page_title: USCGC Acacia (WLB-406)
section_title: Construction and characteristics
hierarchical_section_title: USCGC Acacia (WLB-406) / Construction and characteristics
caption_attribution_description: English: USCGC Acacia under construction in Duluth, Minnesota in 1944 at the Zenith Dredge Shipyard
context_page_description: The USCGC Acacia was an Iris-class 180-foot seagoing buoy tender operated by the United States Coast Guard. Acacia was a multi-purpose vessel, nominally a buoy tender, but with equipment and capabilities for ice breaking, search and rescue, fire fighting, logistics, oil spill response, and other tasks as well. She spent almost all of her 62-year Coast Guard career on the Great Lakes. After decommissioning she became a museum ship in Manistee, Michigan.
context_section_description: Acacia was built at the Zenith Dredge Company shipyard in Duluth, Minnesota.  Her keel was laid down on January 16, 1944, she was launched on April 7, 1944, and she was commissioned on September 1, 1944.  She was the second-to-last of the 39 similar 180-foot seagoing buoy tenders built.  Her original coast was $927,156.
  Her hull was constructed of welded steel plates framed with steel I-beams.  As originally built, Acacia was 180 feet (55 m) long, with a beam of 37 feet (11 m), and a draft of 12 feet (3.7 m).  Her displacement was 935 tons.  While her overall dimensions remained the same over her career, the addition of new equipment raised her displacement to 1,025 tons by the end of her Coast Guard service.
  She was designed to perform light ice-breaking.  Her hull was reinforced with an "ice belt" of thicker steel around her waterline to protect it from punctures.  Similarly, her bow was reinforced and shaped to ride over ice in order to crush it with the weight of the ship.
  Acacia had a single 5-blade propeller 8.5 feet (2.6 m) in diameter.  It was driven by a diesel-electric propulsion system.  Two Cooper-Bessemer GND-8 4-cycle 8-cylinder Diesel engines produced 600 horsepower each.  They provided power to two Westinghouse generators.  The electricity from the generators ran an electric motor which turned the propeller.
  She had a single cargo boom which had the ability to lift 20 tons onto her buoy deck.
  The ship's fuel tanks had a capacity of approximately 28,875 US gallons (109,300 L). Acacia's unrefueled range was 8,000 nautical miles (15,000 km) at 13 knots, 12,000 nautical miles (22,000 km) at 12 knots, and 17,000 nautical miles (31,000 km) at 8.3 knots.  Her potable water tanks had a capacity of 30,499 US gallons (115,450 L).  Considering dry storage capacity and other factors, her at-sea endurance was 21 days.
  Her wartime complement was 6 officers and 74 enlisted men.  By 1964 this was reduced to 5 officers, 2 warrant officers, and 42 enlisted personnel.
  Acacia was initially armed with a 3"/50 caliber gun mounted behind the pilot house.  She also had two 20mm guns, one mounted on top of the wheelhouse and one on the aft deck.  She carried these weapons in the Great Lakes under a wartime agreement with the Government of Canada.  The Rush-Bagot Treaty had largely demilitarized the lakes, but the United States and Canada agreed to suspend some of its provisions during World War II.  After the war ended, the treaty came back into full effect and all of Acacia's on-deck armament was removed, leaving only small arms for law enforcement actions.  In 2006 Acacia and the other 10 Coast Guard cutters in the Great Lakes were armed with M 240B machine guns.  This action was taken due to greater concerns regarding smuggling and terrorists entering the United States by boat.  It was preceded by consultation with the Government of Canada under the terms of the Rush-Bagot Treaty.
  At the time of construction, Acacia was designated WAGL, an auxiliary vessel, lighthouse tender.  The designation was system was changed in 1965, and she was redsignated WLB, an oceangoing buoy tender.
  The ship's original name was Thistle, but when it was learned that the US Army was operating USAHS Thistle  the Coast Guard changed it to Acacia.  She was named after the United States Lighthouse Service tender Acacia, the only tender sunk during World War II.
caption: USCGC Acacia under construction in 1944
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