Australia’s Unsinkable Aircraft Carriers

Christmas Island is actually the summit of a steep undersea mountain. It is located close to the Indian Oceans’s deepest point and just south of the very deep Java Trench, which runs from the Bay of Bengal to Timor and is ideally suited to subs marine operations. A reef extending up to200m offshore fringes the 35sq km island and there is an almost continuous cliff shoreline of from 300 metres above sea level, making an amphibious assault on the island a difficult proposition. The highest point is Murray Hill, 361m above sea level. There is a ready supply of fresh water to support the population of about 1,500, halt of whom are Australian citizens with most others holding permanent resident status. Almost all facilities are located atop the island plateau, which is described as undulating and rain forest covered. Strategically, the most important facility is the 2,100m sealed airstrip. 2 .

The Cocos Islands are of much different character to their north-eastern counterpart. Cocos is actually a pair of coral atolls consisting of 27 small islands with a total land area of 14sq km, though just two islands (Home and West) are permanently settled by its 650 inhabitants. Most land is only a few metres above sea level and the soil is poor. There is no fresh surface water but on the larger islands wells and rainwater are sufficient for the population’s needs. Like Christmas Island, the main strategic facility is the 2,440m sealed runway.

Both island territories’ strategic values have long been recognised. The Cocos (Keeling) Islands were annexed by Britain in 1857 and in 1901 a telegraph cable relay station was installed, leading to the raid by the German cruiser Emden in 1914 and its subsequent sinking by HMAS Sydney. In World War II Qantas used the islands as a stopover point on the Perth/Colombo run after Singapore fell. The Japanese planned to invade the islands to disrupt allied shipping but this did not occur, due to other commitments. The RAF operated Catalina flying boats from the islands on anti submarine patrols and in 1945 an airfield was completed to support Liberator bombing operations against Malaya and the Netherlands East Indies (Indonesia). The wartime strip was resurfaced in 1966 to support jet aircraft and during the period of strained relations with Indonesia, Cocos was often used by RAAF and RNZAF aircraft transiting to or from Singapore.

Christmas Island was occupied by the Japanese in April 1941 after its Indian garrison mutinied at the sight of the invasion fleet, but the island was destined to play no more part in the war. Not until 1974 was its 2,100m sealed airstrip completed tQ permit charter airliners to land, a strip which immediately provided potential for future air operations, being capable of supporting Australia’s tighter, strike/reconnaissance, maritime patrol and most transport aircraft.

Today, the islands, primarily because of their airfields, remain prime assets for the defence of Australia, though neither is regarded as absolutely vital – just extremely useful. Their usefulness is virtually restricted to air operations and related radar coverage, for neither possesses facilities suited for naval ship operations, other than as shelter for smaller vessels during rough weather. Only a small force would be required tor defence of air or electronic surveillance facilities which could be established on the islands, though at present there is no permanent garrison at either territory.

Perhaps the prime strategic value of the islands is their proximity to Australia’s sea lanes, linking the country with the Middle East, Europe and Africa. The 1987 White Paper stated that: “The first aim of defence self-reliance is to give Australia the military capability to prevent an aggressor attacking us successfully in our sea and air approaches. . . “•The Cocos Islands and Christmas Island are extremely important strategic assets because they give Australia that military capability.

The obvious reason for the islands’ importance is their locations in the Indian Ocean, their airfields effectively extending the range capabilities of RAAF maritime patrol and strike aircraft so that they can fully cover Australia’s sea approaches. From the islands Lockheed P-3 Orions are capable of patrolling the southern approaches to India and can fly well south into the Southern Ocean during a typical 17 hour patrol, flown at 200kt on two engines at 1500ft, without the use of air-to-air refuelling. F-111 strike aircraft and Hornets also possess useful extended range to either attack or monitor vessels in the open seas.

What this primarily means to Australia is that the RAAF can provide aerial cover of the important Indian Ocean trade routes, providing a marked degree of protection against a hostile naval force which may attempt a blockade of Australia. The importance of this is obvious: trade represents a primary survival factor for Australia – as it does most countries – and the only method of handling the high volume of incoming and outgoing trade goods is to use shipping.

It is not considered likely by ADF planners that actual invasion of the Australian mainland would be attempted, certainly not by any nation in the foreseeable future, however a successful blockade is a possibility that would be damaging. Though there will always remain the option of shipping goods the longer route around South America or through the Panama Canal to Europe and the Middle East, this will ultimately prove time consuming and very costly. The Cocos and Christmas Islands would be key assets for the prevention of an Indian Ocean blockade. The protection of Australia’s sea routes is very much a defensive action, though admittedly the primary role of Australia’s armed forces is defence rather than offence. But it should also be noted that the use of the Cocos and Christmas Islands provides Australia with a very useful offensive weapon, for many regional nations also rely on the same trade routes as Australia. RAAF aircraft could well cover the western sea approaches to Asia, as well as the vital Sunda Strait between Sumatra and Java and the Strait of Malacca between Malaysia and northern Sumatra. Thus there is the potential, if necessary, for a combined aerial/ naval blockade of other nations’ important trade routes. It is therefore even conceivable that a standoff between Australia and another regional nation could primarily be contested in the Indian Ocean, using naval vessels and aircraft and land based RAAF aircraft. In this scenario, Australia’s Indian Ocean island territories could play a key role in any military operations.

