| Aerofreighter - Liberty Class | |
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| Tweet Topic Started: Oct 31 2009, 10:31 AM (3 Views) | |
| Alfegos | Oct 31 2009, 10:31 AM Post #1 |
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LIBERTY SERIES Introduction The Liberty series is an older, mainstream series of airships used for standard lift operations. Originally in 1962, the Liberty 100 and 400 were the only intended craft for production, the 100 being a smaller short-range hauling craft and the 400 being a heavier mid-range lifter for inter-regional transport. Since then, further airships have been introduced, with modifications enhancing performance and a wider variety of airship size being provided on this popular product. All models listed are ones currently on offer for commission by Alfegos Aeronautics, with older models likely to appear as surplus with details supplied. Superstructure The modern liberty series is cheap to produce due to the modular nature of the internal framework: the internal cylindrical section can be divided into large 25m long units across the entire unit, prefabricated and bolted into place with additional ship-length support beams with the ability for quick construction at a lowered cost than constructing the whole unit. Additional length in different models is able to be provided by insertion of further framework units in the centre, adding length up to the maximum 525m-length model. The framework is made from a mix of aluminium and CFRP beams configured to provide a rigid skeleton, bolted and welded together and intersections, with aluminium working in tension and CFRP working in compression. All beams are coated with a thin plastic anti-corrosion film. Additional strength to the structure is provided by the use of steel cabling over major stress points. The airship cell system is constructed from prefabricated 15mx15mx15m Aerofilm cells, stapled onto the supporting beams and heat-sealed to each other. The majority of cells are designed for the holding of helium, with a central region of the airship (varying from airship to airship in size) dedicated for the holding of fuel gas for the engines. Fuelling is provided by PVC piping for the helium cells under low-pressue filling, and coated steel piping for the fuel gas cells and high-pressue sections of the helium network. The exterior of the airship is covered with an Aerofibre envelope, stapled to the structure and providing standard protection from the elements and heat changes. The airship utilises the control gondola for both crew and for fuel systems, the region above enclosed inside the airship envelope by a 2-metre extension into the airship above, to provide protection to the gas systems, and quick access in the case of maintenance being necessary. This also reduces the need for internal walkways within the airship, being limited to ladder-style mountings on major beams for access to damaged cell regions and to points on the exterior. The control gondola is manufactured from a three-layer aluminium/insulation cavity/CFRP panelling system, used for both external and internal division. This is mounted upon a cage-style skeleton to provide support to the gondola, externally mounted as an 'exoskeleton' to increase internal floor space. This extends up the walls, but does not include the roof of the upper section. Viewing ports in the gondola are manufactured from triple-glazed polycarbonate panels mounted upon the skeleton. Cargo gondola options are discussed later. Propulsion All models utilise fuel gases as main fuels, held within the airship gas cells to provide extra buoyancy. These may be either Methane, Aergas mix (3:2 methane to hydrogen), Syngas or Acetylene. Methane is used as standard to provide the longest range for the airship, with Aergas used to provide extra initial lift in airships and often used with heavier loads or in mountainous regions. The fuel capacity of the airships is detailed with each one. Fuel is removed from the cells via a primary pump, designed to deflate the cells uniformly to prevent rupture. This is mixed with air before being pumped at 1.2 bar into the engines. A 'reserve' of fuel is kept along with the fuel pump unit, in the form of 10x1m^3 cylinders pressurised to 400 bar working pressure. This is pumped into the air/fuel mixing unit under 1.2 bar, after passing through a two-stage regulator. Engines are mounted externally on the cargo gondola, that providing the largest amount of space. Different models have the ability to hold different numbers of the same engine, the AAe-AL15k 'Turboflow' turbojet, mounted on a vector mount allowing for angles of between +20 degrees and -60 degrees of thrust, the entire turbojet unit moved into position. Helium gas movement is controlled via cell region, gas levels increased or decreased via two methods: the movement of helium between cells and the reserve tanks, and by the mixing of helium with air in ballast cells, decreasing cell lift. The former is used for the control of the pitch and roll cell groups (around the sides and in the two ends), whilst the latter is used with the majority of the lifting cells. An onboard reserve of helium is kept in 10x3m^3 high pressure cylinders operating at 250 bar average, a pump unit located there for the compression of