FRIGATES & EXOCETS & NEW ZEALAND DEFENCE SPENDING

BY: Joel Cayford – 23^rd February 1994

SUMMARY: It is argued that by investing in the ANZAC frigate project the New Zealand Defence Force will be equipping itself with nothing more than flag-carrying missile-magnets. It is also argued that New Zealand needs to move on from its World War II, Rule Britannia, blue-water navy policy, and learn from the cost-effective defence expenditure of developing countries with recent experience in dealing with the problems that might affect New Zealand in the 1990's.

It has been admitted by MPs on both sides of the house that the decision to buy ANZAC frigates was more to do with Closer Economic Relations (CER) than it was to do with improving New Zealand's defences. The first two frigates will cost New Zealand $1000 million. Second-hand frigates with almost the same capability can be purchased today for around $25 million each. Wisdom after the event accuses Minister of Defence Mr Cooper. Maybe, but the $400 million contract-out fee would still save New Zealand a great deal of money.

Australian Defence Minister Senator Robert Day defence has expressed concern about New Zealand's defence budget. That $1.4 billion is very low (1.4% of GDP). That New Zealand is not pulling its weight. As if defence capability can only be measured in dollar terms.

A hostile exchange during the "Three Day War" between Israel and Egypt came as a big surprise to Western military intelligence. The pride of the Israeli Navy, recently supplied by the United States at vast expense and bristling with high tech electronic equipment, was put out of action by a single Exocet missile launched from an Egyptian fishing boat hidden over the horizon. Ever since that moment, and spurred on by the surgical effect of Exocets against the British Navy during the Falklands War, Western Navy equipment designers have allocated huge resources trying to keep ahead of these immensely cost-effective anti-ship weapons.

In the early 1980's I worked on the design of Naval Defence systems for a leading European military equipment manufacturer, and learned a lot about the capability of the much feared Exocet sea-skimming missile and how defenceless modern warships were against it.

An Exocet missile weighs a tonne and approaches its target at mach 3. That is about 3,500 kph. Even if it doesn't explode the impact of that weight at that speed is equivalent to a fully laden freight train at 80 kph. In tests during development, unexploded Exocet missiles passed completely through target ships. In the Falklands war one British Ship - HMS Sheffield - was penetrated by an Exocet missile which did not explode. However the missile's jet engine exhaust actually burned the light aluminium metal alloy used in the ship's construction triggering a fire which destroyed the ship.

My work was the design and implementation of computer simulations to assess Navy ship survival in the event of airborne attack from sea-skimming missiles (like Exocet), laser guided bombs dropped from planes, and pop-up missiles. The purpose of the simulations was to test various Threat Evaluation and Weapon Assignment tactics in combination with different "bolt-on" defence systems including electronic counter measures, anti-missile-missiles and quick-firing guns.

An Exocet travels about ten metres above the sea surface. That means the earliest warning a ship gets is when the missile is about 35 kilometres away - about 40 seconds - provided the ship's surveillance radar is looking the right way. Detection is followed by a period of Threat Evaluation - is it a plane? is it a missile? is it a mistake? how long to impact? Once the command computer has decided a hostile Exocet is approaching, the ship has between 15 and 30 seconds to engage it by entering and executing its Weapon Assignment phase.

Options open to the ship will depend on what has been bolted on. These could include aluminium chaff (so the air round the ship gets filled with aluminium ribbons to confuse the Exocet radar); electronic countermeasures (which for example listen to the Exocet radar and send back "echoes" designed to trick the Exocet into thinking the ship is further away or nearer than it really is); an anti-missile-missile; or a quick firing gun system.

In practice the tactics for dealing with an Exocet will usually be a mixture, a sort of defensive cocktail, throwing everything at it. Typically the ship Command and Control system will first assign a Tracking Radar to the Exocet to determine its trajectory. It takes precious seconds while the tracking radar looks for the missile, locks on to it, then uses a computer to predict the missile trajectory.

And here is where an Exocet is especially tricky. It does not follow a straight line. That would make it too easy to knock down. Instead the Exocet flies in a corkscrew trajectory - but not a predictable one. It flies along a corkscrew that gets wider then narrower in a random pattern. Only when the target ship is around a kilometre away - about 1 second to impact - does the Exocet fly straight.

The trajectory calculated by the Tracking Radar computer is then fed to the weapon system. The public have been led to believe that the most effective system is the anti-missile-missile. During the Gulf War the media was full of reports about US built super-expensive Patriot anti-missile-missiles knocking down Hussein's Scuds. It was only after the war that US intelligence reluctantly conceded that Patriot missiles might have been responsible for downing just one Scud.

The New Zealand navy cannot afford to equip its frigates with anti-missile-missile systems - even if they did work reliably. But it can afford the quick-firing gun bolt-on system which is fully automatic. It contains its own surveillance radar, tracking radar, and multiple quick-firing guns shooting around 3000 one inch shells/minute. Once switched on it automatically detects any incoming missile, tracks it, then fills the air with shells where it predicts the missile will pass when about two kilometres away. In early tests the system automatically killed many seagulls, mistaking them for incoming missiles!

My work showed that, with luck, a frigate with a gun system would be able to deal with an Exocet in certain scenarios. But what became hideously clear was that a frigate had no chance of dealing with two Exocets launched a second or so apart.

Today Exocets are out of date. They have been superseded by much more sophisticated antiship missile systems. But you can still buy them. Argentina still has quite a few which black market arms traders would have easy access to for the right price. It would be easy for a stroppy Pacific neighbour to buy some. The Indonesian Navy is bound to have some. Neither our existing frigates, nor our ANZAC frigates would stand a chance against a fishing boat with a couple of bargain basement Exocets.

Despite their relatively small size, frigates suffer from the same shortcomings that the old battleships did. They are big, slow and made of metal. Missile magnets.

Britain, the US and Russia are selling off their cruisers, destroyers and frigates at bargain basement prices because it is accepted ships are so vulnerable. But they're not selling their submarines. Developing countries are buying some of these second hadn ships cheaply, but they are putting serious money into helicopters and fast, modern, patrol boats often made from materials which render them almost invisible to radar. These newer countries are responding to fast reaction coastal protection needs similar to those that New Zealand has. They are not strait-jacketed into military procurement patterns which merely bolster traditions hanging over from World War II.

We can make fast patrol boats in New Zealand. We could have one in every port. They could be used for fisheries patrols and search and rescue. For distance work we need multipurpose ships - like HMNZS Endeavour - which carry tracked vehicles and other emergency cargoes, and which should provide facilities for helicopters.

But the New Zealand Navy does not need patrol boats like the ones it has only just sold and which failed the taxpayer so miserably. Twenty five years ago one of the Navy bureaucrats at Defence Headquarters who understood Pacific sea conditions recommended the patrol boats be a particular length because of the distance between wave crests off our coast. He argued that otherwise they would be very uncomfortable to be at sea in for any length of time. The patrol boats finally ordered and delivered were two thirds the recommended length - probably to save money! They performed so badly in New Zealand waters that the bunks in all of them were fitted with seat belts to prevent sleeping sailors being pitched out.

It's time we learned from the Falklands and from our nearer developing world neighbours. Today we should use the defence tax dollar more cost effectively, for defence systems which integrate our air,sea and land based forces and which can serve to meet civil requirements as well.

By: Joel Cayford, 23/2/94