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COST AND CREATIVITY – SUBMARINE DESIGN IN A CHANGING WORLD
Michael Wear, BAE SYSTEMS Submarine Solutions, UK
John Salisbury, BAE SYSTEMS Submarine Solutions, UK
SUMMARY
Nuclear powered submarines are among the most complex of engineering products. As currently developed, they are
mature and highly optimised, with limited opportunities for change after the concept design stage. The cost and time
impacts of such changes are reinforced by the large and highly structured organisations required to design, build and
operate them. Even at the concept stage, changes to the fundamental concept or ‘planform’ are difficult and can limit
real change to detailed or incremental development.
Fundamental change in such products comes generally from major changes of requirement, or when the development
possibilities of the current ‘planform’ have been exhausted. Modular Architectures have been examined as a means of
reducing cost and increasing the opportunities for change. A design philosophy has been developed to allow
sophisticated submarines to be made cost effective both as built and through life.
NOMENCLATURE
BAESSS BAE SYSTEMS Submarine Solutions
SSN Nuclear powered attack submarine
SSK Conventionally powered submarine
SSBN Nuclear powered ballistic missile
submarine
TRIZ Theory of inventive problem solving
NRE Non Recurring Expenditure
UPC Unit Procurement Cost
NSRP Nuclear Steam Raising Plant
TGs Turbo Generators
SQEP Suitably qualified and experienced
personnel
1. INTRODUCTION
The art of the submarine designer is a fascinating but a
hard one. To carry it out effectively requires a wide
knowledge not only of engineering but of customers,
cultures, psychology and the art of war, (if in fact there is
a difference between these two). Even in a time of slow
change this is a demanding requirement to add to the
perennial questions to be answered in every branch of
transport engineering:
‘what must we carry
how far
how fast
- what do we do when we get there ?’
In a time of change the task is still harder. Previous
assumptions may be roughly challenged, processes
designed for slow development pushed aside, and
guesses made about – or allowances made for – future
developments which those accustomed to slow change
will fight against with a desperate conviction. None of
this is new to submarine designers. What is perhaps new
is to have a time of rapid change after a period of as
much as fifty years of largely incremental development.
2. A SHORT HISTORY
2.1 ORIGINS
The history of submarine design can be traced back at
least three hundred years, from the earliest pioneers,
perhaps more successful than their contemporaries who
threw themselves from towers in the search for human
flight, through Fulton and the ‘Nautilus’ to the
emergence of the practicable submarine with the work of
John P Holland. Much, though not all, of this work was
the work of lonely visionaries such as the Reverend Mr
Garret and his ‘Resurgam’.
Once the practicality of the submarine had been
established, in France, the United States and then in
Britain, a period of intense development followed. While
a British Admiral was loudly proclaiming that
submarines were ‘Underwater, Underhand and Damned
un-English’ his more practical colleagues were soon
ordering the Royal Navy’s first submarines at such a rate
that by the outbreak of global war in August 1914 the
Royal Navy alone had ordered no less than ten
successive classes from Holland 1 onwards.
Figure 1: HMS Holland 1
2
Some common threads quickly emerged. The true
submarine intent of John Holland’s work was modified
into the submersible torpedo-boat, travelling mainly on
the surface and submerging to hide or attack, familiar in
modified form until the 1970s. At the same time, the
early coastal defence boats were replaced by larger and
more capable vessels with increasing range and
armament, until the familiar form was reached.
2.2 PLANFORMS
The term ‘planforms’ is used in biology to describe the
different body shapes and arrangements of living
creatures. The dominant ‘planform’ of the submarine
quickly became standardised as a twin screw submersible,
propelled by diesel engines on the surface and electric
motors when submerged, armed with torpedo and gun,
and capable of first littoral and then of oceanic operations.
With some exceptions this became and remained the
dominant form for some thirty years, despite variations
and improvements in detail, and some remarkable
pressure hull configurations which would now horrify
both structural engineers and production managers alike.
2.2 CHALLENGE AND CHANGE
Some brave attempts to widen the scope of the new
weapon were made. The UK’s Royal Navy saw the
unfortunate ‘K’ class high speed fleet submarine, a
concept which the technology of the period was not able
to sustain, the more enduring ‘M’ class submarine
monitor for land attack, and the ‘R’ class with its high
underwater speed, prototype of the SSK. Nevertheless,
the dominant planform remained the submersible torpedo
gunboat, progressively refined and improved but with an
architecture which for twenty years remained largely
unchanged.
The first challenges appeared late in the 1930s with the
appearance of the schnorkel on submarines of the Royal
Netherlands Navy, and continued under the pressures of
war through the succeeding decade. The schnorkel,
removed from Dutch submarines by British dockyards,
reappeared on their German opponents and profoundly
changed the balance of anti submarine warfare. Most
significant change of all was the appearance of the Type
XXI U-Boat, with its air independent Walter turbines and
high underwater speed. The Type XXI’s hydrodynamics
informed a generation of conventional submarine designs,
but in the 1950s the true submarine arrived with the
marriage of the USS ‘Albacore’ and ‘Nautilus’ to create
the high speed nuclear powered attack submarine,
effectively independent of the surface, and limited in
endurance only by the capacity of its stores and its crew.
Once established, the SSN mutated into its opponent for
forty years, the SSBN, establishing on both sides of the
Atlantic a sequence of large submarine designs optimised
for oceanic warfare, particularly in the North Atlantic. In
addition to similar SSN and SSBN designs used
elsewhere in the world, the SSN influenced the design of
the SSK, from the descendants of ‘Albacore’ to large
SSKs typified among others by the French Scorpene, the
UK’s Upholder class and the Russian ‘Kilo’.
