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Author Topic: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’  (Read 5932 times)

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Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« on: December 23, 2020, 10:49:16 am »

I’m not able to do much model sailing at the moment for obvious reasons so I thought I would post the build story of my Bristol Channel Sailing Pilot Cutter, Eliza Rose.  The model was built between 2008 and 2012 and has since clocked up about 60 hours of sailing at the Woodspring Model Sailing Club and also occasionally at the Cheddar Steam Club.  I hope this account makes a good read while we are so restricted in where and when we can go sailing.  Also it may be of use to anyone else who is setting out to build a sailing model from a bare GRP hull – this certainly isn’t the only way to do it, but it works well and has withstood a number of years of sailing.
The idea of building a Bristol Channel Pilot Cutter took hold with me in 2007.  I had moved to the Bristol area in 2005 and I was keen to build a sailing model for myself and also to make a model that would cope better with a variety of sailing conditions than my very delicate Thames Sailing Barge model.  Having looked at a range of scale models belonging to other club members I decided that I wanted a model with a nice beamy and deep hull, with internal ballast rather than an external keel, and a straightforward single-masted rig that would lie flat on the model for transportation.  The Bristol Channel Sailing Pilot Cutter type seemed to fit the bill – they are typically around 1:3 beam-to-length and there were a number of nice examples in the club that sailed well even in stronger winds. 
To start things off, here are a couple of current photos showing Eliza Rose as she is now - one sailing in light winds this summer and the other on the display stand taken yesterday.
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #1 on: December 23, 2020, 11:22:30 am »

My approach to scale modelling is to aim for a decent level of detail and realism while still achieving a robust working model.  My models need to withstand being de-rigged and rigged frequently along with the usual shipping backwards and forwards to the lake and exhibitions.  I can therefore use good quality materials such as limewood strip decking, mahogany capping etc.  but I tend to simplify or leave off some of the finer details that you might find on very accurate scale models.  There is always the possibility to add more fine detailing later on with this approach, and I have added a few items to this model over the years since it was first built.
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #2 on: December 23, 2020, 11:27:49 am »

In January 2008 I bought a GRP hull for the ‘Dyarchy’ Pilot Cutter from Mike Mayhew at Waverley Models (as it was then).  I wanted a reasonably large model and this bare hull is just over 40” long, modelled at 1/12 scale.  Only two drawings came with it – a plan view of the deck and a side-on sail plan.  The latter was not even for the Dyarchy cutter, judging by the hull outline which did not closely match my hull.  These were not sufficient to complete the model alone and I realised that I would need to work from a variety of sources including photographs of real cutters and other people’s models.  I also decided early on that I would not attempt to model a specific Pilot Cutter in its original working appearance.  Instead, I have attempted to build a model that is representative of the Bristol Channel Pilot Cutter type, and finished as you would see such a boat in a marina today, probably converted for pleasure/ cruising use. 
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #3 on: December 23, 2020, 11:38:39 am »

The most obvious change in these modern cruising conversions is usually to add a skylight in the centre of the deck, where the original working boats would have had a plain deck to maximise the room for handling the rowing boat (or ‘punt’).  For the same reason, the model isn’t named after a full-size cutter either.  My wife came up with the name ‘Eliza Rose’ as a suitable west country name for a boat, given that several of the originals were named after wives and daughters etc.  There are also several records of a full-size sailing pilot cutter called ‘Eliza’ on the register of Bristol Pilots with dates from 1856 to around 1894, so there is some precedent for the name at least!  Incidentally, this information came from the book ‘The Bristol Pilots’ by John Rich (ISBN 0 9528082 0 X, published in 1996) which gives a very thorough account of the history of the Bristol Channel pilots including a tabulation of over 1000 men who have served as Bristol Pilots together with the names of their yawls or cutters where known.
I’ve included pictures of the bare GRP hull as I received it.  Someone had written ‘DYCHARY’ inside the hull in pencil – I’m pretty sure the original cutter was called ‘Dyarchy’ though!  Unusually for a Bristol Channel Sailing Pilot Cutter, she has a flat transom rather than the counter-stern extending rearwards of the tiller that you see on original examples such as ‘Cariad’ or ‘Mascotte’.  The GRP felt reasonably solid although I reinforced an area of it near the keel where I could see light shining through and I assumed that there was a thinner patch.  I used standard 2 part resin and chopped strand glassfibre matting for this.
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #4 on: December 24, 2020, 02:37:27 pm »

