WI: County Class Destroyers with RIM-24 Tartar?

[NOMISYRRUC]

Interesting. However it faulty in some of it's detail, in the thrust of your argument you are correct. The only problem was, Australia couldn't afford to build it's one DDGs. Which was why it decided to purchase the Adams class from the US (and of course, the Government of the day was hell bent on over-identifying it's ambitions with the US's foreign policy). It lacked the technological edge and it lacked the weapons' system experience.

Should the third sentence read?

The only problem was, Australia couldn't afford to build it's own DDGs.

If that's correct do you meant that the 3 Adams class destroyers that were bought for the RAN were built in America because it would have been prohibitively expensive to build them in Australia?

ITTL the Australians build 4 ALT-Type 81 frigates modified to suit the RAN's requirements instead of the 4 Yarra class frigates that were built IOTL. The ALT-Perth was an enlarged ALT-Type 81 fitted with a US-supplied Tatar system (Mk 13 launcher, magazine for 40 missiles and 2 SPG-51 radars). I had it built in Australia because I thought they could because they had already built 4 similar ships and because the Australian Government would want them to be built domestically for political reasons. However, the ship was designed for the RAN by the British DNC's Department.

Therefore, if you think that Australia wasn't capable of building Tatar armed ships in the 1960s I've no objection to the ALT-Perth class being built in the UK.

 

[NOMISYRRUC]

Do you have any info on the fuel consumption etc of the different parts of the COSAG power plant?

My understanding is that gas turbines have the same or better fuel consumption than steam turbines and that the fuel consumption of both types of turbine engine is worse than diesels.

However, I have no information on the fuel consumption of the steam and gas turbine portions of the OTL Type 81. I don't have any figures to the fuel consumption of the Rothesay and Leander classes steam turbines either and 35 ALT-Type 81 frigates are built instead of them. My ALT-County class has all gas turbine machinery too and I don't have any information on the fuel consumption of the different parts of the OTL County's COSAG machinery.

I.e. would the ship still have the same range as presumably the Steam was used for cruising and the Gas for fast starts and more top speed?

That was the intention, but according to Royal Navy Frigates 1945-1983 by Leo Marriott, "Experience was to show that the gas turbine was reliable enough to be run continuously for long periods rather than just as a boost engine. This fact was to lead to improved gas turbines being used as the sole form of propulsion in later designs." I thought that as these ships have four G.6 engines one or two of them would be run in rotation while the ship was cruising and all four would only be run when maximum speed was required.

The ALT-Type 81 is larger than the real one to accommodate the more powerful engines and second shaft. I though that the larger hull would also be able to have bigger fuel tanks so they would have more fuel to offset any increase in fuel consumption.

One of the reasons for the earlier introduction of all gas turbine machinery is the it needs less men to operate it. Therefore, the TTL RN of the 1960s and 1970s aught to keep more ships in commission with the same number of men because some of the ships have smaller crews. However, if it's the same number of ships with smaller crews the money saved in wages can be used to pay for more fuel.

 

[NOMISYRRUC]

Do you have any info on the fuel consumption etc of the different parts of the COSAG power plant? Ie would the ship still have the same range as presumably the Steam was used for cruising and the Gas for fast starts and more top speed?

As I wrote in my previous reply, no I haven't, but my understanding is that gas turbines have better fuel consumption than steam turbines. This is a quote from Leo Marriott's Royal Navy Frigates 1945-83, Appendix 3 RN Gas Turbine Development, Page 122.

The advantages of the gas turbine as a warship propulsion plant are numerous. They are slightly more economic on fuel than an equivalent steam plant and are easy to control, replying almost simultaneously to changes of power settings. This in turn leads to less engine room staff required on watch, a factor which is also helped by the fact that a complete engine module can be easily removed and replaced which means that an on-board maintenance is reduced. The fact that major overhauls can be carried out while ashore while another engine is installed in the ship means that the amount of time a ship needs to spend in dockyard hands is sharply reduced. In fact, as was shown in the Falkland Islands, large ships such as the carrier Invincible can actually carry out an engine change while at sea. Of course this is not possible in a small ship such as a frigate but it does illustrate the advantages of the modular concept of the gas turbine. The Type 42 destroyer HMS Southampton changed one of the Tyne units while under anchor alongside the repair ship Stena Seaspread in the relative calm of San Carlos Water, showing that with limited facilities this sort of work can be carried out when required.

 

[Rickshaw]

Should the third sentence read?

If that's correct do you meant that the 3 Adams class destroyers that were bought for the RAN were built in America because it would have been prohibitively expensive to build them in Australia?

Basically yes. The Adams class were OTL the most advanced US ship entering service, in that class. They had guided systems which were judged to be superior to the UK ones. It wasn't just expense, it was their technology which was the problem.

 

[NOMISYRRUC]

Basically yes. The Adams class were OTL the most advanced US ship entering service, in that class. They had guided systems which were judged to be superior to the UK ones. It wasn't just expense, it was their technology which was the problem.

ITTL the Australians built 4 ALT-Type 81 frigates (modified to suit the RAN's requirements) in their own yards. These were built instead of the 4 Yarra class frigates (Type 12s modified to suit the RAN's requirements) that were built in Australian yards IOTL.

The ALT-Perth was an ALT-Type 81 fitted with a US-supplied Tatar system (one Mk 13 launcher with a magazine for 40 missiles and 2 SPG-51 radars) with an enlarged hull to provide the necessary space and four Metrovick G.6 gas turbines uprated from 7,500shp to 10,000shp to maintain the maximum speed of at least 28 knots.

The ALT-Perth was designed for the RAN by the British DNC's Department. This fits OTL because the British designed several Tatar armed ships for the RAN in 1960. They included Tatar armed Counties and a proposal to rearm the RAN's Daring class destroyers with Tatar. According to my source (Friedman) two or three were to be built in the UK with the first two delivered in 1966 and the third in 1967. However, Friedman wrote.

In the end, the Australians decided to buy, not only the American missile, but also the American destroyer, the Charles F. Adams class. That was despite the fact that the Adams lacked some features they badly wanted, such as helicopter capacity.

I had the ALT-Perths built in Australia because the RAN had already built 4 similar ALT-Type 81s. A secondary reason was that the Australian Government would want them to be built domestically for political reasons: jobs for Australian workers and suchlike.

I'm perfectly happy to have the ALT-Perths built in the UK. Does that satisfy your objections?

However, in that case it would have been better for the for the RAN to buy County class destroyers which ITTL were armed with Terrier instead of Seaslug. That's what I wanted to do in the first place. I didn't partly because of the extra cost and mainly because the RAN's Adams class destroyers had a crew of 333 and the OTL-County had a crew of 471 (Source: Jane's Fighting Ships 1968-69) so I thought that the RAN would have trouble finding the extra men.