Figure 2: USS Albacore
These SSKs are commonly sized for littoral rather than
oceanic warfare, but the larger members of the type are
little smaller than some SSNs, and with the substitution
of diesel electric propulsion for nuclear, are remarkably
similar in both overall architecture and in combat system
philosophy. The SSN ‘planform’ has shown a remarkable
ability to survive, developing progressively over a period
of some fifty years.
3. SUBMARINES – COMPLEX PRODUCTS
3.1 THE PRODUCT LIFE CYCLE
A survey of past practice may seem out of place in a
paper entitled ‘Submarine Design in a changing world’.
As always, an understanding of the past is necessary in
order to understand the present and look, however
uncertainly, towards the future.
It is possible to trace in the design of submarines, as in
other complex engineering products, a cycle of
development which underlies its entire history.
Figure 3: The product life cycle
Product life cycle
‘ Mad Visionary ’ stage
Possibility driven
First successful use
Development stage
Performance driven
Many ‘ planforms ’
Rapid concept innovation
Mature product
Cost driven Few planforms or one
Innovation in detail Modularisation
Technology insertion - ie NSRP
PRODUCT MATURITY
Obsolescence
Niche use
Replacement by new product
‘ Mad Visionary ’ stage
Possibility driven
First successful use
Development stage
Performance driven
Many ‘ planforms ’
Rapid concept innovation
Mature product
Cost driven Few planforms or one
Innovation in detail Modularisation
Technology insertion - ie NSRP
PRODUCT MATURITY
Obsolescence
Niche use
Replacement by new product
‘ Mad Visionary ’ stage
Possibility driven
First successful use
Development stage
Performance driven
Many ‘ planforms ’
Rapid concept innovation
Mature product
Cost driven Few planforms or one
Innovation in detail Modularisation
Technology insertion - ie NSRP
PRODUCT MATURITY
‘ Mad Visionary ’ stage
Possibility driven
First successful use
Development stage
Performance driven
Many ‘ planforms ’
Rapid concept innovation
Mature product
Cost driven Few planforms or one
Innovation in detail Modularisation
Technology insertion - ie NSRP
PRODUCT MATURITY
Obsolescence
Niche use
Replacement by new product
Performance
Time
Sources: Harvey - Jones, Sir J Churchward, GJ Stewart, I, Cohen, J & Pratchett, T Stone, J Huddleston, C Wear, M & Associates LeRoy, JF
WE ARE ? HERE
Performance
Time
Performance
Time
Sources: Harvey - Jones, Sir J Churchward, GJ Stewart, I, Cohen, J & Pratchett, T Stone, J Huddleston, C Wear, M & Associates LeRoy, JF
WE ARE ? HERE WE ARE ? HERE
3
It typically begins with a heroic stage, typified by
visionaries such as Garret. At this stage development of a
new product is carried on by dedicated – or obsessed –
believers, often in the face of disbelief or outright
opposition. Design is driven by the need to make the
concept work at all, and it may be difficult to distinguish
the truly valuable from the purely misinformed. Cost is
borne by the pioneers, or by organisations and
governments willing to risk money on an uncertain result.
Once the new concept – steam engine, aeroplane,
submarine or car – can be seen to work, a different
dynamic takes over. The visionaries disappear and
development takes charge. In this ‘performance driven’
phase cost is not unimportant, but the value of having the
product at all is so great that even a small and poor
nation will bear the cost of acquiring it. The engineer
and novelist Nevil Shute described this period in aviation
as a time when ‘aeroplanes would fly when you wanted
them to, but there was something new to be learned on
every flight’ [1]
.
At this stage planforms proliferate as designers explore
the possibilities open to them. The ‘K’ and ‘M’ boats of
the Royal Navy belong to this phase, as do the prototype
hunter-killers, the ‘Rs’. Cultural differences also play
their part in this phase: it is alleged that while the Royal
Navy provided a hotplate and a kettle to feed a crew of
forty, another nation’s boats had three galleys, one each
for Officers, Petty Officers and ratings!
This phase also sees an increasing degree of detailed
development as the solutions found by the pioneers are
elaborated or replaced. Variant planforms are culled by
experience or war and a single ‘planform’ supported by a
standard set of technologies comes to predominate. This
phase merges with the last phase, one of incremental
development, which might be labelled ‘production
driven’. Basic capability is now taken for granted, and
unless overridden by the pressures of actual war, cost
becomes the dominating factor. The search for cost
reduction may actually reduce performance in some areas
provided that the overall effectiveness of the platform is
maintained. This is broadly the situation of the
submersible torpedo-boat by the late 1930s, and the SSN,
SSBN, and SSK now. It is a situation typical of complex
engineering products such as submarines and aircraft,
where the complexity and risk of developing an original
solution encourage incremental development.
3.1 COMPLEX PRODUCTS
From a designer’s perspective it is worth distinguishing
between complex and complicated products. A
complicated product, to a designer, is simply one with a
large number of components. Behaviour is generally
linear, typically quasi static or steady state, and may be
predicted directly from the individual components.
In functional analysis terms, each function may be
mapped directly to a component or system of
components. A machine designed by Heath Robinson or
Rube Goldberg is ‘complicated’ in this sense. The
humour, in fact, comes from the sheer complication used
to carry out a simple task.
A complex machine may have few components, but has
limited correlation between the individual behaviour of
those components and its behaviour overall.
Figure 4: Simple and complex products
It is characteristic of a complex product that its high level
behaviour is dynamic and often non linear. Behaviour
emerges from the interaction of all the components
involved, and is contingent on both operator behaviour
and inputs from the surrounding environment. In the
submarine context typical inputs are from currents, near
surface effects and wave action, water depth and salinity.
A manoeuvre as simple as a minor depth change involves
the interaction of hydrostatic stability, hull, propulsion
and control surface hydrodynamics, control surface
operating gear, propulsion plant behaviour, sensors,
platform management systems and operator actions.
