws for these jobs and I use 10 BA, 8 BA, and sometimes 6 BA brass screws that are readily available. (For shackles I use 12 BA). I drill and tap wood to take these screws. This needs some thought. If you have some hard wood like box or beech it can be tapped as it is. I usually tap it and then run in some thin cyanoacrylate but blow out any surplus. When the glue is set I put the tap through again but this time lubricated with beeswax. This gives a hard strong thread that is more than adequate for holding servos. But we often want to fix to flat surfaces, for example, the pulpit to the deck. I do not think that ordinary 1/8² birch ply is suitable because the grain is too coarse. Then I laminate two or three pieces of 1/16² ply that is made necessarily from wood with a much closer grain. This gives a good material for tapping and gives the opportunity to flatten or curve the wood as the glue sets. Two layers of 1/32² ply stuck together is better than one piece of 1/16² ply and for companionway covers 2 or 3 layers of 1/64 stuck together gives a curved rigid cover.

 

I use laminated balsa for deck beams. Even if the grain of the laminations are in the same direction the resulting laminate is stronger than an equivalent piece of unlaminated wood because the grain does not now run right through the beam. Use 2 or 3 or 4 laminations and cross the grain if the application needs it. Use balsa laminate cross grained for making servo mounts with small hardwood blocks stuck to the mount for the machine screws.

 

Laminate with cyano for small areas and with epoxy resin glues for larger areas.

 

Hard points

The hull will require hard points under the deck. These are giving fixings for attaching deck fittings. There will be one for the pulpit, two for the main horse and perhaps the fore horse, and hard points for the stays for the mizzen mast, the steering etc. Check,

 

The deck

The deck can be made  from 0.8 mm ply stuck directly to the deck beams and then plank it with 1/32² basswood stuck on like the outer skin of the hull. Before this can be done we have to prepare for the two holds, the deck house for crew accommodation and the companionway forward. When modelling a barge it is best to arrange for as much access to the hull as possible This means that it is necessary to make covers  for the holds and deck houses must be removable. These covers must fit like the tops of cardboard boxes and this, in turn, means that the holds must have false coamings for the covers to fit over to keep water out. (See figure 1.15 where to hatch cover is raised above the coamings.) You should have outstanding ends on the frames ready to take these false coamings. But the frames may not coincide with the ends of the holds so more deck beams are needed. I have shown the arrangement in figure 16. Make the deck beams from 2 layers of 1/16² balsa laminated together and notch them under the inwale. Two extra beams will settle the length of the hold. Make proper allowance for the thickness of the cover. Now the false coamings can be fitted all round by gluing directly to the ends of the frames and to the two extra beams. Then add strips of 3/16² square balsa between the frames to improve the joint between the edging and the frames and give a gluing area for the deck. Do the same for the deck house and any other deck furniture.

 

Before you do anything else make pencil rubbings of all the deck so that the locations of hard points etc can be found again. Save them.

 

There is no requirement to make the ply deck in one piece. It can be fitted in four pieces, a fore deck, an after deck and sides. If the ply will not take the compound curvature on the fore deck or after deck split it along the centre line and trim it until it does. 

 

Deck planking

I have seen a variety of methods used to plank the deck. It seems to me that one should start by looking at a real deck. When you do it becomes obvious that the deck is intentionally not smooth presumably to give a better foothold on a slanting deck. As I understand it the deck planks were laid with a gap into which a sealant was rammed. The sealant was traditionally used rope that has been unpicked and bonded with tar (oakum). It was, and still is, painted so it just appears as uneven lines on the deck. See figure 1.17 which is a photograph taken in 2006 of the deck of Reminder. The lines are visible but would disappear if the deck were to be painted.

The delineation of these lines by fitting planks with black thread or black card between them and varnishing may have been appropriate for a new ketch-rigged barge but not I suggest for a run-of -the-mill sprit-sail barge. I fit my planks with chamfered edges as shown in figure 18. The chamfer can be cut with a new scalpel blade and a steel rule. Painting the planks with matt paint fills the grooves a bit haphazardly so that they show. Take the planking to the edge of the deck.

