Supplementary memorandum from Professor
Richard L Garwin
These brief comments respond to those aspects
of the Ministry of Defence Testimony of 6 February 2007 that bear
on my written evidence and oral testimony of 23 January 2007. I
have been authorized to write on behalf of my colleagues, Philip
Coyle, Ted Postol, and Frank von Hippel.
In response to our statement that the Vanguard
class SSBN could well have its operational life extended by 15
years, as was the case with the US Ohio class, the MoD refers
to the various systems that would have to be maintained and perhaps
replaced if this life extension were to be achieved, and they
summarize with the assertion that "the evidence that we
have suggests that it would be poor value for money."
Before the MoD can reach a conclusion (going beyond "suggests"),
there should be a breakdown of costs by subsystem, and a discounted-present-value
analysis of the options of new construction vs. life extension,
as we indicated in our written evidence. There should be an explicit
discount rate for the comparison of the alternatives.
Defence Minister has rejected the observation
that the reduced at-sea hours for Vanguard in comparison with
the Ohio-class should make an operational life of 45 years easier
to achieve because "The critical time from the point of
view of when we measure the life of a boat is from when the reactors
first go critical. My understanding is that you may well be able
to bring the boat in but you cannot switch the reactor off and
there are other parts of the system which will age no matter whether
the boat is at sea or not, . . . " Detailed description
of the maintenance cycle of the Trident submarines has been provided
by the US Navy[125]
in an article describing the 200th dry-docking of an Ohio-class
SSBN at the Intermediate Maintenance Facility, Bangor, Maine.
These refits, taking 18-22 days are "designed to be incremental
overhauls, conducted approximately three times a year for each
TRIDENT boat." The reactor does not operate while the
SSBN is in dry-dock.
Adding to the confusion is that Rear Admiral
Andrew Mathews either misspoke or that the transcript understandably
erred in recording his statement as "The difference with
the Americans is of course that they are generating two or three
hulls from 14 ..." Perhaps he said or meant to say
"... they are generating two of three hulls from 14 ..."
In fact, the overall at-sea rate of the US Trident
is 66%. Roughly 10% of the entire fleet is in refurbishment (one
year out of 10) and the remainder is on a normal operating schedule
(73% at-sea rate for operational SSBNs). The typical deployment
schedule is at-sea for roughly 78 days, and in-port for 28. During
the 28 day "refit" period (18-22 of these days may be
in dry-dock) the crew that completed its at-sea operations works
with the second crew to prepare the ship for its next 78-day second-crew
tour.
I do not know the corresponding numbers for
Vanguard.
Rear Admiral Mathews identified "things
like cables" as components that age at similar rate whether
the SSBN is operating or is in maintenance, but it is clear that
many do not, among those most of those listed by Defence Minister
as problematical for life extension: "replacement of some
of the systems critical to submarine operations, such as external
hydraulic systems, elements of the control systems (plane and
the rudder), sonar systems, electrical systems (including the
main battery) and refurbishment or replacement of elements of
the nuclear propulsion system."
So far as non-operational deployments are concerned,
such as "training," these can and should be minimized
and at the same time the quality of training and evaluation much
improved by the aggressive use of simulators. A Vanguard simulator
should have, of course, the same human interface as the submarine,
but it would be a "virtual Vanguard" that responds to
commands and manipulations as the real SSBN should, but can readily
be put into conditions that would be impractical or dangerous
for the real ship. Such a capable simulator is no minor matter,
but it is of great value.
I close by restating our judgment that the MoD
has not communicated sufficient information for the Defence Committee
to judge the merits of its case to commit to a renewal of the
Vanguard fleet, and our recommendation that more work be done
on the substance and cost of a 15-year life extension program,
in preparation for an informed decision next year. It would be
most helpful to the Committee's work (and to the MoD itself) to
have an in-depth technical review of the issue by an outside expert
panel.
19 February 2007
125 http://www.chinfo.navy.mil/NAVPALIB/CNO/N87/usw/issue_18/imf.htm Back
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