SEA 1000
SUBMARINE TACTICAL LAND STRIKE
Byline: Rex Patrick / Sydney
Introduction
Just after noon on 19th January 1991, during operation “Dessert Storm”, USS LOUISVILLE became the first submarine to launch a land attack missile in anger when she fired eight missiles at targets in Iraq. She did this operating from the Red Sea. Shortly afterwards, USS PITTSBURG became the second when she fired four more missiles from the Mediterranean Sea.
Submarines have subsequently fired land attack missiles in a number of other operations. USS MIAMI fired some into Iraq In 1998 at the start of “Desert Fox” (the 4 day bombing operation undertaken in response to Iraq’s failure to comply with UN Security Council resolutions). USS ALBUQUERQUE, USS MIAMI and HMS SPLENDID fired some into Kosovo a year later as part of “Allied Force”. HMS TRAFALGAR and TRIUMPH fired them into Afghanistan In 2001 as part of operation “Enduring Freedom and in 2003, 12 USN submarines and the RN submarines HMS SPLENDID and TURBULENT attacked land targets in Iraq as part of “Iraqi Freedom”. Finally, in March this year SSGN USS FLORIDA, and SSNs USS PROVIDENCE, USS SCRANTON and HMS TRIUMP fired some into Libya as part of “Odyssey Dawn”. It is clear that land strike from submarines is not an aberration In this day and age.
Looking at the number of submarine launched land attack missiles used as a percentage of total land attack missiles used in each operation is also interesting. Submarines accounted for 4 per cent of the 288 Tomahawks fired during “Desert Storm”, 25 per cent of 450 used during “Allied Force” and 33 per cent of the 800+ Tomahawks fired during “Iraqi Freedom”. A significant portion of the 112 Tomahawks fired into Libya in the opening rounds of “Odyssey Dawn” were fired from submarines.
It should come as no surprise that more than 20 land attack missiles are now routinely carried on each USN submarine.
Land Strike from Submarines
The objective in land strike is to destroy or incapacitate enemy Command & Control facilities, strategic air defences, intelligence systems, infrastructure, key production facilities and military forces. These strikes would normally be conducted as joint operations with targeting information provided by strategic commanders on shore and co-ordinated in time and space to produce a synergistic approach.
But why land strike from submarines?
A submarine’s endurance, autonomy and relative impunity to detection allow pre-strike positioning to occur several weeks or months prior to the commencement of hostilities. This can occur without the “presence” of a force that might otherwise negatively influence diplomatic activities. The submarine can also conduct intelligence, surveillance and reconnaissance until such time as the land strike capability is needed. The submarine can be discretely withdrawn if offensive action is not required.
The submarine also allows a land strike capability to be deployed into an area of operation (AO) where there is a lack of sea or air control, with the aim of incapacitating enemy defences to make the area safer for other more vulnerable units to enter.
Finally, when the strike order is given, having an undetected submarine very close to shore provides an advantage when striking the most sensitive of military targets or executing the most time critical attacks. Launch surprise maximises targeting effectiveness and minimises the chance of the weapons being intercepted. Close-to-shore submarines can also reach targets that are further inland.
Submarine Land Strike Limitations
Whilst clear advantage is to be had by utilising submarines in a land strike role, they have limitations.
The first relates to their inability to arrive early on scene in distant theatres in situations where conflict arises unexpectedly. Many of the advantages associated with using a submarine for land attack stem from positioning them before and using them during the opening stages of a campaign. Once initial salvoes have been fired and targets critical to gaining sea and air control have been eliminated, the benefits of using a submarine for the task evaporate. To manage this, most nations have or will implement this capability on nuclear powered submarines. Additionally, some of them preposition these submarines. Spain is implementing a land strike capability on its S-80 submarines but their AO distances are likely to be relatively small resulting in the low speed of advance of a conventional boat having less impact. The same is true for Israeli Dolphin submarines, which have an extant land strike capability.