(It is worthy of note that in much the same way as the islands’ utilisation for sea surveillance would benefit Australia, their similar use could also benefit friendly nations, should Australia be drawn in on the side of a neighbouring country. Australia’s western sea approaches are also those of several other countries in our region, so that their importance extends beyond just that of protecting Australian interests. )

Another very important maritime role for which the islands could be utilised is the surveillance and combating of submarines, which may be used against the trade sea lanes. With the Java Trench and the Indian Ocean’s deepest point nearby, Christmas Island is the more important of the two island territories in combating submarine warfare. From 1971-78 a series of submarine detection experiments were conducted from the island under the code-name Project Flowerless. Although the results of the experiments have never been made public, it is known that they involved the placing of a moored sonar array about 24km north of the island on the edge of the Java Trench; signals received by the array were relayed back to the island by cable, from where they were processed.

The site of the sonar array would have been ideal for detection of submarines in the Trench, however the fact that it was apparently little used by Soviet (or other ‘unfriendly’ nations) is believed to have made it unnecessary to permanently base a sonar array in the area. Soviet submarines usually proceed through the Malacca Strait on the surface when transiting to or from the Indian Ocean, so there are easier methods of tracking them. So as Ross Babbage has concluded, unless Soviet submarines use alternative routes “. . . or the strategic situation changes fundamentally, there would seem to be little little incentive to establish an operational passive sonar on Christmas Island. “‘

But the strategic situation is markedly changing, more noticeably since 1988 when Babbage’s book was published; the Soviet Union is cutting back its military presence worldwide whilst India’s military growth continues at a somewhat alarming rate. Given this fact, the Java Trench’s linking of the Bay of Bengal and an area south of Timor is significant. Therefore, as Babbage notes, the possibility of further sonar experiments cannot be excluded; Christmas Island could be set to gain renewed importance against submarines, and a sonar detection array could be used in conjunction with island based Orions to combat or provide surveillance of submarines in the area.

The role of the islands in a future conflict or military standoff is not restricted to the protection or surveillance of sea lanes. The two island territories also offer an advanced striking and reconnaissance capability into south east Asia. From Cocos the P-3 Orion is able to extend operations to India (unrefuelled) and can operate into south-east Asia to cover Burma, Thailand, Vietnam and the Philippines, and of course their sea approaches. The F-111 strike or reconnaissance aircraft can operate over southun Vietnam, Cambodia and Malaysia. Indonesia is fully covered by these aircraft, offering either the potential to mount offensive operations against that country or defensive operations in its aid.

Without air-to-air refuelling, F-111s cannot reach India from the Cocos Islands (the closer of the two territories to this rising international power), though the RAAF’s newly acquired air-to-air refuelling capability could extend range to give the aircraft a striking capability over parts of that nation if a boom was fitted to the 707 tankers at a later date. Provision in additional hydraulic power and appropriate plumbing has already been made to more easily facilitate such a mod. Meanwhile, F-18 Hornets are provided with a useful unrefuelled range which enables them to fly cover over Singapore and a large section of Indonesia and its two important straits.

The alternatives to making use of the Cocos and Christmas Islands include,as noted, the utilisation of the RAAF’s 707 air-toair refuelling capability, which would extend the operational range of aircraft but would require more planning to allow several patrol aircraft to use the service during the one patrolling period. Provided that a conflict or military standoff also received the backing of the United States, then use of the USN’s Diego Garcia facilities midway across the Indian Ocean would also be an option, aircraft being able to patrol westward, refuel at Diego Garcia and then patrol eastward before completing the round mission on an Australian mainland base. The idea that the United States would immediately provide effective military aid can no longer be taken for fact, however, so seriousAustralian defence planning must not place full emphasis on outside aid; the use of Christmas and Cocos does not necessarily do this. So there remain options to the use of the island territories, but the fact remains that Cocos and Christmas Islands are valuable strategic assets to Australia. But are they in fact worth defending? This is a question posed by defence analyst Ross Babbage in his publication Should Australia defend the Christmas and Cocos Islands?’, and by successive Australian military planners. At present the islands lack military defensive positions and there are few ADF facilities. The airstrips are of course available for military use, and radar or sonar stations can be established with relative ease – but can these facilities and the islands’ inhabitants be defended, and is it worth trying?

