Page 25 - Australian Defence Magazine July-August 2022

JULY-AUGUST 2022 | WWW.AUSTRALIANDEFENCE.COM.AU
DEFENCE BUSINESS COLLINS LOTE 25
rior submarines without specifying a land attack capability either for them or for Collins.
Similarly, there was no reference to submarine-based land attack capability in the 2020 Defence Strategic Up- date, nor any specific references to this requirement for the now-cancelled Attack-class.
Nevertheless, renewed interest in the Collins’ potential for land attack has clearly been triggered by strategic concerns and Australia’s lack of meaningful long-range strike capability.
Although neither Defence, ASC, Raytheon Australia nor the US Navy (at Raytheon’s suggestion) responded to ADM questions on the work likely to be required for Collins boats to deploy the TLAM, this could be less oner-
ous than assumed.
profile beneath the flight path with a stored map reference. If necessary, a course correction is then made to direct the missile to the target.
Terminal guidance in the target area is based on GPS or a Digital Scene-Matching Area Correlation using a down- ward facing electro-optical sensor. This compares a stored target image with the actual target image, producing a claimed accuracy of about 10 metres.
Tomahawk can be re-programmed in flight via two-way ultra-high frequency satellite communications to strike any of 15 pre-programmed alternate targets, or be redirected to any GPS target coordinates. It can also loiter over a target
As pointed out by sources familiar with the situation, the same AN/BYG-1 combat man- agement system equipping the Collins-class is also aboard the US Navy’s Virginia and Los Angeles-class fast attack submarines (SSNs) and is configured for Tomahawk.
To be able to employ Tomahawks the Col- lins’ software would simply need an upgrade to that configuration, the sources said. “We could do that today; it’s just a software drop from the USN.”
“TOMAHAWK-LINKED STRUCTURAL CHANGES WOULD HOWEVER ALMOST CERTAINLY BE INCORPORATED WITHIN LOTE WORKSCOPES”
area to respond to emerging targets, or pro- vide indication battle damage imagery with its onboard camera.
From where would RAN tube-launched Tomahawks be sourced? Or indeed, ship- launched Tomahawks for Navy’s Hobart- class air warfare destroyers?
Production of Block IV Tomahawks ceased in 2020 after completion of approximately 4,000 missiles but was replaced a year later with production of Block V missiles featuring a new navigation and communications suite.
Additionally, engineering validation would be required to ensure that the Collins’ weapon loading gear and tor- pedo storage racks were rated to accommodate Tomahawk, hence the mid-2023 timeframe for the feasibility study.
This would appear to be a safe bet considering the load- ing gear and storage racks already handle Mk.48 Mod 7 heavyweight torpedoes weighing 1,675 kg (Tomahawk 1,300 kg or 1,600 kg with booster), 5.8 metres long (Toma- hawk 5.56 metres or 6.25 metres with booster) and a diam- eter of 53 cm (Tomahawk 52 cm).
TOMAHAWK CAPABILITY
And what tube-launched capability would the RAN be get- ting for its money?
The UGM-109E Tomahawk Block IV TLAM, also known as Tactical Tomahawk, achieved initial operational capability in 2004 and can deliver its 454 kg high explosive unitary war- head out to a range of around 900 nautical miles (1,600 km).
A solid propellant rocket motor accelerates the missile through the initial boost phase of flight until a Williams International turbofan engine takes over.
Tomahawk is designed to fly on a preset course over wa- ter at high subsonic speeds and extremely low altitudes us- ing inertial guidance or GPS. Once over land the guidance system is aided by Terrain Contour Matching (TERCOM), using the missile’s radar altimeter to compare the terrain
LEFT: Collins-class submarines HMAS Collins, HMAS Farncomb, HMAS Dechaineux and HMAS Sheean in formation while transiting through Cockburn Sound
RIGHT: The Collins LOTE program will extend the operational life of each boat by a further ten years
Additionally, missiles upgraded to the Block V standard and recertified for 15 years’ service are concur- rently being created from the existing Block IV inventory. Some 300 US Navy missiles are scheduled for recertification in FY 2023 alone and the UK’s existing stock of 65 Toma-
hawks will be upgraded to Block V standard from 2024. Defence’s statement that the Tomahawk feasibility study is being conducted separate to the Collins LOTE pre- sumably means exactly that; Tomahawk-linked structural changes would however almost certainly be incorporated
within LOTE workscopes.
COLLINS LOTE
Intended to avoid a capability gap prior to the anticipated entry into service from 2035 of the cancelled Attack-class, the Col- lins LOTE (Project CN62 – previously Sea 1450) has assumed even greater importance as a risk buffer given the uncertainties surrounding the nascent nuclear-powered program.
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