Design and construction of a low-impact amphibious vehicle for efficient and sustainable oyster farming

Project Overview

Project Type: Farmer
Funds awarded in 2015: $15,000.00
Projected End Date: 12/31/2016
Region: Northeast
State: New Jersey
Project Leader:
Gustavo and Lisa Calvo
Sweet Amalia Oyster Farm

Annual Reports

Information Products


  • Animals: fish


  • Animal Production: aquaculture

    Proposal summary:

    Many oyster farms in the United States are located in inter-tidal zone, near shore areas that are covered at high tide and exposed at low tide. While offering benefits, such areas also provide many challenges for the oyster farmer. Dynamic topographies of alternating sand bars and sloughs, tide-dependent work windows, and environmentally sensitive habitats create challenges when developing environmentally sound, optimal and efficient farm operations. Focusing their efforts during the low tide, many oyster farmers who operate intertidal farms have at best 2 hours on either side of a low tide to carry out daily husbandry and harvest tasks. This limited period heightens the need for equipment and practices that maximize efficiencies while minimizing environmental impacts. A critical problem is the lack of a low impact versatile vehicle that allow oyster growers to efficiently transport oysters and gear to and from, and within the farm, and provide a platform for production activities, such as harvesting and sorting stocks. We propose to design and build an innovative, nimble, versatile, and low impact amphibious module to serve as transport and working platform for sustainable and efficient operations of inter-tidal and shallow sub-tidal oyster farms. The main component is constituted of a multipurpose aluminum frame designed as a cross-platform to link a jon boat with a light wheel base with balloon tires.

    Project objectives from proposal:

    We propose to design and build an innovative, nimble, versatile, and low impact amphibious module to serve as transport and working platform for sustainable and efficient operations of inter-tidal and shallow sub-tidal oyster farms.


    1. To design and build a specialized amphibious farm vehicle to improve farm operation efficiency and minimize environmental impacts.

    2. To optimize vehicle design through an iterative process of trial and modification.

    3. To demonstrate the amphibious farm vehicle to local and regional shellfish growers through various outreach initiatives.

    The main component is constituted of a multipurpose aluminum frame designed as a cross-platform to link a jon boat with a light wheel base with balloon tires. Design criteria includes:

    • Operated by a single individual

    • Stable, lightweight, and easy to move over varied terrains

    • Low environmental impact

    • Easy to maneuver between rows of racks

    • Fits in pick-up truck bed

    • Easy and rapid to anchor/release

    • Provides working station space (sorting/grading) for up to 4 workers

    • Payload - 20 bags market oysters

    • Space for bundles of mesh bags/cages

    • Space/load for 10-20 racks

    • Easy to load onto a truck or trailer

    • Ability to lock it for storage

    Conceptualization. This proposed project is a result of a collaborative team consisting of a farmer (Gustavo Calvo, Sweet Amalia Oyster Fram), architect (David Bosco, Bosco Architects), and steel fabricator (Dan Dutra, Dutra Fabrication). A preliminary design has been established and has become the basis for further development and implementation. Factors such as function, efficiency, material compatibility, and life cycle costs have been at the forefront of all prior discussions. This amphibious farm vehicle is composed of several key components, however its core is a structural frame that unites: a floating storage vessel, a wheel assembly suitable for operation over sand-flat/mud-flat intertidal environments, a variety of flexible work surfaces designed to maximize the efficiency of the farmer’s tasks, and a shading component (See attached schematics, Figures 1 and 2).

    Design. Upon securing funds, the team will begin the Design Development Phase to further work out the vehicles overall functional layout. Two key variables in the design, the vessel and wheels, will need to be acquired for context as their profiles/construct will directly influence the overall connection detailing.

    Fabrication. Fabrication begins with the structural frame and its connection to the vessel; it’s anticipated that the point of connection will be the vessel’s top flange/edge. Marine grade aluminum has been chosen for its resistance to the harsh environment as well as its ability to be easily machined and adapted to. The proposed framework allows all the other components to be physically connected back to the vessel component. The frame shall have bookend extensions that act as push/pull leverage points and aid in steering the vehicle. The frame will also have anchor points that allow the vehicle to anchor lightly to the ground as to resist minor drifting if operations occur during the floatation phase.

