Cascade General Rebuilds Bow Of Turkish Freighter

While transiting the Columbia River to unload deck cargo in Vancouver, Washington, the 568' Turkish bulk carrier, Cenk Kaptanoglu, lost power and collided with the BHP dock in Kalama, Washington. The impact caused major damage to the bow and left the ship wedged solidly into the dock. It was pulled free by a tug and moored for inspection. The area of impact extended from the starboard hawse pipe to the portside of #1 hold and ran from the waterline to the forecastle deck. The 36,788 ton DWT vessel was given an exhaustive survey, a temporary patch at the waterline, and towed to Vancouver.

After consultations between the U.S. Coast Guard, the Kaptanoglu Shipping Group and the insurers, the ship was moved to Portland Shipyard for repair by Cascade General. In a sheltered berth between the yard's dry dock #1 and #3, three work barges were rigged around the bow, and staging erected to permit a complete, in-water repair. While preparatory work proceeded, Cascade General's loft crew obtained the original design offsets used by Hyundai to build the ship in 1982. These were input to a CAD program, then converted to CNC files, allowing all the replacement steel to be computer-cut and pre-fabricated.

The entire port bow above the waterline and much of the starboard bow was cut away, leaving only the starboard half of the forecastle deck intact. The warped section of deck was released from the deck beams and straightened using a combination of heavy girders, weights and hydraulic jacks. With the cargo of mahogany curtained off in the #1 hold, the re-building began with the replacement of damaged shell frames forward of the #1 bulkhead. The port half of the forepeak tank bottom was replaced and a new, prefabricated centerline bulkhead and port chainlocker were moved into position.

The shape of the bow was reconstructed on the port side with seventeen new frames, including four web frames, plus five frames on the starboard side. The complete framework for the stem was fabricated onshore and lifted into place, followed by the new port half of the forepeak deck and the upper portside frames. At the same time, a 20'-wide section of the #1 (collision) bulkhead was replaced and the parts for the port summer ballast tank were lifted into position and assembled, permitting the forward hold to be closed up. With the bow, web frames and some temporary supports erected, the new forecastle deck was lowered onto the ship.

Re-plating the hull with 5/8" steel began at the waterline, then progressed up the overhanging bow sections, matching the interior progress. Rolled 3/4" steel wrapper panels were fitted at the stem, then X-ray testing was used to check the quality of exterior welds and to meet the standards for Lloyd's certification. The original bollards and both hawse pipes were re-attached and a new bulwark fitted to complete the deck work.

"This project required 165 tons of steel and a total re-build of the bow. Fortunately, we were able to use our automated production systems to pre-fabricate all the components for the new bow," explained Cascade General Executive Vice President Andrew Rowe. "However the actual re-construction with the ship afloat, was very much a hands-on job, which demanded precise work in difficult conditions. That's when we rely on the craftsmanship of our workforce at Portland Shipyard. We're all very satisfied with the results."

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Cascade General operates Portland Shipyard, the largest and most complete ship repair and industrial facility on the West Coast of the United States. We provide full-service repairs and conversions for tankers, cruise ships, bulk carriers, container ships, government vessels, tugs, barges and workboats. Cascade General's Portland facility includes a 60-acre (24.2 ha) yard, 550,000 square feet (51,096 square meters) of craft shops, more than 7,600 ft. (2,326 meters) of full-service repair berths, and two floating dry docks.