The Air Ballast Cargo Ship maintains buoyancy while carrying cargo using an air-filled hull made of tear-resistant material. A series of inflatable compartments attach to the ship’s hull to provide lift, countering the cargo’s weight while still maintaining stability. The additive buoyant force provided by each compartment is equal to the total weight of the cargo, creating an adjustable system for stabilizing the cargo ship. This environmentally sustainable design inflates to the same size and shape as a typical, fully loaded cargo ship. And, because it uses air instead of water as ballast, it reduces the transport of invasive aquatic species.

Biomimicry Story

While competing in the Biomimicry Student Design Challenge addressing transportation, Team Dédale looked at over forty organisms in the local Great Lakes and St. Lawrence River/Saguenay biome.  They recognized aquatic animals, specifically ray-finned fishes and cuttlefish, for their ability to maintain buoyancy by managing amounts of air in internal compartments. They mimicked several aquatic animals’ strategies and designed a ship hull composed of multiple expandable gas-filled compartments. Before choosing this design, they considered and discarded other ideas based on chemical and mechanical approaches. Although chemical reactions could provide buoyancy, the team was unable to find suitable life-friendly processes. And the mechanical options that mimicked humpback whale’s flippers or the shape of a sea turtle’s belly were soon determined to be infeasible due to the large physical scale it would require. In order to combat mechanical wear from inflation, deflation, and bumping of the inflatable compartment, they looked to nature for materials that could resist mechanical battering. They found and mimicked grass leaves’ ribbed structure to strengthen the material and resist tearing. Team Dédale members include Alexander Grant, Naomi Eterman, Chloé Grison, Luke Matus, Laurie Bouchard, and Philip Zimny, of McGill University.Check out this video to learn more about the Air Ballast Biomimetic Cargo Ship. And, listen below to Team Dédale’s discussion about potential design approaches.  This page was contributed by Team Dédale.

Challenges Solved

Traditional cargo ships are designed such that their dead weight tonnage (the amount of weight a ship can safely carry) is equivalent to the weight of their cargo, requiring ballast water to compensate for any empty weight. The Air Ballast Cargo Ship design eliminates the need for ballast water by using air to control buoyancy — a life-friendly solution because it reduces the transport of non-native species that can harm ecosystems and has led to billions of dollars in damages to the Great Lakes.

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