An early decision was to follow the advice of several club members to add a metal ‘false keel’ underneath the scale keel on the GRP hull, in order to get a good part of the ballast very low down in the hull for stability.  Sailing Pilot Cutters have a very long, straight keel line which slopes downwards slightly to become deepest at the stern.  It is therefore fairly straightforward to add a piece of square-section metal bar stock to this keel.  I am not keen on melting and casting lead so I bought a length of ¾” square section brass (19mm x 19mm) which I bolted through the bottom of the GRP keel, after gluing in some small hardwood blocks within the keel to support the nuts on the inside.  I then faired this brass bar in to the existing hull shape at the front and the back using blocks of wood.  There isn’t much to choose between brass and lead for density – lead is 11 times more dense than water and brass 9 times, so the brass bar alone added more than 5lb of ballast.  My model is therefore 19mm deeper in the keel than the scale design, but the difference is small and completely invisible when sailing. 
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #5 on: December 24, 2020, 02:39:52 pm »

The brass bar and wooden blocks were all bolted to the GRP hull using 4mm nuts and bolts, with the bolt heads recessed into the wood and brass, and the nuts inside the hull.  I also put a layer of epoxy glue between the brass bar and the bottom of the keel.  The drawn brass bar is surprisingly hard to drill through and my original 4mm drill bit expired in heat and smoke!  A new drill bit solved the problem and cut cleanly through. 
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #6 on: December 24, 2020, 02:49:33 pm »

The wooden stem was carved from softwood to fit inside the GRP hull and it serves to extend the stem to the required height above the hull.  This was glued in with epoxy.  The next step was to line the insides of the hull with 1/16” (1.6mm) plywood from the gunwales down to below deck level.  Perhaps not everyone would choose to do this with a GRP hull, but I didn’t want the GRP matt texture to show inside the gunwales above the deck level, so I lined it.  I suspect any good quality thin plywood from 1mm to 2mm thick would do for this.  I extended the plywood liner further down in the midships region to provide some purchase to bolt the chainplates on to the hull later on.  I used epoxy for all wood-to-fibreglass bonding.   Once this had set, I scribed a pencil line around the inside of the hull to mark the deck level and then glued some hardwood strips to the plywood liners at this level to support the deck. 
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #7 on: December 24, 2020, 05:52:26 pm »

Merry Christmas to all - Christmas Eve has arrived and I hope your plans and wishes for the festive period work out well.  I'll continue this in a day or two...
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #8 on: December 28, 2020, 02:38:19 pm »

At this point I started thinking about where to put the radio gear, battery and other internal fittings such as the footing for the mast.  I started off with the sealed lead/ gel battery (6V, 4.5Ah which gives a useful bit of extra ballast) and drew out a plywood box structure around this.  The box serves many purposes – it holds the battery upright, it provides a footing for the mast tube, it has an upright side against which to bolt the bracket for the sail winch and the radio receiver goes in a plastic box on top.    The box was was glued and screwed together (white waterproof PVA glue for wood-to-wood joints) and then epoxied to the hull with some glassfibre matting for strength.
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #9 on: December 28, 2020, 02:48:18 pm »

Next I started to work out how much ballast to put inside the hull.  The plan gave the weight of the original boat as 24 tons displacement.  I assume this means ‘long’ tons (2240 lbs) but I’m not sure – does anyone know what is normally used for boats like this?  An estimate of the total weight for the model (at 1/12th scale) is therefore obtained by dividing 24 tons by 12 cubed (12 x 12 x 12).  This estimate gave a model weight of about 31 lbs, which has turned out to be quite close to the weight of the finished model which is 28lbs.  The GRP hull with the brass bar on the keel and the sealed lead/ gel battery inside only weighed 12lb, so quite a bit of extra ballast was needed.  I wasn’t very sure how much weight to allow for the remaining building (deck, rigging, deck fittings and hatches etc) but I made a guess and bought 12lb of lead shot.  The next part of the work was very experimental.  I bagged up the lead in 1lb and 2lb quantities and marked the intended waterline on the stern and the stem of the hull.  Then I filled 10” of water in the bath, put the hull in the bath and started putting bags of lead in.  After some shuffling around I found a suitable distribution of lead along the bottom of the hull and made a note of the positions.  Other club members advised to leave several pounds of lead in loose bags in the finished model, to give some flexibility on trimming.  I therefore decided to fix in only 5lb of lead at this stage.  Not being keen on melting and pouring lead I decided to put the lead in as a slurry of roughly 3 parts lead shot to 1 part epoxy resin by volume.  This is easy to mix up and pour into the hull and has the advantage that you have quite a few minutes to move the shot around and smooth it before the epoxy goes off. 
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #10 on: December 28, 2020, 02:55:15 pm »

