I do not see China as a risk, they are already buying as much of
Australia as they need and will continue.
After all they already have a large population here and an increasing
amount of land, so why invade ?
They already have !

Dear Pete,

According to the “London and Paris Conferences” of 1954 Germany was allowed a displacement of just 350 t for submarines. It was raised to 1,000 t in 1962 and finally lifted in 1991 “Treaty on the Final Settlement with Respect to Germany”. Despite that submarines with a displacement of more than 1,000 t were built and delivered to allies.

The reason for Type 212 was far more range and a different crewing system. The crew will be replaced and the submarine will stay close to the theater with minimal support. A reliable submarine is necessary to operate in such a way.

This crewing system would be suitable for RAN. A reliable submarine could be stationed at Christmas Island e.g. Type 210mod. Trip to center of South Chinese Sea in about a week and 2 or 3 weeks on station are feasible.

“1. An Australian submarine tender sitting beside the South China Sea is not a serious solution as it would be under permanent Chinese satellite or "fishing boat" surveillance. This could escalate to permanent, dangerous, Chinese (or Russian?) SSK surveillance.”

A submarine operating out of Christmas Island won’t need a tender submarine but a tender is a very nice tool. As you noted the tender would remain under close surveillance. Fishing boat surveillance would be nice for a fast tender with high sustained speed. RAN could easily distinguish the "fishing boat" from the fishing boats.

SSK surveillance would be the best thing what could happen. Your tender just needs a towed sonar system to record SSK noise. A tender should be cheaper than a submarine doing this job (not sure about a canoe tender by ASC being cheaper).

...
“2. the ability of an Australian sub to rapidly move unrefueled from Fremantle to the mid South China Sea, operate there for 2-3 weeks and return to Fremantle is essential. This is something the lower range and small tired crew of a HDW 210 couldn't do. “

That is the way Collins-class is operated. Just the way from Garden Island to Christmas Islands is about 1,400 nm or about 6 days for Collins-class and also back. Nearly 2 weeks worth nothing only necessary due to an unreliable submarine that needs a lot of maintenance after such a patrol.

Why should the Type 210mod crew being tired? The way of doing it with a Type 210mod would be quite different. 5 or 6 weeks patrol, back to Christmas Island, one week or less maintenance and back on patrol with a new crew. Two weeks more travel for Collins-class crew. There is also a big difference between maintaining 3 Garden Island-Hedemora with 18-cylinder each against two well proven MTU 12-cylinder at sea or the Type 212 solution 1 MTU 16V and fuel cells.

Check the following page according to Time Between Overhauls (TBO) for MTU 396: 7,250 hours or 300 days. That is far more than one year on station and then back to overhauls. BTW For how many days was the Collins-class fleet at sea this year?
http://www.bmtdsl.co.uk/media/5045649/BMTDSL-Multiengine-submarine-power-supplies-Pacific10-Jan10.pdf
(I know submarine diesel won't run 24 hours a day...)

“3. Unlike Germany Australia does not have the large population and technical density to provide full submarine service ports for 210s in Broome, Darwin, Townsville, Cairns etc.”
Check for MTU maintenance in Australia http://www.mtudda.com.au/corporate/overview/
The point is with Type 210mod RAN would not need full service ports around Australia as for Collins-class.
Start to think different;-)

Regards,
MHalblaub

Obviously MHalblaub and some others know more about submarines than me.
In peace time the submarines could go to Singapore to refuel and change
crews. Perhaps they do that anyway.
However in time of hostilities Singapore might not want to be involved
so I guess Darwin or Broome might be an alternative fueling port.

However if Singapore was not available then fuel would not be available
in Australia. So I guess you just tie them up somewhere.

There is no way around that. In a time of hostilities fuel will not be
available so what is the point of buying diesel submarines anyway ?

Dear MHalblaub

Thanks for the info on the 1954 etc tonnage restrictions on West German Navy subs.

On Type 210 you win.

By 2025 retire the Collins and replace with:

6 x Type 210modAUs https://www.thyssenkrupp-marinesystems.com/en/hdw-class-210mod.html .

With Australian specifications for:

- comfortable 60 days endurance

- 21,000 km unrefueled range

- 25 knots speed submerged

- fuel cell AIP

- 20 x Mk 48 torpedos/Harpoon SLCM/Tomahawk SLCM/mines

- combat system interoperable with satellite, undersea arrays, and all allied subs.

- detachable dry dock shelter sufficient to carry SEAL delivery vehicle for 10 divers http://gentleseas.blogspot.com.au/2014/08/navy-seal-and-submarine-capabilities.html

By 2035 4 x Virgina Class SSNs.

Cheers :)

Pete

err Plantagent, whats the point if fuel is not available ?