Silent Service



Typed out by tsr

NES-IV-USA

Ultra(r) Games

How to play Silent Service(tm)

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Find 'em, chase 'em, sink 'em!

Just above the beat of your heart, you hear hostile propellors churning
through calm seas. At any second the first depth charge will explode. Your
watch ticks. Sweat rolls into your eyes. As the enemy's sonar ping intensifies
you hold your breath, realizing that the pressure of an unmerciful sea is all
around you.

Such is your life as a commander in the elite Silent Service Force, a detailed
simulation of World War II submarine missions in the bloody South Pacific.

From the moment you dive into action, you'll be confronted with the same
information, problems and resources available to an actual sub captain. Your
primary mission will be to take on the Japanese Navy in their home waters and
to neutralize the Japanese Merchant Merine.

With a limited number of torpedoes and fuel, your goal is to sink a maximum
tonnage of enemy ships and bring your sub safely back to base. Your overall
evaluation from Fleet Command will be based on the number and types of ships
you sink.

So go get 'em commander. Your crew is counting on you... because they know if
you fail, they'll become instant shark bait!

US Attack Sub
The US Fleet Submarine of the Second World War was an outstanding weapon. With
200 tons of diesel fuel and a cruising range of 12,000 miles, no area of the
Pacific was safe for enemy shipping.

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Mission options
There are three types of scenarios. "Torpedo/Gun Practice" places you outside
the America base at Midway Island. Four old cargo ships are anchored there as
torpedo and gunnery practice targets. "Convoy Actions" recreate a variety of
actual submarine attacks on a convoy. "War Patrols" allow you to command an
entire patrol, putting out to sea from submarine bases at Midway, Brisbane or
Fremantle, continuing through a number of convoy actions, and concluding with
a victorious return. (Or sunken dreams!)

To select your mission option, press the Control Pad Up or Down and lock in
your decision with the A Button.

Skill levels
There are four skill levels: MIDSHIPMAN (beginner), LIEUTENANT, COMMANDER
(designed to be the most historically correct), and CAPTAIN (expert). The
skill level effects the accuracy of torpedo runs, damage from depth charge
attacks, and the skill of enemy lookouts and sonar operators.

Lock in your skill level by pressing the A Button.

Combat difficulty levels

You can customize your mission with various "combat levels." Each level
introduces an element that's more realistic and more difficult. They include:

Limited visibility. If this level is selected, enemy ships which are beyond
radar/sonar range won't appear on the map displays.
Convoy zig-zags. If this level is selected, enemy convoys will "zig-zag"
(change course) at regular intervals. If this level is not selected, cargo
ships will steam straight ahead unless they are attacked by torpedoes or
encounter land masses.
Dud torpedoes. Some of your torpedoes may be "lemons" if you select Dud
Torpedoes instead of No Dud Torpedoes. Dud torpedoes may hit the enemy but
will not explode.
Port repairs only. If this level is selected (instead of Repairs Under Fire),
repairs will no longer occur automatically while in battle or on patrol.
Expert destroyers. IF this level is selected (instead of Standard Destroyers),
certain enemy convoys will be escorted by "expert" destroyers. These escorts
are more persistent and have better trained sonar operators.
Convoy search. If this level is selected (instead of Close convoys), convoys
will not always appear within radar range. You'll need to search them out.
Far off convoys are best sighted by performing a 360 degree periscope/
binocular sweep of the horizon.

To choose your levels, press the Control Pad Up or Down, then make your
selections by pressing the A Button.

Overall difficulty

The skill level and difficulty levels you select combine to produce an overall
difficulty factor from 1 to 9. This difficulty and the tonnage you sink will
determine your ranking in the "Submariner's Hall of Fame" at the conclusion of
your mission.

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Terminology

Port: the left side of the ship.
Starboard: the right side of the ship.
Bearing: the direction you are looking.
Heading: the direction your ship is going.

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Control functions

Raise or Lower Periscope: This command raises scope if it's down, and lowers
it if it's up. It also sets the visual bearing to be the same as the sub's
heading. You can use the periscope, in daylight only, down to a maximum depth
of 44 feet.

