We offer a range of vessel conversion and modification consulting services to fit any need. In our decades of consultation work, we have successfully engineered solutions for challenges of every type, scope, and scale. No consulting job is too big or too small for Gilbert Associates.
Whether you need a soft patch or a full vessel retrofit, we prioritize meeting your needs, on time, on budget, and in CFR compliance.
While not comprehensive, common examples of our services include:
We are ready to put our consulting expertise to work for you. While consultation projects may vary greatly, our process generally follows this outline:
Once you contact us with your vision, challenge, or question, we work with you to assess the scope of the project.
We determine the availability of the required documentation going forward.
If necessary, we do a site visit at the front end of the project.
We discuss timelines and realistic project benchmarks.
We consider the potential involvement of third parties in the project, such as vendors and other contractors.
We make an initial assessment and follow up with you to ensure our expectations are aligned.
We provide you with a quote and project proposal.
Gilbert Associates frequently completes repowering projects for current ferries. We analyze the existing structural and mechanical components and design a new system to integrate into the vessel.
The 130 ft double-ended ferry was originally built in 1913, making it the oldest in-service double-ended American ferryboat of all time. She was brought to Lake Champlain, VT, and had two Detroit Diesel 12V71 engines installed in 1970. We replaced those engines with CAT 3412D 540 HP engines.
Three passenger ferries, the J.J. Callis, the Shahan II, and the Daniel Salmon, were repowered for the United States Department of Homeland Security Plum Island Animal Disease Center in NY. The energy-saving effects of these ferries reaching higher speeds at the same fuel consumption rate have been a major asset for the facility.
This consulting project for the State of Maine included repowering, stability analysis, and installing a new exhaust system for the Governor Curtis.
In 2002-03, Gilbert Associates facilitated the repowering of Lake Champlain Transportation’s M/V Grand Isle.
Starting in 2006, we have been involved with engineering upkeep and improvements to Steamship Authority’s M/V Martha’s Vineyard. Throughout these modifications, Gilbert Associates has kept track of Martha’s Vineyard’s changing weight. In 2018, Gilbert also conducted a stability test (AKA “inclining experiment”) for the vessel.
Gilbert Associates regularly performs stability tests and midlife retrofits for existing vessels in this fishing fleet.
GAI completed updates to all of the shipboard mechanical and electrical systems for the sailing vessel Poincare to bring her into compliance with the USCG inspection requirements for 49 passenger service in and around Boston.
This consulting project included revisions to vessel stability for the carriage of additional passengers between Long Beach, CA, and Catalina Island.
In 2009, Miller Boat Line contacted Gilbert Associates Inc. to commission a new larger ferry to service Put-In-Bay, Ohio. Gilbert Associates recommended the more economical solution of lengthening one of Miller Boat Line’s existing ferries, the M/V Put-In-Bay. Miller Boat Lines quickly agreed.
As part of the modification, Gilbert Associates engineered the addition of a 40’ midsection, advanced Deflector rudders, and new Caterpillar C18 engines. The result was increased revenue and lower operating costs, as the M/V Put-In-Bay could carry 55% more vehicles and travel 2 knots faster with reduced fuel consumption.
Gilbert Associates has performed several upgrades to the 250 ft LOA passenger vehicle ferry Susan Anne since 1997. Most recently, we completed plans for a new steering gear and revised the structural arrangement to accommodate the new equipment arrangement. We also added a handicap-accessible elevator.
In 1997, GAI designed and facilitated a refit of Lake George Steamship Company’s sternwheeler, Minni-Ha-Ha. The refit included lengthening the vessel by 34 ft and adding an auxiliary diesel engine and ADA-compliant elevator.
GAI developed plans for the midlife retrofit of the passenger/vehicle ferry New London. A 50 ft section of midbody was added giving the vessel an overall length of 260 ft.
The 141’ Schooner Columbia was built in 2014 as a replica of the original gaff-rigged topsail fishing schooner built in Essex, Massachusetts in 1923. While staying faithful to the Columbia’s original lines, American white oak and pine were traded out for a steel hull, resulting in a fast and durable ocean yacht worthy of her name.
In 2023, Cross Sound Ferry acquired two 200’ offshore supply vessels for conversion into passenger/vehicle ferries as a more rapid and affordable alternative to all-new construction.
To facilitate the vessel conversion, Gilbert Associates is designing a new superstructure, passenger cabin, stern extension, bow door, and stability letter among other modifications. When completed, the converted ferries will serve Cross Sound Ferry’s route between New London, CT, and Orient Point, NY.
In 2010-11, the M/V Matthew J. Hughes was converted from a passenger ferry to an offshore support vessel. This conversion included reducing the superstructure to form a large freight/operations deck. Gilbert Associates also designed an A-frame for the launch and recovery of submerged objects. Today, the Hughes regularly services Boston’s offshore LNG terminal and participates in the launch and recovery of underwater autonomous vehicles.
Gilbert Associates oversaw the design and engineering for this vessel conversion project, transforming two river tank barges into an overnight river excursion cruise vessel.
The topside renovations for this vessel included a new passenger deckhouse, a new pilot house, and modifications to the mezzanine deck passenger cabin. Passenger evacuation measures were improved by rearranging the cabin layout and installing marine evacuation slides. We also redesigned the engine room ventilation system, installed a new anchor and winch, upgraded the HVAC system, and reinforced the freight deck structure.
This 160 ft LOA Catamaran Passenger Vessel, P/V Jessica W. was purchased in Mexico by Cross Sound Ferry Services. GAI prepared plans and calculations for changes to machinery, safety systems, and general arrangements. The extensive scope of work included a repowering and many life safety upgrades.
The M/V Mary Ellen is a 280’ passenger/vehicle ferry originally built by Offshore Shipbuilding in 1983 (not Gilbert Designed). The M/V Mary Ellen was originally in service with Bridgeport & Port Jefferson Ferry Company under the name Grand Republic. When Cross Sound Ferry acquired the vessel in the early 2000s, Gilbert Associates was contracted to facilitate the conversion.
The conversion included repowering with EPA Tier II engines, vehicle deck modifications, and vibration mitigation. Today, the M/V Mary Ellen provides daily service between New London, CT, and Orient Point, NY.
The ferry was built as a WWII landing ship (LST 510) and participated in the D-Day invasion at Normandy. In 1966, it was converted to a passenger/auto ferry. The latest improvement has been to the bow compartment, where the old ramp and other preexisting structures have been removed. GAI was tasked with the design of the new structural details which tie to the original.
Since 2006, Gilbert Associates has aided in continual upgrades and maintenance to the Steamship Authority’s M/V Sankaty. These projects included replacing the bow thruster and reanalyzing the vessel’s stability after changes to the vessel’s tank configuration which improved its weight, trim, and stability characteristics.
Whatever the challenges, our marine engineers have the experience, skills, and creativity to find solutions for every vessel. No issue is too big or small to benefit from our consulting expertise. To learn more about how we can provide the functionality you need while staying within your budget and on your schedule, contact Gilbert Associates today.
