From chalk lines to immortality – the Sopwith Pup

It all started with some chalk marks on the floor of the Sopwith Aviation Company factory. Harry Hawker, Sopwith’s test pilot, wanted a sporty runabout for his personal use, and at this stage of the First World War, the company could well justify it. The rough chalk outline was examined by T.O.M Sopwith, Fred Sigrist and others, and it was generally agreed that it looked promising. The date was 1915, and Sopwith’s quickly put together the little biplane with its single-bay wings using wing-warping for control, 50hp Gnome rotary engine, and distinctive ‘Sopwith’ fin and rudder. It seemed that this aircraft – often referred to as ‘Hawker’s Runabout’ – owed something to the company’s highly successful ‘1½ Strutter’ two-seater, and it certainly had excellent handling characteristics.

It became obvious to the company that a developed version of the ‘Runabout’ could be a useful ‘scout’ (the early name for a fighter). Consequently, Herbert Smith, the chief designer, lengthened the fuselage slightly, and increased the wingspan and area substantially, so much so that the ‘cabane’ struts between the fuselage and the upper wing were no longer vertical, but inclined at an angle of about 45°. The engine was changed to an 80hp Le Rhône rotary, and the initial chosen armament for the machines was a single Lewis .303″ machine gun, mounted in front of the pilot at an angle, so as to fire through a cut-out in the center of the upper wing. The company name for this aircraft was the ’80 hp Le Rhône Single Seat Biplane’. Since Sopwith’s were main aeroplane contractors to the Admiralty, it became apparent to their Lordships that the Royal Naval Air Service needed just such an aircraft to replace the Nieuport 11’s which the French had supplied them with. The Sopwith’s structure was light and strong, based on a box of four wire-braced ash longerons strengthened by spruce spacers. The fuselage was fabric-covered, apart from the front section which was clad with curved aluminum panels. The wings had spruce spars, carefully lightened by being drilled out where possible; indeed, every possible way of lightening the aircraft, whilst still maintaining structural strength was undertaken, so that the maximum performance could be gained from the 80 hp that was available.

Testing of the prototype at Upavon in March, 1916 caused the Royal Naval Air Service to order two more prototypes. A production order quickly followed, and the first machines reached Naval “A” Fighting Squadron at Furnes, in West Flanders, Belgium. Soon, No. 8 (Naval) Squadron was the first unit to be fully-equipped with the new fighter, and pilots began referring to it as the ‘Pup’, because ‘it looked like a Sopwith 1½ Strutter had had a Pup’. The Admiralty was NOT amused, and official orders were issued that it was to be called the Sopwith Admiralty Type 9901, or Sopwith Scout. Pilots being pilots, they just ignored this, and Sopwith Pup it became.

The little biplane climbed like a homesick angel, and had beautifully light controls, although it was a touch unstable fore and aft. You could loop a Pup immediately after take-off – not only that, but it would carry on gaining altitude in a series of continuous loops! The higher it climbed (and its ceiling was 18,000 ft), the greater its advantage over the German Albatros and Halberstadt fighters became, so much so that it could complete two 360° circles whilst the German opposition was turning once. This supreme manouverability, and climb rate, meant that No. 3 (Naval) Squadron alone piled up a score of 80 enemy aircraft against only 9 losses between February and June, 1917. If necessary, the Pup could always break combat by climbing away from the opposition. The RNAS was so desperate for Pups that it agreed to salvage 80 hp Le Rhône engines from crashed Nieuports – supplemented by whatever engines that could be wheedled out of the French naval authorities – overhaul them in their Dunkirk workshops, then ship the ‘new’ engines to Dover, where they could be fitted to ‘bare’ Pup airframes!

The Royal Flying Corps wanted the Pup as soon as it saw what it could do, but Sopwith’s were committed to yet more Admiralty orders, plus orders for the new Sopwith Triplane, so contracts for the Pup were placed, instead, with both the Standard Motor Company Ltd (later to built the de Havilland Mosquito in WW2) and Whitehead Aircraft Ltd. The armament for RFC aircraft was changed to the standard Vickers .303″ machine gun mounted centrally, and synchronized to fire through the propeller, although some did have special mountings attached to the inter-wing struts for a total of 8 Le Prieur rockets. These electrically-fired projectiles, with their long sticks like ‘bottle rockets’, were effective against observation balloons (and – theoretically – airships) but they were wildly inaccurate, and had to be delivered in a steep dive at close range (c. 100 yards). No. 54 Squadron was the first Royal Flying Corps unit to take Pups to France, arriving during Christmas, 1916. It was rapidly followed by No. 66 and 46, just in time to take part in the stiff fighting over the Arras battlefields.