Throttle (Speed): Choose from Dead Stop (0) to Full Speed Ahead (4).

Reverse: Use to reverse engines for an emergency escape. To change speed while
in reverse, adjust the Throttle, then select Reverse again.

Guidance Control: To dive, move the arrow onto the down pointer of the
Guidance Control. To surface, move the arrow onto the up pointer of the
Guidance Control.

For left rudder, move the arrow onto the left pointer of the Guidance Control.
This turns the sub toward the left (port). If looking at the Map screen, you
will see the sub turn counterclockwise.

For right rudder, move the arrow onto the right pointer of the Guidance
Control. This turns the sub toward the right (starboard). If looking at the
Map screen, you will see the sub turn clockwise.

To cancel all dive and turn commands, move the arrow to the center of the
Guidance Control and press the A Button.

You can also blow emergency tanks by holding down the B Button and pressing
the A Button on the player 2 controller. This can halt an otherwise fatal
dive, and usually brings your sub to the surface. You may perform this only
once per engagement.

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Time scaling defined

In order to ensure accuracy, all ship movements, sightings, torpedo runs and
dive rates are recalculated every two seconds of simulated game time. However,
under most conditions it is desirable to speed up the action somewhat.

Normally the simulation proceeds at four times real-time: One minute of game
time takes 15 seconds. If the "F" is selected on the clock, the time scale is
doubled. Repeated pressing will continue to increase the Time Scale up to a
maximum of 32 times real times (ie. one hour of game time will take 2 minutes
at time scale 8).

To increase the Time Scale, move the arrow to the "F" of the Time Scale and
press the A Button. Each subsequent key press doubles the speed, to a maximum
of 32 times real time speed (three key presses).

To return to the normal Time Scale, move the arrow to the "N" on the Time
Scale and press the A Button. Note: You automatically return to normal time
when detected by the enemy or when you fire a torpedo or the deck gun.

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The conning tower menu screen

The Conning Tower screen acts as a menu screen. From this screen, you may
select any of the four detailed battle station screens: Instruments and
Gauges, Maps and Charts, Periscope/Binoculars, and Damage Reports. (See below)
Use the arrow to position the captain at the desired battle station, then
press the A Button. Moving the arrow to the Map Table, for example, moves the
captain to the table. Press the A Button and the Map screen will appear.

You may also select two special functions from this screen. If you are playing
a Training or Convoy Action scenario, the "End of Game" function will end your
mission. If you are playing a War Patrol scenario, the "Continue Patrol"
function ends the current convoy battle and returns you to the patrolling
screen. You cannot end the battle if you are being tracked by the enemy
escorts, have torpedoes active, or if an enemy ship is still sinking.

The "Quartermaster's Log" option (located at the bottom right corner of the
command compartment) is used to review your accomplishments during the current
patrol.

When you are at the Conning Tower screen, the simulation is paused. Note:
some selections are unavailable under certain conditions.

To choose the Conning Tower Menu, press the Select Button. Once in the Conning
Tower, make selections by moving the arrow to different areas (ie. the
periscope, the map, etc.) and then press the A Button.

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Combat controls

These controls are at your command when at Periscope/Binocular Battle Stations
(see below). Once again, move the arrow to your selection and press the A
Button.

Attack controls
To identify the target under the crosshairs on the periscope/binoculars, move
the arrow to the Target ID.

To fire a torpedo at the target under the white crosshairs, move the arrow
onto the Torpedo Firing Control. Bow or aft tubes will be selected
automatically, depending on which ones face the target.

To fire the four-inch deck gun at the target under the white crosshairs, move
the arrow onto the Deck Gun Firing Control. The gun may be fired only when
your sub is on the surface.

Note: Four torpedoes and gun shells (total) may be active at any one time.

To increase gun deflection, press the Player 2 Control Pad UP. Each additional
press adds 25 more yards to the deflection. You want to increase deflection
when the target is moving away from you. To decrease the gun deflection, press
the Player 2 Control Pad DOWN. Each additional press subtracts 25 yards from
the deflection. You want to decrease deflection when the target is moving
toward you. (See DECK GUN below)

To rotate the periscope view left, press the Player 2 Control Pad LEFT. To
rotate the periscope view right, press the Player 2 Control Pad RIGHT.
(Rotating the view changes its bearing.)

