Global Aviator April 2018 / Vol. 10 / No. 4 69
that General Dynamics Electric Boat
was chosen as the prime contractor
and lead design yard, carrying out
the majority of the work on all 12
submarines, including final assembly.
The company will also manufacture the
new tactical missile tubes able to fire
nuclear-armed Trident II D5 missiles.
The contract award is for the design,
completion, component and technology
development and prototyping efforts
for the Columbia Class Fleet Ballistic
Missile Submarines (SSBNs).
Procurement of the first submarine
is scheduled for 2021 with completion of
the first submarine scheduled for 2030,
followed by its entry into service in 2031.
All 12 submarines are expected to be
completed by 2042 and remain in service
until 2084 and are set to carry out 124
deterrent patrols during its service life.
Nuclear capabilities
The Columbia class will have missile
launch tubes that are the same size as
those of the Ohio class, with a diameter
of 2 200 mm and a length sufficient to
accommodate a D-5 Trident II missile
Its beam will be at least as great
as the 13m beam of the Ohio-class
submarines. There will be 16 missile
launch tubes instead of 24 missile
launch tubes on Ohio-class submarines.
SSBN(X) is expected to have a
submerged displacement about the
same as that of Ohio-class submarines
The SSBN(X)s are to be fitted with
the most up-to-date capabilities and
stealth to ensure they are survivable
throughout their full 40-year life
span according to a naval report.
X-shaped stern control surfaces
(hydroplanes), sail-mounted dive planes,
electric drive (a propulsion system that
uses an electric motor that turns the
propeller of a vessel) and off-the-shelf
equipment developed for previous
submarine designs (Virginia-class
SSNs), including a pump-jet propulsor,
anechoic coating and a Large Aperture
Bow (LAB) sonar system form part of
the equipment fitted to the new boats.
It is part of a concept aimed at
creating an ‘all electric’ which should
reduce the life cycle cost of submarines
while at the same time reducing acoustic
signature. Turbo-electric drive hadbeen used on US battleships and aircraft
carriers in the first half of the twentieth
century. Two nuclear-powered submarines
were equipped with turboelectric drive
but reliability issues during their service
life resulted in them being regarded as
underpowered and maintenance heavy.
Electric drive does not replace the
nuclear reactor or the steam turbines
but replaces reduction gearing used on
earlier nuclear-powered submarines.
The Columbia-Class will utilize
Virginia-class’s fly-by-wire joystick
control system and large-aperture bow
array sonar. The automated control
fly-by-wire navigation system is also a
technology that is on the Virginia-Class
attack submarines. A computer built-into
the ship's control system uses algorithms
to maintain course and depth by sending
a signal to the rudder and the stern.
In 2014, Northrop Grumman was
chosen as the prime designer and
manufacturer of the turbine generator
units used to convert mechanical
energy from the steam turbines into
electrical energy that is then used for
powering on board systems as well as
for propulsion via electric motor. •The first submarine is scheduled
to begin construction in 2021 and
enter service in 2031. From there,
the submarine class will serve
through to 2085