Eduard 1/72 Sopwith HS

Designed by Harry Hawker and Fred Sigrist, the Sopwith SS, nicknamed “Tabloid”, first flew on 27th November 1913, as a side-by-side two seat sporting aircraft. Powered by an 80 h.p. Gnome rotary engine, it's performance was so good that a single seat version was ordered for the R.F.C. and the R.N.A.S. It was one of the very first mass produced military aircraft.

In February 1914, T. O. M. Sopwith started planning a float-plane version to compete in the upcoming Coupe d'Aviation Maritime Jacques Schneider, later known as the Schneider Trophy race, to be held at Monaco on 20th April that year.

Fred Sigrist made only minor changes to the SS, adding a small triangular fin and enlarging the rudder. A 100 h.p. 9 cylinder Gnome Monosoupape (one valve per cylinder) engine was fitted, the first such engine imported into Britain. Floatation gear was designed by Sidney Burgoyne, a large central float was added, with small floats under the wings, and a tail float. 

The aircraft, called the Sopwith HS, was completed on 31 March 1914, and transported to the Hamble river near Southampton. Harry Hawker, Sopwith's usual test pilot, was in Australia trying to sell more Tabloids, so Howard Pixton, who had joined the company a few weeks before, attempted the first flight on the evening of April 1st. On opening the throttle, the HS nosed in and tipped onto it's back, dumping Howard into the river. After waiting for the tide, the aircraft was recovered at 2 o'clock the next morning and returned to the factory for repair 

Running out of time, Sigrist and Burgoyne redesigned the float system for twin floats. The large float was sawn in two, and sealed, the wing floats were removed. A simple strut arrangement was used to support the floats. Early in the morning of the 7th of April, the aircraft was taken to the Thames, where brief flotation tests were done. Flying as prevented by Thames Conservancy river wardens, an early attack by greenies. The next morning the aircraft was taken further down river, outside the Thames Conservancy area, and a brief test flight was completed, the only problem being a misfiring engine. The aircraft was then returned to the factory, dismantled and packed for shipping to Monaco.

The Sopwith team arrived at Monaco on the 15th of April, the aircraft was released by customs the next day and quickly assembled. The Gnome engine was rusted from it's swim a few weeks before, and needed a thorough overhaul. The aircraft was ready to fly on the 18th, but rough weather led to a postponement until the 19th, the day before the race.

After the test flight the propeller was changed, and an extra six gallon fuel tank was fitted. Some of the chassis rigging wire was replaced, as it had stretched. This is very obvious in one of the photos of the HS on the beach at Monaco, the float rigging wires are very slack.

The race, really a time trial, was held over a 10km triangular course, 28 laps being required. The first competitors started just after the gun at 8am. Pixton started at about quarter past the hour. The Sopwith HS had no problems completing the course, other than the engine starting to misfire on the 15th lap, so was running on 8 cylinders for almost half the way. Pixton completed the course in a 2 hours and 39 seconds, with an average speed of 139.6 kph, (86.78 mph) which included two compulsory downwind touchdowns. He then did another two laps of the course, setting a float-plane speed record over a 300km distance.

Of the other competitors, Lord Carberry, flying a Deperdussin, only completed a single lap. Gabriel Espanet in a Nieuport dropped out after 17, and Adrien Levasseur, also flying a Nieuport finished on lap 18. The only other competitor to finish was the Swiss Ernest Burri, flying a Franco-British Aviation Co. FBA type A flying boat. He took an hour and 23 minutes longer than the Sopwith to complete the course, stopping for fuel on lap 24 didn't help. 

The result was a emphatic win for the Sopwith HS floatplane. When Jacques Schneider congratulated Howard Pixton, he offered a glass of champagne, Pixton declined, saying he would prefer a Bass (beer). Sopwith went on to build 160 “Schneider” float-planes, based on the HS, for the R.N.A.S., some of which were still serving in 1918.

A Sopwith Schneider, re-engined with a 450h.p. Cosmos Jupiter radial, was entered in the 1919 Schneider Trophy race. Conditions were so bad, with thick fog, that Harry Hawker did not start the race.

Released by Eduard, kit 7201 represents the military version of the “Tabloid” float-plane, known unofficially as the Sopwith Schneider. Judging by the kit number, this might be the first 1/72 kit Eduard produced.

There is a single moulded sprue in soft grey plastic, with 20 parts, crudely moulded with large gates, lots of flash and stray lumps and bumps. An alternate fin and rudder part is supplied to allow a late built “Schneider”. There is a very exaggerated hills and valleys fabric effect on the wings, but little other detail.

Somewhat making up for the horrible plastic parts, there are three frets of etched brass, with detailing parts for the cockpit, engine, and various other bits. One fret has all the struts. A small film sheet has an instrument panel, which is to be laminated to the brass part.

The decal sheet, printed by Propagteam, has 14 roundels in different sizes and styles, two different fin flashes and four sets of serials. The decals are bright and in good registration, though the colours seem a little transparent. I didn't use them, so cannot comment on their effectiveness. The instructions are several folded sheets, with 12 stages, and detail early and late rigging. They have profiles for four marking versions.

Some minor changes are needed to convert the model into a HS. Fill the aileron gaps and gun port on the wings, change the shape and mounting of the tail-float, alter the float struts, and make new markings.

 Started with the cockpit, which was entirely brass, with a floor, seat, controls, three part instrument panel, and seat-belts. All the usual stuff. Hold on a bit, dry fitting revealed the floor and instrument panel were far too wide to fit inside the fuselage. To avoid having to shave the plastic to paper thickness, I abandoned the whole thing and painted the inside of the fuselage dark grey, joined up the fuselage halves and left it at that. Despite sanding the mating surfaces, there was still a gap to deal with along the entire fuselage, but unusually there was no step to deal with, the height of the halves being the same.