To release debris and oil, use the Player 2 Control Pad and hold down the A
Button while you press the B Button. The debris will rise to the surface and
may convince the enemy that your sub has sunk. You may release debris only
once per engagement.

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Battle station screens

Silent Service contains multiple Battle Station screens. On each screen
different information is available and different commands can be entered. The
battle stations represent the main locations from which the captain manages
the battle. Not all controls are operable from all screens. Be sure to note
what controls are available on each screen.

War patrol navigation maps battle station (War Patrol scenarios only)

When you select a War Patrol scenario you start out on this screen, which
displays a map of the South Pacific Ocean. You are free to explore any area of
the map. Your ship is a tiny white dot near the starting port of Fremantle,
Brismane or Midway. The patrol screen simulates the time required to proceed
from your base to enemy-controlled waters, as well as the patrolling activity
between engagements. (A typical patrol lasted up to two months.)

Moving on the War Patrol map: Using the Control Pad, move the arrow in the
direction you wish to go. Time moves quickly while patrolling. The ocean
changes from light to dark to represent day and night.

Finding the Enemy: When the ocean or screen border turns red, you've spotted
a convoy. Press the A Button to exit from patrol if you want to engage in
battle. Note: Enemy ships are generally found along the heavily travelled
convoy routes and close to land. Valuable tanker and troop ship convoys are
more likely to be found near Japan.

Getting Home: The submarine bases at Midway Island, Fremantle and Brisbane are
indicated by flashing dots. When you have reached your base and the ocean
turns green, you can return to port. Press the A Button to end the patrol and
record your score in the Submariner's Hall of Fame.

Important Note: No other controls function on the patrol navigation screen.
To make other controls you must exit the War Patrol.

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Instruments and gauges battle stations


a d e f
bc g
i k l n
h j
m o

A. Battery Level - indicares electricity remaining in the battery. Recharge by
surfacing. A fully charged battery allows one hour of high-speed maneuvering
underwater and 5 to 6 hours at slow speed. If your battery is drained,
you'll be unable to move underwater.

B. Battery Charge Light

C. Battery Drain Light

D. Speed - Maximum surface speed is 20 knots. Maximum submerged speed is 10
knots.

E. Depth - Zero means sub is on the surface. Maximum diving level is 500 feet.

F. Periscope Indicator - Green means it's up, black means it's down.

G. Torpedo Ready Indicator - Green means forward and aft torpedo tubes are
ready. Torpedo reloading takes 10 minutes per tube. The number under each
column indicates how many torpedoes remain in addition to those already in
the the tube. The number alongside shows the number of deck gun shells
remaining.

H. Fuel Levels - Shows the amount of fuel in the three main tanks.

I. Depth Under The Keel - Depth from sub to ocean's bottom. When gauge reads
zero you'll run aground.

J. Water Temperature - When the dial is in the blue section, it indicates the
submarine is below a thermal gradient layer. Note: Hiding below a thermal
gradient layer can provide extra protection against the enemy's counter
attack.

K. Christmas Tree - Indicates status of hull openings. Green means closed, red
means open. Hull openings close automatically when you dive.

L. Compass - Indicates direction sub is heading.

M. Throttle - 0-4 settings: All Stop, 1/3, 2/3, Full Speed and Flank (reverse)
Speed.

N. Clock - Shows time of day. Dusk in the Pacific is from 7:00 pm (Hour 19) to
8:00 pm (Hour 20). Dawn is from 5:00 am to 6:00 am.

O. Dive Bubble - Shows whether the sub is diving or surfacing. The bottom line
displays your current speed (in knots), depth (in feet) and heading (in
degrees).

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Maps and charts battle station

The maps and charts screen displays information available from the navigator
and the tracking party. Map information, visual sightings, radar and sonar are
combined on this screen to show the location of your submaring, torpedoes and
all known enemy ships. Remember that your submarine is represented by a white
dot. Torpedoes and enemy ships are black dots, and green areas represent land
masses and islands.