Feedback loops abound, and while functional mapping is
valid at sub-system level, high level behaviour is both
emergent and contingent.
A submarine, like any vehicle, provides such behaviour
to a high degree. Its high level functions of float, move,
fight – and survive – are mutually dependent and emerge
from the interaction of the components. Its purpose is to
fight, or to offer the threat of fighting, but to do so it
must both float and move: a submarine which does not
float is lost, while one which cannot move will not long
fight or survive.
3.2 THE HARVEY-JONES DICTUM
In this situation the uncertainties of change encourage
producers and buyers, if not designers or operators, to
stay as long as possible on the development plateau. Ill-
informed innovation may actually be counter-productive,
as any engineer knows. Fashions may change, but
physics stays the same.
Glider
Airship
Sailing ship
Submarine (SSN)
Space Shuttle
Combat aircraft
Steam loco
Road vehicle
Diesel loco
Hammer & nail
Heath Robinson machine
Offshore platform
Mobile phone
Simple
Simple
Complicated
Complex
Glider
Airship
Sailing ship
Submarine (SSN)
Space Shuttle
Combat aircraft
Steam loco
Road vehicle
Diesel loco
Hammer & nail
Heath Robinson machine
Offshore platform
Mobile phone
Simple
Simple
Complicated
Complex
4
Figure 5: functional relationships
Unfortunately, it is not possible to stay on the plateau
forever. At some point any process or product reaches
the end of its development potential. Even when some
potential remains, outside circumstances may force
change through new technology, commercial competition,
legislation or war. This situation has been reached in the
aviation industry, where despite huge changes in detail,
the ‘planform’ of large passenger transport aircraft has
changed little in the fifty years since the arrival of the De
Havilland Comet and the Boeing 707. Competition and
environmental concerns are now forcing radical change
in the form of the blended wing-body aircraft.
At some point evolution must be abandoned for
revolution. This is the business philosophy of the
management guru (and submarine officer) Sir John
Harvey-Jones [2]
, and the same lesson is taught by the
techniques of TRIZ.
In submarine history such changes have arrived at least
twice. The increasing effectiveness of Anti Submarine
Warfare created the need for the Type XXI and its SSK
successors, while the combination of ‘Albacore’
hydrodynamics with nuclear propulsion and increasingly
sophisticated sonar systems created the true submarine in
the form we now know it.
An outcome of these changes has been a great increase in
the complexity of the submarine. While the last
generation submersible boats remained comparatively
simple, after four or more generations even a modest
SSK is hugely sophisticated, with inevitable effects on
design approach and cost.
3.3 COMPLEXITY, COST AND CHANGE
Complexity of design affects cost in a way which is itself
complex. When the cost of a sophisticated platform is
estimated by both ‘bottom up’ and ‘top down’ methods,
it is normal to find a substantial difference between the
two. Cost, it appears, is an emergent property of the
design and of the organisations which produce and
support it.
Highly developed and integrated products, cost driven
and optimised for a limit range of roles, acquire
organisations to suit. Much of the product knowledge
may reside in the culture rather than being written down,
and the reasons for past decisions may be lost with their
originators. When such organisations are tuned to low
risk – and low cost – development, their culture may be
unable to adapt to rapid or innovative change.
4. THE CHANGING WORLD
4.1 CHANGE AND CHALLENGE
Much of the development of the modern submarine has
taken place in the context of confrontation in the oceans
of the northern hemisphere, and the maintenance of large
fleets of SSBNs and their opposing SSNs. Over the last
fifteen years this situation has been changed by both
world events and by technology.
Political change has seen major reductions in strategic
nuclear weapons and the de-targeting of those which
remain. Littoral warfare and land attack have re-emerged
as major submarine roles with cruise missiles or anti ship
missiles replacing the deck gun.
At the same time the potential of the SSK has been
increased as Air Independent Propulsion based on
Stirling engines, fuel cells or Closed Cycle Diesel has
increased the submerged endurance of the SSK without
the hazards of Hydrogen Peroxide. From a battery-based
endurance measured in hours, SSK submerged endurance
has increased until it can be measured in days, if not
convincingly in weeks. The result is a covert mobility
still less of the SSN but far greater than anything
available to the last generation of submersibles.
These changes have taken place in parallel with a general
reduction in military budgets. Affordability has become
paramount at the same time as a need for innovation to
meet the changing military requirement.
This places the designer in a dilemma. While it is fair to
say that all engineering design is creative, development
as carried out in a time of low budgets requires a
different and less obvious talent from that required to
originate new solutions, that of a Chapman rather than a
Brunel. When low cost and innovation are both seen to
be necessary, ‘turning the handle’ or adapting past
solutions is no longer sufficient. It is in this context that
BAESSS have carried out the work described in the
following sections.
FIGHT
FLOAT
MOVE
SURVIVE
Boat exists for ‘Fight’ function
Functions are emergent properties of ‘whole boat’ design
‘Float’, ‘Move’, ‘Fight’ and ‘survive’ are interdependent
5
5. THE APPROACH
5.1 DRIVERS OF COST
By any standards nuclear submarines are complex and
expensive. The current classes of submarines drive
significant through life costs and a very high annual cost
of ownership. Key areas are:
Large numbers of crew and significant numbers
of other uniformed personnel.
A large commitment to infrastructure for their
build, support and disposal. The UK has
currently one design and build yard, two former
Naval Dockyards, one now 300 years old, naval
bases, major procurement and support
organisations, and a substantial nuclear
infrastructure.