The second limitation is associated with submarine communication restrictions. Land strike operations are planned ashore and tightly co-ordinated in their execution. This places a requirement on submarines to spend significant periods at periscope depth downloading targeting packages, which include missile flight path waypoints and associated terrain matching data, and then remaining at periscope depth so that launch instructions can be received in a timely and own force co-ordinated manner. Operating at periscope depth, the only depth where a submarine can receive high data rate communications, compromises the very operational and tactical stealth that gives a submarine advantage in the land strike case (although new entrant buoy mounted/tethered communications systems will likely improve this situation).
The third limitation is the payload capacity of most submarines, which are generally constrained in their ability to carry large numbers of missiles in comparison to surface ships. One way to address this limitation is to do as the USN have done with its former ballistic missile submarines, USS OHIO, MICHIGAN, FLORIDA and GEORGIA. These boats have been modified to specifically carry out land strike. Designated SSGNs, they can carry up to 154 land attack missiles each, all of which can be launched over a period of 6 minutes. They have a land strike capability unmatched by any other platform and one on par with the normal land strike load out of an entire USN Carrier Battle Group. Some have commented that the involvement of SSGNs in particular conflicts may well reduce the land attack role of USN SSNs enabling them to carry out other missions and also allowing theatre equipped cruisers and destroyers to adjust their payloads in favour of other missile types. The transformation of a further two ballistic missile submarines into SSGNs is now being considered by the US.
The final limitation, one common to all naval vessels, is their inability to withdraw, reload and return to the campaign rapidly. Aircraft are the only realistic solution to this. Only aircraft have the ability to return day after day, night after night, to repeatedly attack an enemy.
Land Strike in the Australian Context
Australia’s future land strike capability, as defined in the Defence White Paper, will consist of an F-35 based air combat land strike capability, a Special Forces targeting support and direct strike capability and a maritime-based land strike capability. This capability will serve as a strong deterrence for Australia and as a significant background influencer in regional diplomatic discussions. Should deterrence fail, this capability would be employed against various strategic and operational military targets in a proactive manner that seeks to control the dynamic nature of conflict. An interim solution will soon be available, with the Joint Air-to-Surface Stand Off Missile (JASSM) that is currently being integrated onto the RAAF’s ‘Classic’ Hornets.
The maritime component of Australia’s land strike capability will come in the form of cruise missiles fitted to the AWDs, future frigates and future submarines. The land strike role for its submarines will vary depending on the strategic interest context laid out in the Defence White Paper.
In the Defence of Australia role our submarines will utilise their stealth, endurance and freedom of movement operational characteristics to conduct land strikes against adversary’s operating bases, staging areas and critical military infrastructure in well defended areas and/or difficult to access targets.
Submarines involved in contributing to stability and security in the South Pacific and East Timor will conduct similar land strike operations to submarines involved in Defending Australia. They may also be called upon to participate in low level conflicts where timely and unpredicted surgical strikes could be quite useful.
There are numerous scenarios that could be considered in the context of contributing to military contingencies in the Asia-Pacific Region, but for now the theme from March APDR’s article, that being a war between China and a US backed coalition, will be used. With sufficient warning Australian submarines could participate in land strike operations in conjunction with a range of US military assets. That aside, it is fair to say that the participation of a small ally such as Australia in a large scale land strike operation would potentially have political benefit to the US, but have next to no impact on the outcome; consider the effect of an Australian submarine carrying, say, 12 cruise missiles in comparison to a couple of USN SSGN carrying 154 tomahawks each.