gas from the airship control cells. Crew & Crew Amenities The airship crew for most is recommended to twelve airmen and two officers, in addition to two engineers (up to three for longer-haul flights). The airship gondola is commonly divided into three sections for the crew, with the bridge and equipment store needing no explanation. The crew section is designed for mixed role sleeping and recreation, with three-tier bunk units provided for sleeping and sound-proof screening available between the sleeping area and the communal messing/recreational area. The unit may also be provided with a chemical toilet, with limited capacity for the onboard crew. Water is piped into the messing area, with 'grey water' being recycled via a charcoal filter system for use in washing. Liberty 125 Length - 350m Diameter - 60m Volume - 933 000m^3 Mass - 180t Control Gondola Mass: 16 tonnes Control Gondola Length: 14m Control Gondola Width: 5m Control Gondola Height: 3m Raw Helium Lift - 1100t Maximum Helium Payload - 850t Fuel - Gaseous (see note in 'Propulsion' Section) Fuel Capacity - 33 750 m^3 Maximum Engine Speed - 100km/h Range - 8000km Service Ceiling - 5500m Liberty 200 Length - 400m Diameter - 60m Volume - 1 074 000m^3 Control Gondola Mass: 18 tonnes Control Gondola Length: 15m Control Gondola Width: 4.5m Control Gondola Height: 3m Raw Gas Lift - 1280t Maximum Helium Payload - 1050t Fuel - Gaseous (see note in 'Propulsion' Section) Fuel Capacity - 38 000 m^3 Maximum Engine Speed - 110km/h Range - 8000km Service Ceiling - 5500m Liberty 300 Length - 450m Diameter - 60m Volume - 1 215 000m^3 Control Gondola Mass: 10 tonnes Control Gondola Length: 14m Control Gondola Width: 4m Control Gondola Height: 3m Raw Gas Lift - 1458t Maximum Helium Payload - 1150t Fuel - Gaseous (see note in 'Propulsion' Section) Fuel Capacity - 39 500 m^3 Maximum Engine Speed - 120km/h Range - 7800km Service Ceiling - 5500m Liberty 425 Length - 500m Diameter - 60m Volume - 1 357 000m^3 Control Gondola Mass: 10 tonnes Control Gondola Length: 14m Control Gondola Width: 4m Control Gondola Height: 3m Raw Gas Lift - 1628t Maximum Helium Payload - 1300t Maximum Payload (Including 45 degree VT): 1380 tonnes Fuel - Gaseous (see note in 'Propulsion' Section) Fuel Capacity - 42 000 m^3 Maximum Engine Speed - 130km/h Range - 8100km Service Ceiling - 6000m Liberty 500 Length - 525m Diameter - 60m Volume - 1 427 000m^3 Control Gondola Mass: 10 tonnes Control Gondola Length: 14m Control Gondola Width: 4m Control Gondola Height: 3m Raw Gas Lift - 1712t Maximum Helium Payload - 1350t Maximum Payload (Including 45 degree VT): 1430 tonnes Fuel - Gaseous (see note in 'Propulsion' Section) Fuel Capacity - 43 500 m^3 Maximum Engine Speed - 130km/h Range - 8100km Service Ceiling - 6000m Liberty 550 Length - 525m Diameter - 60m Volume - 1 427 000m^3 Control Gondola Mass: 10 tonnes Control Gondola Length: 14m Control Gondola Width: 4m Control Gondola Height: 3m Raw Gas Lift - 1712t Maximum Helium Payload - 1350t Maximum Payload (Including 45 degree VT): 1500 tonnes Fuel - Gaseous (see note in 'Propulsion' Section) Fuel Capacity - 43 500 m^3 Maximum Engine Speed - 130km/h Range - 7900km Service Ceiling - 6000m ___________________________________________ Cargo Gondola Options: Type 1 Contained Load The standard load option for the 125 and 200. Length - 60m Width - 15m Height - 3.6m Volume - 3240m^3 Empty Mass - 40 tonnes Type 2 Contained Load The standard load option for the 300 and 425. Length - 80m Width - 15m Height - 3.6m Volume - 4320m^3 Empty Mass - 48 tonnes Type 3 Contained Load The standard load option for the 500 and 550. Length - 100m Width - 15m Height - 3.6m Volume - 5400m^3 Empty Mass - 55 tonnes Liquid Load An interchangeable liquid load module for all of the series. As many as desired by the client can be fitted on the underside of the craft. Length - 40m Diameter - 8m Volume - 2010m^3 Mass - 80 tonnes RIRO Vehicle Load Designed to be used for a large car ferry-type airship, mainly for the 500 and 550 but also for any of the smaller airships in the series. A drive on drive-off system is employed for the vehicles to use, with basic convenience facilities provided with the assumption that any trips are to be under 12 hours for the drivers. Length - 100m Width - 20m Height - 5m Volume - 10 000m^3 Mass - 110 tonnes Vehicle Capacity - 180 cars/90 lorries Cage Load A skeletal frame for holding either irregular or very heavy loads, with fix points provided for any suspended loads needed. Length - 100m Width - 20m Height - 3.6m Mass - 45 tonnes Hopper Load A main use of airships in Alfegos originally was for the rapid transportation of processed or raw mineral ores to refineries and blast furnaces en masse, at speeds higher than the railways or waterways could manage. Still with an important role, a hopper system is provided for any mineral loadings - a large container with a fill point at either end for conveyor-belt feeding into it, with two underside doors for quick release of the payload into a storage heap. A myriad of minor roles, from mass dumping of earth or concrete to fighting fires can also be derived from minor tinkerings with the system. Length - 100m Width - 2m Height - 2.75m Volume - 550m^3 Mass - 53 tonnes |
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3:42 PM Jul 11