Note: Sometimes there are enemy ships out there that you have not yet
detected. These undetected ships do NOT appear on the map. Your lookouts
aren't always reliable - it's wise to leave the Maps Battle Station and look
around the horizon with the periscope/binoculars.

Zoom: You may enlarge or shrink the scale of the map to any of four levels of
detail by moving the arrow onto the Small Scale or Large Scale Map and
pressing the A Button. The initial map shows the entire South Pacific. The
Patrol Area Map shows a 500 by 300 mile area. Zoom again and you'll see the
Navigation Map, which shows 60 by 40 miles. The most detailed map is the
Attack Plot Map, which shows an area of 8 miles by 5 miles. Ships are
displayed on the Attack Plot.

Note: When the screen begins flashing, the enemy is either within range or you
may have wandered off the map. You'll also notice, as you patrol the seas,
that the map color changes from dark to light. This represents the passing of
days and nights.

Controls Available: All Submarine and Time and Scale controls, plus "Release
Debris".

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Periscope/binoculars battle station

This screen displays the view through the attack periscope during daylight/
dusk/dawn, and the view from the bridge's Target Bearing Transmitter
Binoculars at night. The viewing area shows an enlarged image of visible ships
and land. This screen may be selected when the sub is on the surface, or at
periscope depth (44 feet or less) during daylight hours.

Torpedo Data Computer: When the crosshairs turn white the Torpedo Data
Computer is activated and target tracking is displayed. The TDC displays the
range to the target, the target's speed, and the target's course. To fire a
torpedo, fire the deck gun or request information, move the arrow onto the
appropriate control and press the A Button.

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Damage reports battle station

This screen indicates the nature of any damage to the submarine. Damage may
be caused by depth charge attacks or enemy gunfire. Types of damage include:

Bow/Aft Torpedo Damage: Torpedo tube doors have been damaged. The torpedoes
will not fire.

Periscope Damage: The periscope housing has been damaged. The periscope cannot
be lowered or raised.

Dive Plane Damage: The bow and stern dive planes have been damaged. The
submarine will only dive or surface at half its normal rate.

Fuel Leaking: The external fuel tanks are leaking. Fuel will be consumed at
twice the normal rate. In addition, fuel rising to the surface will make the
submarine easier to detect by enemy destroyers.

Engine Damage: The main diesel engines are damaged. Surface speeds are reduced
by half.

Machinery Damage: Internal pumps and engines are damaged. The extra noise
makes the enemy's sonar tracking easier.

Battery Damage: Batteries are used up at twice the normal rate when submerged.
If the "Port Repairs Only" combat level is not selected, repairs are attempted
by the crew automatically.

Water Damage: If your sub is taking on water, the leakage rate is indicated in
gallons per second (GPS). Leakage will often cause your sub to descend,
although the dive planes may be able to counter-act the dive. This information
is provided in the top right hand side of the Damage Reports screen.

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Messages and sounds

You may receive messages at any time from various members of the crew. They
will appear on the top line of the screen. You will also hear the sounds of
your own engines, nearby ships and torpedoes.

Sonar reports destroyers closing ("ping" sound)
Sonar reports depth charges dropped ("splash" sound)
Depth charges exploding! (explosion sound)
Lookouts report destroyers firing (gun sound)
Shell hit! Sub damaged (whistling explosion sound)
Bow (aft) torpedo fired! 135' track (torpedo launch, torpedo motor sound)
Deck gun fired! (gun fire sound)
Sonar reports distant explosions (distant explosion sound)
Warning: test depth exceeded (hull creaking sound - check the Damage Reports
screen!)
We have run aground! (grinding sound)
Repairs completed (check the Damage Reports screen)
Blow emergency tank! (alarm sound)
Collision! Abandon ship! (grinding sound)

Completing your mission

Convoy Action missions end when you select the "End of Game" option. War
Patrol missions end when you return to one of your bases. Either mission
category ends ifyou are sunk or beached. In all cases you will see a screen
displaying all ships which you have sunk and your final rank.

All players will rank at least Ensign. Higher levels are Lieutenant JG,
Lieutenant, Lieutenant Commander, Commander, Captain, Vice-Admiral, Admiral,
Fleet Admiral and ultimately WGSC (World's Greatest Submarine Captain)!