    Components. The vessel is a pre-manufactured readily available product. For this project a (10’) ten foot “Jon Boat” has been selected due to its: shape/size, affordability, weight, and material construct which resists the marine environment. The volume of the vessel also promises ample real estate for programed/transient storage.

    The wheel assembly is made up of (4) four fixed axel wheels that are anchored to a ridge aluminum structural mast/outrigger. The low-pressure polyurethane wheels are designed for the harsh marine environment and are proven to transport large loads across sand and irregular beach terrain. Concerning projected maintenance, the wheel’s stainless steel bearings are the only foreseen part that may need to be replaced after years of service in the salt water. The manufacture readily sells replacements, and for (4) four wheels the costs would total $50 USdollars plus shipping.

    The work surfaces will accommodate multiple workers/tasks. The tops are removable as well as adjustable in height. Ergonomics will now enhance the employee’s workstations. Because the surfaces need to be versatile, for the sake of the prototype/budget, they will initially be constructed and mocked up out of a combination of light gauge steel and plywood. Their final construction shall be of marine grade aluminum, which offers a tremendous strength to weight ratio. The ideal design and configuration would best address the oyster farmer’s day-to-dayoperations with the ability to accommodate additional projected tasks. Some task are less frequent but just as critical in the overall scheme of the farm’s production and maintenance, such as the task of power-washing the mud packed oyster bags or the transportation of the (10’) ten foot long steel support racks.

    The shading component consists of either two standard beach umbrellas one at each end of the vehicle or a custom fabric sail that anchors to guide wires and attaches to removable masts. Reducing the suns exposure during the hot summer months is a benefit to both the employees and the oysters.

    Field testing. Field testing begins once the vehicle takes shape in the shop, it will be necessary to test the basic functions. While some of these tests can be performed in the shop, ultimately they will need to be put to the test on the oyster farm.

    Maneuverability will be maximized with experimenting with the: wheel span, wheel mounting height, and the handle/steering component. The work surface configuration will directly influence the storage layout/availability. The overall loading configurations and ease of maneuverability will yield a vehicle can be easily operated by a one person.

    Prototype Modification. Modification and redesign shall occur as a result to the field/task testing. This process may involve physically altering some of the key components such as the structural frame’s design to accommodate additional functions/flexibility. The work surfaces may transform as to accommodate additionally discovered configurations. Depending on the severity of the modification(s) the work may be performed on site or back within the fabrication shop. Findings and recommendations will become evident though out the entire fabrication and testing phases. There will become a point at which modification to the prototype may become too costly and out of reach for this project scope. However it is anticipated that vehicle will be in functioning order and put in use on the Sweet Amalia Oyster Farm in Cape May, New Jersey, whereas ongoing field testing will most certainty lead to future recommendations and modifications.

    Project timetable

    The project will start April 1, 2015 and end on December 31, 2015

    April - Design development, purchasing of materials and preparation for construction (D. Bosco, G. Calvo, D. Munroe)

    May – Construction (D. Bosco, metal fabrication subcontractor)

    June, July, August, September – Testing and refinement (D. Bosco, G. Calvo, metal fabrication subcontractor)

    October-December – Outreach and report writing (G. Calvo, D. Bosco, D. Munroe)

    Outreach plan

    Our primary outreach mechanism to reach local farmers will be an on-farm demonstration opportunity. Growers will be invited to my farm to see and interact with the low impact amphibious farm vehicle (AFV) first hand. Additionally, an information fact sheet on the design and construction of the AFV will be disseminated to other oyster farmers in the area via the Rutgers University extension New Jersey Oyster email listserve, which includes all oyster growers in New Jersey. Similarly in order to reach a broader audience the project results fact sheet will be posted on the East Coast Shellfish Growers listserve, which is widely subscribed to by shellfish growers from Maine to Florida. Finally, a short demonstration clip will be posted on We will welcome the opportunity to provide assembled models for purchase to interested parties and will beavailable to assist individuals with design modifications to suit their specific farm operation needs.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.