 

Figure 1.19  shows the partly planked deck of my wherry The veneer was painted before it was cut ready to fit. I expect to give it a coat of Sikkens Cetol wood preserver which is translucent teak.in colour. This should fill the grooves and make them stand out. Note the ply sub deck.

 

 

 

 

 

 

Rails

The rails, shown diagrammatically in figure 1.20 run right round the deck and they have several functions. The rails are about 2 feet high, that is a bit more than knee height for a man. At this height it affords some protection against going over the side but is not so high or low as to put bones at risk. The rail is canted inwards by about 5° on the outside and, as the rails taper from bottom to top, by about 3.5° inside. The flat cap on the rail is fitted horizontally. These rails are awkward things to make.

 

Figure 1.21 is of my sprit-sail barge. I show it to draw attention to the two beads that are made of iron on  the full size but of wood on the model. The top one covers the deck edge. Further the rail is set in from the edge of the deck.

 

 

 

 

 

 

Figure 1.22 shows the timber fitting that is fixed to the deck to hold the lee board. It also has chain plates that run down to the wale to anchor the shrouds. This fitting is flush with the deck edge but about two and a half times the thickness of the rail. It can be made with a slot at both ends to take the rails and the joints can be covered by the capping strip that widens at this fitting.

 

The rails can be made by laminating. They have to curve round the bow and be angled. I laminate with a core of balsa and surface it with 1/64² ply. If two layers of 1/16² balsa and one of 1/32² feathered to nothing are used for the core to give the taper from bottom to top this comes out at the scale thickness. I cut a piece of 1² thick soft wood to the deck curve to use as a former to bend the rail whilst the glue sets. Fix it finally with epoxy resin.

 

 The capping strips are cut to shape to fit the rails and joined as shown in figure 1.23. When newly done on the full size the joints are scarcely visible. I found it difficult to make my model joints invisible. The grain is just too big.

 

Lettering and scroll work.

In figure 1.21 the name of my barge is shown on the rail. This was made using “Mayspies” labelling film. This is a clear adhesive film that can be printed in black or colour  using a laser colour printer. Use Word to type the mame in whatever font is appropriate and set its sze checking by taking a print. Copy it to your software for handling digital photos eg Paint Shop Pro and change it to negative. Choose a background size to suit you model. Print two on your laser printer. The letters become clear in a black background. Paint the rail over the area of the letters in white or yellow as the full size. When it is dry fit the label as I have done and just the white shows through the label. Do the transom as well where the arrowheads can be included.

 

This method can be used for the scroll work. Draw your scroll work in black on white paper much larger than the size to go on the model. Use Pentel correcting fluid and a Pilot Hi-Tecpoint Fine pen to get the curves smooth and the whole shape attractive. Scan it and paste it to say Paint Shop Pro change to negative and save it. Create a mirror negative image and save that so that you have images for right and left sides of the barge. Now reduce both to the correct size and print on the labelling film. Proceed as for the name.

 

Of course you might care to carve it all as I did for my ketch rigged barge using the computer to set up the letters on paper that could be stuck with Pritt stick to the model and carving through with a scalpel.

 

The fin and bulb.

I have discussed the fin and bulb at length in section 2, now I am interested in construction. I presume that the bulb will be cast from lead and that a wooden fin will be constructed and that the two will be joined to form a unit. Then, before you can start, you have to decide how to attach the bulb to the fin. I think that it is best to fit a ply tongue to the fin, make a suitable slot in the bulb and stick them together with an epoxy based filler.

 

I have suggested that the weight should be about 9.5 pounds.This is the weight on my ketch-rigged barge and figure 1.24 shows how much it heels in a strong wind. I think that this has a scale-like heel.

 

So let me start with the bulb. This has to be cast and a mould will be required. In turn this means that we need a plug to make a mould from plaster of Paris. I think that the easy  way is to make the mould like a plank on frame hull using semicircular frames. In figure 1.25 I have made a freehand sketch of the frames. To realise this in balsa we need a profile for the base and diameters for the frames.

 

The  information needed is given in Chapter 19 of my book “The RC Yacht Explained” on this website.

