Ship Design

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Greenheart considers all of its designs to be Open Source.

For more detailed explanation, the latest technical design documents, and opportunities for discussion, please visit the Design Forum!

Shallow Hull

32m length, 7.5m beam, 220t displacement. 10-11kn hull speed. Steel (for ease and cost of construction and repair). Intentionally shallow to allow easy beach landing as well as travel in shallow estuaries and upriver. Opens up thousands of miles of undeveloped coastline and gives millions direct access to the open seas. Beach landing also simplifies inspections and hull-maintenance.


Primary propulsion system. Approx 400 m2. A-Frame mast(s) with roller furling staysails. Draws on advances from modern recreational sailing for materials and operating efficiency – e.g. eliminating most rigging (and hence labor) to automated guidance. Low-investment, low-maintenance, cost-free green propulsion.

Folding Mast/Crane

Mast(s) designed to pivot on an axis, filling two separate needs: (1) To double as a crane, giving the vessel built-in heavy cargo handling capability. (2) To lower completely to the deck, entering a “ducking” mode, wherein the vessel can travel under bridges and through other confined areas.

Solar Panels

Source of electricity for auxiliary motors and onboard electronics. Regular well-proven, affordable rooftop-style panels adapted to maritime usage. Provide an additional source of green energy suitable for powering onboard systems from navigation equipment to fish refrigeration and motor-propulsion in calms or through locks and docks.


Deep-cycle lead-acid traction batteries. Standard, proven, dependable, inexpensive, widely available. Recyclable and refurbishable. Weight acts as ballast for ship. Estimate about 20 tons of batteries, or about 600kWh. Goal is to store enough energy to motor through Panama Canal.


For precision or auxiliary propulsion around ports, through locks, and during calms. Expect to use 2x 150kW electric drive motors. Note that 300kW (150kW x2) is full power, used only in rare cases. Less than 100kW is needed to propel the ship at about 5kn in good conditions, stretching out battery life considerably.

Cargo Hold

Container-ready for 3x standard 20ft shipping containers (3 TEU), or alternately 70t weight in pallets, bags, or loose cargo, depending on users needs and capabilities. Shipping containers could theoretically be modular inserts (e.g. fish freezers, science equipment, etc.), converting the basic cargo design to specialty ship.

"Twin" Bilge Keels

Provide extra stability for shallow hull and serve as sturdy “legs” during beach landing for cargo and maintenance operations. Make traveling in shallow and tidal waters safer and easier, in addition to being perfectly capable on the open seas. Act as skids to kedge vessel above high water. Another technology borrowed from advances in recreational sail.


“Roll-On, Roll-Off” access to stern (think cars driving onto a ferry) facilitates cargo handling, as well as activities including, but not limited to: fishing, ferry services, and boat (or kayak) launching and retrieval. Eases transfer of goods from low docks and seawalls.