Graham, nice of you to ask. I have to admit that though the Whaleback is finished, I hadn't worked out how to shrink photos down to a manageable size so that I could write about it for the site, but your last reminder has prompted me to learn. How successful I have been remains to be seen!
Right, in summary the boat I settled on is a 1/12 scale Whaleback to the 1/24 scale Pritchard drawings. If you are going to be fussy, the drawings leave a bit to be desired, but a bit of patience and a lot of searching for detail has helped me to build what I think is reasonably accurate. Mr Pritchard hasn't got the frames quite right and to be fair, some Whalebacks varied in build, but I wanted mine right! How to tackle the actual construction is really down to our friend 'Bluebird', I followed his excellent article religiously. It's 63" loa and 17.5" beam and one of the biggest problems has been what to power it with. I settled on three 850 torpedos powered by 5 x 3S lipos, with Action Electronics control. I think it is essential that the boat looks right on the water, not tearing about like a hydroplane or chugging along like a tug and the power has turned out just right, it rises onto the plane perfectly and sits with a bow wave breaking at exactly the right point on the keel. It wallows at idle and sits low with the rear deck horizontal for rescue work, but I only managed to get that right thanks to 6 kg. of ballast. On the plane you can see why the foredeck was sloped. The coxswain would have been completely blind otherwise. I've used a form of Ackerman steering on the triple rudders and also the Action Electronics slow the inner motor in the turn, so although it has a very long keel, it steers reasonably well, especially on turns to port, which you would expect with three l.h. props. Starboard turns leave only a bit to be desired but steering going aft is totally random, anybody's guess. I originally used brass props, which look superb, but you really need plastic racing props to get it going properly.
The build was a pleasure, twelve months in the garage so I am looking forward to starting another boat asap. Marine ply keel and frames, lime planks for the first hull skin and mahogany for the outer skin, scale planks of course, but no layer of treated canvas between. The deck was firstly formed out of 1mm ply pieces, then an outer layer of mahogany planks again. Painting and waterproofing gave me sleepless nights. I treated the insides to a coat of polyurethane and the outside to epoxy resin. I used the epoxy on a really hot day (for the UK anyway), so it went on really thin, but the hotter it is the faster it dries, so you need to get a move on applying it. I had to be careful rubbing down. I didn't want to loose the planking detail, so I couldn't go too smooth, but I didn't want it looking as rough as a log cabin. British Power Boats built these boats fairly quickly and they didn't waste too much time on smooth finishes, so I have left the decking so that the individual planks can easily be seen and the hull so that the planks can only be seen in the light. From what I have seen of the real thing, this is just about right. Halfords spray cans have given me the colour I wanted, but in retrospect it may have been cheaper to buy a spray gun and compressor! Big boats need a LOT of paint!
As the main cabin structure on the real thing was built using ply moulded skinning over formers, I didn't have the problems of planking here, but the opening doors to allow ingress of a stretcher and the mountings for the two turrets needed a bit of pre-planning. Those cabin windows and top gutters were a bit tricky and getting the windows in the right place (unlike the positions shown on the drawing) was a real pain. I have photos inside the rear cabin and also a dvd, "For those in Peril", so details like the windows, the turrets and the forward cabin can be determined, which I think is half the pleasure of scale building. You may notice a piece of pipe going across the cabin roof from the deck level at either side, just behind the main mast. No-one seems to know much detail about this, apart from the odd photo, but I am fairly certain it is the main vent from the two midship fuel tanks. This only appeared on some boats, most seems to have the '?' shaped vents on each side of the cabin. I only added this to be different, unfortunately I have no idea whether 132 had this vent or the ? type. As neither the RAF nor the National Maritime Museum have any record of 132, its service, its crew, its fate (or its fuel vents), I feel fairly sure that no-one will argue about it!
To be perfectly honest, the build was fairly straightforward, with one exception. The gun turret domes proved to be a nightmare. I photographed the real thing at the RAF Museum at Hendon, so I knew what it should look like and exactly how big it was. I also managed to get the manufacturer's spec on the whole turret, so I had no excuse to not get it right, but all that information didn't make it any easier making a scale model of it. Firstly I tried to make a blank male plug with a view to casting the dome in clear resin by taking a female mould off the plug. I used an 80mm diameter Christmas bauble with a tapered skirt, mounted on a piece of wood, with plasticard framework. This was polished up and then painted. I then spent a small ransom on some rubber moulding stuff, guaranteed to replicate fine detail and copy the lovely, smooth finish I had achieved on the plug. (Mistake 1) This I poured over the plug, allowed to harden and then carefully I managed to get it off the tapered plug all in one piece. So far, so good. Then I spent a much larger ransom on some "Water clear" moulding resin. This I mixed exactly to the instructions, poured it into the mould and swirled it round to obtain a consistent thickness of about 1.5mm as the "water clear" resin gelled (20 minutes). Leave for 24 hours, carefully remove from the rubber mould and hey presto, an almost opaque turret dome with a totally frosted outer surface! (Mistake 2). £100 worse off, I made the final domes as I had made the plug, by gluing a Perspex tapered skirt onto a carefully cut hemisphere of 80mm Christmas bauble. All I had to do then (!) was to add the plasticard framework, cut out the gun aperture, mount on a base ring and add the gunners seat/gun mounting. Gluing the dome to the skirt was one of those jobs that needs four hands and the patience of Job. Bear in mind that you can't get glue on the dome, the real thing tended not to have huge fingerprints all over it. Mind you, I was pleased with the finished article, although I cheated with the gun, it is 3D printed, like the 20mm Oerlikon on the stern. Thank you Shapeways.
What else can I tell you about it? The rigging was good fun, especially the aerials. I used stainless cable for the stays and rigging chord for the aerials. The fore aerial is fixed to the foremast, but all the other bits of rigging are fixed to the cabin structure. By making a telescopic main mast, it is easy to drop the mast, which slackens all the rigging, and then lift off the whole cabin. This gives access to the batteries. The rear hatch lifts off to give access to the rudder mechanism and rudder servo.
The liferaft is as close to real as I could make it. Canvas (silk) covered, scale rope and netting to hold the floor boards frame. However you throw the liferaft into the sea, the floor can be stood upon so that it hangs below the buoyancy, allowing crew to sit on the buoyancy with feet on the planks inside and the rest of the stricken crew to hang on to the outer ropes, which of course float due to the cork balls on them. Clever design. Last of all, the CQR anchor. From what I can glean, only Whalebacks
had these anchors, but the design is still used on many yachts, so it is easy to obtain all the dimensions. I had to make this from scratch, complete with pivot on the shank and a chain shackle on the end. Apparently, these were rarely used, so they never bothered to attach a chain, the chain being housed in the locker below the winch.
So, there we are. 1/12 scale has its drawbacks, as I am sure many of you already know. The boat is quite a handful to carry about and only just fits in the car. There are very few commercial parts made to that scale, but at least I managed to get the main vents and lifebelts and the components for most of the winch. It would be nice to have a scale crew, at least a Captain in the cab top hatch and a Coxswain, but no such luck and I'm not tempted to try making some. Shapeways supplied the Lewis and Oerlikon guns as well as the deck lights. I used Mantua Models in Windsor for almost all the materials and they were a real pleasure to deal with, and excellent quality.
I loved building it and I'm hooked on the large scale. So much so that I fancy a 1/12 scale Vosper MTB next. That comes in at 72.5" long. What on earth am I going to power that with?
I've added a few photos (I think), but if you are interested and want more, just let me know.
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Topic: 1:12 BPB Whaleback advice requested please (Read 6674 times)