 

A suitable length for the bulb is 12² and then the diameter is 2². Using the table in the book and changing it for these dimensions gives table 1.26 where A is the distance from the nose and B is the diameter.

 

Table 1.26

A	1.2	2.4	3.6	4.8	6	7.2	8.4	9.6	10.8	12
B	0.66	0.866	0.967	1	0.971	0.968	0.753	0.56	0.309	0

 

 These dimensions permit drawing the base. In figure 1.27 I have shown the section at the thickest point where the radius is 2². The base is 3/16² balsa and the planks 3/32² balsa. Clearly the radius of the former is 1² minus the thickness of the planks, that is, 0.906². The semicircle has now to be cropped for the base. Given these formers and using blocks at nose and tail, the making of the plug is straightforward. It should be coated with sanding sealer and sanded and filled and sanded again as required. It must be waterproof so coat it with epoxy resin or the like. Make a box to hold the plaster of Paris and make the mould. Leave it to get really dry, any residual moisture will turn to steam whem molten lead is poured into it and this could be dangerous.  Make two mouldings. These will have to be cleaned up, slotted to take the tongue in the fin and then stuck together. I stick them with Leak Fix from the Plastic Padding range of products and I have had no problems with my bulbs coming apart.

 

The fin has to be attached to the hull in some way so that it can be detached. It seems to me that there are two preferred ways of doing this and they come from the common practice in model yachting. Use either a tongue or a carbon fibre tube. I use carbon fibre tubes. For this application carbon fibre tubes are available in metric sizes all with one millimetre thick walls. For my barges I use a 10 mm OD tube in a 12 mm OD tube. It is so easy.

Figure1.28 shows the top of my fin for the wherry. The carbon tube has a screwed insert stuck inside it and a fancy thumb nut to hold it in place. The fixing in the hull is shown in figure 1.29 with the fin in place. The wooden blocks are made of cedar and they are very light.

 

Generally the mountings that people make are too strong and heavy. Figure 1.30 shows the fixing for my sprit-sailed barge. The pundits said it would break out of the hull but it has not done so yet.

 

So a fin has to be made and a tongue fitted for the bulb and the tube fitted into it. I build fins just in the same way as I used to build the wings of aeroplanes.

 

The ribs are shown in figure 1.31

 

 

 

 

 

 

Figure 1.32 shows the details of the construction of the leading and trailing edges. The ribs shown in figure 31 have an allowance made for the thickness of the 0.8 mm ply skins. The only way that I know to make this fin is to use a jig. Beneath each rib there is the shape to make the jig that I have shown in figure 32. These shapes can be cut out in 1/8² balsa.  The sections range in length from 7² to 5² and this jig was raked back by 3/4² at the leading edge. The jig shapes were set at 1.45² apart to give an area of 45 square inches but the ribs and their jig shape can be enlarged or reduced and the ribs re-spaced to give other areas.

 

Glue the jig shapes to a board against lines that extend beyond the leading and trailing edges. Fit strips at leading and trailing edges and sand them to the correct angle. I usually cover the jig with sellotape so that the fin does not stick to it.

 

Start building by cutting a piece of 0.8 mm ply to the shape of the fin with due allowance for the curvature and for dressing. Now add the inner leading edge shown in the detail. This will be a piece of hard balsa cut to the required taper and stuck square to the leading edge of the ply leaving a little for dressing. Place the ply and its leading edge strip  in the jig and hold it down at the top with lead weights. If you do not have any you should have, they are very useful in lots of ways.

 

Figure 1.34 shows the basic construction of the fin. Cut a set of ribs from either 3/32² hard balsa or from 1/16² ply. The tongue can be made by laminating 3 or 4 pieces of 1/16² ply using epoxy resin. The three lower ribs will have to be slotted to take the tongue. Once they are slotted fit them using cyano. They should fit at the inner leading edge when the rib and the skin are pressed into the jig. This gives a partly constructed fin that has the correct curvature at the bottom and can be weighted on the three ribs to fit snugly into the jig.. Clamp the top three ribs together to drill the holes for the tube which must be square with the top rib. Clamp again to drill for the dowel. Assemble the three ribs and the tube and the dowel and check that the assembly fits into the existing structure. If it does, stick it in using cyano. Make a straight saw cut to trim all the ends of the ribs and fit a trailing edge of hard balsa. Fit the tongue and glue it in to complete the basic structure.

