Patrol Corvettes a Showcase for the World
SA Shipping News
When the SAS AMATOLA reaches our shores on 4 November the country will go down in history as the world's first user of laser welding technology for warships: to have the first warship worldwide with water jet propulsion; and to have the first warship with a horizontal main exhaust.
It will also house the MEKO A200 SAN platform - a general purpose combination of a range of combat system modules which have been customised for the South African Navy only, making it a first of its class in the world.
The length of the patrol corvette is 121 metres (2 metres longer than SAS Drakensberg). It is 16 metres wide, can steam in water of roughly 6 metres deep, its maximum speed is ± 29 knots and it can cruise at an economical speed for 7700 nautical miles (15000 km - SA to New York) without refuelling. It weighs 3590 tonnes when fully loaded and accommodates 110 crew on board. This includes medical staff and airforce crew for the helicopter. Provision is also made for a Formation Commander staff of 4, as well as 39 training berths.
Unlike the construction of a normal ship where the keel is built first, the corvette was built in 9 modules before they were welded together. The keel laying ceremony, which took place on 2 August 2001, was the day that the first module, being Module Number 4, was put into the dry dock.
According to Commander Andrew Cothill, the project engineer for the combat suite, at the outset of the project it had been a consideration that the design is done overseas and that the vessels get built locally. However it soon became apparent that it would not be viable to build the corvettes locally for a variety of reasons, one of these being a lack of local expertise of building a specialised warship. The warship building industry can not be viably sustained in South Africa.
Effort was then made to source a suitable shipyard capable of handling the scope of work required, resulting in a shortlist of just 4 companies from shipyards approached worldwide. The four shipyards (German, British, Spanish, and French) were further whittled down to a German Frigate Consortium (Blohm &Voss in Hamburg, HDW in Kiel and Thyssen). Work is shared between the companies in an effort to meet the tight schedule of producing all four vessels by 2004 (B+V constructs platforms 1 and 3, whilst HDW constructs platforms 2 and 4).The SAN Patrol Corvette Contract was awarded to the European South African Corvette Consortium (ESACC) consisting of the GFC (platforms) and TNA (combatsuite). TNA in turn consists of Thales Naval France and African Defence Systems South Africa. Meanwhile agreement was being reached between African Defence Systems (ADS) and the SA maritime defence industry to act as sub contractors to ADS for the development and supply of a sophisticated Combat System.
"The requirements for warship construction are very different to that of normal commercial vessels," says Commander Cothill.
"They are divided into water-tight damage control zones horizontally and vertically and a requirement was for armour to be built into the superstructure. Furthermore construction is such that all surfaces are slanted at about 10 degrees to deflect radar away from the vessel and nowhere on the vessel will you find a guard rail or aperture that can act as a significant radar reflector," he adds.
The lines of the vessel are so sleek that when the ship went for its first river trial just before Christmas, pilots on the Elbe River apparently reported that they couldn't detect the ship on the normal navigation range. Cothill says the R6.1 billion price the SA Navy is paying for the four corvettes is very good and that the shipyards recognise that the SA government is taking a risk with all the 'world firsts'.
"By us accepting a reduced price, the German Frigate Consortium ensures that once we accept the ship it is a showcase for the world market,'' he adds.
It was also noted that considerable effort went into contract negotiation at government-to-government level to ensure counter trade in the form of RSA industrial participation. In fact, a large percentage of the corvette contract cost is pumped back into South Africa.
A lot of components for the corvettes have been built in South Africa. This includes the bulk of the extensive Combat System (fitted after arrival) and various masts, superstructure modules, fittings, engines, generators and steering gear, etc. - the latter all built locally and transported to Germany for installation.
The engines are supplied by MTU; the gas turbine is similar to that of a Boeing turbine and the water jet inlet has a diameter of 2 metres.
The exhaust system has water sprays on both sides of the exhaust to cool down the water temperature to as low as between 60 and 90 degrees Celsius. The horizontal exhaust outlet and water jet bucket (to regulate or reverse thrust) are massive. Indications are that by closing the water jet bucket to redirect the water to the front of the vessel when the ship is at full steam ahead (29 knots), the vessel will stop in one and half ship lengths.
"To give an indication of the power of the water jet - it will empty an Olympic size swimming pool in about 3.21 seconds," says Cothill.
With acknowledgement to the Shipping News.