At the Strategic and Defence Studies Centre’s 1986 Air Power conference, former Chief of the Air Staff, Air Marshal David Evans, stated that it would be “somewhat naive” to assume that the mere status of the islands being Australian territories makes them worth defending. 3 Obviously, something more is needed – a strategic military significance. Fortunately the Cocos and Christmas Islands have this significance, but even this does not ensure that they would be defended if attacked by an enemy. The islands are small, distant and difficult to defend. Cocos’ problems are compounded by its location even further in distance from the Australian mainland than Christmas Island.

The Cocos Islands have the immediately obvious strategic advantage of increasing the aerial coverage of Australia’s western sea approaches. Its defence, however, would be a daunting proposition. The island’s position one third across the Indian Ocean leaves it far from Australian mainland forces, but its defence must at least be considered. Just as its use as a base for aircraft operations is an extremely useful asset to Australia, its possession by a hostile nation could also be of advantage to that nation. Not only would it deny Australia the increased range for coverage of the Indian Ocean, but it would significantly hamper Australian operations in the area. Defence of the island is therefore of considerable advantage to Australia, and must be considered seriously.

Christmas Island’s chief asset is really its proximity to Indonesia and the Java Trench and deeper points of the Indian Ocean, though at this stage the area is little used by hostile submarines; in the future, however, this may change. The island could, however, also be a valuable asset as far as basing surveillance equipment is concerned. Like Cocos, Christmas Island may conceivably be used for future space support, intelligence or scientific research functions and its airfield, of course, increases the effective striking range of strike and maritime patrol aircraft. Again – a very important asset, more so in that its possession is considered to make defence of Cocos easier.

Because of their remote locations and their size, the islands are difficult to protect from small scale raids or invasion. To properly defend the islands, early detection, identification and interception of hostile surface vessels or aircraft is essential. Fortunately, the now officially approved Jindalee over-the-horizon/ backscatter radar provides an essential means of detecting and intercepting both surface vessels and aircraft, at a distance allowing them to be attacked when probably still grouped in formation and most vulnerable. If such raids were to be expected, F-18 Hornets could be based at each location to provide defence. In the event of ground forces being needed, Ross Babbage states that an ideal garrison to deal with low level contingencies would be about two companies (200 men) at each island, ideally one being a reserve unit with ahigh proportion of local personnel. 2

It would be possible to defend the islands, given the use of modern surveillance technology, strike aircraft and some well equipped ground troops. However, their defence is not guaranteed, and many military analysts are of the opinion that their defence is not absolutely vital, and they certainly should not be defended at all costs. Of course the islands are extremely useful and “could be made a painful thorn in an opponent’s side . . . “2, but if the cost of defence is too high (in strategic, equipment and human terms) then, as Air Marshal David Evans stated in 1986, the defence of the island territories would be “totally irresponsible [if it] was clearly impractical and strenuous attempts to do so could cause heavy and futile losses and could weaken the defence of continental Australia . . . “2 If defence did prove impractical, Ross Babbage has stated: “It would probably be possible to evacuate all personnel from the islands, remove or destroy all facilities of value and at the same time conduct intensive operations in the region so as to exact heavy losses on the opponent’s assaulting forces. Operations to harass occupying elements and, in particular, to disrupt their lines of air and sea-borne logistic support could be continued at limited cost to Australia. ”

Thus, the islands need not necessarily be defended at all costs, despite their strategic value to Australia. Attacks on enemy forces could continue from mainland Australia – using naval and air forces which would deny the enemy effective use of the islands, but once the islands are lost, their recapture can be considered an extremely difficult – if not impossible – task. Even if the island garrisons were able to hold out, resupply would be very difficult, though already training missions involving the dropping of supplies and troops on to Christmas Island have been successfully carried out. Despite its inherent difficulties, some defence is necessary, if only to show Australia’s defiance and to show a hostile nation that its actions will not be taken lightly. A precedence cannot be set of simply leaving an Australian territory because defence may prove costly, especially if It has distinct strategic importance, as is the case with Cocos and Christmas Islands.

Thus, despite potential difficulties for their defence, Australia’s Indian Ocean territories are worth defending, to a point. They are strategically important, not only for the defence of Australia’s sea lanes and approaches, but also defensive operations against other regional countries’ sea approaches and for aerial coverage of several south-east Asian nations. Their airfields, which are so important in providing additional range capabilites to Australia’s strike and patrol aircraft, do in fact make the islands Australia’s “unsinkable aircraft carriers”.

1 R Babbage, Should Australia Plan to Defend Christmas and Cocos Islands?, ANU Strategic & Defence Studies Centre, Can- berra, 1988

2 R Babbage. A Coast Too Long: Defending Australia beyond the 1990s, Allen & Unwin, Sydney, 1990

3 D Ball (ed. ), Air Power: Global developments and Australian perspectives, Pergamon-Brassey, Sydney, 1988

4 P Criss & D Schubert, The Leading Edge: Air power in Australia’s unique environment, ANU Strategic & Defence Studies Centre, 1990