The Roadless Revolution: Airships, Trucks and the Last Mile

The Roadless Revolution: Airships, Trucks and the Last Mile

The Roadless Revolution: Airships, Trucks and the Last Mile

A claim sometimes made by aspiring airship builders is that airships can offer a “point to point” transport solution. Airplanes, trains, and ships haul cargo long distances, then require motor vehicles to complete the “last mile” of the journey. This airship claim has some merit, but “point to point” cargo operations are likely to be limited to special projects, rather than routine deliveries.

In logistics and communications, the “last mile” refers to the link that brings cargo, passengers, or information to the final destination. Often this differs from the mode that gets the freight most of the way there. This principle is familiar to anyone who has made a long journey by airplane to an airport in a distant city, followed by a short drive to get to a specific address. The airplane does the “long haul” component of such a journey, the taxicab does the “last mile,” which obviously need not be literally a mile.

Last-mile freight applications require fine control, efficient transshipment, complementary communications technologies and price competitiveness. Trucks can make door-to-door deliveries very well and have an entrenched, large market share. For most general freight, cargo airships are likely to be more complementary to trucking, rather than competitive.

Airships and the Last Mile

Where airships can offer “point to point” transport could lead to big changes in everyday logistics and distribution. Aspiring airship entrepreneur, Andre Houssney, has coined the term “Roadless Revolution” to describe the all-aerial supply chains that might emerge in the age of giant airships. Certainly, in areas without roads, airship services could be transformative. Where airships have to compete with established infrastructure, the case is more difficult to make.

Airships can go the last mile in a sense. They can go to and hover over most destinations, putting them at an advantage compared to planes, trains and ships. But landing safely and quickly is harder. Landing will need stations, or at least large fields and perhaps some preparation. The means to transfer cargo between a hovering airship and the ground (ladders, cables) also needs to consider ballast exchange. The CargoLifter CL160 design required some destination preparation for a complex anchoring system and on-site source of water for ballasting. The economics of the CargoLifter system limited it to large, high-value, indivisible freight, but this is exactly what it was designed to carry.

The FLYING WHALES airship is also designed to provide point-to-point deliveries using water ballast. Whereas the CargoLifter airship would lower a load platform that contained ballast tanks to be filled on the ground, the FLYING WHALES design envisions pumping/lifting water into the hovering airship. The CargoLifter load transfer system was successfully tested using a large 75-tonne lift balloon. The FLYING WHALES concept is still at the design stage.

Another alternative is to use a hybrid airship as proposed by Lockheed-Martin and Hybrid Air Vehicles. The hybrid airship is heavier than air when empty and does not need ballasting to return to base. However, these vehicles are designed to land and take-off from a short landing strip. Their ability to position a load vertically would be quite limited.

The other proposed solution to eliminate ballasting is to use a gas compression system to offset the weight of the cargo delivery. Varialift and Worldwide Aeros have both followed this route, but the economic feasibility of gas compression is yet to be proven.

Airships for Wholesale Resupply

Notwithstanding the growth of online shopping, most goods are not delivered door-to-door. They are bought in stores. The very last mile is provided by the customer, hauling goods home in a car. In general, the minimum efficient payload sizes for giant airships’ will be too large to be economical for most “last mile” applications that involve general freight movements to the retail consumer. As far as commercial logistics is concerned, the last mile delivery is from the wholesale distribution centre (DC) by truck to retail stores.

The economics of truck door-to-door delivery decrease with distance, while the benefits of cargo airships generally increase with the length of haul. Airships could make direct deliveries from distant manufacturing sites to a DC warehouse, situated on city outskirts, or perhaps at a future airship inland port. DCs require restocking on a large enough scale that the minimum efficient payload size of airships would allow them to compete with trucks. Having an airship deliver many truckloads’ worth of goods in one visit might be good for productivity, congestion and the environment.

To be restocked by airship, DCs would need to be turned into airship stations, with landing, mooring and transshipment facilities, so that airships could land next to them, or on their roofs. This would take a fair amount of space, so the warehouses or stores would need to be large and/or in low density areas to have room around it. Once landed, people or robotic forklifts could move products from the airship’s hold to storage areas within the warehouse. DCs able to receive goods by airship could order from overseas sources avoid intermodal transshipment, simplifying logistics, speeding delivery, and reducing damage en route.

In the case of perishables, airship resupply might yield important advantages in freshness and quality. Fruit is easily bruised. Airships would offer a smoother ride than trucks, or any mode of transport available today. On the Hindenburg, someone stood a pencil on end to see just how stable the ship really was. They watched to see how long it would stand, until they got bored. This kind of smooth ride could enable fruit growers to deliver to retail shelves varieties that will not bear truck shipment well. Ripeness is a desirable quality for any fruit or vegetables. Most produce varieties are bred to survive truck rides, and are picked “green-ripe.” Tomatoes delivered by airships from Mexico would not only look like tomatoes, they would taste like tomatoes, too.

A recent proposal is to use airships as aerial distribution centers, from which drones would pick up products to deliver. It might seem easier and cheaper to have drones work from a distribution vehicle located on the ground. The prospect of a floating warehouse may seem far-fetched, but both Amazon and Walmart have already registered the idea; successfully in Amazon’s case, for patents to implement it. Amazon suggests that there is a big advantage in having a drone only go down when it is loaded and up when it is unencumbered and lightweight.

Figure 1 illustrates Amazon’s proposal for drone deliveries from an airship. There are a number of challenges that this idea presents to anyone familiar with airship technology, but dropping drones vertically may offer more appeal than sending drones crisscrossing the city.

Figure 1 Illustration of the Amazon’s Airship-drone delivery concept

Factory Resupply and All-Aerial Supply Chains

Another potential last mile market is factory resupply. Many factories turn small parts and raw materials into value-added intermediate goods to be passed on down the supply chain to another factory for final assembly. Inputs flow in, outputs flow out. Sometimes factories locate next to train tracks, airports, or navigable waterways so that they can be resupplied, and/or can move out their products. If not, they must be resupplied, and move their products out, by trucks.

Airships could resupply any factory, regardless of location, if it were equipped to serve as an airship station. An obvious application would be in the manufacture of over-dimensional equipment, like airplanes. The movement of the wings and fuselage from an input supplier to the final aircraft assembly hall involves some complicated logistics and substantial expense. Certainly, cargo airships have been considered as a possible transport vehicle for this purpose in the past.

Another important market for over-dimensional inputs is the transport of wind turbine blades. The existing road and rail systems limit the length of wind turbine blades to less than 100 feet. Doubling the length of the blades, quadruples the power, making it economically desirable. Such blades are now used at marine installations, but even in this case, getting the longer blades from the factories to the coast presents major challenges.

Price Competitiveness of Trucks and Airships in Last Mile Logistics

A world of all-aerial supply chains is about as technologically remote from the present as smartphones are from the age telephone operators physically connecting calls. Trucking companies have little to nothing to fear from cargo airship competition for the last mile pickup and delivery. Aside from certain kinds of special projects involving remote access and/or oversized project cargo, airships are unlikely to be in the “last mile” business.

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