Despite their disappointing early problems, and lack of spare...

Despite their disappointing early problems, and lack of spare parts, that reduced reliability and required expensive fixes, when they work Collins subs have worked very well in past exercises with the US Navy.

In exercise Rimpac 2000, HMAS Waller “sank” two USN nuclear subs, and the aircraft carrier USS Abraham Lincoln.  In exercise Tandem Thrust 2001, HMAS Waller “sank” two 40,000 ton USN amphibious assault ships.
http://newwars.wordpress.com/2009/07/02/sub-hunters-take-a-dive-pt-4/

In a 2002 exercise HMAS Sheean "sank" a USN nuclear sub and two destroyers.
http://www.smh.com.au/articles/2002/10/12/1034222635835.html

In two 2003 exercises off the Australian coast Collins class submarines "sank" two USN nuclear subs and an aircraft carrier.
http://www.theage.com.au/articles/2003/09/23/1064082993693.html

A very interesting 10 min clip shows HMAS Rankin taking part in the 2005 exercise Silent Fury off Hawaii. Despite the Americans cheating, HMAS Rankin avoids detection by the 5 USN ships hunting for her and "sinks" the brand new Arleigh Burke-class destroyer USS O'Kane.


That said it is certainly time to start the replacement process for the now aging Collins Class.