ADF Deployability of Armoured Elements
Conceptually, the ADF may need to deploy company or battalion group sized elements regionally within the neighbouring wet tropics archipelago environs. Wherever deployed, such forces should have adequate integral mobile fire support expeditiously lodged as close as practicable to prospective scenes of action, which means air insertion and sustainment.
Existing and planned air resources employable for this purpose are 4 x C-17, 12 x C130J, 12 x C130H, 6 x CH-47D (to be replaced by 7 x CH-47F). Under the now outsourced system of aircraft maintenance, it is realistic to assume only 50 percent of these assets will be continuously on-line. Not all aircrew conversion training/currency requirements can be achieved in flight simulators and this need is fundamental to maintain adequate manning otherwise the system would grind to a halt; so some of the on-line availability must be dedicated to this purpose but perhaps intermittently. And; allowance must be made for support of military exercises and training for the same reason.
An optimistic assumption is that these air mobility assets would be continuously available to support operations: 2 x C-17, 6 x C130J, 6 x C-130H, 4 x CH-47F with the Chinooks providing only in theatre mobility.
For the small ADF, these principles of war should be paramount: flexibility, versatility, economy of effort so the nature of integral fire support must be tailored to what can be cost-effectively deployed and sustained. Deployment of towed artillery would also require towing vehicles whereas light armoured vehicles equipped with cannon and mortar ('poor man's artillery') would arguably be more flexible in the wet tropics.
Australian Army primary armour assets are Abrams tanks, ASLAV, enhanced stretched M113. For simplicity, let's assume empty weights approximate 67, 15 and 15 tonnes respectively. ASLAV has cannon and some M113 will have mortars, but neither as yet have dual fire support capabilities. Some physical characteristics for these vehicles are available via Wikipedia and see also this link: Australia’s M113 APC Family Upgrades
A C-17 can carry 1 x Abrams or 4 x ASLAV/M113 and a C-130 2 x ASLAV/M113. Characteristics for these heavy lifters are also found in Wikipedia.
While landing heavy C-17 and C-130 on unsealed airstrips is possible, there are limitations including bogging potential, foreign object damage to engines/propellors, manoeuvring constraints on small aprons. The C-130 would be less restricted than the C-17, but the Hercs could not necessarily go into all airfields in say PNG where Caribou once went. Nevertheless, some capability exists to deploy armour nearer to prospective scenes of action than an airhead.
If main battle tanks are employed anywhere, large transporter/recovery vehicles must also be deployed (see this link: Heavy Equipment Transport System - Wikipedia, the free encyclopedia), but not mandatory for lighter armour which is more mobile and easier recovered. Strength of pavement, roads, bridges also constrain movement of heavy armour and whether large transporter/recovery vehicles would be able to function off roads in the wet tropics is very dubious.
Deployment of armour by sea is not a quick reaction option and presently constrained by availability and strength of wharves and cranes. The LPDs when (if?) they come into service may offset some present limitations, but then Abrams tanks would have to be ferried from a destination port to a scene of action if not close to a coastline, provided roads exist. The escort requirements for an LPD carrying substantial equipment and personnel assets is also another economy of effort consideration.
In theatre heavy lift would require Chinook deployment and it seems unlikely that more than 2 could be operationally deployed, even when the CH-47F comes into service; but one Chinook properly utilized can do a lot of work. Armour guzzles fuel that is generally externally loaded by Chinooks in big rubber 'donut' bladders, although M113 were often used to carry fuel for their own elements in Vietnam.
The whole Army concept of operations really comes into question as employment of main battle tanks seems a core principle. Present Air Force mobility resources would enable quick reaction deployment of light armoured vehicles closer to prospective scenes of action to provide integral mobile fire support. But are C-17, C-130, CH-47 resources adequate to cope with multiple ADF deployments and contingencies that might emerge at short notice?