Supermarine S-6 and S-6a/B
The line of Supermarine racers, designed to attack and eventually acquire the Schneider Trophy for Seaplanes, actually began with the S.4, a mid-wing cantilever monoplane with amazing aerodynamic form for its time, 1925. This floatplane racer was sent to the United States for the eighth Schneider Cup races at Baltimore, where it suffered a number of mishaps before it finally was wrecked when the pilot lost control, fortunately with no injuries. The race was won by Lt. Jimmy Doolittle, with the backup Gloster III placing second.
The FAI eventually decided to run the even every two years to allow for the development time of new airplanes, and next began preparations for the 1927 event at Lido, Venice, Italy. The Royal Air Force had established the High Speed Flight at Felixstowe, and was training on the Gloster III and the Short-Bristol Crusader. However, the RAF had ordered several Supermarine racers, purportedly for high speed aerodynamic research, but actually for an assault on the Schneider Trophy, which required the team’s victory for three years in a row. The original S.4, having been lost in the 1925 race, was replaced by two S.5’s, N219 and N220. Powered by Napier Lion engines, and using wing-surface radiators, the S-5, N220, piloted by Flt. Lt. Webster, won the event with a speed of 281 mph, while N119 took second with 272 mph. This established the British as the team to beat.
In 1929, the second round of races took place at Ride, off of the Isle of Wight. Two new aircraft, designated S-6, competed and won this event. These were powered by the new Rolls Royce Buzzard engine, rated at 1900 hp. Now it was necessary to wait until 1931 for the third and final event, and Supermarine upgraded their S-6 design, installing an improved Rolls Royce engine rated at 2,350 hp.
Obviously, this was a lot of power for such a light airframe, and the engineers had their hands full matching a propeller to the engine that would allow takeoffs with the tremendous torque and P-factors without loss of control. F/O Waghorn won the even in N247, while S/Ldr. Orlebar later set a world speed record with the same aircraft.
However, another problem entered the picture, the onset of the Great Depression. There was no money for the British Parliament to support such a frivolous activity as air racing, but Lady Houston came to the rescue and provided the necessary funds to complete the S-6B’s, and also modifying the original two S-6’s to be used as trainers and backups. The S-6B’s, with their more powerful engines, won the event, although the Italian entry might have placed in the event had it been ready in time. S-1595, flown by Flt. Lt. Boothman, won the Schneider race, while the companion airplane, S1596, flown by Flt. Lt. Stainforth, set a world speed record for seaplanes of 407.5 mph. These victories gained permanent possession of the Schneider Cup for Britain. S1595 currently resides in the Science Museum in London, appropriately near its descendant, a Spitfire.
There are two good references on the Supermarine Racers. One is the old Supermarine S-4-S6B Profile, No. 39, by C.F. Andrews and W.G. Cox (1965), which describes the whole series. Another is a Dulcimas publication, “Supermarine Spitfire”, a paperback by Peter Moss dating back to 1970. The Spitfire book actually contains better material, while the Profile has more drawings and photos.
The Kits of the Supermarine
The first 1/72 scale kit of the Supermarine S-6B was issued by Airfix in the 1950’s, and these can still be found at swap meets and IPMS meetings. Shortly afterwards, Frog issued a kit of the S-6B, and this was a little better in terms of detail and accuracy. Its main problems were the struts between the floats, which were actually flying wires, and the contours ahead of the windscreen, which should be faired in to a streamlined shape. For many years, these were the only kits available of the S-6’s, but recently, Pavla has come to the rescue by issuing TWO kits of the S-6. One, #72066, is a resin issue of the 1929 Supermarine S-6 Racer, covering N247 and N248. Later, they issued an injection molded styrene kit of the S-6A/B series, 72060. The moldings are very similar, and some parts appear to be common to both kits, but, of course, one is resin and the other regular plastic. I requested the privilege of building both kits side-by-side to compare them, and I really can consider this to have been a learning experience. I would suggest that anyone buying and building these kits should have considerable modeling experience, as they are definitely not for beginners.
One interesting point is that on the box of the injection molded S-6A/B kit is shown what are apparently intended for release shortly, the Macchi-Castoldi MC.72 racer and the Curtiss CR-3 racer. The Macchi was released by Delta, an Italian company in 1/72 scale many years ago, but the Curtiss has only been available from Hawk in 1/48 scale, being a vintage kit appearing in the late nineteen forties. It was actually one of the first plastic kits to appear on the market in the U.S., and was issued in both landplane and seaplane form.
The Pavla Supermarine S-6 Kit (Resin) (72066)
The instructions consist of 8 pages of approximately 5 x 7 inch paper, and include a history, sprue diagram, painting guide, and exploded assembly drawings. The drawings are clear, although there are a few confusing parts, especially with the extra short float. Painting instructions are included for two aircraft, N247 (two schemes) and N248. Rigging information is a little sketchy, so you’ll need some photos to get the wires in the right places. The decals appear to be accurate, and with some prodding, will settle down over the irregular surfaces. They are, however, labeled S-6A/B, but are actually for the S-6.
