a DoD spokesperson, the RAN
has implemented a “whole of life”
management plan for its assets
as recommended by government
reviews carried out in 2008 and
2011. “The plans factor the
overall costs for maintenance
into the acquisition process,” the
spokesperson said. “A culture
of accountability has also been
instituted which considers the riskversus
cost benefits of deferring
preventative maintenance.”
There are a number of ways
to estimate the financial cost
of corrosion of RAN assets,
including scaling the costs of a
foreign navy operating similar
warships. According to the RAN
spokesperson, the economic
impact of corrosion and it’s
degradation of naval assets and
infrastructure is estimated to
be between $135M and $650M
annually, depending on the metric
used to calculate the cost of
maintenance and remedial repairs.
The planning now being
implemented by the RAN is
condition-based maintenance
which optimises maintenance
costs by only intervening when
a monitored system’s condition
indicates a problem. Corrosion
Prognostic Health Management
(CPHM) uses these principles to
predict current and future corrosion
conditions based on platform usage
in an operational environment.
CPHM uses a combination of
sensors and models to predict and
plan future maintenance activities
and operations.
“Moving from a time-based to a
condition-based maintenance
system through use of
environmental and corrosion
sensors, allied with corrosion
prognostics and modelling, should
allow targeted maintenance and
more efficient use of limited
resources,” the RAN spokesperson
added. “It will also allow improved
scheduling of maintenance,
resulting in optimum usage of
platforms and equipment.”
Ship staff on a warship are directed
to report changes in appearance
or obvious signs of corrosion. If
staff have the relevant training they
may apply corrective maintenance
if it is safe and timely to do so.
However, maintenance at sea or on
operations is usually only carried
out if it is high priority. The majority
of maintenance is carried out while
the ship is alongside or in dry-dock
in accordance with the technical
maintenance plan.
The RAN's mission includes
maintaining Australia’s sea lines
of communication and defending
Australia’s sovereign interests.
Additionally, it undertakes
humanitarian missions around
Australia and the Asia Pacific region.
From a long term perspective,
corrosion shortens the “life of
type” of vessels that can create a
capability gap as it may be several
years before replacement vessels
come into service and may have
a large impact on the ongoing
maintenance budget as the older
vessels are kept for a longer time
than planned.
It is important to manage corrosion
in the defence industry using
preventative measures over
both short and long timescales.
Unidentified or untreated corrosion
issues can lead to unplanned
corrective maintenance that can
affect availability, readiness, safety
and capability of RAN vessels and
rotary wing aircraft for operations,
all of which result in significant
costs.
Protective coatings are critical to
mitigating corrosion as they form
the barrier between the metal and
the aggressive marine environment.
The RAN spokesperson stated that
a paint specification document
that details the coatings systems
to be applied to every part of
the ship, from underwater hulls,
superstructure and decks to all
internal areas, is prepared for each
vessel prior to construction.
Safety-of-flight is paramount
for the RAN's air assets—this
demands very strict inspection
and maintenance programs to
mitigate risk of failure. Failure of a
key component in flight could result
in accidents leading to loss of the
helicopter and loss of life.
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