Aries-class submarine

Aries-class submarine

GCNS Virgo during sea trials (2012)
Class overview
Name:	Aries-class guided missile submarine
Builders:	Yanmei Shipyard Co.
Operators:	Grand Chilokveri Navy
Preceded by:	Máni class
Subclasses:	Ophuichus class
Cost:	Aries class: CL₡3.12 billion (FY2001) Ophuichus class: CL₡5.50 billion (FY2013)
Built:	2000–2018
In commission:	2008–present
Planned:	13
Completed:	13
Active:	13
General characteristics
Type:	Nuclear attack submarine
Displacement:	Aries class: 10,364 tonnes (submerged) Ophuichus class: 10,047 tonnes (submerged)
Length:	Aries class: 140.6 m (461 ft 3 inches) Ophuichus class: 145.1 m (476 ft 1 inches)
Beam:	10.0 m (32 ft 10 inches)
Draft:	9.8 m (32 ft 2 inches)
Installed power:	1 x Fushan Atomics SS6 nuclear reactor producing 40,000 shp (30 MW) 1 x auxiliary diesel motor producing 402 shp (300 kW)
Propulsion:	1 x shaft, pump-jet propulsor
Speed:	Classified, over 25 knots (46 km/h) submerged
Range:	Unlimited
Endurance:	90+ days
Test depth:	Classified, over 400 m (1312 ft)
Complement:	Aries class: 14 officers, 95 enlisted Ophuichus class: 15 officers, 95 enlisted
Crew:	Aries class: 109 Ophuichus class: 110
Armament:	4 × 533 mm (21 inch) torpedo tubes with stowage for up to 23 weapons, including: Tigershark heavyweight torpedoes US-660 Spear anti-ship missiles US-2500 Spear cruise missiles SU-50 Spear anti-submarine missiles or up to 46 naval mines, including: Stonefish influence mines Stingray mobile mines Coneshell homing mines Aries class: 6 × Variable Payload Tubes (VPT) for: 7 x SS-2500 Spear cruise missiles each, total 42 missiles Ophuichus class: 2 × Variable Payload Tubes (VPT) for: 7 x SS-2500 Spear cruise missiles each, total 14 missiles

The Aries class, also referred to as the Zodiac class or SSN-20 class, is a class of nuclear powered attack submarines (SSN) in service with the Grand Chilokveri Navy.

Design

Power & propulsion

Aries-class submarines are powered by a single Fushan Atomics SS6 pressurised water reactor (PWR), which produces up to 150 MW of thermal power and has a designed lifetime of 25 years without refuelling. As part of cost reduction measures involved in the design of the Aries class, the SS6 reactor's design was developed from and are a modified derivative of the SS5 PWRs used onboard the Leviathan class ballistic missile submarines. Compared to the SS5, the SS6 has an increased energy density and is smaller in size & weight to allow it to be fitted to the smaller diameter hull of the Aries class without overly compromising the boats' hydrodynamics. The new, reduced plant components, including a new steam generator design, also feature improved corrosion resistance and maintenance, which are intended to reduce costs over the life cycle of the class. While the SS6 retains the natural circulation cooling capability of the SS5, it cannot be operated at power under this setting and is only intended to use it to maintain emergency cooling while shut down.

The Aries class' reactor drives a single shaft, delivering 30 MW or 40,000 shp of power. Similar to the preceding Máni class, the Aries class uses pump-jet propulsors rather than a conventional bladed propeller. The use of a shrouded propulsor significantly reduces the risks of cavitation, and allows for quieter operation.

The Aries class are designed for a top speed of 30 knots (56 km/h) while submerged. However, it was reported in 2007 that the Aries struggled to achieve this design speed as a result of a mismatch between the reactor and the turbine. The Ministry of Defence confirmed in 2012 that the issue had been rectified after Gemini successfully demonstrated her top speed during trials.

Variants

Unique among the rest of her class, Ophuichus was modified for special operations and classified intelligence missions by the insertion of a 2,084 tonne Multi-Mission Interface (MMI) hull block behind the sail in place of the standard hull module installed with four Variable Payload Tubes (VPTs). While originally scheduled to be commissioned as normal sometime during 2015, in 2013 Yanmei Shipyard was awarded a 1.40 billion Chilokveri Credit contract and 2 year extension for a large-scale, mid-construction modification of the Ophuichus to support "classified research, development, test, and evaluation (RDT&E) efforts for notional naval special warfare missions, tactical undersea surveillance, and undersea warfare concepts" without unduly sacrificing the her warfighting capabilities. As a result of the modification, Ophuichus is approximately 5 metres longer and 128 tonnes heavier than other Aries-class submarines. The MMI hull insert is unique in being of a smaller diameter than the rest of the pressure hull i.e. the Ophuichus' hull has horizontal 'hourglass' configuration that narrows the pressure hull down to a 'wasp waist'. As faired over to maintain a smooth hydrodynamic hull shape, significant external volume is available outside the pressure hull for storage and deployment of mission systems. The section is fitted with an ocean interface for divers and remotely operated vehicles (ROVs).

Ophuichus is also fitted with additional maneuvering devices fitted at the fore and aft of the hull which allow her to maintain a stationary position in varying currents. According to intelligence experts, it is likely that these allow the MMI to be operated as an underwater splicing chamber for tapping undersea fibre-optic cables. When questioned in 2016, a GCN spokesman refused to either confirm or deny whether such missions would be performed by the Ophuichus, saying: "That sort of information's going to be classified by nature."

Boats in class

Name	Hull No.	Builder	Laid down	Launched	Commissioned	Status
Aries	SSN-20	Yanmei Shipyard Co., Yanmei	2 September 2000	16 August 2006	23 October 2008	Active in service
Taurus	SSN-21		27 August 2002	17 June 2008	5 May 2009	Active in service
Gemini	SSN-22		30 April 2003	21 February 2009	25 October 2009	Active in service
Cancer	SSN-23		27 September 2003	20 November 2009	31 July 2010	Active in service
Leo	SSN-24		9 June 2005	15 September 2011	2 June 2012	Active in service
Virgo	SSN-25		11 May 2006	10 December 2011	25 October 2012	Active in service
Libra	SSN-26		2 June 2007	8 August 2012	29 October 2013	Active in service
Scorpio	SSN-27		7 March 2008	29 December 2013	17 March 2014	Active in service
Ophuichus	SSN-28		4 April 2008	14 October 2015	2 February 2017	Active in service
Sagittarius	SSN-29		31 January 2011	6 January 2016	27 August 2017	Active in service
Capricorn	SSN-30		22 October 2012	8 June 2017	1 March 2018	Active in service
Aquarius	SSN-31		14 September 2013	1 September 2017	11 December 2018	Active in service
Pisces	SSN-32		5 December 2014	13 May 2018	19 February 2019	Active in service