In response to a shortage of plate steel during the Second World War, the United States Maritime Commission ordered 24 ships and 58 barges to be constructed with lightweight concrete. The ships were typically about 336 ft (110 m) long with a beam of 54 ft (16.5 m) and a displacement of about 11,000 tons (10,000 t). These ships and barges performed various levels of military service but typically for relatively short times due to several factors, not the least of which was the end to hostilities shortly after their launches. The useful service of these vessels (as ships and barges) was measured in months, with some being decommissioned immediately after delivery. However, at Powell River in British Columbia, Canada, as a floating breakwater and impoundment for the log storage pond, most of the surviving hulks have over 50 years of service in a saltwater environment. The Powell River floating breakwater is comprised of seven WWII steam-ships, two WWII barges, and one WWI steamship. The paper mill in Powell River acquired these ships between 1948 and 1966. After their arrival, the ships were stripped of amenities and machinery and the hulks placed in service as a breakwater.
For most of the hulks™ life as a breakwater, they were protected from direct barge impact by the numerous logs floating in the storage pond defined by the hulks. With the changing operations of the mill and the removal of the logs, the hulks became vulnerable to impact by barges also operating in the pond. This article describes the recent shotcrete repair of the impact damage to some of the hulks.
Need for Repair
While the hulks are showing deterioration related to the corrosion of the reinforcing steel due