Seymourpowell recently unveiled its Aircruise concept, which it is pitching as a clipper in the clouds and a hotel in the sky. You see, slow is the new fast:
Nick Talbot, design director at Seymourpowell explains, “The Aircruise concept questions whether the future of luxury travel should be based around space-constrained, resource hungry, and all too often stressful airline travel. A more serene transport experience will appeal to people looking for a more reflective journey, where the experience of travel itself is more important than getting from A to B quickly.”On Aircruise, it is the very abundance of time and space that defines the luxury experience. In a world where speed is an almost universal obsession, the idea of making a leisurely journey in comfort is a welcome contrast. Talbot explains, “The physics of the airship requires a gigantic volume of lifting gas, yet simultaneously demands a relatively limited amount of weight. This allows for a potentially large amount of space with relatively few people onboard — a luxury for any traveller.”
None of this is new, of course — airships have always been good for slowly moving a large volume but low weight — but now it has an environmental spin. The technical details are interesting:
From the docking rig at the base to the tip, the ship is 265 metres tall. Hydrogen, the lightest gas, is used as the lifting gas, and is capable of lifting around 1.2 kg per cubic metre of volume. Large PEM hydrogen fuel cells will provide on board power and some drinking water.The volume of the main envelope in the ship is calculated at 330,000 cubic metres, which equals 396,000 kg of available lift at sea level (1,000 kg = 1 Tonne (t)).
Estimated weights:
Primary structure, envelope and systems [270 t] around the same weight as an airbus A380 super jumbo, empty
Consumables, water, ballast etc. [20 t]
People (estimate max 100 people on board) [15 t]
Control deck and staff (20 staff) [6 t]
Bar/Lounge/communal zone fit out [15 t]
4 Duplex apartments at 5 t each [20 t]
Penthouse apartment [12 t]
5 smaller apartments at 4 t each [20 t]
Total load factor [378 t]
Available lift excess is therefore 18-20 t or 20,000 kg of lift.Part of the renewed interest in airships derives from advances in materials, structures, stabilisation and clean propulsion technologies. Utilising composite frames and fabrications, lightweight semi flexible structures can be built at large scales. Although large, this is nevertheless a semi rigid ship, the primary tensioned structure consisting of 8 vertical composite lattices supporting four main flexible envelopes, which contain 330,000 cubic metres of hydrogen gas. Lower decks are ‘hung’ off these primary supports.
Each of the 4 external envelopes contains modular self-sealing lifting bags, minimising the incidence of bag rupture and ensuring safe flight even with a major external skin rupture.
Automatic stability thrusters and altitude control using automatic adjustment of the gas density ensures a smooth ride compared to previous airships. Although still susceptible to storms and very poor weather, advanced weather radar and weather prediction systems allow the ship to route around major problems.
Despite the perceived risks, hydrogen is used for its inherent lifting efficiency and as a power source. Flexible photovoltaic (solar panel) cells cover the upper part of the envelope, augmenting the primary power generation, in this case from fuel cells. Large surface area PEM fuel cells generate the primary power for on board systems and turn low speed compressors located in the mid section of the ship. This compressed gas is ducted to provide directional thrust and auto stabilisation. Compressed hydrogen stored in parts of the main structure provides fuel for longer ranges and by venting to the envelope or re-compressing these volumes, altitude stability is achieved.
By combining the lifting gas and the fuel for thrust the overall weight of the ship can be minimised, whilst ensuring a silent, pollution free passage. Water vapour is harnessed to augment on board potable water.
The service ceiling is limited to 12,000 feet, given the attenuation of the atmosphere (the hotel is not pressurised) and the limits of gas expansion within the envelope. If however, there are specific locations of interest en route, the ship can drop down to within a few hundred feet of the ground.
Cruising speed without tail or headwind is 100–150 km/hr. This equates to journey times that are appropriate to the cruise experience: London to New York in 37 hours; Los Angeles to Shanghai in 90 hours.
Six-flight crew will include two flight engineers, and will fly the ship in shifts, given the likely cruise durations. 14 support staff will run the hotel experience for the guest passengers.