This kit consists of 27 resin parts and a small vacuform canopy, and is molded in medium grey resin. The parts come loose in the box, but were not damaged in any way. An extra float is provided for an asymmetrical float arrangement which is, unfortunately, not correct for the S-6, as it was only used on the first S-5 prototype for a short time. Part R7, a small elbow shaped scoop, goes somewhere, but I’m not sure where, as photos I have don’t show it. The cockpit interior is very tiny, with no sidewall detail, but this would be hard to see anyway. The seat, seatbelts, stick, rudder pedals, and instrument panel are nicely done.
The outline of the kit looks quite accurate, and the overall impression is a model that looks exactly like an S-6. The main problem is the location markings for the struts that the floats are mounted on, which should have some kind of pegs and holes to assure proper locations. I drilled these out and inserted a small price of plastic rod in the ends of each strut. It worked, but it took some maneuvering to get it right. The fuselage consists of two halves and a center section that is supposed to snap in place on the bottom. The problem is that the bottom section is poorly cast, and needs a lot of trimming to make it fit properly. The engine exhaust fairings just glue on to the forward cowling, and they look pretty good.
The tail unit and wings butt fit onto the fuselage, while the prop needs to be glued onto the nose.
All parts need careful trimming, and some filling is required. The instructions don’t mention adding weight to the nose for balance, but I added some lead shot in both floats and the forward cowling, as otherwise, the airplane will sit back on its tail.
The kit (both kits, actually) comes with a resin dolly and four sawhorse type braces for the floats. Each front and rear pair is identical, but the rear ones with the smaller “V” should be higher, while the front braces should be shorter to match the photo accompanying this article. Otherwise, both braces just touch the tips of the floats. The dolly has a pair of spoke wheels.
The biggest problem with this kit is the floats. The mounting struts are very thin, and with no secure method of attachment except for butting them onto the fuselage, a very weak structure results. To make this easier, I mounted the floats on the dolly with masking tape, and when they were in the right position, I mounted the struts on the airframe, measuring to make sure that the struts were in exactly the right position. With superglue, it was a rather tedious process, but once set, the structure was strong enough if you don’t breathe too hard on it.
Obviously, this model has to be painted before the floats are attached. I waited until the floats were on before putting on the decals. Then I used wire rigging on the floats and wings after removing the dolly from the plane. These wires are in some awkward positions, and the instructions are a little confusing.
Once I finished the model, I glued it to the dolly, more for stability than anything else
All in all, it makes up into a nice little model that looks the part.
The Pavla Supermarine S-6A/B Kit (Injection Molded with Resin Parts) (72060)
This kit comes in a soft box, with one sprue containing 21 parts, 8 resin sprues, and one vacuform canopy piece containing two canopies. The instructions are about identical to those of the resin kit, with a sprue diagram, exploded drawings, and color schemes and decals for three different airplanes.
I did the S-6A, mainly because I already had the S-6B #1 that I built from a Frog kit many years ago.
The thing to remember here is that this model represents two different airplanes with almost identical structures. The resin kit, the S-6, was flown in the 1929 race, and the upgrade was the S-6B, while the S-6A was a rebuilt S-6. The kit contains two propellers, which are almost indistinguishable. The only real differences in the kits are the longer floats of the S-6A/B, and external aileron and rudder balances.
This kit has a LOT of flash, and much trimming is required. Compared to the resin kit, there is more flash on most parts. The floats were warped, and had to be clamped together overnight to assure a secure joint. As with the resin kit, the center belly strip did not fit, and required a lot of trimming and filling. The floats required some sanding and filling. One of the resin aileron balances was broken off and missing and this required repair. These also need to be trimmed. The float struts need a lot of trimming, and also need rod inserts for location. They were slightly easier to install than those of the resin kit, as they could be attached with Tenax. The instructions say to weight the tips of the floats for balance purposes.
A major problem was the fact that the fuselage did not line up properly with the center belly strip in place, requiring some whittling to get the wing close to straight, and I still didn’t get it the way I really wanted it. The engine exhaust covers mount the same was as on the resin kit, and look pretty good once installed. They are, however, very slightly different from the ones on the resin kit.
Once basic assembly was done, I painted the airframe, silver and then medium blue. Then I installed the floats, again using the dolly to locate the floats in place. Thanks Pavla, for including that dolly. There is, however, no mention in the instructions on using the dolly for this purpose.
Conclusions and Recommendations
This was certainly an education, building a resin and injection molded kit of virtually the same airplane side by side. Each kit has its strengths and weaknesses, and I guess just by its vintage, the old Frog kit has been made obsolete by these issues. These kits have much more detail, but I’m not throwing away the Frog kits, as there are a couple more of these to be built to complete my collection. My gut feeling would be to say that the resin kit is better in outline, but a little more difficult to build. The Injection molded S-6A/B kit is a little easier to build, but it has more structural issues. I enjoyed building both of them, and would only recommend them to very experienced modelers. For modelers with limited experience, stay with the Frog.
While I was building these, I wondered. What would have happened if R.J. Mitchell had been asked by the RAF to develop a landplane fighter version of this airplane? It certainly would have been fast, and even with only 1000 hp, it would have been a very high performance airplane. So I took an old Airfix kit and whacked it together in a couple of evenings to see what it would look like. Who knows? Maybe history would have turned out differently.