Design and build organisation and cost
Maintenance and upgrade organisation and cost
Organisations are as complex and as costly as
the submarines
Acquiring large and even sophisticated fleets is not
difficult if the will is there – sustaining them is costly,
and has proved so over many centuries and across
cultures. The fate of Zheng He’s fleets and those of early
modern Europe are cases in point [3].
It is the authors’ experience that the focus on cost
reduction:
Usually occurs after the requirement and
programme budget has been decided, and after
the target design and build programme timeline
has become fixed in contractual terms
The ability to trade between NRE and UPC
within the bounds of the contract placed on
Industry is difficult and the ability to trade
between requirement and contract even more so,
as the reluctance to introduce change and
uncertainty in a commercial sense increases.
Is on the platform UPC, and invariably a real
inability to trade between UPC and Through life
costs.
The impact of any requirement to include legacy
in the solution can be a major constraint and
cost driver in the overall solution
As has been already presented, the ability to really
influence the outcome occurs in the early stage of the
design – but the level of knowledge of the design is still
very immature and the cost incurred and costs committed
are disproportionate. The work conducted by BAE
Systems Submarines would contend that the only way to
approach this dichotomy is as follows:
5.2 UNDERSTANDING THE CONTEXT
Systems can be studied in terms of time and space at
subsystem and super system levels.
For the Nuclear Submarine, this could be represented as
shown in figures 5 and 6.
By investigating the problem with this “Top Down”
approach we isolated the following key cost drivers in
the programme and identified the technical challenges
associated with their resolution.
1. Unit Production Cost
2. Crew
3. Electronic Systems
4. Infrastructure
5. Maintaining an Operational Capability
Figure 5: system relationships
Figure 6: functional relationships
5.3 LEGACY TECHNOLOGIES DRIVE UP
WHOLE LIFE COSTS
Despite major improvements in productivity and
operating efficiency, real costs of ownership have been
growing since the mid 1980’s and they continue to rise.
Some of this cost growth arises from the need to operate
a fixed infrastructure and supply base in support of a
falling population of operational submarines; some is
6
associated with meeting increasing safety standards,
which affect both design solutions and training regimes.
However, the technologies employed in submarines have
a major impact on whole life cost as they determine:
The complexity and duration of the design
and construction programme.
The intrinsic operational availability of the
submarines and consequently the number
of platforms needed to maintain required
availability levels.
The number of uniformed personnel
required to operate the submarine who,
apart from their direct costs, place
additional demands on hotel services and
contribute to the overall size, complexity
and cost of the submarine, as well as non
availability for operational duties as the
vessel is used to support essential at sea
crew training.
The submarine maintenance programme
and particularly the size, shape and
complexity of the naval base and dockyard
infrastructure.
The practical difficulties of adapting an
existing, legacy design to provide
additional capability, to overcome
obsolescence or to accommodate new
safety requirements.
The scale and frequency of the intervention
activities long term sustainment of the
submarine supply base.
With the obvious exception of combat systems, the
majority of technologies employed in UK Nuclear
Submarines have fallen significantly behind the
benchmark set by comparable commercial sectors. The
continued use of old technology and business practices
drives cost into the programme and perpetuates poor
availability and supply chain vulnerability.
5.4 DESIGN FOR MINIMUM WHOLE LIFE
COSTS
For UK RN Nuclear Submarines, the issue of providing
the required capability at an affordable cost is more acute
now than it has ever been. But opportunities to update
technologies at the whole platform level are rare and
invariably coincide with the design of a new class (once
every 14 years).
Capitalising on this opportunity is difficult, because by
the end of the Concept Phase the key technologies and
system solutions have largely been dictated. Astute was
originally conceived as a minimum change development
of Trafalgar, in itself an evolution from the Swiftsure
Class. The last opportunity for radical redesign arose for
Vanguard class, but this was at a time when whole life
cost reduction was not a design priority, so the
opportunity was lost.
For a new programme therefore, the question is “can
designers on their own address affordability sufficiently
to make the necessary differences?”- The evidence would
suggest they can to an extent, but the window of
opportunity to make a real difference is only open for a
short period.
The other key issue is that constraints, forces and events
that occur long after key decisions have been taken can
conspire to undo much of the good work, unless such
issues are recognised, considered and the decisions taken
and follow up actions are robust and risk reduction
enacted in a timely fashion.
5.5 NEW TECHNOLOGIES TO DRIVE DOWN
WHOLE LIFE COSTS
In our search for cost saving solutions and measures, we
undertook extensive surveys (not limited to the marine
environment) of both current and planned technology
programmes and products that could be adapted for
submarine application to create a technology database.
5.6 BOTTOM UP PROBLEM SOLVING AND
TRIZ
TRIZ – or the Theory of Creative Problem Solving – is a
systematic approach that forces thinking beyond personal
experience and the randomness of brainstorming or
epiphany moments. It approaches problem solving from
3 directions:
Problem Analysis – understanding what is wanted, what
are the priorities of all the requirements and the
inadequacies of the system that delivers them. We
derived a vision of the future submarine (which we
named Concept 35), describing what would represent
success, both in terms of the platform solution and how it
would be delivered against a set of ambitious targets –
50% reduction in whole life cost, 30% reduction in UPC
and a 50% reduction in crew numbers).
Analogy – reducing the current problem/requirements to
its simplest terms to understand it in its most general
form to recognise which technologies and subsequently
systems could deliver what is wanted. We conducted a
detailed functional analysis of contemporary submarine
designs and their subsystems to capture the interactions
between them and identify the cost drivers. We identified
both positive and negative functional relationships with
analysis being conducted at the following levels:
Whole Boat
- Availability, Survivability, ‘ilities
and Safety
- Move, Fight, Float
Structure
o Propulsion and Steering, including
Main Turbines
7
Power Generation, Distribution and Storage,
including NSRP and TGs
Sensors, Navigation, Communications & Data
Fusion, including Combat Systems
Platform Services and Control, including
Buoyancy Control
Weapons, Storage and Delivery
Crew
Functional diagrams were created down to second order
subsystems for a current SSN and the causes of cost in
the system identified (Harms), searching out excesses
(duplication, redundancy), weaknesses (Complexity,
insufficiency, lack of performance) and undesirable
interdependencies.