Next step was the engine, the plastic lump needed a lot of clean up before it was usable, then I added two brass bosses, and 9 of the 18 supplied tiny brass push-rods. Only one per cylinder, as the engine is a Monosoupape. The instructions got this a bit wrong. Some painting and dry brushing with Mr Metal Color, Aluminium and Iron, brought out the detail, most of which is completely hidden by the unusual bull-nosed cowling, which has a badly fitting brass plate on it's underside.

The wings needed a bit of work. First filling the engraved ailerons, the Tabloids and early Schneiders were wing warpers, and didn't have any ailerons. The instructions suggest binding the gaps for an early version. I filled the gun port in the upper wing with a small piece of card, and more putty. The wings then got a good sand to reduce the 'hills and valleys'. The wings probably only looked that saggy when the plane was recovered from the Hamble. The lower wing was a poor fit to the fuselage, needed a bit of hack and slash to get it to fit, and a lot of filling to cover the resulting gaps.

I removed the elevator from the tailplane, and re-attached it hanging down. The pictures of the HS when not flying, show the elevator drooping. The tailplane and early version fin was then attached to the fuselage, with a bit more filling needed.

I assembled the main and tail float halves, the fit on the main floats was not good, with a large hollow needing filling along one of the joints. The tail float was very much the wrong shape, photos and plans of the HS show the float is tear-drop shaped in plan, and rectangular in elevation. A lot of sanding, and some card and filler, fixed that. The tail float was then attached directly to the fuselage.  

 This seemed a good point to paint the model, the cowling and forward part of the fuselage was painted with Mr. Metal aluminium then masked. Did the upper deck with Tamiya flat earth then clear orange to represent varnished plywood. The rest of the airframe, including the still separated upper wing and main floats was painted XF-57 buff.

Drilled out holes for the brass struts, there were only tiny dimples moulded into the wing surface. Bent and added the inter-plane struts, then the upper wing. While it was flexible, I aligned it with the plans to get the gap and stagger right. The cabane struts were too short, by about 4mm, so were replaced with thin plastic strip.

Assembled the main float structure, again using the etched brass struts provided. The kit supplied 'N' struts for the main legs, correct for a Schneider, but not for the HS, so the diagonal leg was cut away. The slots in the main floats were then filled and smoothed over, hiding the joint. The float assembly was joined to the fuselage and aligned while still flexible.

Just about to start rigging, when I noticed that the HS, unlike the later Schneiders, had the float cross struts proud of the float, not recessed. Looks just like a plank laid across the top. Chipped off the paint and superglue, then fitted an Evergreen strip that looked about the right size.

The brass struts looked very two-dimensional so I ran a bead of medium thickness slow superglue down both sides of each strut. Surface tension was enough to pull the bead into a reasonable shape, thin along the edges and thicker down the middle. Painted the struts Tamiya XF-68 NATO brown, then gave them a coat of X-26 clear orange.

The prop, with a tiny brass boss, was painted XF-9 hull red, then over-coated with X-24 clear yellow, just to make it slightly different to the struts. I used some rod to attach the prop to the engine, nothing was supplied with the kit. Photos show the prop to be well forward of the cowling, a bit of trial fitting was needed to get it looking right.

The HS had simple markings, A Sopwith logo on the fuselage sides, and the race number, 3, on the tail. Using the draw program that came with Open Office, I picked similar fonts and drew up the markings. After the usual trial and error, I got the size about right, and laser printed the markings onto Microscale clear trim film. As the markings were black text, not pictures, there was no problems with pixelation. 

I gave the model an overall coat of floor polish to help the decals. It looked much better slightly gloss, so I gave it another coat over the decals. I intended the model to represent the Sopwith HS on the 20th April 1914, the day of the race. As it had only been assembled a few days before, and flown once, I did not do any weathering, other than some oil staining under the cowl.

When it came to rigging, I used Uschi standard size rigging thread (0.005 inch o.d.) for the cabane, inter-plane and control wire. For the twinned flying wires, landing wires and the floats, I used smoke coloured invisible thread, not sure how thick it is, but it's a lot thicker and easier to see and handle than the Uschi!

A number of brass control horns were supplied, and added as required. A long and tedious job, about 30 rigging wires at about 15 minutes each, and another couple of hours for the control wires. I can only do it in short shifts, looking at and handling invisible threads, through an Optivisor makes me cross-eyed. The rigging adds a lot of strength and rigidity to a biplane model, and is well worth the effort.

A modest conversion to produce an interesting aircraft, the first British Schneider Trophy winner. It was a difficult and challenging build, small size, badly fitting parts and general fragility meant that a lot of time I was doing repair work, rather than progressing. The build took eight months, significantly longer than the two months it took from concept to winning the race. Try it, if you want to stretch your skills.

Fortunately, a number of high quality photographs of the HS were taken at Monaco, flying, on the water and the beach. These photos formed the best reference for the model. 

C. G. Grey, Sea-Flyers, Faber and Faber, London, 1942

Owen Thetford, British Naval Aircraft since 1912, Putnam, London, 1958.

Malcolm Hall, Sopwith Aviation Company, History Press, Stroud, 2011

Ralph Pegram, Schneider Trophy Seaplanes and Flying boats, Fonthill, England, 2012

http://en.wikipedia.org/wiki/Sopwith_Tabloid

http://en.wikipedia.org/wiki/Gnome_Monosoupape

 Peter Burstow

December 2014