User Guide

Left-clicking on the panel selection knob changes to the Angle Solver panel
which has the Gyro Angle Forward and Aft dials and Offset Angle dial. The
Offset Angle dial is used to establish a “spread” of torpedoes by locking a
course offset into each torpedo from the first torpedo fired. The Gyro Angle
Forward and Aft dials are primarily indicators unless the TDC is set to man-
ual, when they become active for setting the offset from the submarine’s
heading that the torpedo will need to intercept the target.
For example, if the target is dead ahead, the relative target bearing would
be 0 degrees. The Relative Target Bearing dial shows an arrow pointing
straight up, aligned along the centerline of the submarine.
Calculating a firing solution is a very complex process. For more information
about the basic formulas of fire control, see Appendix C on page 73.
The Torpedo Depth setting dial and Torpedo Run Time dial are found on the
Torpedo Data panel, as are the Torpedo Speed knob and Torpedo Type knob.
The depth setting control is used to adjust the depth that torpedoes run.
Different classes of ship have a different draft, and a torpedo set to hit an air-
craft carrier will pass harmlessly beneath a destroyer.
There is also a Torpedo Speed knob where the speed can be changed for
variable speed torpedoes. Common practice was to fire torpedoes at the
highest speed available unless the target is motionless. A slow torpedo is
more likely to be evaded by wary prey. The slow speed setting is useful
when shooting at stationary targets at long range, such as inside a shallow
harbor, where a close approach is too dangerous.
Making a Torpedo Attack
When using the TDC on automatic, the most important features to keep track
of are the target’s course, relative bearing, range, speed, and the firing solu-
tion quality. These are all located on the Position Keeper panel. All other
factors can be left to the game’s artificial intelligence (AI). The range indicator
is particularly important because a torpedo only arms itself after travelling 500
yards. The ideal range for torpedo launch at a moving target is between 500
and 1000 yards. Only targets that are at anchor or damaged should be shot at
from farther away than 1000 yards, particularly at higher levels of realism.
Once a target has been selected and locked into the TDC, the computer will
continue to calculate a firing solution. Making a successful torpedo attack
is a combination of having an accurate firing solution and being in range.
While the torpedoes used in U.S. submarines had maximum ranges of
between 3500 and 9000 yards, they were only used at ranges beyond 1500
yards in extreme situations.
SILENT
HUNTER
30 COMMANDING THE SUBMARINE: Up Scope
Using the Local TDC
The full TDC panel is not visible from the Periscope or the Target Bearing
Transmitter (TBT) stations, but has been divided into three separate panels
which appear to the right and left side of the Periscope and across the bottom
of the TBT. Some components of the TDC which do not change are the
Auto/Manual and Panel Selection switches and the firing buttons which are
just above the right handle of the periscope and at the far right of the TBT.
Pressing the “N” key restores the maneuver controls panel.
The panel that is visible the first time that a local TDC station is seen, is the
Position Keeper panel. It shows the Target Course and Relative Target
Bearing dials as well as the Target Range, Target Speed and Solution indi-
cators. The Solution dial indicates the quality of any firing solution as a
percentage, from zero to one hundred percent. When a potential target is
visible in the eyepiece, a red arrow will flash beneath the target indicating
that the TDC is receiving information on that target. The longer a target is
in view, the more accurate a firing solution the TDC will provide. Locking
the target into the TDC allows the TBT or periscope to be used to view the
rest of the horizon, while the TDC continues to calculate. This is done
using the Mark button at the TBT station and the Spacebar at the Periscope.
Leaving the TBT or periscope station resets the TDC.
SILENT
HUNTER
29 COMMANDING THE SUBMARINE: Up Scope