Figure 7: Simplified Example of the Functional Diagram
Functional Analysis enables us to suggest solutions to
improve the design and to understand the overall impact
of these solutions.
Likewise, external solutions can also be assessed to
understand the overall impact, and this is particularly
suitable for understanding the impact of key technology
solutions - consequential impacts.
Problem Solving – contradictions, trends, standard
solutions (of which there are 40) and mapping of where
and when solutions are needed. We used TRIZ
techniques to break the interactions, identify potential
solutions to contradictions and alternative solutions. The
real problem solving exercise was then based on the
following challenges:
Is the sub-system needed?
Can the subsystem be trimmed? (ie can its
functionality be combined with another system
performing a similar function)
What of the 40 Inventive principles recognised by
TRIZ could be used to solve a contradiction or
find an alternative solution to a problem.
Developed from this work, Figure 9 summarises the
cause and effect relationships surrounding the key cost
drivers, the technical challenges and Design changes
necessary to effect a change.
The Team strove to avoid developing submarine
solutions until as late as possible in the process, with the
objective of exploring as wide a scope of potential
submarine configurations as possible, without locking on
to any specific arrangement solution. To facilitate this
aim, a set of building blocks of submarine characteristics
were developed, which when combined in a complete set
formed a “Planform”. Using the results from this, the
Technology Taxonomy and technology database, was
used to aid the development of Planforms. By using the
Planform approach and differing technology mixes the
extreme ranges of performance we were seeking were
provided.
A number of key conclusions were found from the
functional analysis and the problem solving process:
Tactical Weapons are complicated: containing
many components and requiring crew, services,
combat systems and infrastructure to support
them. They also impact the structure and affect
boat hydrodynamics and layout. Are they always
required?
Hydraulic Powered Steering and Control Surfaces
make the overall solution complicated. Electric
actuation may not only reduce hydraulic power
plants, but may also make the whole control
system much simpler.
Platform Control and Crew Local Control are
practically duplicated
Platform services are highly complicated - simply
many systems - and drive the cost of ownership.
However, platform services are mainly a support
function so efforts to drive out functionality from
all areas may well yield savings here.
Platform Services also identified that fresh water
should be removed and that an Integrated
Buoyancy System would reduce some of the
complexity. Variable Speed Drives were also
identified as being able to reduce system
complexity
The NSRP has a clear dependency on
infrastructure to maintain and provide the boat
safety case.
Direct Drive propulsion has many specific
components and interactions with the whole boat.
Shaftless electric propulsion removes many
components and greatly simplifies the overall
design and support of the programme.
Fly-by-wire standard control systems and
automation, in particular for Power Generation /
NSRP, may significantly improve operation and
support by reducing manning, improving
8
operating profiles and allowing condition
monitoring.
Figure 8 TRIZ principles
5. THE APPROACH
5.1 CONCEPT DESIGN WORK
Using the historical designs as the cost reference and a
current design as the technology baseline, all the
subsequent submarine concept designs options were
developed around the common set of design principles
shown in figure 9:
Development of these concept designs and subsequent
evaluations concluded that:
Evolutionary enhancements will not yield the
scale of whole life cost savings being sought,
as none of the big cost drivers are impacted.
A submarine designed from the outset for
minimum whole life cost could deliver the
target savings in build, and through life.
The use of parallel, non submarine related,
military or high end civil programmes might
provide appropriate technologies for an
alternative submarine solution.
There is significant value in challenging
elements of the user requirement, particularly
those that drive UPC, such as depth, speed,
shock.
We also confirmed that design measures taken
to reduce build costs added both weight and
volume, exposing, once again, that the
misconception that to be cheaper, Nuclear
Submarines with X and Y capabilities need to
be lighter and smaller. Indeed, we concluded
that setting weight and volume targets for a
future submarine could prove counter
productive, particularly in the early stages of
design.
9
Figure 9: Cost drivers
Title Cost Driver Design Changes
Prog
ram
mes
Dep
en
den
t u
po
n r
emov
ing
or r
ed
ucin
g c
ost
s a
sso
cia
ted
wit
h:
Ma
inta
inin
g t
he
Op
era
tio
nal
Ca
pa
bil
ity
o LOP’s /any extended maintenance periods
o Using submarine for non operational duties. o Unreliable plant driving contingency & unplanned
outages
Durable secondary circuit (system)
Materials selection and preservation
Elimination of intrusive inspection
Self monitoring and control of signatures
Increased use of alternative training solutions
Over engineering & lower stressed duty cycle
Ele
ctr
on
ic S
yst
em
s
o Difficulty & time for upgrades
o Number of cables & connectors
o Differing power & cooling requirements o Number & range of spares
Open systems architecture
Use of standardised COTS modules
Reduced number of functions
Wireless Communications
Fly-by-wire
Effective FOLAN
Reduced services
Distributed Power Systems
Standard interfaces
Rationalized cooling and energy efficiency
Standard interfaces
Infr
a-
stru
ctu
re
o Seismic justification of facilities
o Fuel handling (used & new) o Production & maintenance of safety case
o Requirement for dock to undertake maintenance
Step change redesign of NSRP
Design for disposal
Inherent safety features
Reduced dependence on shore facilities
Reduced reliance for high integrity supplies
Concurrent system design, boat & facility safety case
development (analogous to pre-construction safety report
before detailed design)
Develop in-water engineering solutions for all expected
maintenance actions
UP
C
o Build time
o Production support o Capital finance
o Packing density and piece part complexity
o Material Costs o Volumes & piece part count
o Number of bespoke submarine components
Modular build and test of independent functional areas where cost and time effective
Eliminate other demanding alignment requirements.