Inevitably, technology overtook the little Pup, especially since it had only half the firepower of every enemy it faced, and half the horsepower. However, it still gave excellent service during the Battle of Ypres and at Cambrai, where British Mark IV tanks tried to make a break-through, but failed. Since few fighters performed so well at 15,000 feet and over at this stage, the RFC worked out that the best composition of a ‘mixed’ offensive patrol over the German Lines was a formation of de Havilland DH.5’s at 9,000 feet, one of Bristol F.2B two-seat fighters at 12,000 feet, and ‘top cover’ given by Sopwith Pups at 15,000 feet. A few pilots with No. 54 Squadron tried to boost the Pup’s firepower by adding a Lewis gun above the top wing, but the extra weight was just too much for the Pup, and performance suffered.

With the withdrawal of the Pup from frontline units on the Western Front in late 1917 (it was, mostly, replaced by the Sopwith Triplane in RNAS, and the Camel in RFC units), there was still work for it to do. Some Home Defence Squadrons were formed in England on the Pup during the summer of 1917 (No. 61 and 112 Squadrons) in order to join other units in an attempt to stem the growing number of German Gotha bombers which were penetrating as far as London – the ‘first’ aerial Battle of Britain. Some of these Pups were fitted with Gnome Monosoupape engines of 100 hp, and the lower section of their cowlings removed to improve cooling. The effect of this upgrade was to add about 1,000 feet to the Pup’s ceiling, and improve the climb rate still further. Even when the Pup was no longer being used as a fighter, it kept being built! It turned out to be an ideal ‘fighter trainer’. Some of my American friends might be looking at the above photograph rather quizzically, and be thinking, ‘Now where have I seen that before?’ If I said, ‘Thomas-Morse S-4’, you would not be surprised to find out that the ‘Tommy’ was not just powered by an 80 hp radial like the Pup, but was designed by Benjamin D Thomas, who had formerly worked for the Sopwith Aviation Company! Production of the Pup (as a trainer) continued right up until the end of the war in November, 1918, for a total of at least 1,770 aircraft.

The was one more starring rôle for the magnificent Sopwith Pup. The Royal Navy was amongst the first in the field of sea-borne aircraft, with several seaplane-equipped carriers, such as HMS Campania and HMS Manxman. It was decided that the Pup would replace the Sopwith Baby seaplanes in these ships. As well as this, the Pup proved capable of taking off from tiny platforms mounted on top of the heavy gun turrets of the Royal Navy’s light cruiser squadrons. Unfortunately, the Pup usually had to ditch alongside a friendly ship at the end of the mission, if out of range of land. HMS Furious, a converted light cruiser was fitted with a 228 foot ‘flying deck’ ahead of its superstructure, on 2nd August, 1917, Squadron Commander E. H. Dunning overtook the ‘proto-carrier’ and crabbed in to one side, just above the Pup’s stalling speed of 35 mph, to made a successful landing. He was aided in this by having the waiting handling crew grab onto leather straps which had been fixed under each lower wing. Having performed the world’s first landing aboard a warship under way, this brave officer repeated the feat; unfortunately, when he tried a third time, on the 7th August, he was killed. The technology was ‘improved’ by fitting some Pups with curved wooden skid undercarriages (they looked like rocking horses), and building an aft ‘landing deck’ on the Furious, giving a landing run of 284 feet. The skid-equipped Pups landed easily on this, and it was found that they could take off and land quite well from grass airfields, too. The Scottish firm, William Beardmore and Company, which were already building the Pup under license, designed a navalized version called the Beardmore WB.III, with folding wings and an undercarriage which could either be jettisoned or folded; about 100 were built for the Royal Navy.

The aircraft you can see above is the Shuttleworth Trust’s superb Pup, ‘9917’. This started out as one of ten Sopwith Doves, a post-war two-seat conversion for use as a civil aircraft. It was acquired by Richard Shuttleworth in April, 1934, and ‘deconverted’ to Pup status, as you can see. This is a magnificent restoration, and even includes the launching rails for the Le Prieur rockets – the black metal fittings on the outside of the interplane struts (I have seen the Pup fly with dummy rockets fitted).

The Sopwith Pup, whatever their Lordships of the Admiralty wanted to call it, was truly a wonderful flying machine.

2 comments on “From chalk lines to immortality – the Sopwith Pup”

  1. “…climb like a homesick angel…” What a wonderful phrase 🙂


  2. You’ve done it again! There is a “Tommy” in the National Naval Aviation Museum in Pensacola FL — whether it is an S-4 or S-5 I am not sure but there is a photo of it in the blog. I see how these aircraft are so similar — but only after you made the observation 😉


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