Although little physical evidence remains these days, for 30 years Borstal was home to the factory of British flight pioneers Horace, Eustace and Oswald Short. They occupied a significant part of the Esplanade from 1915 when they established a design department there, aircraft building starting 2 years later, until they transferred their entire flying boat operations to their Belfast factory in 1946. They also had a factory at Rochester airport from 1933 until 1947, and one of the hangars now houses part of BAE Systems.

Short Brothers started out with Oswald and Eustace Short making gas balloons beneath railway arches in Battersea. In 1908, the company of Short Brothers was first registered, now with older brother Horace part of the company as chief designer. They built their first plane at their Battersea works, moving to Shellbeach, Leysdown on the Isle of Sheppey in 1909, moving to Eastchurch also on Sheppey in 1910 at the invitation of Francis McLean, a member of the Royal Aero Club who owned the rights to use Eastchurch as an airfield. During this time, Short Brothers were making Wright Flyers under license from the Wright Brothers but they soon started producing aircraft to their own designs, including the flying boats (then known as seaplanes) for which they were to become most famous.

The seaplanes built at Eastchurch had to be taken to Queenborough to be launched, being taken by barge to the Isle of Grain for testing. This involved a six mile road journey, necessitating a folding wing arrangement to facilitate this. With an increasing order book, it soon became necessary to find somewhere more suitable, choosing a area on the eastern bank of the River Medway just south of Rochester where the river was wide, allowing planes to take off to the south towards Safety Bay, where the motorway and railway crossings now stand. The first flying boats, the Porte F3 and F5, were built here, but after the end of the Great War times became hard as there were no military contracts to bolster the order book, and during 1919 they began to produce boats and bodies for buses. Orders did not pick up again by 1924 when they company went back into full time aircraft production.

Although the move to the Esplanade was to make the building and launching of the seaplanes easier, they still built landplanes, which would be transported to the airfield at Port Victoria on the Isle of Grain in order to be launched, but when this closed down they were forced to transport the aircraft to Lympne, which proved to be impractical, and somewhere closer was needed, and when Rochester Council announced they were to open a municipal airport in 1933, Short Brothers approached the council to acquire the lease, which was granted on the condition that the public flying rights were to be maintained.

Perhaps the best known of Shorts’ aircraft are the Sunderlands which were developed from the S23 ‘C’ Class, known as the Empire Flying Boats, a picture of the first of which, the Canopus, can be seen on the sign of the pub that carries its name, at the top of Cookham Hill in Borstal. The Canopus first flew in July 1936 and entered service with Imperial Airways in October the same year. The prototype Sunderland first flew in October 1937 at Rochester. A total of 721 Sunderlands were built, and the ones built for the RAF continued in service until 1959.

The Sunderlands were later developed into the Solent, initially for the RAF. The design was larger and had a longer range, and although intended for the air force, twelve were built for BOAC. The last of the large flying boats, the twelfth of the BOAC order was also the last to be built at Rochester. A further nine were built but at the Belfast factory in Northern Island.

It wasn’t all huge seaplanes, though. In the thirties there was a race to see who could deliver trans-Atlantic mail the fastest. It would have been possible for an Empire to cross the Atlantic, but only if its entire load was fuel, so the disadvantage there was obvious. However, it was also known that an aircraft can maintain flight with a greater load than is possible to take off with. Robert Mayo, Technical General Manager at Imperial Airways, proposed a composite design consisting of two aircraft. This was implemented with a modified Empire flying boat, Maia, and a smaller four engine seaplane, Mercury. The idea was that Mercury would be heavily laden with mail and sit on top of Maia. Maia would then fly to operational height and Mercury would then be literally catapulted into flight, and would then fly on to its destination. Stephen Rayner writes:

The revolutionary Short Brothers “composite” mail planes, the Mercury-Maia, were launched successfully at Borstal one afternoon in February, 1938.

My father Ewart, then a Rochester Technical School boy on the cross-country run at the old greyhound track on City Way, recalled: “We knew something was being planned, because the two planes had been flying around over the weekend. So we all stopped and watched – we had a wonderful grandstand view of a piece of aviation history.”

The British Air Ministry and Imperial Airways liked the idea and contracted Shorts, based on Rochester Esplanade, to design and build a composite unit.

…

Shorts had high hopes for this revolutionary idea – this was, after all, when Britain was an industrial nation and the Medway Towns were in the thick of it – and allowed all the staff to watch the great launch.

Workers traipsed along the Esplanade and stood on the Backfields behind St. Margaret’s Church and waited for the moment. After a few turns over Rochester Bridge, the little plane lurched and separated just near Safety Bay (now in the shadow of the M2 bridges). The huge cheer echoed across the river.”

Mercury made its first trans-Atlantic crossing on 21 July 1938. Laden with 600 lb of mail, it was launched over Foynes, on the west coast of Ireland and flew on to Boucherville, Montreal, where it landed 20 hours and 20 minutes later. On 6 October that same year, Mercury established a long-standing record for an unbroken seaplane distance flight from Dundee to the Orange River, South Africa – a distance of 5,997 miles. Unfortunately, although Shorts had high hopes for this method of air mail delivery, the Second World War intervened and Mercury was broken up and Maia was destroyed by enemy action in 1941.

Today, Shorts still exist as a company, but are part of the Canadian Bombardier Group, and no longer build complete aircraft but large structural components for a number of different aircraft. The last complete aircraft built by Shorts was a version of the Brazilian Tucano, modified for the RAF, licensed from the Embraer company. The company is remembered in Rochester in the roads branching from Shorts Way, a short stretch of road that reaches from the end of the Esplanade up the hill to Borstal Street, with names such as Mercury Close, Sterling Close and Sunderland Close, and a development of luxury flats on the Esplanade known as Shorts Reach. The old launch ramp from the Esplanade into the river is still there, but it is in an advanced state of decay.