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Convoy action scenarios

Convoy action scenarios are shorter missions which place you in specific
historical situations. They are useful for becoming acquainted with the
features of this simulation, practicing specific tactics or when time is
short.

Plunger in the inland sea (Lt. Commander DC White)
Day/Submerged
Jan. 18, 1942, Latitude 33-30N, Longitude 135-00E.
The USS Plunger, patrolling off the southern coast of Japan, sights an
escorted cargo ship steaming east at high speed. This scenario gives you the
opportunity to set up a torpedo firing solution against a moving ship.
Remember that even though the Torpedo Data Computer calculates the correct
lead gyro angle to hit the target, it is often a good idea to fire a spread of
torpedoes in case your targes changes course unexpectedly.

Wahoo vs. Convoy (Lt. Commander "Mush" Morton)
Day/Surface
Jan. 26, 1943, Latitude 2-37N, Longitude 139-42E.
Off the New Guinea coast, USS Wahoo sights a small Japanese convoy. The
situation is a submariner's dream: an unescorted convoy including a troop ship
and a large oil tanker. However, the convoy has radioed for help and a
destroyer is on the way! Your objective is to strike quickly and cause as much
damage as possible. Be sure to use your aft torpedoes if your bow tubes are
empty.

Hammerhead at Borneo (Commander JC Martin)
Night/Radar
October 1, 1944, Latitude 6-30N, Longitude 116-11E.
SJ radar picks up a large escorted convoy as the USS Hammerhead patrols the
northern coast of Borneo. The tanker, one of Japan's dwindling handful
remaining at this stage of the war, should be your primary target. This
scenario introduces night combat against an escorted convoy. You should take
care to avoid being spotted as long as possible. Use moderate speeds, keep a
minimum profile toward the escort, and try to time your attack so that the
escort is on the other side of the convoy.

Searaven at Toagel Mlingui (Commander H. Cassedy)
January 13, 1943, Latitude 9-12N, Longitude 130-38E.
Somewhere between the Philippine Islands and the Japanese naval base at Truk
Lagoon, USS Searaven comes across a northbound convoy. You are in a bad
position: astern of the convoy in daylight.

Tautog at night (Lt. Commander Sieglaff)
Radar/Visual Night
March 16, 1944, Latitude 42-25N, Longitude 144-55E.
Off the eastern coast of Japan, USS Tautog encounters a Japanese convoy. Night
attacks depend very much on the prevailing visibility conditions. During poor
visibility, a low lying sub can safely close with its target on the surface.
If visibility is good, however, more caution is required.

Grayback in the China Sea (Lt. Commander JA Moore)
Submerged Radar
October 21, 1944, Latitude 26-48N, Longitude 124-56E.
A very difficult situation. Three radar-equipped escorts are guarding the
convoy! Your best hope is a dawn or dusk periscope attack.

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War patrol scenarios

The War Patrol scenarios are the true test of a submariner's skill. Your
mission is to scour the Japanese convoy lanes, finding, attacking and sinking
the maximum tonnage of enemy shipping. You will encounter a wide variety of
situations, opportunities and dangers. Note that each submarine is equipped
differently - your tactics should take into account the strengths and
weaknesses of your sub.

For an overview of Japanese convoy lanes, see the map. All of these convoy
lanes are active in scenarios that occur early in the war. As the war
progresses, and the area of the pacific controlled by Japan gradually shrinks,
it becomes very difficult to find convoys in areas distant from Japan. In the
scenarios that occur later in the war, it is easiest to find targets in the
waters around the islands of Japan.

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Torpedoes

Primary submarine armament consisted of six torpedo tubes forward and four
tubes aft. A total of 24 torpedoes were carried: 14 forward and 10 aft. A
torpedo reload required about 10 minutes.

Most torpedoes were fired at a range of 1000-3000 yards. The best torpedo
track was one which was perpendicular to the course of the target ship. This
provided the largest potential target area. Head-on shots or stern shots were
unlikely to hit their targets.

