|Upholder class (Type 2400)|
The Upholder/Victoria-class submarines also known as the Type 2400 (due to their displacement of 2,400t) are diesel-electric hunter-killer (SSK) submarines designed in the UK in the late 1970s to supplement the Royal Navy's nuclear submarine force. In 1998, Canada purchased the submarines and a suite of trainers from the Royal Navy to replace the decommissioned Oberon-class of submarines.
To meet the requirement for a diesel-electric submarine type to succeed the Oberon-class in Royal Navy service, Vickers Shipbuilding and Engineering Ltd developed the Upholder-class. The price of each submarine was published at US$215 million, but actual cost after correcting the design flaws was higher. As in most new submarine classes, the emphasis was placed on standardisation and automation to reduce manning requirements. The first of the class (Upholder) was ordered in 1983 and completed in 1990, and there followed three boats (Unseen, Ursula & Unicorn) ordered in 1986 and completed in 1991-1993. The Royal Navy had planned to order 12 such boats; but this scheme was trimmed first to 10 and then to nine before being curtailed at just four as part of the "peace dividend" at the end of the Cold War in the early 1990s.
The Upholder-class was withdrawn from service in the Royal Navy in 1994, following a defence review by the UK government that decided to maintain an all-nuclear submarine fleet. After all four subs were leased to the Canadian Navy, the Canadian Forces renamed them the Victoria-class. The first of class, HMCS Victoria, was commissioned in Halifax in December 2000, HMCS Windsor in June 2003, HMCS Corner Brook in March 2003, and HMCS Chicoutimi in September 2004. The submarines are packed with technology, generally found only on nuclear-power submarines, and are still widely regarded as being among the best diesel-electric submarines in the world.
In 2002, Canada accepted the four Upholders as replacements for their old Oberon-class submarines. One will operate in the Pacific fleet, with three in the Atlantic.
The boats are named after Canadian port cities. Victoria operates out of Esquimalt, British Columbia and operates in Maritime Forces Pacific (MARPAC) fleet in the Pacific Ocean, while the three remaining boats are based in Halifax, Nova Scotia and operate in the Maritime Forces Atlantic (MARLANT) Fleet within the Atlantic and Arctic oceans.
Although the Canadian government touted the procurement as a bargain, there have been arguments over the quality of the submarines with some suggestions that the purchase price of ?244m will be at least spent again putting things right. Canadian opposition parties are demanding that the British government fund any further costs, since it is widely believed that the submarines deteriorated during mothballs and the Royal Navy was not completely forthcoming on their condition during the sale. However it cost the Royal Navy ?900m to build the submarines and even if there are some minor problems Stephen Saunders, editor of Jane's Fighting Ships, argues that "there is not something inherently wrong with the class of submarines."
On October 5 2004 HMCS Chicoutimi, sailing from Faslane Naval Base, Scotland to Nova Scotia declared an emergency north-west of Ireland following a fire onboard. The fire was caused by seawater ingress through open hatches in rough seas. It soaked electrical insulation which had not been sufficiently waterproofed, since it conformed to an older specification than the other three submarines, starting the fire. The submarine lost power and was rescued by Royal Navy frigates HMS Montrose and HMS Marlborough on October 6. Lt(N) Chris Saunders died subsequently from the effects of smoke inhalation, due to the rough weather it was not possible to airlift him and the other casualties to a hospital for two days. Chicoutimi was later transported to Halifax for repair. A board of inquiry cleared the captain of any fault but the regulations permitting the submarine to run on the surface with open hatches is being revised.
The boats were designed and built by Vickers Shipbuilding and Engineering Ltd for the Royal Navy, but saw only brief service before being mothballed in favour of an all nuclear force. They are essentially identical to modern nuclear submarines (with the distinctive nuclear shape and sonar-deflecting tiles) but run on diesel engines instead of nuclear reactors (which limits their range, but conversely makes them quieter and more manoeuvrable). It is foreseen that with the maturity of fuel cell technology the ships will be converted over to that power system, which could allow them to operate at sea almost indefinitely without the problems, real and perceived, of nuclear power.
The boats were designed with advanced noise-attenuation features to reduce the radiated noise levels below those of the already very quiet Oberon-class. There was also a reduction in the short time required to recharge the batteries to ensure a minimum exposure time of any part of the masts above the water. The design included an updated version of the fire-control system being installed on the SSNs under construction at the same time, designed to reduce stability problems at torpedo launch, a state-of-the-art French passive sonar system, the then-current towed array, and a passive ranging set.
