Future Australian SSNs entering service must be coordinated with Collins SSKs leaving.
Anonymous on of February
19, 2022, has well argued:
I have been looking at
the question of time to construct SSNs, cost and what program must be achieved
to minimise the time Collins Class subs must remain in service. This is
particularly critical to avoid capability gaps for the RAN. For this purpose I
am assuming it is undesirable to keep any Collins SSK in service longer than 40
years from commissioning, even after life extension.
One of the problems in
replacement the RAN faces is that the six Collins Class SSKs were built
quickly, with a one year "drumbeat" starting in 1990, and an average
construction time of 7 years. This means, if we adopt the "40 year
rule" that they all need replacement between 2036 (HMAS Collins) and 2043
(HMAS Rankin). Note that in 1995, the ASC shipyard, Adelaide, had the fully or partially
completed hulls of all six Collins Class subs present at the one time.
From the little we know
about the defunct Attack Class SSK construction program from the ANAO Audit, the intent was
to start construction in 2023, with a 2 year "drumbeat" and delivery
starting from 2023. With the delays that occurred, the best that could have
occurred now was a 2025 start, with delivery commencing from 2035 onwards. This
meant the critical 6th Attack SSK, which would replace the last Collins SSK
(Rankin) would commission in 2045, when Rankin would be 42 years old. The worst
case would be HMAS Sheean, which would not be replaced until 2043, when Sheean would
be 43 years old. This ignores any yard capacity constraints, and assumes up to
5 Attack Class hulls could be present in ASC simultaneously.
So had we continued with
the Attack Class at the leisurely pace proposed, we would have faced a
capability gap risk anyway. This was because we were replacing an SSK class
built at a one year drumbeat, with an SSK class to be built at a 2 year
drumbeat.
Can we do better? I think
the answer is yes. The key is the drumbeat. I have constructed a schedule that
assumes the following:
- ASC would build an
"AUStute" [Pete comment: Have used "AUStute" rather than "Austute" so it doesn't look like a typo of "Astute".] modified Astute Class SSN, with S9G reactor fitted
- ASC would need to be
upgraded to a nuclear engineering standard, taking 3 years to 2025.
- The first AUStute would
be laid down in 2026, take 8 years to launch (same as BAE Astute #1)
- AUStutes would be built
in batches of 3, with a one year drumbeat between each, but then a gap till the
previous boat was launched, assuming ASC can only fit 3 boats at a time,
similar to Barrow shipyard in the UK.
- This would give AUStute commission dates of 2034, 3035, 2036, 2041, 2042, 2043, 2047, 2048, and 2049.
- Note that the first
batch are assumed to take 8 years each, 7 years for the second, 6 years for the
third. This is the same as Electric Boat achieved on Virginia construction,
using modular techniques. The same approach should be used for the
"AUStutes".
The result is the
critical 6th AUStute enters commission in 2043, allowing retirement of Rankin
at age 41.
Two other points to note:
1. if we did build RAN
SSNs in sequential batches of 3, I see no reason not to build 9 instead of 8.
The extra cost and build time would be small once the process is set up.
2. Assuming the AUStute build went from 2026 to 2049, by the time some extra years were added for mid
life upgrades of the nine AUStutes, it would be time to start building the next
class, nominally in 2056. Hence a continuous build would be achieved.
I have estimated the
total program cost in $2022 and outturn $ assuming:
- AUStute cost is BAE
Astute cost, converted to Au$, inflated by 1.3 for Australian shipbuilding cost
premium (Rand report of 2015), S9G reactor cost added,
- $30 million per annum
extra (each) for ANSTO and ARPANSA,
- $558 million of design
costs,
- $2.4 billion for ASC
upgrade, and $2 billion each for Fleet Base West (2025-2027) and Fleet Base East (2033-2035) upgrades.
The end result is a 2022
cost for nine Australian built Astutes with S9G reactors of $54.6 billion, and
an outturn cost of $78.8 billion. This is only Capital Expenditure and regulatory cost, not Operational Expenditure. Also it assumes no differential extra cost to go from the Astute combat system to the US combat system. If that is more, add another $9 billion.
I know this is only
speculation, but all is based on public sources. To me, the most critical thing
to avoid capability gaps is to start upgrading Fleet Base West and ASC to a nuclear
engineering standard ASAP. Sorry for the long post. Not sure how to send you
the cost spreadsheet.
Pete Comment
For commercial, legal and
political reasons US and UK corporations and governments are unlikely to accept
the concept of a UK designed SSN using a US reactor labeled "S9G".
This is why a UK reactor
labeled "PWR3", with mixed US S9G and UK Rolls Royce characteristics, seems acceptable.
See https://en.wikipedia.org/wiki/Rolls-Royce_PWR#PWR3
"PWR3 was a new
system "based on a US design but using UK reactor
technology". The Royal Institution of Naval Architects reported
that it was likely that the UK was given access to the US Navy S9G reactor
design used in their Virginia-class submarines."
As with a larger version
PRW2 going into Vanguards and smaller PWR2 version into Astutes, I suspect a larger version PWR3
is going into the Dreadnoughts and smaller version PWR3 into the SSN(Rs) aka
SSNRs.