The County Class were impressive ships certainly to this raw Midshipman who drooled over HMS Kent when in company with her in 1968, veritable Gin Palaces.
The RAN showed keen interest in them in the late 1950s but with Seaslug being replaced by Tartar and fitted with Ikara.
The following old article by Dave Shackleton, ex neighbour, one class ahead of me in both initial training and UK PWO courses, explains the RAN’s rationale for going ahead with the USN CFA class in lieu.
From its origins in 1901 until the late 1950s, through its deep association with the Royal Navy, the Royal Australian Navy became unmistakably British in outlook, practices and culture. It was a relationship of great ...
www.aspistrategist.org.au
I have wondered if Australia's involvment with the development testing of Seaslug at Woomera coloured view of the system. There were plans for the light cruiser Hobart to be converted to a CLG in the 50s, likely with Seaslug, that went nowhere.
Tartar was attractive because it was designed with a launcher able to replace a Mk-38 twin 5" mount and it below deck arrangements. Technically it could also do the same for the Mk-6 4.5" twin and it was assumed could have been fitted to the RANs Daring and maybe even Battle class destroyers in midlife upgrades. It's not as simple as swapping guns for missiles but the compact Tartar system was definately a simpler prospect for such than Seaslug, Terrier, or Talos.
If I recall correctly Dr Shackleton's thesis (the article is based on this paper) also suggested the USN Belknap Class DLG may have been, though more expensive, better value for money, than the CFA DDG. This was because of the USNs development of the class through a series of incremental upgrades, capped off with the NTU program that delivered a massive capability improvement far beyond what we were able to achieve with the DDGs.
The RAN, wanted a smaller, steam only destroyer based on the County, basically a DDG version of the Daring, with Tartar, and a helicopter (or two), while retaining two twin 4.5" gun mounts and possibly shipping Ikara, all on the same displacement as a CFA. A bit of a stretch.
The UK responded that they didn't have the capacity to develop such a design and suggested Australia procure either the baseline County, or alternatively wait for the Escort Cruiser, which more closely fit the RAN requirement (except for displacement.
The Escort Cruiser continued to evolve, eventually becoming the complement to what became the Type 82, to escort the CVA01 carriers. When the carriers were cancelled the escort cruiser concept grew (through multiple iterations, concepts, stops and starts) into what became the Invincible class Through Deck Cruisers, later acknowledged to be carriers. There was even a version based on the Type 82 with a large hangar and helideck with Seadart moved forward in place of Ikara.
I wonder what would have happened if the UK had developed a version of the County to meet RAN requirements. Perhaps merging it with their Escort Cruiser requirement, instead of trying to design a Leander based air defence frigate, that grew into the Type 82.
Tartar was originally developed in part due to a UK request for a point defence missile based on the interceptor stage of the Terrier missile, and the Seadart missile launcher and magazine was conceptually similar, if not actually based upon, the USN Mk-11 GMLS of the original Tartar system.
A 1960s version of AUKUS could have had some very interesting progeny.