I can see a number of problems with attempting to have land-based Tomahawks. Apart from the costs involved (USD$2 mil. per missile for FY2022...), all sorts of force structure and infrastructure questions would need to be answered, as well as how such a capability would be utilized in Australian service. I will be honest and state that I do not think such a capability would be particularly easily for Australia to bring to an operational level, or be particularly useful, and certainly not for the likely costs involved. In many respects it sounds much like proposals and assertions about turning ~1,600 tonne OPV's into warships equivalent to FFG's.
Firstly, would these proposed Tomahawk missiles be in launchers at a fixed location, would be they be mobile in vehicle, trailer, or even train car-mounted launchers? If the launchers are fixed, then Australia just put a large "Shoot Here" sign on wherever the launch site is. If the missiles are supposed to be mobile, then vehicle systems for all the necessary bits to actually launch the cruise missiles need to be produced and integrated into Australian military service. IMO this would not be a particularly easy task, as I suspect quite a few vehicles would be required to enable a strike of useful/effective size. Each TEL from when ground-launched Tomahawks were in service, could transport four missiles, and multiple TEL's would be required, as well as command & control vehicles, comms, etc.
There would also need to a OODA loop setup, with assets needed to provide the observation capability and target quality data. Without that, Tomahawks would only be useful to hit fixed targets that are within range of the launch site. To provide some context, a launch site near Darwin could potentially reach out into Indonesian waters around the southern portion of the Celebes Sea ~1,800 km away. Such a distant target would also take ~2hrs for the missiles to reach the target, which would present a problem if the target was supposed to be a ship or taskforce. Such a target if only cruising at 18 kts could easily be over 60 km away from where they were at the time of missile launch. Therefore some observation asset would need to be able to provide regular, frequent updates of target quality data which could then be relayed to the missiles while in route. Before any were to suggest it, whilst JORN provides a very good, wide area surveillance capability, it does NOT provide target quality data, additional systems would be required for that. Also, I would expect that Australia would be rather reluctant to blindly fire missiles at contacted detected 1,800 km away, without first identifying what the contact was.
As mentioned, the range of a Tomahawk tops out around 1,800 km, so apart from being able to hit targets in Indonesia, or in Indonesian waters, any land-based launchers would be limited in target options when based in Australia. Good luck getting permission for Australia to have land-based Tomahawk launchers operating in another country. Final note for this idea. 2k Tomahawk missiles works out to ~USD$4 bil. for just the missiles alone. It does not include any vehicles or launchers, any control systems, training and maintenance, etc. It also does not provide for any of the additional personnel that the ADF would need in order to operate and maintain the missiles and launchers, never mind whatever surveillance systems and comms arrays in order for Australia to be able to detect, target, and then engage something with land-based Tomahawks.
As for the idea of Australia building Arleigh Burke-class DDG's, in Australia... Yes, I suppose that is a possibility. However, the designs would all need to either be re-worked since the USN does not use the exact same systems as Australia for a number of things, or the RAN would need to adopt the exact same specific pieces of kit the USN uses aboard their DDG's. In short, the things that the US ironed out with their destroyer builds would not necessarily translate into an Australian build, because the two builds would not be identical. There would also be the reality that whatever Australian yard were to do such a build would still have a bit of a learning curve getting up to speed on the design.