They are the first conventional submarines to feature the hydrodynamic tear-drop shape seen in nuclear powered submarines, and also the first to feature sound-absorbing tiling on the outer surface of the submarine; both features greatly reducing the sound levels produced by the boat while cruising. The design was effectively that of a nuclear powered submarine, but without the reactor, leaving the submarine with a far shorter range and smaller performance, but also much quieter, an important advantage in under-water warfare.
A large double-armature motor was powered by a 9000-ampere-hour battery or a pair of Paxman Valenta diesel engines. Slow patrolling would require only 30 to 60 minutes of snorkling per day; an eight knot (15 km/h) transit would require snorkling some 30% of the time. Top speed matched any comparable SSK class and could be sustained for some 90 minutes.
It was highly automated to reduce manning, however during construction of the first of class, it was recognised that the weapon-discharge system design did contain flaws. The torpedo tube slide valve controlling operation of the torpedo tube doors, could have, under certain system failure conditions, allowed the opening of the inner door while the outer door was open. There was never any chance of this occurring as all tube operations were disabled until this fault was rectified. Had such an event actually occurred, large flowrate flooding could have resulted. The flaw was quickly fixed in the first three boats and the modifications included in the fourth boat while still under construction.
Miscalculations were made in the design of the main-motor control circuitry. During the sea trials of the lead ship of the class, when performing the specified trial for an emergency reversal ("crash back"), a flash-over incident occurred, which resulted in catastrophic complete loss of all power and propulsion. On investigation this was traced to a make-before-break fault in the design of the control circuitry resulting in a discharge-to-earth current of more than 60,000 amperes.
The diesels were originally designed for use in railway locomotives, and were not intended to be rapidly stopped and started. Shutting them down after snorkling led to many failures. Similarly, the motor-generators were operated at full power for longer than expected, and consumed brushes and filters rapidly, (the brush problems were not specific to the Upholders, and were a widespread issue on all UK RN vessels at that time).
Acceptance of the class into service was delayed for three years, partly due to the programme being scaled back by the MoD, while such problems were corrected. The result of those corrections, however, was an extremely capable design. When operating on battery power, Upholders were almost undetectable on passive sonar, and when snorkling, their acoustic signature was comparable to their SSN contemporaries in normal operation. They were physically small, and thus difficult to detect by magnetic anomaly or other non-acoustic means.
A local area network was built into the Upholders, supporting most of the sensors and fire-control systems, including remote viewing through the periscopes using both low-light television and infrared, an unmanned helm, and direct control of the main motor from the conn. The boat could fight with a team of four in the sonar room and a conn team of eight. Fire-suppression in unmanned compartments could be initiated remotely, and watch-keeping logs were automatically recorded. In port, the boats could be electronically linked such that one duty watchstander could monitor several submarines.
The submarine has a single skin hull constructed of NQ1 high tensile steel. The outer side of the hull, casing, and fin, of the submarine is fitted with about 22,000 elastomeric acoustic tiles to reduce the submarine's acoustic signature. The hull is a classical teardrop shape design, 70.3 m in length by 7.6 m in width and with a depth of hull of 5.5 m. The fin or main sail houses a five-man lockout chamber. The submarine's escape and rescue system has been extensively upgraded with additional stowage space for escape stores and an underwater telephone to meet the Canadian Maritime Force requirements. The hull displacement is 2,168 t surfaced and 2,455 t dived.
The submarine accommodates a crew of 48 including seven officers. There is room for an additional five mission crew, observers or training crew.
The submarines are fitted with a diesel-electric propulsion system driving a single shaft, based on two Paxman Valenta 16SZ diesel engines each rated at 2.7MW sustained power with two 2.8MW Alsthom alternators and an Alsthom motor rated at 4MW. The propulsion and power systems are controlled from the Machinery Control Room.
For operation under ice, the Victoria-class submarines could be fitted with an air independent power system. The installation of an air-independent propulsion system might be considered in a future refit or upgrade program.
The surface speed is 12 knots and the dived speed is in excess of 20 knots. In snorting mode, travelling at low speed at periscope depth using an extendable air breathing system, the submarine can continue at up to 12 knots. The range at an 8 knots snorting speed is 8,000 miles. The submarine has a patrol endurance of 56 days.
The hull is rated to a diving depth over 200m.