 

This structure is not adequate as it stands. It needs stiffening and the tube and the tongue need more support. The extra pieces are shown in figure 1.35. The web running from top to bottom is needed to ensure that the skin does not buckle. The other pieces should be stuck in with epoxy resin to give a proper transfer to the tube of the external forces acting on the fin from the weight and from the water flowing over it.

 

When this is done sand the leadiing and trailing edges and the web etc to give a smooth curved surface for the second skin. The inside must be waterproof. So coat the whole inner structure wth thinned epoxy resin that will set quickly or polyester resin that will set slowly.. At the same time coat a piece of ply ready for the second skin

 

When it is set stick the second skin with epoxy resin using weights on a foam kneeling mat to hold it down. Dress the leading and trailing edges, add a ply skin to the top rib and that is it.

 

If you prefer to use a tongue in the hull the changes are not very drastic.

 

The bulb must be slotted in some way. I suppose that if I did not have a milling machine I would cast the slot into the two halves or assemble the bulb and drill a series of holes and dig out the slot with a wood chisel. However you do it, stick the bulb together and make sure that it will fit on the tongue. It can now be sanded to give its final shape using coarse sand paper. Then stick it on. Fill the gap between the bulb and the lowest rib with Leak Fix to make it all tidy. Coat the whole thing, bulb and all, with fine surfacing glass cloth and polyester resin, sand off the wrinkles to finish it and paint it black.

 

With the rake that is shown in figure 3 the fin should fit so that a point that is 40% from the leading edge of the top rib coincides with a point 40% of the waterline length back from the stem of the barge. This involves drilling a hole in the keel. Think carefully before you do it and consider starting with a small drill and working up and getting an extra pair of hands to hold the hull.

 

I do not know much about fitting the fin tube inside a fibreglass hull but when I was building yachts with very thin fibre glass hulls I started by fixing a strip of 1/16 ply about 2² wide across the hull with the grain fore and aft just to get a firm grip. Then it is much like working in wood. If your hull is thin you might consider a removeable stabiliser for the top of the tube set between the false coamings. Make sure that the fin is square to the hull.

 

The rudder

Assuming that you have drawings of the rudder making it is just a modelling job. Mostly the rudders are built by carpentry on a single baulk of timber about 12² square ie 1/2² to scale. It is mounted on the rudder-post that can be stuck to the transom of a model. The full-size uses smithed brackets and a long rod to form a hinge as is evident in figure1.36.

 

Figure 1.37 shows the head of the rudder in greater detail because it shows the arrangement for connecting the steering gear to the rudder.

 

The timber on which the rudder is built is cut down to take a casting in the form of a collar with lugs though which the connecting pins go.

Figure 1.38 shows the steering mechanism. The diagram comes from “ The Handbook of Sailing Barges” by Cooper and Chancellor. (This is a book of limited scope but, what there is, is accurate and very useful to the modeller.) Unhappily this mechanism would jam if it were to be made accurately. It relies on the slack in the nuts and screws to permit it to function and this slack is a problem in its own right.

 

Modellers do not usually attempt to make this mechanism because it would be much too slow in operation for a model barge. It is covered anyway. The head of my model is shown in figure 1.39. The lugs are too long, but this was necessary to limit the slack that would have been inevitable with scale lugs. The servo is connected to only one lug, the other has a dummy operating link. The rudder moves through about 30° either way.

 

For those intending to race the rudder will need to move about 60° and two links will be needed. The length of the rudder arms and the servo arms should be the same.

 

Modellers will have their own ideas on the rudder extension and its attachment.

 

The deck hatches

On sprit sail barges the hold sizes were standardised. The coamings had rebates cut round the inner edges for standard size hatches to rest on. These hatches (see figure 1.40) were cambered, between 18² and 24² wide, spanned the hold and about 15 were needed to cover the main hold. When these hatches were in place they were  covered with a heavy hatch cloth that was held down by tucking their edges into the batten hooks and fitting a batten and oak wedges.

