Army Corps of Engineers (1903–1946)
Plans to convert Grant into a dredge were completed in November 1902.[69] After a lengthy and contested bidding process, the contract for the conversion work was awarded to the Mare Island Naval Shipyard in February 1903.[70] The work was completed in October 1903.[71] The cost of the conversion was about $270,000.[67] She was given a new name, United States Engineers Department Chinook.[72] She was the largest dredge of her type in the world when completed, and remained so until 1938, when she was supplanted by USED Goethals.[1]Chinook was a hopper dredge, or suction dredge. Much of her internal volume were two 40 ft-deep hoppers, bins that could hold 4050 yd3 of sand. Underneath the hoppers were 16 gates that could be opened to discharge the sand. On each side of the ship was a drag arm, a steel pipe, that could be lowered to the bottom. The pipe was 20 in in diameter. At the end of each drag arm was a drag shoe which was covered by a grate to keep large items from being sucked up the drag arm.
When Chinook was dredging, her drag arms were lowered to the bottom. Powerful pumps sucked sand and gravel up through the drag arms and dumped it into the hoppers. In 1903, the ship was fitted with two 20 in centrifugal pumps that were capable of pumping 2500 yd3 of sand per hour.[73] Each pump was powered by its own triple-expansion steam engine with high, medium, and low-pressure cylinders of 13, 20, and 31 1/2 inches and a stroke of 20 inches.[74] When the hoppers were full, Chinook would raise her drag arms, sail to a designated dumping ground, open the gates in the bottom of the hoppers, and let gravity discharge the dredging spoil into the water.
Chinook reached Astoria, Oregon, at the mouth of the Columbia, on 3 November 1903. She was not ready to begin operations, but completed some short test and training dredges with her new crew. Among the things that the testing revealed was that her boiler problems had not been fixed. Chinook went to the shipyard in Portland where 14 patches on the boilers were repaired in April 1904.[67]
In May and June 1904, Chinook was finally able to begin dredging the Columbia Bar. In that two month period, she dredged for 40 days, and removed 141476 yd3 of sand and gravel from the river at a cost of $0.143 per yard. In fiscal year 1905, Chinook removed an additional 245220 yd3. Dredging was discontinued in April 1905 and the ship was laid up.[75] Once again, the problem was that her boilers were unsafe and there was no money to fix them. The ship was idle for four years. Finally, plans were made to replace her four boilers and convert them from coal to oil-burning. During the same shipyard visit, tons of steel in her unneeded passenger cabins and superstructure were to be removed so as to give her a smaller draft, allowing her to work in shallower water.[76] Bids for the work were opened on 22 December 1909 and the work completed on 25 August 1910.[77] The cost of this refit was $137,075.[74] Her new displacement was reported as 7,400 tons.[78] Another shipyard visit in 1914 added two 30 in centrifugal pumps connected to drag arms 30 inches in diameter.[79]
The Columbia Bar was too rough for dredging in the stormy winter months, so Chinook dredged from May to October. She was idle or undergoing maintenance the rest of the year. When conditions were calm, she would work productive 16-hour days. For example, on 13 May 1916 she removed 16280 yd3 of sand weighing approximately 32,000 tons from the shipping channel.[81] In June 1918, Chinook set a ship record, removing 370000 yd3.[82] As a result of her work, other dredges, and the construction of jetties at the river mouth, in 1918, the shipping channel at the Columbia Bar was 40 ft deep and 1000 ft wide.[83] This met the Congressional mandate for the river and Chinook was reassigned. She left Astoria on 22 January 1919.[84] Chinook arrived in Charleston, South Carolina, via the Panama Canal, on 27 February 1919.[85] She participated in a project to deepen the channel into the harbor. She was then transferred to Hampton Roads, Virginia to dredge the Thimble Shoal channel.[86]
Chinook completed a variety of short-term assignments around in the country. At the end of 1920, Chinook was ordered to work in Galveston, Texas.[88] In 1931, she spent a month dredging the channel to Philadelphia.[89] In 1932, and 1933 she was dispatched to New Orleans.[90][91] Chinook dredged the Egmont Key channel in Florida at various times from 1934 to 1936[92][93] In 1936 and 1937, she completed a dredging project in New York Harbor[94] before returning to work in Tampa Bay in 1938.[95]
In 1925, Newport News Shipbuilding replaced her four boilers with six new ones, and overhauled a number of other systems for $98,500.[97] In 1926, her 20-inch drag arms were removed.
