These buoyant fixtures are low-captured & tethered lenticular aerostats, designed with multiple line restraints allowing them to rise under control from the ground to a maximum height of 20 m. They then can be used for overhead light-show displays or video projection purposes as fixed floating screens at events and/or as shelters. They may be seen from afar and viewed from the ground but are recovered to ground level when not in use for safe keeping.
The aerostats have 2 principal chambers, as follows:
- an outer torus tube chamber (like a bicycle wheel inner tube) that is pressure stabilised as a stiff chassis holding aerostat form and
- an inner main chamber bounded by upper and lower dishes affixed at tangential positions to the torus.
The main chamber isn’t pressurised, where its lower dish freely flexes up or down to accommodate contained LTA-gas volume changes.
As non-rigid fabric structures, the aerostats are partially LTA-gas inflated and then air is used to complete the inflation process and to pressurise the torus – enabling them to maintain form for atmosphere displacement purposes, thus developing excess buoyancy lifting their weight. Excess buoyancy keeps them aloft, imparting sufficient tension into their multiple restraint lines – preventing them from slackening against wind and other loads.
Projection onto the aerostat’s lower surface (an essentially large flat disk area) is best undertaken with systems on the ground. However, the projectors also can be carried by the aerostat if desired, but involves additional expense, complexity and safety aspects to be covered. The aerostat also may carry lighting and other systems (e.g., cameras and loud speakers).
Luffships Ltd (LSL) has arrangements with specialist suppliers for the aerostats/fabric facilities and ground systems production. We also cooperate with specialists for the light-show projection facilities, not part of the basic captured aerostat package.
The low captured aerostats may be used as big parasols or rain shelters (i.e., large floating roofs) with a stage below. Fitted with a skirt (an extra facility) that the aerostat raises and supports, they then may be used like marquees for many other purposes. The aerostats are provided with attachment points for such skirts, attached routinely for storm protection when held at ground level (minimising gust effects) and/or advertising banners for daylight hours. LSL also plans to integrate solar panels on the aerostat’s upper surface for power above ground.
The designs stem from mooring arrangements for similar lenticular aerostats intended for omni-directional airships and the need to develop them in an assured way through field tests before attempting free flight. The overhead captured aerostats thus were arranged as useful products for just ground use, perhaps later upgraded for dirigible flight purposes.
Designs prepared include: Mk 1 (LS-LT18) and Mk 2 (LS-LT15-V1), as below:
- Mk 1 is Ø18 m. It was produced as a test prototype called Vikki – see above photographs.
- Mk 2 is smaller (Ø15 m) to minimise cost. Its design incorporates lessons learned from Vikki. For further information, see its leaflet.
Vikki, as shown above, was designed in 2009 followed by a programme of production, inflation, assembly, training, tests/operation and qualification. The arrangements therefore are known to work. However, production versions needed reduced costs and better efficiency. LSL (under previous management) put Vikki into storage until investment for a formal certification programme and to enable further production/development was provided.
Under new management in 2018, designs for the Mk 2 version were established, yet to be produced. The Mk 2 design thus is mature but needs to be certified before it would be allowed to enter public service. Please contact us if you would like to support further development.
LSL plans to use Vikki for further purposes to train new operators and serve as a demonstrator. We plan to certify the Mk 2 design instead (including new ground facilities) and then produce series types supplied to operators for various purposes as products under lease or purchase arrangements.
The smaller, cheaper, more efficient Mk 2 design therefore is planned to be the first type for supply. It will be packaged as a turnkey system in a single container with ground infrastructure able to be transported in a van – sufficient for new operators to begin. LSL also will provide training and support as necessary. People interested to become an operator should register with us via contact.