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From Multirole to Modularity

Jack Watling
RUSI Defence Systems, 10 December 2020
Land Operations, Martial Power Programme, Military Sciences
Three decades of low-intensity warfare has led to the development of numerous exquisite platforms, bristling with capability, but their cost makes them scarce, and consequently vulnerable. Generating mass and resilience requires federating capabilities.

The British Army’s WK450 Watchkeeper is a highly capable UAV. With 17 hours endurance, and the ability to operate 150 km from its ground control station, the platform provides a command post with a combination of high-fidelity ground moving target indication (GMTI) radar and electro-optical sensors. It is a flexible ISR asset that can scan a large area at reach, and then investigate what it finds. 

The Watchkeeper is also a contradiction. A GMTI radar on a UAV flying at 5,000 ft should be able to monitor activity 150 km away. An electro-optical sensor will likely be effective out to 12 km in good visibility. Therefore, while the Watchkeeper could loiter at altitude above the divisional support area and provide excellent coverage of the enemy deep, its electro-optical sensor would be redundant. Meanwhile, if it moved forward to investigate, it would need to fly much lower to avoid being detected, rendering its radar less effective, while remaining highly vulnerable to MANPADS and AAA.

The problem with the Watchkeeper is not just inefficiency, however. The additional payload means carrying more weight than the base Hermes 450 UAV from which it was derived. More data being generated means that it requires greater bandwidth to transmit. The result has been spiralling costs and delays so that the Watchkeeper is now used by NASA as a case study in system failure. Additionally, given the limited fleet size and cost per airframe, the impact of crashes on operations does not bode well given how many could be shot down if they were ever used against an enemy with anti-air or electronic warfare capabilities.

If Watchkeeper was an isolated case study, it might be written up as a mistake. But it is indicative of a much wider problem. Consider Ajax: supposedly a recce vehicle, it is a 42-tonne behemoth that will need to remain static if it wishes to be undetected. It has a range of impressive sensor systems that mean it could prove effective as a stand-off ISR platform. However, it is simultaneously supposed to provide a ‘medium armour’ capability, necessitating manoeuvre. To perform this role, it wields a highly lethal 40-mm cannon which, just like its sensors, is exquisitely expensive.

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Dr Jack Watling
Research Fellow, Land Warfare

Dr Jack Watling is Research Fellow for Land Warfare. Jack has recently conducted studies of deterrence against Russia, force... read more

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