CANBY FERRY PROPULSION SYSTEM REPLACEMENT 

CANBY, OR

From a study of the feasibility and comparative economics in 1994 to the preparation of a concept design and complete contract design package (plans and specifications and cost estimate) in 1995 to serving as the owner’s representative during construction through 1997, Art Anderson (AA) designed Clackamas County’s Canby ferry, the M.J.LEE. The cable ferry, which carries motorists and pedestrians across the Willamette River in Oregon near the town of Canby, has a carrying capacity of 9 automobiles and 49 passengers and also carries trucks, farm vehicles, recreational vehicles, and bicycles.

In June of 2010, AA was contracted to provide naval architecture and design for upgrades to the vessel during its extended drydock period in 2011/12. While our original vessel design was unique by virtue of an electro-hydraulic propulsion system, which drew its electric power from overhead trolley wires spanning the river, the County was looking to upgrade the deck-mounted Z-drive thrusters to a new, completely electric, system that could still utilize the existing electric trolley power source. Vessel upgrade design work was accomplished for the County during three tasks.

Task 1: AA field verified that the current configurations and conditions on board the vessel were to County furnished drawings and documents. Design requirements were analyzed in a feasibility study that included an evaluation of propulsion alternatives providing a review of offerings of Z-drive manufacturers; a review of experiences of other cable ferryboat operations that utilized electric power only; a review of the electric load analysis, with emphasis on the retention of the existing overhead transmission cables, trolley, and downcomer; and a study to compare the estimated electrical consumption among the propulsion alternatives. Concept designs were developed to a level sufficient to prepare preliminary drawings, an outline specification, and initial cost estimate taking into consideration information from the feasibility study regarding component machinery cost, reliability, energy efficiency, ease of installation, ease of repair by County shop force and the availability of service and parts. After receiving County approval, design documents were submitted to the U.S. Coast Guard for review and approval.

Task 2: AA further developed the upgrade design drawings, specifications, and cost estimates to a 100% completion to be used in bid documents for construction by a qualified shipyard.

Task 3: AA provided support to Clackamas County in preparing the public bid documents, and in answering bidder’s questions as required during the bidding process. We then went on to provide construction support during the extended drydock period.

Naval architecture and design services for optional improvements to the vessel included providing design solutions and installation drawings for the replacement of hydraulic pipes and hoses for the ramp/barrier actuation with emphasis on noise reduction; specifications for vegetable oil hydraulic fluid for the auxiliary system in order to mitigate the environmental risk of an accidental spill of hydraulic fluid into the river; replacement of manhole covers with quick-acting, watertight hatches; modifications to solve reported trouble with sea valves; an improved ramp lifting system with a goal of greatly extending longevity of the wire ropes; and the addition of an air conditioning unit to the roof of the pilot house.

Art Anderson also conducted a comprehensive study of electrical panel locations from the standpoint of access, wiring, and voltage drop; designed the relocation of below-deck electrical gear to locations above the deck; specified and sketched improvements in switchboard access; studied the feasibility of an air-cooled “take-home” generator and prepared the installation drawing; and designed the replacement of incandescent running lights with LED lights.

AA was contracted by the County to provide all As-Built drawings for their vessel maintenance and overhaul files.