Icebreaker A.R.A. "Almirante Irízar"                              

The research/supply  icebreaker  A.R.A. "Almirante   Irizar",  ordered  in  1975   by   the   Argentine Government,  was delivered on   December 15,  1978    by   Wärtsilä´s   Helnki   Shipyard, Finland. The A.R.A.  "Almirante   Irizar" is  of a   completely new  type, dsigned for  supplying the  Argentinean   research stations  on the antarctic continent.A special requirement made of the icebreaker was that it should be capable of overwintering in the Antarctica with some 200 persons on board.


The vessel is designed and built to the highest class of Det norske Veritas +1A1 and included in the design is the Wärtsilä air-bubbling system and also fin stabilisers are provided to decrease the rolling of the vessel during the long voyager in open sea to the antarctic continent. The stabilisers were supplied by AEG Schiffbau and are of type AEG/Denny Brown. The compressors for the air bubbling system were supplied by Helsingor Skibsverft.

Hull design

The hull design is typical of icebreakers built at this yard with closely spaced frames located in the conventional way amidships, but perpendicular to the hull plating fore and aft. The frames are supported by a network of heavy web  famed  longitudinal girders. The maximun plate thickness in the ice strake forward is 40 mm, the plating being constructed of special quality steel of high impact strength even at the low temperatures that the vessel will encounter    during her service life. All the steel plates were supplied by Rautaruukki Oy.

  Although the accommodation looks somewhat square shaped in design, the standard of the various cabins, messrooms and saloons is very impressive. There is a high level  of decor and width for the 100 passengers sailing with the vessel, in addition to the crew, making a total of  233 persons onboard during the operational time the vessel spends in Antarctica.

  The accommodations is fitted with a complete air-conditioning system is capable of maintaining an inner temperature  of    20ºC at an  ambient  temperature of –27 ºC. During summer weather, an inner temperature of 24ºc and a relative humidity of 60% can be achieved at an ambient temperature of        30 ºC and 80% relative humidity.

  The air-conditioning system was supplied by SvenskaFlaktfabriken. The galley equipment, electric range and all the other galley equipment ( all supplied in stainless steel ) the majority being delivered by Instrumentarium Oy/Metos.

  The refrigerated stores with stainless steel panelling of a prefabricated modular type were supplied by Huurre Oy. The vessel fulfils the regulations of the IMCO (International Conference in Marine Polution, 1973), and is equipped by the Wärtsilä Ekenas Pottery factory. The sewage treatment plant has being supplied by Chemie & Aparate GmbH. There is also an incinerator for oil sludge and combustible waste, the unit being supplied by Fredriksstad Mekaniske Verksted.

Main Machinery

  The primary power is supplied by four Wärtsilä-SEMT Pielstick eigth cylinder PC 2.5 L / 400 medium speed, non reversible, four stroke diesels engines built at Wärtsilä´s factory at Vasa. The units are directly connected to AEG generators wich in turn feed the vessel´s propeller motors. There are two d.c. propellers motors of double armature type each with an output of 2975 kW. These units are also of AEG manufacture and operate between 100 and 200 r.p.m.

  The propeller motors drive two cast stainless steel propellers designed with bolted blades. The propellers are of the Helsinki Shipyard´s special design and manufactured by Wärtsilä´s Dalsbruck steelworks. The auxiliary power is supplied by four Wärtsilä diesel engines type 624 TS, each with an output of 660 kW and each coupled to an AEG synchronised compound alternator.

  The steering gear comprises an electrohydraulic steering gear supplied by the yard and this operates a rudder of welded construction. The stern frame is , however, fitted with an ice knife to protect the rudder during reverse manoeuvering.

A special feature of the A.R.A. "Almirante Irizar" is the Canadian manufactured RAS system, i.e. a special helicopter take-down winch, wich makes the helicopter ladings possible also during bad weather conditions. The 16 t hydraulic cranes for handling snow cats and cargo were supplied by the yard.

  The vessel is also fitted with a Rauma Repola electric towning winch, fitted with automatic wire length and tow type force control. The unit has a maximun pull of 60 t.



Technical Specifications


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A.R.A. "Almirante Irízar" - Q5
Diesel-electric icebreaking Antarctic research/supply vessel
Displacement 14 899 Tn full load
Physical  Dimensions
Length: 121.3 mts
Beam: 25.2 mts
Draft: 9.5 mts
Top of mast above waterline: 42.2 mts
Decks: 12
Propulsion Type: Diesel-Electric
4 motors Semt Pielstick 8 PC-2.5
Diesel output 4 × 3 584 kW ( 19 500 hp )
4 generators 600 VCA  4 000 KVA
2 double motors 700 VCC 
Shaft output: 2 ×  5 950 kW  (16 200 hp)
Service Speed Maximun 17.2 knots
Cruising 14 knots
Endurance 60 days
Complement Crew 135
Passengers 45
Transport Capacity 1800 m³ 
Radar Air/Surface Search AWS2
Helicopters Aft Deck and Hangar
2 Helicopters Sea King SH-3D o similar
Boats on Board 2 Hydrographic boats-Harding boat
Neumatic boats
Ice Breaking Capability Continuous ice thick: 1 m
Ramming ice thick: 6 mts
Builders OY Wärtsilä, Helsinki, Finland
Built at Wärtsilä Helsinki Shipyard
today Kvaerner Masa-Yards Helsinki New Shipyard
Keel laid July 4, 1977
Launched February 3, 1978
Delivered December 15, 1978
Trials winter 1979, Weddell Sea, Antarctica
First antarctic campaign summer 1979-1980
The A.R.A. Almirante Irizar was the first icebreaker with main engines placed "one deck up"in order to give better open water characteristics.
Sources: Argentine Navy / Kvaerner Masa-Yards Inc.


Acknowledge: special thanks to Henrik Segercrantz.