 

 

 

 

 

 

 

 

 

Figure 1.41 shows the cover (with a pole resting on it) the way the cover is turned under, the batten hook, the batten and the wedge. Note that the batten hooks are, necessarily, let into the coamings.

 

On a model the cloth, the battens and the batten hooks serve no purpose other than viual. From this it is clear that we need a box lid with a cambered top covered with something that looks like a waterproof cloth and sets of battens, batten hooks and wedges. Some take the view that it is best to assemble all these parts with glue as there is no call to disassemble them.

 

The hatch cover is ordinary scale modelling except that it does curve to follow the run of the deck and it is probably best to make a quite substantial structure from medium balsa just to give something to which thin ply can be attached. The batten hooks are the only problem although I took a long time to find a way to make wedges that were consistent in size and to scale. 

I made batten hooks by machining a strip to the correct shape and looking like an extrusion and then cut it into short pieces. Given the right equipment, a milling machine, a dividing head and a rotary table it is quite straight forward!

 

 

 

John Smead makes them from a strip of KP brass sheet folded in the sequence in figure 1.43 and then solders them.

 

 

 

 

 

 

 

 

Peter Mortimer got round the problem by using a different shape. There is some support for the change as Bagshaw sketches something like it on page 39. Regardless batten hooks are easily made this way from KP brass if they are bent in a piece of aluminium with a saw cut made in it..

 

 

 

 

The hatches were used to store ladders barge poles and rope so these are all part of the modelling.

 

Deck houses

Barges have at least one accommodation structure and a companionway. I usually build up the structure in balsa of suitable thickness and then clad it with bass wood or 1/64 ² ply as is appropriate. This way the carcase can be straight and true before it is clad and it can be fitted to the false comings.

Figure 1.45 shows the fo’c’sle hatch on my spritsail barge and figure 1.46 shows it removed. It covers the radio switch.

 

Figure 1.47 shows the roof of the cabin. This structure was built on to the deck and is strong enough to support the mizzen pulpit and the steering gear

 

It is useful on a model to have access to the stern of the hull for fitting and maintaining the rudder servo and for fitting ballast, probably the radio battery, as far aft as possible. This means that it is best to make this cabin roof detachable.

 

The mizzen mast has to be supported by four guy ropes and these are secured to eyebolts on the deck. We can use the same method and this will serve the second function of holding the cabin roof on. These eyebolts will need hard points for them to be fixed to.

 

 

 

 

 

 

Winches and windlasses

I find myself at something of a loss to be very helpful about making model winches to go on a model barge. They present the most difficult problem for the model maker because they need gears and representations of the side castings and so on. They are really a job for a model engineer and even then most model engineers do not make their own gears. As I make all these things I may not be of much help in what I say. If I fail you are no worse off.

 

The main winches fitted on sprit-sail barges were one brail winch, two lee board winches and a windlass for the anchor. There were also one or two dolly winches on the mast case and one dolly winch on the windlass.

 

I have given two pages of photographs of various windlasses and of a brail winch and Bagshaw gives sketches of winches that are very helpful.

 

Starting with the windlass it is clear from just looking at photographs and various existing barges that there was a common mechanism of a wooden drum with eight flats mounted on a spindle with step down gears at each end to turn it. The spindle and the gears are mounted on a wooden frame in the form of two bitts, made from substantial timbers that were mounted through the deck. The precise design of these bitts seems to have varied from shipwright to shipwright but the castings for the bearings seemed to be standard. Some barges had a kingpost to mount either a fixed bowsprit or a bowsprit that could be raised. Then a ratchet wheel, called a ruffle in barge terms, was fitted in the middle of the drum dividing the drum in two and a pawl was mounted on the kingpost. Otherwise ratchet wheels were fitted at both ends of the drum and the pawls to the bitts or the deck. A dolly winch was mounted on the bitts on the forward faces and cleats fitted to the bitts as deemed to be necessary.

