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For more photos of QM2
     QUEEN MARY 2 has two independent Electronic
Chart Display Information Systems (ECDIS) and a
Route Planning Terminal.  The electronic charts are
updated weekly in order to reflect changes in depths,
aides to navigation, and other pertinent information.  In
addition to providing timely information, with these
systems a navigational chart can be displayed on the
computer screens located above the steering controls
and elsewhere on the bridge.  Since the ship’s
navigational systems are integrated, the ship’s position
can be shown on the chart.
     In the Photo 10, the ship’s position is shown off the
East Coast of the United States.  The red line is the ship’
s course.  The chart also shows schedule information
such as the distance to the destination and the speed
required to get to that destination by the desired time.
    The chart obtains the ship’s position from the  GPS.  
At the heart of this system are 24 satellites in stationary
orbit above the earth.  Signals from the GPS satellites
can be used to triangulate the user’s position to within
less than 100 meters and signals from shore based
stations which correct for errors improve the accuracy
to less than 10 meters.  In addition, QM2 is able to
obtain her speed over the ground by taking a series of
position readings and calculating what speed was
required to move the ship from one spot to the next in
the time it took to take the readings.  Such a series of
readings also yields the direction in which the ship is
    There is also a traditional chart table on the bridge
for use with paper charts.
     QM2 has five radar scanners and four radar
processors.  Four radar antennas are mounted on the
main mast while the other is mounted on the stern to
ensure full 360 degree coverage.   Of the four main
radars, two operate at a wavelength of 3 cm which
provides good definition while two operate at 10 cm and
are better at penetrating through precipitation.  There are
two of each type primarily for back-up purposes - -
nearly all of the systems on the bridge are duplicated so
as to have back-up.
    With the Automatic Radar Plotting Aid, more than
40 targets (
e.g. other ships, land) can be tracked
simultaneously.  Radar works by sending out an
electronic pulse which is reflected back to the sender
when it strikes an object.  The system on QM2,
however, does not show just a blip on a screen.  It also
gives the target’s course and speed, closest point of
approach, the time of closest approach and how far
ahead of QM2’s bow the target will cross.  Among
other things, this information tells the officer on QM2
whether the closest point of approach is such that a
course alteration is required.  Usually, the officers
arrange to pass other ships at a distance of at least 1
nautical mile.
    Combined with the Automatic Information System
(AIS), the officer can also obtain the name of the target
(assuming it is a ship and is transmitting AIS data), its
registry, its call sign and where it is going.
    QM2’s charted course can also be overlain on the
radar screen and compared against the ship’s actual
course.  This acts as a cross-check to the electronic
chart system.
    In Photo 11, the white area are reflects from the
waves around QM2.  The green line is the ship’s actual
course and the red line overlying it is the ship’s charted
    QM2 has both a magnetic compass and two gyro
compasses which are electronic compasses that align
themselves with true north.  A magnetic compass points
to magnetic north rather than to true north.  The
difference between the two can become important in
determining position when a ship has to travel for several
days in a relatively straight course such as on a
transatlantic crossing.  The gyro compass is not subject
to this problem or to certain other anomalies that may
affect a magnetic compass such as differences in the
earth’s magnetic field and the magnetic influence of ship’
s steel.
    The ship’s a draft is usually stated as 33 feet 10
inches.  However, when a ship is in motion, it is subject
to a phenomenon known as “squat” which increases the
draft. The bridge uses an echo sounder to determine the
depth of the water under the ship’s keel.  A pulse is sent
out and the depth is calculated by how long it takes for
that signal to return.   QM2 does not have a forward
searching sonar.  Such sonars are typically only found on
warships and certain research vessels.
    To minimize rolling, QM2 has four stabilizers (two on
each side) that can be extended 15 feet from the sides of
the hull.  These can be likened to the flap on an airplane
wing.  As the ship tries to roll toward one side, the angle
of the stabilizers will change in order to increase the
pressure on the opposite side and bring the ship
upright.   Because the stabilizers are dependent on the
flow of water past them to create the necessary lift, they
are less effective at slow speeds.  The stabilizers are
folded flush with the hull in port and can be extended
individually as conditions warrant.
    Unlike earlier liners, QM2 has no radio room per se.  
Instead, communication is controlled from the bridge.  
Coming in and out of ports, VHF radio transmissions
are used for communicating with other ships and harbor
authorities that are within an approximately 30 mile
radius.   To talk with someone further away, there are
medium and high frequency radios. In addition, there are
two INMARSAT-C satellite terminals, which can
communicate essentially to points all over the globe.  
The satellites also receive weather forecasts and
navigational information and warnings.  These forecasts
are noted on weather charts on the bridge and the
Commodore informed so that all know what to expect
    With the Global Maritime Distress and Safety
System, a distress signal containing the ship’s name,
position and a request for assistance can be sent out
within five seconds by pushing a button.  This signal will
go out over all three of the transmission systems
described above and thus be sent to ships in the vicinity
and throughout the world.  If there is more time, one can
send the nature of the distress (
e.g., fire, grounding).
    The Computer Safety System allows the bridge to
monitor all of the safety systems throughout the ship and
to have visual displays showing where on the ship a
situation is developing.  For example, there are fire and
smoke detectors throughout the ship. When one of these
detects fire or smoke, a signal is sent to the bridge.   The
watch officer can then dispatch the Assessment Party,
consisting of officers from various departments, to the
location on the ship from where the alarm signal was
sent.   They report their findings to the Safety Centre
located in the aft of the ship.  However, all watertight
doors, fire screen doors, ventilation, low level lighting
and other safety systems can be operated by either the
bridge or the Safety Centre.   
     Because the navigation and safety systems depend
upon electricity, the bridge has a battery back-up system
to enable its electrical systems to function even in the
event of a power failure.  However, the officers are also
trained in the traditional methods of navigation such as
the use of sextons and plotting a course on a paper chart.
     Access to QM2's bridge is restricted.  However,
passengers can view what is happening on the bridge
through a window on Deck 12.  The viewing room is
normally open during the day when the ship is at sea.
Photo 9  An electronic chart display.
Above and Below: (Photos 11 and 12).  The officers have a
choice of which radar to display.
Above: (Photo 13) Officers huddle around the central
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