The size and distances associated with Australia’s likely AOs needs to be discussed in the context of land strike in the three strategic interests above. Defence of Australia and contributing to stability and security in the South Pacific and East Timor submarine land strike tasks are most likely to be conducted in forward areas within the northern archipelago. One would expect reasonable warning in relation to the need to defend Australia, therefore it is likely that submarines would either be forward deployed to Northern Australian ports or already positioned in the operating area. In this scenario the low SOA of conventional submarines would not be a serious issue. There is a possibility that some South Pacific and East Timor stability and security events will occur without notice. If caught unawares, distance would erode the platform’s selection as the ideal participating land strike candidate. In the contributing to military contingencies in the Asia-Pacific Region, late notice would almost certainly preclude submarines participating in land strike operations. This limitation could be offset by forward basing out of ports like Guam, Kure or Singapore at the first hint of war.
Finally, as discussed in the March article, an Australian submarine’s role, let alone a land strike one, is unlikely for contributions to military contingencies in support of global security noting the great distances involved and the slow deployment times. For example, even if the Collins Class already had a land strike capability and there was a desire by the Australian Government to participate, they would not have been able to contribute to the opening phase of Operation Odyssey Dawn in Libya on account of the distance involved and the short decision cycle from NATO on how it wanted to interpret and enforce UN resolution 1973.
Australian Land Strike Capability Options
Whilst there is a land strike role for Australia submarines, it is only one of many roles we might reasonably ask of our submarines, and perhaps not as significant as others in the big scheme of things. As such, there would be danger in choosing a submarine provider or design based principally around a particular land strike capability.
A number of design choices and equipment options in relation to submarine land strike need to be considered.
Perhaps the first choice to be made would be that of “which missile”? Two seem obvious: the US Tomahawk missile and the naval variant of the French/UK SCALP-Storm Shadow missile under development, called the Naval Cruise Missile (NCM). Both weapons are similar in size and capability. Both missiles, once launched, use similar guidance techniques to get closed to the target; a combination of GPS and terrain contour matching. The Tomahawk uses Digital Scene Matching Area Correlation to improve navigation in the terminal stages leading to accuracies of the order of ten metres. The NCM uses Automatic Target Recognition for terminal guidance to achieve metric accuracy. The submarine launched Tomahawk missile is battle proven. Whilst the air launched SCALP missile is battle proven in Iraq and Libya, there are significant difference between it and NCM, with NCM having a significant increase in range over SCALP. This implies some risk in development, although it is acknowledged that the first test firing from of the surface ship VLS configuration took place at France’s Biscarosse test range on 28th May 2010 and the program is reportedly on schedule to achieve Initial Operational Capability certification on the FREMM frigate in 2013. Once the FREMM capability is up and running the missile needs to be integrated into a capsule such that it is ready for delivery to the French Barracuda SSN in 2017. This will also involve some risk but it is noted that MBDA, the NCM designer, has extensive expertise in this domain from their experience in the submarine launched SM 39 Exocet program.
Strike planning capabilities also need to be considered, as it is fundamental with respect to national sovereign use of supplied missiles. Two stages of planning are conducted for both missile options. Planning for the maritime cruise (overwater) phase is normally carried out by the launch submarine, cognisant of the current surface and air picture. Programming of the land cruise (overland) phase and target selection is normally carried out by a Theatre Mission Planning Centre ashore, although both missiles can be fully programmed on-board if necessary. The Defence White Paper states that our maritime strike capability will be supported by enhanced geospatial capabilities and targeting analysis support which implies we will require independent planning tools for full sovereign control. Such tools have been provided to the RN for its Tomahawk program, but it is not clear whether the same tools have been made available to the Spanish Amada. MBDA sells its weapon system package with tools that allow target models to be developed locally, ensuring the customer navy has full sovereign rights with respect to its use.
Another planning issue that needs to be considered is how joint planning for coalition operations, say with the US, would be handled, but it is clear that co-ordination has taken place between the US and France in Iraq and Libya; probably via the exchange of such information as the tactical picture and target data.
