Keep it simple and do like Abe suggested, look at how many ships you need and their estimated life of type and space the procurement accordingly. The other thing you need to do is allow enough time to plan, do your design and development and sort your first of class issues before entering series production. Do these two things and voila you have a sustainable ship building industry.
The area where I would be concerned, is that if a yard only did naval work, is that the yard workers would essentially be government employees. The issue I have with that, is that if the funding for operating the yard only comes from naval build programmes, changes in Government/government priorities (like a budget crisis) would have negative impacts upon continuity at the yard. A case in point from other defence build programmes is when Government made a platform production choice on what was most advantageous politically for the party in power at the time, instead of choosing the best piece of kit for defence. In point of fact, I suspect this political interference is at least partially to blame for why there are so many 'half-arsed' shipyards around Australia, instead of just one or two yards which can competently do all the work.
From the reading, it sounds as though the now-closed Cockatoo Island Dockyards at the time was in a position to do everything which needed doing for RAN naval construction, both in terms of facilities as well as having the skilled work force.
Now, I readily admit I do not know very much about the industries involved in naval or commercial shipping construction. Having said that, it sounds to me like it would like a good idea if there was a single facility or pair of facilities within Australia able to meet RAN naval construction needs, which also had sufficient space and capacity (if not the workforce) to also allow for work to be done for commercial and foreign naval shipping construction. Even if the non-RAN vessels were sold at 'cost' or with a CoA-subsidized discount, this would seem more economical than the sort of haphazard boom/bust which has been going on in Australian shipyards.
Well, wouldn't buying overseas be the logical solution?
There are several points which really need to be addressed here.
Advantages;
You get your stuff at the right price.
This only really works if there is either a very well drawn, tight contract agreed to by the purchaser and the builder. As seen with the A400M military contract where Airbus guaranteed a certain price, but due to programme issues had to raise the price, getting things at the 'right' price does not always happen, even with a signed contract in hand promising just that. IMO the circumstance where an order for naval vessels is most likely to be delivered at the 'right' price is for a MOTS purchase from an ongoing build programme.
The possible counter-arguments I have heard:
"Independence":
Anyway, unless you are the USN, you are going to rely on foreign friends for key systems. A warship is not to much good if doesn't f.ex. have modern weapons or sensors - and hopefully few suggest that AUS undertakes her own missile projects or radar projects...
I think you are either seriously undervaluing 'independence' or perhaps taking an entirely too narrow view of it. Consider, for instance, what a MOTS purchase is, and what that entails. A MOTS purchase is a Military Off the Shelf purchase. Some piece of kit, aircraft, ship, etc has been designed, tested, developed and put into production to meet some set of requirements someone drew up. Sometimes (not so much nowadays apart from some UAVs) this has even been done on speculation by a defence manufacturer. For a force like the ADF/RAN, a MOTS purchase means getting a piece of kit which meets requirements and specifications drawn up by someone else. If the ADF/RAN happens to have the same specifications or perhaps a looser version of those specifications for the same piece of kit, that is fine, or if the RAN or ADF specification can be met with very minor tweaks to the kit. By very minor I mean something like was done with the RAAF SHornet MOTS purchase, where the instrumentation (altimeter, fuel gauge, etc) as used by USN/USMC pilots was replaced with instrumentation providing metric system readouts.
Given Australia's literal place in the world, an the areas of interest to Australia, kit used by the ADF could be operating in environments ranging from the bitter cold of Antarctica, the extreme wind/sea conditions of the Roaring Forties, to the heat and humidity of tropical jungle in northern Australia, or as found in portions of ASEAN and South Pacific Islands. With the potential for a stop in the desert in the Outback along the way.
While the RAN is not going to be operating ships in a desert, the above does illustrate that ADF kit does need to be able to operate across a wider range of environments than most. That in turn means that specifications drawn up for equipment used by other forces might be sufficient for equipment Australia is looking to use.
A ship designed and built to operate in the North Atlantic or in the Artic Ocean, with an ice-strengthened hull and appropriate heating system would likely be appropriate for Southern Ocean operations, though depending on the ships ballast systems and bouyancy, the sea states in the Southern Ocean might still be a bit much. However, if that same vessel does not have the appropriate cooling and ventilation systems for a cruise in the tropics, then service in northern Australia and/or the islands north would be a problem for such a RAN vessel.
In short, it is not just about being able to 'build' everything oneself. It is very much also about being able to build what one wants/needs, and then retaining the ability to maintain and modify the same as needed.
While a foreign build for some of the same broad environmental specifications that the RAN needs could be done, there would then be exposure to programme risk, cost and delay, without the work and money staying within Australia.
"The poor workers about to loose their jobs"
The absolutely worst thing you can do to avoid job loss is to artificially keep something alive that aren't worthwhile, it just works opposite (just look how the UK managed to transform it self from leading industrial power to very much not leading industrial power in about 50 years).
Here too I feel the importance of this is being undervalued. From an economic standpoint, a local build, with high (but not complete) domestic content can be ~30% + more expensive, and still compete with an overseas build. That money, by virtue of staying within Australia, either is used to purchase things to support the shipyard in Australia or ends up getting paid to Australian workers. These workers then pay taxes, or use the money to purchase buy goods and services from other Australian companies, starting the cycle all over again. The flow-on effects from maintaining a local build have the potential to be significant just from an economic position.
As also alluded to above, by keeping the work, or having significant work done within Australia, can make maintenance, modification and support easier within Australia. If Australia did not have shipyards, then the skills of the Australian repair yards might not have been able to be retained sufficiently to meet RAN needs for updates and upgrades to various programmes like the FFG-UP or the ongoing upgrades to the Anzac FFH. What sort of impact would there be upon the RAN if a vessel needed to be sent overseas for prolonged periods of time in order for them to undergo maintenance and upgrades? If a vessel was being fitted with a new radar system like CEAPAR and there was a sudden need for a surge deployment, how long would it be before such a deployment could get back to Australian home waters if the upgrade was being done on the west coast of the US, nevermind in Europe?
It is absolutely true that domestic build programmes are not a 'retain at all costs' type of measure, but they are also very clearly not something to be dropped lightly either, since the advantages of a foreign build are not always so important.
-Cheers
