Vanport was provided with the opportunity to undertake a rather complex project which entailed the restoration of a damaged Cargo Hatch aboard the Cargo Ship Fisher. Allegedly the large hatch (approximately 60ft x 17ft, pinned in four sections) had toppled off of its rails while closing and fallen some 60 feet to the deck below. This left the hatch in a state with permanently deformed steel, inoperable hydraulics, and non-functioning electronic controls.
Vanport began the project by individually removing each hydraulic component while the hatch was still installed. Each hydraulic component removed was then overhauled and stowed for reinstallation at a later date. The individual hatch segments were then lifted from the hatch opening and placed onto the deck of the ship where inspections and repairs would be easier and safer.
Initially a baseline of necessary repairs had to be made. We were granted access to the manufacturer’s drawings to compare against. With the hatches resting on blocks, we deployed laser measuring to gain a 3-Dimensional representation of the flatness of the hatch. This enabled us to determine what areas were “within tolerance” of manufacturers design and which weren’t. Once the areas of concern were explicitly identified we formulated a repair plan with the assistance of the manufacturer. This involved experienced-based comprehension of steel under stress, particularly whether the deformations were plastic or elastic. We constructed a plan and presented it to the customer and ABS who blessed our plan, trusting our intuition and reputation. The areas with plastic deformation were cropped and renewed, the adjacent areas with elastic deformation were partially released to allow the steel to regain its natural positioning. Regions were welded out and inspected once more via laser measurement devices. Vanport restored the flatness of the hatch to within 1/8” of flatness across, acceptable by customer/ABS/hatch manufacturer. After this, coatings were applied and the hatch gaskets renewed in full.
Once the structural steel repairs were complete, we reinstalled the hatch panels with the overhauled hydraulic components previously mentioned. We also took this time to overhaul the ship’s electrical controls. We deployed the services of a trusted Marine Electrical company TMS (Technical Marine Services). They implemented new proximity switches onto the hatch and developed a PLC based program that would replace the old relay-board controls.
Upon completion of these steps we lifted the hatch sections into position with assistance from the ship’s large cargo cranes. The hatch segments were pinned together, hydraulic hoses connected and bled, and electrical terminated in new control panel. After these steps were completed, we performed operational testing in front of the customer and ABS. Testing was satisfactory. The hatch was then “Hose Tested” for weather-tightness in the presence of ABS and found to be satisfactory.