Classified as a Medium Gulf/River Icebreaker by the Canadian Coast Guard, Henry Larsen was ordered to a modified design from the rest of the Pierre Radisson-class icebreakers. The vessel's hull form differs from her classmates, with a differently-shaped bow with a raised forecastle and underwater "ice knife".[1] The vessel also has a different propulsion system. Furthermore, the ship has a Wärtsilä air-bubbling system installed to allow the vessel to reduce hull friction and more easily break ice.[2][3]Henry Larsendisplaces 8,290 long tons (8,420 t) at full load. The vessel has a 6,166 gross tonnage (GT) and a 1,756 net tonnage (NT) making her the largest vessel in the class. The icebreaker is 99.8 metres (327 ft 5 in) long overall with a beam of 19.6 metres (64 ft 4 in) and a draught of 7.3 metres (23 ft 11 in).[2][4]
The ship is propelled by two fixed-pitch propellers driven by a diesel-electric system comprising two GE AC generators and three Wärtsilä Vasa 16V32 diesel engines. Combined, the system creates 12,174 kilowatts (16,326 hp), giving the ship a maximum speed of 16 knots (30 km/h; 18 mph). The ship carries 1,650 m3 (360,000 imp gal) of diesel fuel, giving the ship a range of 20,000 nautical miles (37,000 km; 23,000 mi) at 13.5 knots (25.0 km/h; 15.5 mph) and can stay at sea for up to 90 days.[4][2]
The icebreaker is equipped with a Sperry Marine Bridgemaster navigational radar. Henry Larsen has a flight deck and hangar which originally accommodated light helicopters of the MBB Bo 105 or Bell 206L types, but in the 2010s, the Bell 429 GlobalRanger and Bell 412EPI were acquired by the Canadian Coast Guard to replace the older helicopters.[5] The ship can carry 22.0 m3 (4,800 imp gal) of aviation fuel for the helicopters. The vessel is certified as Arctic Class 4 and has a complement of 31 with 11 officers and 20 crew and 40 additional berths. The vessel is also equipped with a hospital ward.[3][4]
Henry Larsen, besides icebreaking duties along Atlantic Canada, provides search and rescue support, ship escort in iced-up areas in southern Canada during the winter and in Arctic waters in the summer and supports scientific research.[3] On the ship's maiden voyage from Victoria, British Columbia to Dartmouth, Nova Scotia, the vessel transited the Northwest Passage, performing sea trials on the trip.[8] The ship was initially assigned to the Coast Guard base at Dartmouth, but later transferred to St. John's, Newfoundland and Labrador.[1] In 1998, an engine room fire took the ship out of service for some time.[2]
In September 2013, Henry Larsen was sent to aid sister shipCCGS Amundsen in recovering a MBB Bo 155 helicopter that had deployed from Amundsen and crashed near Banks Island killing three crew members including Amundsen's master. The helicopter had sunk in 420 metres (1,380 ft) of water and Henry Larsen assisted Amundsen in keeping the ice clear while Amundsen brought the helicopter wreckage back to the surface.[11] In August 2014, Henry Larsen took part in Operation Nanook, a joint military exercise that took place in the Davis Strait.[12] On 7 July 2015, it was announced that Henry Larsen would undergo a $16 million refit at Davie Yards Incorporated in Lauzon, Quebec.[13] In April 2017, Henry Larsen was dispatched to aid the ferry MV Apollo which had become stuck in ice in the Strait of Belle Isle near Blanc-Sablon, Quebec for over 24 hours. The icebreaker escorted the ferry to port once it was free of the ice.[14]
Maginley, Charles D.; Collin, Bernard (2001). The Ships of Canada's Marine Services. St. Catharines, Ontario: Vanwell Publishing Limited. ISBN1-55125-070-5.