 

Photographs of windlasses

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Photographs of a brail winch on Jock (now scrapped

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The anchor is obviously attached to a chain and that chain is partly stored in a chain locker and accessed through a fitting on the foredeck and partly on a sort of duck-board placed handy to the windlass. This latter gives a length of chain that is readily available to run out. The chain makes three turns around the barrel of the windlass and, as the anchor is raised, these three turns travel along the barrel and when the reach the end the chain is hitched to a dog (hook) on a chain to take the weight off the chain whilst it moved along the barrel to start again.

 

I suppose that most would agree that the difficult items to make to scale are the gears and the pawls. Mine are all machined from stock brass and painted. All my winches work. On the sprit-sail barge they are effectively just decorative modelling but on the boom-sail barge the brail winches are used to set the rig. In order to machine them a milling machine with a dividing head and a rotary table is needed. I know only a few modellers with this equipment. Even so it is still necessary to be able to design the gears and not many will have studied gear profiles to the point where they can do this.

 

It then becomes a question of what can be done without machine tools. Clearly there is a need to fabricate, presumably in wood, gears and pinions. Of these the most difficult is the pinion. I can think of no way to make pinions without machine tools so that they look the part. However it is probably possible to find suitable pinions in bits of hardware such as old servos, time switches, clocks and so on. The pinion needs to be of about 0.2² in diameter with 10 or 12 teeth. Others will be required for the brail winch and the leeboard winches.

 

Just looking at the photographs the impression that one gets of the main gear wheel on a windlass is that it is a spidery looking thing. It is not a clumsy design. Nevertheless dummy gearwheels can be made from three laminations of 0.8 mm ply cut out with a piercing saw in a fret frame. The spokes have a tee section and it is not difficult to produce this in ply as my figures 1.51a and b show. But a drawing of the wheel is needed first.

 

This calls for some dimensions. It is necessary to start with the dimensions of the teeth. This means deciding on how the teeth are to be made. I have made three test gearwheels just for this website and the easiest way of cutting slots in the rim is by using a band saw. Blades for small band saws like those used by modellers are necessarily thin just to run round the wheels they are mounted on and, even with blades with 24 teeth per inch, the cut is only 0.020² wide when we would really like about 0.030². However vee-shaped needle files are about 0.032² on the edge and have an angle of 20° and that is a very suitable angle for filing teeth more or less to shape. If the rim is marked out for the teeth and slots cut to the required depth using the band saw the file can be used to widen the slot and create the shape of a tooth. This means that we want the gearwheel drawn to scale and marks round the edge for cutting the slots.

 

I think that, on the real wheel, the number of teeth varied with the weight of the anchor but it was about 90 teeth. That is too many for me to make on a wooden wheel of the scale diameter so the best that I could do was around 80 teeth. The spokes have to be drawn by hand so it is most convenient to have a number of teeth that is a multiple of 6 so that six of the lines are the centrelines of the spokes.

 

Teeth can be cut if one tooth together with its gap occupies about 0.06² of the circumference. The diameter of the main gear on a windlass is about 1.43² and, if we use this figure the number of teeth will be 75. We have to choose either 72 or 78 teeth. I think that it is best to choose 78. The depth of the teeth is about 0.05².

 

The figure 1.52 was drawn using a mathematics package. It is a guide to cutting the teeth.  There are 78 radial lines and five circles. If the outside diameter is printed at 2² the outer black circle will be the required 1.43²

From the centre these circles represent:-

The diameter of the hub where the upright of the tee is radiused into the hub, (see figure 1/53),

the bottom of the radius between the crosses of the tees of adjacent spokes,

the inside of the rim,

the bottom of the teeth, and

the outside diameter.