Torpedo data computer

The TDC, when fed with the target speed, range and course, automatically
calculated the correct torpedo track. The captain would often aim slightly
ahead or behind the target ship if he expected a particular change in course.
Frequently a "spread" of torpedoes was fired by aiming one slightly ahead of
the target, one directly at the target, and one slightly behind the target.

It was important to make the first set of torpedoes count. Once the torpedo
tracks were spotted, the convoy would begin to zig-zag radically and the
escorts would charge in on the sub's position.

Deck gun

The deck gun was effective in sinking badly damaged targets or to slow a ship
and force it to fall behind the convoy. The gun was also used as a last ditch
measure by subs which were forced to surface.

ATTENTION COMMANDER: The gun may only be fired when your sub is on the
surface. Use the crosshairs on the periscope/binocular screen to aim the gun.
The range is automatically set to the TDC range of the target at which you are
aiming. Press the player 2 Control Pad UP or DOWN to add or subtract deflection
from this range. Example: an 18 knot destroyer coming directly towards you
from 4000 yards away will move over 200 yards in the time it takes the shell
to hit the target. Therefore you should press the Control Pad DOWN to select
a deflection of -200 to -250 yards before firing the gun. At 2000 yards the
shell will only take half the time to reach the target, so a -100 yard
deflection should be used. Your gun is supplied with 80 shells.

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Japanese convoys

Japanese shipping generally travelled in small convoys of three to seven
ships. Convoys consisted of cargo ships, troop ships, tankers and destroyer
escorts.

Tankers were the most important target class. The Japanese were critically
dependent on the flow of oil to keep the Main Battle Fleet in operation.
Troop ships were also important targets. You are more likely to find these
valuable ships sailing through the shipping lanes which lead directly to
Japan.

Cargo ships represented the majority of Japanese shipping. They hauled
supplies and equipment to and from the Japanese homeland.

Escorts came in two classes. Destroyers were often used for escort duty. The
Japanese also constructed a special class of escort for anti-submarine
defense: the "Kaibokan". This sub killer extraordinare was packed with
sophisticated radar and special depth charges. A submarine's best chance
against a Kaibokan was to outrun it on the surface, since its top speed was
less than 20 knots. Destroyers could steam at close to 30 knots.

Japanese convoy traffic tended to concentrate along the routes between major
ports. Refer to the convoy route map above for details.

Submarine tactics

A successful submarine attack was very much a team effort by the entire
submarine crew, with the captain making crucial decisions which spelled the
difference between success or failure. Carefully weighing the number of
escorts, the types of ships, visibility, water depth, number of torpedoes
remaining, battery charge, the convoy's course and speed he decided how, when
and where to attack the enemy.

With their low surface profile and ability to submerge, stealth and surprise
were vital ingredients in all submarine attacks. Once an enemy ship or convoy
had been spotted, a successful attack required a well thought out approach to
within a few thousand yards or the enemy without being detected.

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Escape

If detected by enemy escorts, escape became the sub's main objecting. A
submarine was no match for even a single destroyer in a gun and ramming duel.
The usual tactic was to dive a deeply as possible and rig for silent running.
Maintaining a minimum profile and minimum running noise was especially
important under these circumstances. A strong temperature gradient could also
provide some protection from the enemy's sonar. Leaking fuel or machinery
damage made the escort's job easier.

Submarines gained some benefil from their tighter turning circle and ability
to constantly track the escorts propeller noises. Under extreme circumstances,
a sub might try to convince the attacking destroyers that it had been
destroyed by releasing oil and debris which floated to the surface. (Refer
above for this procedure.)

At night the sub's 20 knot surface speed was sometimes sufficient to outrun
pursuing escorts.

Advice to the captain

Make sure you understand the role of the Torpedo Data Computer (TDC) - most
torpedo shots should be made with the periscope crosshairs directly on your
target.

Make sure you understand the distinction between BEARING and HEADING. BEARING
is the direction in which your periscope/binoculars are looking. HEADING is
the direction your sub is facing. Note that it is generally much faster and
easier to aim your torpedoes and gun by rotating the periscope (changing your
BEARING) rather than by steering the sub (changing your HEADING).

In general, you should plan on making a submerged attack in daylight, and a
surface attack at night. During dawn and dusk you can try both.