Rationalisation/revalidation of SWS/SWSS for new build
with increased UK supply
PH designed for optimum spatial layout & geometric
simplicity
Hotel services in single module
Reduced requirement and functional demands leading to simpler and fewer systems
Challenge ARM & safety requirements to reduce number of
key equipments
Modular TWS
Alternatives to fluid systems
Reduce Packing Density
Distributed as opposed to centralised systems
Use of commercial standards in place of Naval engineering Standards
Extensive use of MOTS/COTS
Crew
o Watch Keeping
o Damage control
Extensive plant automation, unmanned consoles.
Radical restructuring / redesign of fore and aft end consolidation of functions
Throttles in Control room
Fire prevention, detection and suppression
Automated damage control systems
Hard tunnel
Fire protection leading to change in doctrine
Bulkhead protection
Reduced hull penetrations
Self healing systems
Automation
10
5.1 CHANGES ARE REQUIRED TO THE
ENTERPRISE AND ALL LINES OF
DEVELOPMENT
So if a step change in submarine design, incorporating
alternative technologies and architectures can yield
substantial and whole life cost savings, why has it not
happened?.
We concluded, almost inevitably, that the maximum
savings can only be realised if the whole enterprise
changes its mode of operation and focuses on
minimising cost. The potential benefits offered by new
technology necessitate changes to business practice
across the whole enterprise and all lines of
development, for example:
Significant reductions in the size of the crew
will drive changes in the manner in which the
submarine would be operated. The manning
strategy would need to reflect a new approach
to damage control, training, career
development and changes in crew roles and
responsibilities. Concurrent development of
the design and the career structure against a
jointly agreed target range would be essential
if situations of over manning or over specified
automated solutions are to be avoided in
service.
Whole sale changes would be required in
design and build strategies to accommodate
the demands of “design for whole life cost”
and modular build, test and acceptance.
A concerted challenge to the proliferation of
bespoke Naval Engineering Standards would
be required to adapt the supply chain.
A radical change would be required in support
management arrangements to reduce the
amount of unnecessary maintenance and work
in wake. “Design for Availability” rather than
“Design for Support” becomes the watchword.
In addition, getting the right customer organisation that
enables equipment and technology programmes to be
focused on reducing the whole life cost of the
programme is particularly important, supported by
credible submarine cost models that permit whole life
cost measurement, target setting and monitoring.
6 THE DESIGNER’S CHALLENGE.
6.1 DESIGN PHILOSOPHY
From the work described in the preceding section it has
been possible to develop a philosophy of submarine
design. This may be summarized under four headings:
Requirements
Solutions
Tools and processes
Whole boat design
Figure 10 Concept design principles
6.2 REQUIREMENTS
The starting point of design is, of course, to understand
the customer’s needs. These are normally expressed as
a formal requirement, but key points may be implicit
rather than stated. Military submarines exist, in
principle, to fight – or threaten to do so – but there is a
hierarchy of military needs, and it is necessary to
understand the level of need which has to be met. The
design solution will directly reflect this.
A rough hierarchy has been constructed with three
levels of need:
Symbolic.
Credible defence
High intensity war
Simpler and Cheaper
Challenge the requirements at platform,
system & sub-system level;
Develop a rationalised system/equipment,
spatial & modular architecture;
Rationalised approach to engineering
standards, & redundancy;
Reduce the number and variations of piece
parts, equipment & components;
Adopt open architectures to enable ease of
upgrade;
Reduce, minimise & standardise
components;
Minimise bespoke submarine systems,
utilising COTS wherever possible to reduce the
cost of equipment;
A concurrent approach to Naval career
development & the submarine solution;
Identify solutions that minimise additional
infrastructure requirements;
Stealthier
Minimise all energies being transmitted
to/from the hull to meet the required & potential
enhancements in stealth
Energy efficiency to improve core life &
manage undesirable emissions
Safer
Integrate continuous safety improvement
within the design approach
Sooner
Exploit rapid prototyping and product
development techniques to mature technologies
quickly - but avoid any high risk developing
technologies that would disrupt the design and
build tempo.
Minimise critical path activities through
reductions in interdependent solutions.
11
Title
Cost Driver Technical Challenge Enabling Strategy
Prog
ram
mes
Dep
en
den
t u
po
n r
emov
ing
or r
ed
ucin
g c
ost
s a
sso
cia
ted
wit
h:
CA
SD
Ma
inta
inin
g
the
Op
era
tio
na
l
Ca
pa
bil
ity
o LOP’s / any extended
maintenance periods
o Using submarine for non operational duties
(training, etc.)
o Unreliable plant driving contingency for
unplanned outages
Design for RCM
Eliminate the requirement for
extended maintenance
Reduce collective training
through the use of more intuitive
MMI systems
Inherently reliable & durable
plant
Design strategy implements increased RCM in systems design - reducing invasive inspection
requirements
Operating strategy reduces need for at-sea training & maximises the use of shore based training facilities
Plant Operating strategy
Ele
ctr
on
ic S
yst
em
s o Difficulty & time for
upgrades o Number of cables &
connectors
o Differing power & cooling requirements
o Number & range of
spares
Ease of upgrade
Fewer cables & connectors
Standardised power & cooling
Standardisation of parts
Design strategy will demand equipment arrangement
is 'designed to replace', increase confidence in SIF trial results
Supply strategy promotes increased use of COTS and standardisation
Infr
ast
ru
ctu
re
o Seismic justification of
facilities o Fuel handling (used &
new)
o Production & maintenance of safety
case
o Requirement for dock to undertake
maintenance
Remove dependence on seismic justification of nuclear safety case
Fuel for life (preferred) alternatively significantly shorten
refuel
Minimise shore infrastructure
required for de-fuel, treatment &
waste storage
Robust & reusable safety case
centred on platform not facility
Remove docking dependency
Drive design to reduce or eliminate docking
requirements
Design for Disposal
Develop safety case as an integral part of design process linking safety case to availability
Design strategy promotes the elimination of docking for dependent items
UP
C
o Build time
o Production support
o Capital finance o Hotel systems
o Life support
o Auxiliaries o Ships systems
o Volumes & piece part
count o Number of bespoke
nuclear submarine components
Reduce number of overall build critical paths to In Service Date
by eliminating final alignment requirements.