 

 

I started with the pattern stuck to a piece of 0.08 mm ply using Pritt stick. On the pattern I drew two lines for the thin parts of each of the 6 spokes. The piece of ply was stuck using cyanoacrylate to a second piece of ply with the grains crossed. Then the holes between adjacent spokes and the inside of the rim were cut out with a fine piercing saw in a fret frame. The spokes will be about 1/32² in width. The sawing fluff was removed and the “wheel” stuck to a third piece of ply with grains crossed again. The cyano leaves a fillet between the thin spokes and the ply. Now the new full width of the spokes, the hub radius to connect the flanges and the flange on the rim have to be drawn on the third piece of ply. If the sawing had been tidy this really only requires a sharp pencil and the existing edges as a drawing guide to draw lines a set distance from the spokes etc. Cut out the new shapes to leave tee sectioned spokes and a flange on the rim. Now the rim can be sawn out of the triple lamination. It can be cleaned up with a sanding block and then coated with cyanoacrylate just to make sure that the three layers of ply are properly joined where the teeth are to be cut. Cut the slots for the teeth using the band saw. Do not go below the root circle. Then, holding the wheel in a vice, run the file into the slots correcting slight errors in sawing and take a couple of strokes on each side of the slot to give the tooth the involute shape. Finish the wheel to your satisfaction and paint it black. It takes about one hour to make a wheel.

 

Wheels can be made in this way for the other winches given the number of teeth and a drawing of the wheel.

 

Ratchet wheels are needed for the windlass and they have 32 teeth that have a saw-tooth profile. The diameter is about 0.75². In figure 1.54 I give a set of radii to act as a sawing or filing guide and a circle that will be the correct size if the diagram is printed so that the outside diameter is 2²

 

 To the scale of 1/24 the shaft of the windlass drum will be about 0.08² and this is available in the K and S range of brass rod. But as no one will look at it you could use 1/16² or 5/64² or 2.5 mm rod.

 

The bitts are clearly a woodworking job. You will have the dimensions on your working drawing. Use say beech wood sold in strips of 1² by 0.5², 3/4² by 1/4² and so on for engine bearers. It can be cut to thickness on a pillar drill and glued together. The bearings are cast on the real barge but the model ones can be in wood and fabricated from smaller pieces. The bearings are joined by a cast base and bolted to the bitts. We can make ours in wood and glue them to the bitts. When all the parts are ready the bitts can be glued to the deck. Make a location guide to avoid moving the bitts around and getting glue in unwanted places. Do not forget the cleats, you will need them.

 

The crab winches

On barges a family of crab winches was available all based on the same arrangement. I think that they were al dual purpose. The main function would involve the use of a winding drum, driven by step down gears, to stow the mainsail or to lift the leeboards. The secondary function would be a capstan to be used for any purpose and involve a second set of gears. Both functions operate on the same axis one rotating round the other. Designs differ in that some have the main gear wheels inside the two cast frames and others both gear wheels at one side, one inside of one frame and one outside.  They all had locking arrangements that were either a ratchet and pawl for the capstan or a detent wheel for the drum. The photograph in 1.55 shows the simple winch being used as a brail winch to stow the main sail on Wivenhoe. Figure 1- 56 shows the gear wheels inside the frames in the winch that was on British Empire and figure 1-57 shows the two gear wheels at one end and the detent wheel. Bagshaw shows the other end of the winch on p 60 of his book.

 

The frame is made from two side castings, that may be handed, joined by spacing bars that are threaded for nuts and we have to choose one to model making two handed winches for the leeboards and perhaps another as a brail winch.

 

 

A model engineer would make the frames from brass soldering plate together as required. These frames can be made from ply. Figure 1-56 shows the construction. It starts with the profile of the frame cut from 0.8 mm ply and drilled for the three shafts and the three spacing ties. Then a strip of 0.8 mm ply cut across the grain is wrapped round and glued with cyanoacrylate. After tidying the legs it is stuck to a strip across both feet and then the middle removed to leave base plates. Then three bosses cut from ply are stuck on as shown in figure 1-59.

 

Two gear wheels are needed. To scale thay are 0.72² in diameter with 40 teeth. Figure 1-60 is the pattern for cutting 40 teeth with the diameters superimposed. It will be the correct size if the diameter is 2². These wheels had four spokes as I have shown in figure 1-61.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(Past readers will know that I have to rebuild my website. This section is not finished but it is more important to upload the rest of the text than to wait to finish it. I will complete it in due course. Ivor Bittle)