Next up were the rudder and rudder hinges.  Neither the rudder planking nor the hinge design are to scale.  The hinges are also larger than scale as part of my efforts to make the boat robust enough to sail regularly without getting damaged.  In hindsight I think I overdid this – they are too big and now I am picturing archaeologists digging them up in a thousand years’ time and wondering what on earth they were used for.   I also enlarged the rudder relative to the plan as I was told this was necessary for a model sailing boat.  The choices seemed to be either to make a removable rudder extension to fit when sailing the model, or simply to make the rudder larger than scale size.  I opted to make the rudder 50% wider (from the stern of the hull) than the scale drawing on my plan.  The model has now had many hours of sailing and the steering with this rudder design is good.   People who know cutters will see that the rudder is too big but I suspect that most people won’t notice it. 
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #11 on: December 28, 2020, 03:05:11 pm »

The rudder itself is surprisingly thick, in order to match the thickness of the GRP hull at the stern.  It was built up on a core of 8mm plywood with 1/8” planking on either side, giving a maximum thickness of around 14mm.  The plywood core was tapered to be thinner at the trailing edge before planking.  The hinge parts were turned from round brass bar with strips of 1/16” brass silver soldered on and the hinges were glued to the rudder with epoxy.  The upper hinge pin has a small hole in it for a wire pin to stop the hinge from coming apart again.  I bent my own retaining pin from stainless steel wire, but I think they are called ‘R’ clips commercially.
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #12 on: December 28, 2020, 03:19:37 pm »

The rudder was then put away for later and I turned to putting in the remaining internal structures and deck braces.  I decided to operate the rudder using a 2-cord ‘pull-pull’ system, so I needed to mount the rudder servo centrally under the cockpit area, as high up as possible under the cockpit floor.  After some careful measuring I epoxied in a plywood plate to hold the rudder servo.  At the bow end I epoxied in another plywood plate to anchor the bottom end of the ‘bitt head’ posts, which I wanted to extend down several inches below the deck level for strength. 
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #13 on: December 28, 2020, 03:20:54 pm »

The deck braces were made from softwood strip.  They are fitted in front and behind each of the hatch positions and in one or two extra places such as to next to the mast tube.  The finished deck braces and rudder servo mount can be seen in the photo.  The two deck braces in the midship positions are thicker than the others - at that stage I was thinking that I might use them to lift the model in and out of the water, as I had seen some other sailors doing with their models.  I have never trusted the braces in my model to take the full 28lbs weight however and I have always used a trolley to launch it instead.  If you do want to hold your model by the deck when launching (through the hatch) then I suggest to do what I have seen some other modellers do which is to fit woodscrews through the side of the hull and into the ends of the deck braces.
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #14 on: December 28, 2020, 03:33:37 pm »

Before continuing to fit out the inside of the hull I carefully cut and filed out the hole for the bowsprit in the starboard side of the bow.  I also primed the false keel and glued some rubbing strakes along the sides of the hull.  The strakes were made from 1/16” hardwood strip, with bevelled edges top and bottom created by pulling the edges of the strip over the blade of my woodworking plane, with the plane held upside-down in a vice.  The photo below shows the unpainted strakes with three gaps on each side to allow space for fitting the chain plates.  I also drilled the holes in the sides of the hull for the chain plate bolts at this point.
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #15 on: December 28, 2020, 03:37:38 pm »

An anchor point is needed on the stem of the hull close to the waterline for the bobstay chain, which runs from there to the tip of the bowsprit.  I had to find some 1/16” brass wire for this (I didn’t want any steel fittings that might rust on the outside of the boat).  The brass wire is bent into a ‘U’ shape to fit through 2 small holes in the hull and wooden stempost, then the ends are bent over inside the hull and the whole thing secured with epoxy. 
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #16 on: December 28, 2020, 03:52:11 pm »

By now I was ready to paint the hull, so that meant choosing some colours!  For the original sailing pilot cutters this is easy – the hulls were matt black due to being coated with pitch.  I was trying to show a pilot cutter as it would be seen today though, so I looked at some full-size originals for ideas.  I particularly like the green and black combination on the full size ‘Pegasus’ and I was able to take some photos of her one time when she came into Portishead marina.
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #17 on: December 29, 2020, 03:24:36 pm »

I don’t have an airbrush so all my painting is brushed. After washing and lightly sanding the hull I started with a white primer followed by two coats of oil-based green paint.  I am careful to move the brush along the rough direction that the planking would take, so hopefully any remaining lines in the paint won’t look too out of place.  I then painted the hull matt black above the deck level, loosely following the colour scheme of the full size ‘Pegasus’ cutter.  Later on I also gave the whole hull two coats of matt varnish to even out the finish across the various painted and varnished surfaces.
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #18 on: December 29, 2020, 03:46:06 pm »