Improve design maturity of propulsion and Combat System
areas
Reduce crew numbers
Simplification of system solutions
Reduce the number & complexity of systems
Optimise the spatial design of PH volume to match spatial demand
of systems
Specify systems that can be
sourced either:
Through competition Against supplier's embedded
standards
From alternative technologies & industries
Keeping the requirement trade space open and
providing the ability to challenge non functional requirements
Agreement on manning bands and concurrent development of career structure and technology
solution permits optimization of both crew and
platform costs
Conduct rigorous requirement and functional analysis
through a suitably SQEPed body to rationalize demand on systems.
Supply strategy promotes increased standardisation &
use of COTS equipment
Supply strategy promotes increased standardisation &
use of COTS equipment
Design Strategy aligns to alternative military or
commercial industries that exhibit longevity
Consolidation of critical processes into one supplier
Build strategy
Improved management systems & a simplistic
approach to design utilising new standards
implements demonstration & acceptance of performance at modular level
further improves dimensional control & interface
management
Crew
o Watchkeeping
o Damage control
Enable reduction in watch bill
Enable reduction in damage
control parties
Doctrinal challenge
Manning strategy of Navy needs to complement move to reduce manning and incorporate automation as far
as possible.
Manning strategy promotes the removal of high manning levels for damage control & invokes reliance
on automated systems
Figure 11:Cost drivers, technical challenges and Enabling Strategies
If the customer’s need is primarily symbolic, a simple,
affordable design without substantial innovation may
provide all that is required. Shore support may be
limited to the minimum which will keep the boat
running, and simplicity of maintenance as well as
operation will be needed.
12
Where the customer requires a credible defence, the
capability offered must match the perceived threat.
Cost and operability issues may limit the design
solution to a modern but not complex boat which limits
the financial, infrastructure and human investment
required. A robust rather than a sophisticated solution
may be appropriate.
At the highest level of need are customers whose armed
forces must be able to conduct a full range of
operations, up to and including high intensity war. This
is the territory of the SSN, SSBN and high capability
SSK. Financial and human factors may drive the
solution to one of quantity rather than quality, and
again favour robustness over sophistication, but
outright military capability is the objective and is likely
to require both a complex design solution and major
supporting infrastructure.
The design philosophy developed addresses the middle
and upper levels of need.
6.2 SOLUTIONS
To conduct high intensity operations through its design
life a submarine must have adaptability built in from
the start. Capacity is required in:
Space
Weight
System capacities
Stability and trim
These must be physically present in the form of space
allocations as well as stability and weight growth
allowances.
In a tightly packed submarine the cost of uncovenanted
change, during design and through life, is so great that
only if the layout and margins make provision for them
can the submarine be delivered and maintained free
from obsolescence at affordable cost.
In UK submarine design, margins have historically
been confined to weight and centre of gravity margins.
However, the desire for late equipment insertion during
build and for continuous upgrading through life
requires prioritized space allocations for maintenance,
equipment withdrawal and replacement – and a heroic
ability to defend them from encroachment.
Appropriate margins and reduced packing density have
a large role to play in reducing manufacturing cost.
Attempts to reduce boat size (and it is hoped) cost by
attacking them are generally unhelpful. Design time is
increased, manhour productivity is reduced and
rigorous control processes are required to force the
genie into the bottle. These actively increase cost,
directly and through the ‘marching army’ of overhead
costs. Robust design solutions with appropriate margins
and minimum programme time are unheroic but
effective.
6.3 TOOLS AND PROCESSES
Manufacturing tools and processes are clearly
important in reducing the first cost of the submarine.
Less obvious are those used in design and management.
It is axiomatic that effort should go primarily into
productive work, yet it is common for both design
processes and tools to ensure that much of the effort
goes into the process, not the product.
Good design tools and processes should:
Be transparent
Require the minimum of data preparation and
transfer
Carry out all the required design and analysis
tasks
Update automatically
Allow easy configuration control
These points may seem a statement of the obvious, but
the quality of analysis varies surprisingly between
different software suites, and even some well-known
design tools require each module to be individually
rerun after a data change. This requires considerable
effort and makes configuration control laborious.
Fortunately this situation is now changing, with self-
updating software and object-oriented, ‘Building Block’
tools of the UCL type for Early Stages design. The
‘Building block’ approach allows modular architectures
to be used throughout design and build, and has been
adopted for all of BAESSS’s recent designs. Each
module may be treated as a ‘black box’ with minimum
connection to the others through system highways. The
dependencies between the components of the design are
simplified and the effort put into the processes is
reduced.
6.4 WHOLE BOAT DESIGN PHILOSOPHY
The whole boat design and build philosophy which
follows is based on the following assumptions:
Submarines, especially those with nuclear
propulsion, are highly integrated, complex
products in which the cost and risk impacts of
change are very high. These impacts are
magnified by the size and structure of the
organisations required to create and maintain
them.
Submarines have been greatly changed by fifty
years of incremental development, but in
13
many cases the basic planform has changed
very little.