Tomahawk should not be the automatically selected solution. It would be wise for the Australian Department of Defence to consider both options from a planning, technical, operational, through life support, wartime ordinance availability and price perspective. Any premature announcement in relation to either selection would erode Australia’s negotiating position with their suppliers. Note that the final decision on the submarine weapon (SEA 1000 Phase 4) must be cognisant of the need to fit land strike weapons on-board our AWD (SEA 4000 Phase 4) and future frigates (SEA 5000 Phase 3). The Mk 41 Vertical Launcher System (VLS) selected for the AWD is Tomahawk capable which might bias Defence’s decision in favour of the it on the basis of minimising risk, but MBDA might offer up an attractive option for NCM integration into the AWD launcher noting the combined projects mentioned above are worth more than one billion and there are numerous Mk 41 VLS installations in other potential markets.
A choice which could have a large impact on the design of the future submarine is the launch approach; torpedo tube launched or VLS. Defence will need to weigh up the relative merits of including a vertical launch capability, which requires a dedicated launch system as compared to using torpedo tubes.
The vertical launch capability offers the advantage of carrying land strike missiles without offloading other weapon types. A vertical launch system also allows for relatively fast salvo firing. It should be noted, however, that they cannot be reloaded without returning to a base or a submarine tender. Two variants are available; Electric Boat supplies the Ohio Class SSGNs with a war proven Multiple All-Up-Round Canister (MAC) system, a canister which carries seven land strike missiles. The USN intends to install these on the later flights of Virginias in the SSN program in place of the current VLS system. HDW has a vertical payload tube option which can carry seven missiles. It is an option at the advanced concept stage, but has not been fielded yet. It does have the advantage over the MAC of being flexible enough to substitute the land strike missiles for a package of mines, an Autonomous Underwater Vehicle, a Special Forces lock or additional 24 tonnes of additional fuel.
The number of canisters or payload tubes would need to be considered. There would seem to be very little advantage in having only one canister or tube, other than it still allows a full load of torpedoes and other effectors to be carried. Advantage would be had if multiple canisters or vertical tubes are fitted because this would permit a large salvo to be fired with only one launch datum provided to enemy ASW forces. Up to three of the HDW vertical payload tubes can be incorporated into a Collins sized future submarine, and with their loadout flexibility they add to overall mission flexibility.
A vertical payload system, especially where multiple canisters or vertical tubes were used, would require a larger boat, and may rule out some MOTS option (it is noted that HDW have a individual vertical payload tube that is available for their smaller submarines). Noting the stated requirement for caution with respect to land strike bias in the design, and the likely cost and risk involved, the VLS system may not pass the value for money test for Australia. With significantly less risk, all MOTS submarines could be modified to launch land strike missiles through their tubes.
One final question needs to be asked and answered with respect to equipment choice. What impact does land strike weapon choice have on the selection of the future submarine’s combat system? If Tomahawk is selected, would Australia be required to select a US combat system? The answer to such a question comes from inspection of extant implementations. In the case of the Tomahawk integration on-board RN submarines, they employ an Advanced Tomahawk Weapon Control System to control and monitor the targeting, pre-setting and launching of the missiles. This system interfaces to the weapon handling and launch system and the missile via an interface box supplied by Ultra Electronics and also serves as the interface to the RN Combat System, SMCS. In effect, this interface box provides Tomahawk independence from the SMCS combat system. A similar approach is employed on the Spanish S-80 by Lockheed Martin and their Spanish combat system partner, Faba. This limits the impact of the choice of land attack missile on the selection of the combat system.
Summary
Land strike is an important role for modern submarines. Australia has made the choice to have such a capability on-board its future submarines and this article has suggested feasible operational scenarios and contexts under which land strike might occur.
A requirement for this capability can be achieved with a strictly MOTS submarine; in 2015 the first commissioned S-80 will sail fitted for land strike. The capability can also be achieved with some modifications to a MOTS submarine design such as a French Scorpene or a German Type 214. A vertical launch capability could be sought, but this would require careful consideration with respect to the cost benefit and the overall risk that this approach would likely add to the project.
One thing is certain; the requirement for land strike does not force us down a risky and costly own design submarine program. A MOTS or modified MOTS submarine can also do the job.