The camber of the deck means that the deck needs to be raised by around 10-12mm at the centreline and at the point of the widest beam.  For each of the other beams I reduced the height of the camber profile in proportion to the length of each beam.  To achieve the camber profile, I glued firm balsawood strips on top of the deck braces and then shaped and sanded them to give the right shape.  I also fitted a piece of plywood between the two beams forward of the central hatch to provide a secure location for the top of the mast tube.  The mast tube was made from 22mm copper plumbing tube.  The bottom of the mast tube sits on the plywood box in the bottom of the hull. 
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #19 on: December 29, 2020, 04:09:16 pm »

Before going any further with building the deck I did as much as possible to finish the radio installation.  I have fitted the model with a sail winch for the mainsail and a rudder servo.  I considered fitting a third channel to control the foresail and jib but really this isn’t necessary for normal sailing and I decided to leave it out.  The ‘pull-pull’ rudder control arrangement and the main sail sheet both require some guide tubes to be fitted to keep friction to a minimum where the sheets pass through the deck.   I made these tubes up from 1/8” brass tube, taking care to make sure the tube didn’t get crushed at the bends.  The mainsail sheet tube is visible in these photos, pointing up from the deck level between the cockpit and the transom and running down into the hull and then forward towards the sail winch.  The sail winch is fitted into a continuous loop arrangement with a spring tensioner.  The whole sail winch and tensioner loop assembly was supplied by Waverley models and it has worked reliably to date.  I also fitted two sloping pieces of wood just rearward of the rudder servo, ready to hold the two short brass guide tubes for the ‘pull-pull’ rudder sheets. 
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #20 on: December 29, 2020, 05:01:47 pm »

Once I was happy with the radio installation, I removed all of the radio gear to protect it while I continued building.  I completed the glassfibre reinforcement of the deck beams by applying matting and resin to the joints between each deck beam and the sides of the hull.  I also fitted some longitudinal pieces of wood in between the beams to support the hatch coaming.
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #21 on: December 29, 2020, 05:10:46 pm »

I used 10BA brass nuts and bolts to attached the chainplates and bowsprit shroud plates to the sides of the hull.  For a working model these need to be nice and secure so the 10BA bolts (1/16”) are ideal.  They are available from various UK model engineering suppliers and I find them useful for all sorts of modelling jobs.  I put a touch of Loctite on each screw thread to secure the nuts inside the hull as well – I don’t want to have to try to tighten these up again inside the finished model!   The chainplates were laser-cut brass sheet parts supplied by Waverley models.  Each one needed folding over at the top to form a small loop and then silver soldering and painting.  The bowsprit shroud plates were made from ¼” x 1/16” brass strip, filed to shape, folded over into a loop and silver soldered as for the chain plates.
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #22 on: December 29, 2020, 05:23:21 pm »

Then came the lengthy job of sheeting the deck with 1/16” ply.  I imagine any good quality plywood from 1mm to 2mm thick could be used for this.  The deck has strong curvature in both directions (the sheer line from stem to stern and the deck camber from side to side) which gives the boat much of its appeal but also means that large pieces of plywood can’t be used.  I used fifteen pieces of plywood to cover the deck – perhaps others could do it with fewer pieces but using smaller pieces makes them easier to fit.  The two ‘pull-pull’ brass guide tubes for the rudder control can also be seen.  At this point I was able to fit the rudder and try the pull-pull system with a couple of cords inside the brass tubes and it worked very sweetly (sigh of relief).  With this set-up the rudder can be controlled to about 45 degrees either side of neutral.
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #23 on: December 30, 2020, 03:40:19 pm »

Believe it or not it took me 18 months to reach this point – work really does get in the way! In preparation for planking the deck I fitted some 1/16” ply around the edge of the deck.  I also fitted the uprights along the bulwarks (these would be the tops of the boat’s frames on a proper built-up hull, but not on this GRP hull).  These were simply glued to the plywood bulwark liners.   
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Re: Bristol Channel Pilot Cutter Build – ‘Eliza Rose’
« Reply #24 on: December 30, 2020, 03:42:38 pm »

Also visible are three scupper holes just above deck level on either side of the hull.  On a built-up hull, these holes would be formed naturally by leaving a gap between the planking of the hull and the planking along the bulwarks, and the row of scupper holes would probably have run from around amidships to the cockpit area.  On a GRP hull these holes have to be cut out between the uprights and I found this to be a tricky job.  Eventually I chain-drilled a row of holes of about 3mm diameter along the line of the scupper hole and opened these out into a continuous slot with small files.  I limited this to 3 scupper holes each side to avoid weakening the GRP hull too much.  The end result looked neat but at the time I did not realise that it had exposed small gaps between the GRP hull and the plywood hull liner – more on this later!
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