I think Australia can save a lot of money going for ots submarines, just build 1 or 2 slowly to retain skills, and continue skills with the maintenance of the subs, each certain years. The budget announced or commented for the 12 subs programs is so big, it is like 10 or 20 times spanish program for the 12 subs vs 4 spanish subs. I suppose numbers are calculated for something priced like the Collins experience and its priced maintenance. But an ots solution, with most of the subs built overseas, brings, compared to announced budget, brings a great saving in the cost of each unit, and in the cost of modern more typical maintenance.
And having a production facility doing along years 1 or 2 or 3 subs out of the 12, slowly and doing things without time or economic pressure for the yards, plus maintenances, it is enough to retain skills that could be multiplied in emergency times.
And the point to save so much money is what to do with it, wheter a 4th awd, another Camberrra, or instead another Camberra to buy the 2nd Queen Elisabeth aircraft carrrier that England can sell to special ally. Or more Asw assets.
If Australia goes the route of doing all 12 subs in Australia, with an evolved Collins design or some similar in size idea to Collins, then the price of the program will go very much high.
And in respect of endurance and autonomy of subs, if ots solution reaches to 80% of what Australia plans for subs, the 20 % that is not reached, for me it would not justify practically go the so much more expensive program, maybe it would suppose a small change of doctrine, but, newer generation subs have better endurance and autonomy than before.