With the Collins class life extension under discussion it really is a matter of how far they plan to go with them. With figures ranging from $3.5 through to $15 billion it could be anything from new engine and a service through to a complete restoration and upgrade effectively zero hour the boats giving them up to 20+ more years of life. Components can be replaced and as a benefit some of those could be the same or early examples of what will go into the attack class giving industry in some parts a kick start on the learning curve which could flow into further delays on the attack class. As for the hull and internal frame I expect corrosion and stress fractures to be the biggest issue? Which ASC is already working with tech to midigate or eliminate such issues. Tech has come a long way in last few decades so safely. So rather then worrying about the life extension let's think about how we can make it work to our benefit with the attack class.