Introduction

It was in early 1972 that a company by the name, Mercantile Airship Transportation Limited ( MAST ) formed for the development of large rigid airships. Major M.W. Wren was the Managing Director. In 1978: Thermoskyships Limited ( TSL ) formed in the Isle of Man and acquired MAST in early 1979. Major M.W. Wren was the Chairman and Chief Executive. As a Public Limited Company it raised £2.4 million on the London Stock Exchange towards the development of an unconventional rigid airship.

The company had been looking at a series of design concepts, one being the design concept of lenticular airship design (dubbed flying saucers) which included the proposal of using heating of the lifting gas to control buoyancy. The idea that there was a place for airships to fulfill a transportation gap between fast jet air transport, and slower sea transportation. It was then that Malcolm Wren and Roger Munk, realised the value in joining forces, as Munks Airship Developments had already proved the concept of smaller airships with the AD 500. The resulting merger of took place a year later on 29th May 1980, with Thermo Skyships purchasing the company for £1 million. The merger saw the prospect of putting both a large rigid and a smaller non rigid design airship in to production.

The resulting merger, in July 1980, Thermo Skyships name was changed to Airship Industries Ltd.(AI). During the approximately two-and-a-half years the Thermo-Skyships team spent at AI, it proposed several abortive designs, for non-lenticular rigid airships. Much money had already been put in to the Thermo Skyship company and it had grown to a 30 strong design team. The idea being that the non-rigids AI designed ships would provide an income to build the larger and now ellipse shaped 100 seat passenger ferry airship for intercity use. However it soon became clear that the two airship projects could not share the same design lines and concepts.

Wren Skyships Limited

A de-merger from Airship Industries in the 1982 saw the split away from the group of a smaller company headed up by Major Malcolm Wren, and the creation of Wren Skyships Ltd. the reason for this was due to the different design approaches for airships undertaken by both organisations and the structural design question of airships. Wren Skyships Limited was formed from key members of the rigid division of AIL and began operating with Major M.W. Wren as Chairman and Chief Executive, P.W.C. Monk as Technical Director and J.A. Dean as Chief Accountant. It took over the Isle of Man premises of AIL and had two subsidiary companies :-

a) American Skyship Industries Inc., formed in July 1982 and based at Lansdowne Airport, Ohio.
b) New Zealand Airships Limited

Original project ideas from the company, such are the R.30, which was a 1.1 million cubic feet airship, as a design response to the US Coastguard requirements during the U.S. President Jimmy Carter administration. The hull would be of aluminum alloy,Alelad 2024-T3 with a thickness range of .010 to .025 in. Supported by 24 longitudinal and 14 ring frames two of which would be heavy duty to support engines and loads. It would not have individual gas cell, the metal hull covering being itself the gas container for simplicity and weight saving.

On operating and flight costs, the R.30 as a cargo carrier was claimed to be superior to a Boeing 737 aeroplane for ranges up to 600-700 miles, while an early 1980's study of a passenger version between Paris and London city centres at 45 minute intervals using (using 6 airships), showed taking 30% of the existing traffic and making 40% profit after allowing £10m each for the two city centre terminals.

Studies were also made of the R.30 in a naval role, usually regarded as a non-rigid reserve. The view that non-rigids are cheaper to produce than rigids and were starting to prove themselves at the time. Another advantage of a non-rigid airship was that they could be manufactured and assembled in different places removing a possible constraint of the need for hangar space. The idea of a "metalclad" airship was to improve on the concepts gained by by the US Navy with their non rigid experience.

The Chief Designer, Mr Pat Monk, (not to be confused with Roger Munk of Airship Industries) joined the company in 1980 from New Zealand Aerospace, and the Wren Skyships Design team, engaged in designing a sophisticated, metal clad airship, the RS.1.

In 1982, the R.30 concept was later redesigned as the RS.1 and was to be 420ft long with a maximum diameter of 83.25 feet. Two balloonets would give it a pressure height of 5,000 ft, and hold a 1,592,000 cubic ft of gas. The RS.1 would be powered by 4 Airesearch TPE 331-15 turboprops. The design speed at flying at 5,00ft would be 149.3 mph, or at sea level cruising with 3 of the 4 engines at 121 mph. The gondola would be be able to carry out as a multi configurable layout, being some 120ft long and 17ft wide.

At the time the RS.1 was designed as much larger than the Airship Industries Skyship 600, it's contemporary non rigid ship, and similar in concept to the successful US Navy type ZMC2. In 1987, the concept RS.1 proposed as a 25 tonne payload ship for surveillance, search and rescue,resource development and relief work.

The RS.1 concept had a very interesting vectored thrust control, with the power unit being housed in the stub of a short stub wing, which would turn through 180 degrees to assist with control on takeoff and landings. As the stub wing could only rotate through 180 degrees in the forward, up or down position, it was designed with a "bow thruster" in the nose of the ship which would provide more control of the airship.

The tail configuration was decided as the X fin for more control.

RS.1 Multi Role Configuration

A number of configurations were proposed for the RS.1 and these included:

Car Ferry:

including an ingenious "roll on roll off" configuration consisting of "clam shell doors" both forward and aft. The vehicles would access via a ground based ramp, and then be parked in on the vehicle deck. The passengers would then move to the seating area, consiting of 80 seats, positioned 40 per side of the gondola. There would be toliet and galley provisions available. In this configuration the flight deck would be separated and be re-positioned above the front accommodation access doors.

Maritime Patrol:

as a long range and endurance patrol craft co-operating with regular Naval and Military forces. The gondola would carry a an all weather seaboat tender for direct intervention at sea. As a search and rescue patrol craft, with the ability to accommodate 200 survivors. The gondola would have a full aray of equipment for a full maritime patrol crew. The gondoal would be able to lauch a boat through doors on the floor of the rear boatbay compartment. At the rear end of the gondola would be a large rear observers position.

Passenger Cnfiguration:

would be a full seated passenger only configuration with 180, 148 economy seats of which 32 would be assigned as a spacious first class cabin with larger seats. Simliar to a plane, there would be overhead storeage lockers and also the rear of the cabin was assigned as a baggage storeage area. Additional passenger configuration layouts with a bar and viewing area were posible

Other Configuration Concepts:

Many other possible configurations were shown in concept art of the day with:

• Medical configuration
• Ship to shore cargo transfer
• Remote freight delivery

As with later techincal studies, it is uncertain how successful these later options would have been with the ballast and transfer of weight options and controls.

Wren Skyships becomes Advanced Airship Corporation (AAC)

At a board meeting on 16th September 1987, Major Malcolm Wren stepped down as executive chairman from the board due to health issues, and Brigadier John Hooper was appointed to as Chief Executive of the company. In 1987, Wren Skyships Limited was then reorganised and became the Advanced Airship Corporation (AAC) which was formally incorporated in February 1988. The RS.1 concept and project was finally cancelled.

Wren Skyships in Fiction

The story of the later RS.1 airshp, and a fictional character named "Major Malcom Wren" was captured in the 1984 novel by John Gordon Davies called "Seize the Reckless Wind", and follows the adventures of a man building a new airship named the "Rainbow" at Cardington, along the lines of the RS.1 airship, and ensuing adventures and daring rescue.