Undersea Warfare

Question 1

What are the two types of SONAR?

Answer 1

Active
-Operator gets BRG and RNG from an active sensor

Passive
-Operator gets BRG only from a passive sensor

Question 2

What factors affect how sound travels through water?

“TSP, 6-4-2”

Answer 2

Temperature
-Sound speed changes 6ft/sec for every 1 degree of temp change

Salinity
-Sound speed changes 4ft/sec for every 1 ppm of salinity change

Sound
-Sound speed changes 2ft/sec for every 100ft of depth change

Question 3

Describe the specifics of MFTA

Answer 3

Multi-Function Towed Array

-Primary passive sensor
-610ft long array
-5,600ft available cable scope, 400ft has to stay on the winch as an anchor
-150ft long drogue (rope) attached to the end for stabilization

Question 4

Describe the specifics of SCFS

Answer 4

Sonobuoy processor used to re-detection of an existing contact

SCFS integrates with LAMPS (Light Airborne Multi-Purpose Sensor) on helos via SRQ-4 “Hawk Link” for secure comms and data.

Ships can receive buoy data directly via ARR-75.

Question 5

What are the 5 types of sonobuoys?

Answer 5

DIFAR

DICASS

VLAD

BT

ANM

Question 6

Describe the specifics of AN/SQS-53C (AKA AVC15)

Answer 6

Primary active sensor - has the capability to receive passive data

Hull mounted cylindrical array which has 576 transducers, 8 layers, and 72 staves

Has 5 frequency bands, F1-F5

Dome holds 26,000 gallons and is filled with fresh water, pressurized to 39.5 PSIG +2 and backed by firemain

Front of the dome has a rubber wrap called the SONAR Dome Rubber Window

Question 7

Describe the specifics of UCFS

Answer 7

Fire control system of the SONAR Suite

Console is in CIC and the operator is called “UB” (Underwater Battery)

Question 8

What is the 1st torpedo delivery system?

Answer 8

LAMPS

Helo carries up to 3 torpedoes to fire at sub-surface targets over the horizon and away from the ship

Question 9

What is the 2nd torpedo delivery system?

Answer 9

MK 41 VLS

Can carry/fire VLA (Vertically Launched Anti-Submarine Rocket) which is a Mk46 or Mk54 torpedo with a rocket booster on the back to get the torpedo away from the ship.

Used for deliberate attacks (accuracy over speed)

Question 10

What is the third torpedo delivery system?

Answer 10

Mk 32 SVTT (Surface Vessel Torpedo Tubes)

Located on PORT and STBD aft missile decks, fires Mk46 and Mk54 torpedoes.

Used for urgent attacks (speed over accuracy)

Question 11

Range of Mk46 Torpedo

Answer 11

3,000 yards

Question 12

Range of Mk54 Torpedo

Answer 12

5,000 yards

Question 13

Range of VLA

Answer 13

Min: 3,000 yards
Max: 17,800 yards

Question 14

Where can Mk32 SVTT be fired from?

Answer 14

UCFS, TSP in Harpoon Equipment Room, or locally from the torpedo tubes

Question 15

What auxiliary component provides two way unencrypted communications from ship to sub, ship to shore, or vice versa?

Answer 15

WQC-2A “Gertrude”

Question 16

What auxiliary component provides one way encrypted communication from ship to sub?

Answer 16

WQC-2A “Probe Alert”

Question 17

What auxiliary component measures temperature vs. depth?

Answer 17

XBT (Expendable Bathythermograph) - predicts how sound will travel through water.

SPPFS uses input data from all sensors as well as the XBT system.

Question 18

What is the UQN-4A Fathometer?

Answer 18

SONAR Sounding Set that measures the depth of water beneath the keel of the ship

Can be read from main control unit in SONAR Control, from the repeaters in CIC, the pilot house, and the chart room

Question 19

What is the ship’s torpedo countermeasure system?

Answer 19

AN/SLQ 25C “NIXIE”

Consists of two NIXIE “fish”, 2,100ft of cable scope (2,000ft max deployable with 100ft on the winch as an anchor) and a 100ft drogue

Question 20

What are the 5 acoustic modes of NIXIE that lure acoustic homing missiles?

Answer 20

SNAPR

Swept
Noise
Alternating
Pulsed
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