Cost pressures, changing technology, and
changes in the military environment are
bringing the high capability submarine close to
the end of a development plateau. In the long
term it may disappear like the battleship – in
the short and medium term its uses remain but
the vehicle itself must adapt.
These factors have led to a basic design philosophy:
Reduce the complexity of the submarine,
using functional analysis and ‘decoupling’ of
design elements where possible.
Reduce the complexity of the organisations
and processes involved
Make designs adaptable, allowing late
insertion of equipment and continuous
upgrading in service.
Reduce manufacturing cost and complication,
by lowered packing densities, reducing the
numbers and variety of components, and by
keeping work as far as possible ‘off the boat’.
Maintain continuity of personnel and policies,
so that key decisions made at the beginning of
a programme are not challenged at a late stage.
Coupling these with the lessons learned from TRIZ and
while developing design concepts leads to a modular
design approach using:
Self contained modules built, pre-
commissioned or individually commissioned
‘off boat’ and inserted into the pressure hull at
the latest possible stage. These modules may
be treated as ‘black boxes’ in system design
Minimum through systems, organised into
system highways which can also be built and
tested ‘off boat’
Linking of modules via the system highways
with the minimum of interfaces
Physical linking of the modules via the
pressure hull structure. Apart from the module
supports only the minimum necessary of
internal structure is built into the pressure hull.
Pressure hull and external structures treated as
modules with the external form decoupled as
far as possible from the pressure hull. The
heavy and relatively costly pressure hull may
be simplified without sacrificing
hydrodynamic performance.
Weight, space and centre of gravity envelopes
defined for each module. The envelopes are
not defined at the start of the design, but
assessed and defined during the concept
design stage and frozen at the beginning of
detailed design.
Weight, space and moment reservations for
access, maintenance, and replacement of
equipment through life. These are defined
during the concept design stage and defended
by all humane means. Allowances are left for
late insertion of equipment and similarly
defended.
Design integration carried out across
disciplines, with shared ownership of the
whole boat outcome.
6. CONCLUSION
Modern submarines, particularly those with nuclear
propulsion, are among the most complex of human
artefacts, comparable in complexity only to the Space
Shuttle. Current designs are generally the outcome of a
long period of incremental development, fuelled by an
international confrontation now ended. Changes in the
military and political environment and in the available
technology are moving submarine design off a design
plateau at a time when cost of ownership is paramount.
It is the Authors’ belief that these changes cannot be
accommodated solely by incremental development.
Work at BAE SYSTEMS Submarine Solutions has
shown that there are alternative paths available which
will enable a better balance of cost and capability, and
use the skills available to better effect.
To design a submarine for minimum cost requires
changes in the ‘Submarine Enterprise’ which affect
every area, and the abandonment of cherished beliefs -
not least the equation of cost with size. Cost is an
emergent property of the submarine and of the
enterprise which supports it, and cannot be reduced
effectively by a reductionist approach.
The major submarine cost drivers have been identified
and sets of concept design principles and enabling
strategies have been created to allow minimum cost
design. A modular approach to design, build and
maintenance has set out to embody them, and to enable
greater creativity through a reduction in whole boat
complexity.
The title of this paper is ‘cost and creativity’, and it
may seem that it contains a great deal of ‘cost’ but little
‘creativity’. The approach to submarine design
14
described here is an enabler, removing effort from the
process in order that the skills of the designer, builder,
maintainer – and not least, operator – are directed to the
true purpose of the submarine. Without those skills
there would be no creativity, and no submarine.
In the words of a great musician, ‘you cannot legislate
innovation’[4].
7. ACKNOWLEGEMENTS
The Authors would like to acknowledge the work of all
their colleagues on whose work this paper’s substance
depends. The opinions expressed are those of the
authors and not those of BAE SYSTEMS Submarine
Solutions, but without the work of many others the
paper could not have been written.
They would also like to acknowledge the work of
Oxford Creativity, UK, for the training in TRIZ
techniques upon which much of the work described
depends.
8 REFERENCES
1. NEVIL SHUTE NORWAY, ‘Slide Rule: the
Autobiography of an Engineer’, Heinemann, 1954
2. SIR JOHN HARVEY-JONES, ‘Getting It Together:
Memoirs of a trouble shooter’, Heinemann, 1993.
3. NAM RODGER, ‘A Naval History of Britain’ Vol 2 The Command of the Ocean: A Naval History of
Britain: 1649-1815’, Allen Lane, 2004
4. Branford Marsalis, interviewed by Julian Joseph on
BBC Radio 3, UK
9. AUTHORS’ BIOGRAPHIES
Michael Wear holds the current position of Strategic
Programmes Manager at BAE SYSTEMS Submarine
Solutions in Barrow-in-Furness. Throughout his career,
Mike has held responsibilities for the design,
programming and cost estimation of future concepts.
He has over 30 years experience of shipbuilding and in
particular has an in depth knowledge of the planning
and execution of major naval projects. He has
previously held Senior management roles on RN
submarine programmes and is a recognised expert in
the development and delivery of Build Strategies,
among others developing and delivering the strategies
for LPH, LPD(R), and Type 45.
John Salisbury holds the current position of
Consultant Naval Architect at BAE SYSTEMS
Submarine Solutions in Barrow-in-Furness where he is
responsible for Naval Architecture on future
programmes and in Product Development. He has more
than 30 years experience in the shipbuilding, defence
and offshore oil industries, including the design of
commercial vessels, Naval OPVs and Auxiliaries, and
harsh environment FPSOs. Prior to taking up his
present post he held the position of BAESSS Naval
Architecture Manager, having previously worked on
the LPD(R), Auxiliary Oiler, CVF and Astute SSN
programmes
