Brian Toohey has some excellent advice on the matter of submarines…

An objective study would’ve shown the latest conventional ones are superior – they are much harder to detect and are operationally available far more often because they don’t suffer few serious maintenance problems. The program cost of twelve high quality conventional subs is only about $18 billion compared to $368 billion for 11 nuclear ones that repeatedly break down.

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Vice Admiral Jonathan Mead gave an astonishing interview to the Guardian published on March 8 and 9 this year. Mead wrongly described Australia’s existing Collins class conventional submarines as “the most advanced in the world”. They are certainly not. They lack modern equipment such as fuel cells and advanced batteries that let submarines operate extremely quietly for sustained periods without having to rise to the surface to recharge their batteries every day or two, unlike the Collins class. Modern German, Japanese and South Korean ones are in this category. These submarines have low sustainment costs, unlike the Collins class where this burden has hit almost $700 million a year, not including fuel and crew costs. Taking the Collins out of service would free up billions in funding for new conventional submarines.

Because nuclear subs are significantly bigger than most conventional subs, they are easier to detect as they move through the earth’s magnetic field and the water column. Rapid advances in sensor power and computer processing increase the chances of subs’ detection – and destruction. Mead said he had taken account of the prospect oceans would become more transparent by 2050.His solution is to use underwater drones in places where you don’t want a nuclear submarine to be detected. That would be just about everywhere that the presence of nuclear submarine was supposed to be important. Apparently, the nuclear sub would control a drone at a safe distance. In this case, far cheaper platforms can be used to control the drones.

Mead claimed that nuclear-powered submarines enabled them to remain undetected. On the contrary, nuclear submarines are comparatively noisy because they rely on a reactor to heat the water for steam engines to propel the boat. The process creates noise from cooling pumps, turbines, alternating currents, and steam flowing through the pipes. These subs also expel hot water that can be readily detected, as can the wake they leave when travelling at high speeds.

— see the full article at Pearls and Irritations: “Very bad advice: $368b nuclear submarines and the Federal budget”