Long time lurker, but this topic prompted me to join and comment because I have been pondering about such things lately, so a wall of words follows.
The port is owned by the NT Government. If they want to/can be persuaded to add berthing facilities for the Navy, it is less a matter of commercial concerns than if it was a private entity. To be frank, I would imagine the NT Gov would bend over backwards or forwards to have a significant Navy presence over and above the PBs.
A section of the new wharf area is dedicated for loading/unloading equipment and vehicles onto vessels. How set in stone the plans are I don't know, and I can't find details of how the area will be constructed, but surely a birth for side loading large vessels must be a given as that is how the LSD and LHDs are loaded?
I know this is my first post so I can't post links (just replace the underscore with a period), but a combination of...
* This stylistic plan: www_darwinport_nt_gov_au/sites/default/files/images/map-aerial-large.jpg
* And this annotated aerial photograph: img214_imageshack_us/img214/6214/darwineastarm2030.jpg
...shows the size of the planned Defence hardstand. There is room for some changes there.
If they were interested in shifting from Larrakeyah there is room for the Navy to build a substantial base at a number of points (depths and tides permitting), even after the commercial interests are taken care of.
But I think all this is just of academic interest because I don't think such a basing option would be very desirable for Defence. The theoretically ideal option, I would think, would be Townsville and schedule in additional "diversity training seminars" for the two services based in town.
: 48 years after Martin Luther King Jr had a dream, and little Army boys and girls can't hold hands with little Navy boys and girls.
But getting back to the point, the dedicated amphib unit would get to play often with the equipment and people they are likely to use, and so would the local Army Av unit, the ships are there ready to load up so they can leave as soon as the escort gets there, and they are well positioned for a move into the Pacific or to the northern archipelago.
I would think expanding HMAS Cairns for a LHD home would displace a lot of commercial wharf area in a port where it isn't easily replaceable, unless you wanted to build on the eastern side of Trinity (which would leave either a long drive or short boat ride into Cairns).
Is Brisbane not an option? Perhaps on the north bank, close to the airport and the Meeandah Stores area (which could be a more developed Joint logistics hub). You could call it something way out of left-field, like...HMAS Moreton.
Future basing is going to be a real problem. You have the Navy super-sizing like a fat boy at McDonalds and GI isn't getting any bigger. In fact it may get even smaller if the Sydney tourism drones get their way and turn it into a cruise terminal. That the Fed Gov didn't immediately stamp down hard on the proposal with a loud "No" is just awful. Should have left no wriggle room. It means the State Gov will keep whining away like a brat until someone gives in.
Has there been any musings over an HMAS Coonawarra and Cairns redevelopment, in light of the size of the OCV? It's not just wharf space but the ship lifts and maintenance requirements. Coonawarra would need a major redevelopment and Cairns has only just had one.