SSBN 640 Benjamin Franklin

Benjamin Franklin

SSBN 640 Benjamin Franklin (1977)

Type	SSBN
Country	USA
Displacement (t)	8,250
Length (m)	130.0
Beam (m)	10.0
Draft (m)	8.7
Height (m)	10.0
Max speed submerged (kn)	21.0
Max speed surfaced (kn)	16.0
Max safe depth (m)	305
Endurance (days)	60
Propeller	1 x 7 bladed propeller
Nuclear reactors	1
Titanium hull	No
Navigation system	SINS Mk 2 (Inertial Navigation System)
Class year	1977

Sensors

Sonar (6)

Name	Type	Platform	Passive range (km)	Active range (km)
BQA-8A	cav	sub	—	—
BQR-15	Towed	sub	4.3	—
BQR-21	Hull	sub	1.7	—
BQR-7	Hull	sub	2.6	—
BQS-4	Hull	sub	—	1.7
DUUG-2	Active Intercept		—	—

Radar (1)

Name	NATO name	Air search	Surface search	Fire control
BPS-11A		—	Yes	—

Launchers (3)

Name	Tubes	Fire control	Max launch depth (m)
533mm Torpedo Tube (forward) 4 Mk 113 Mod 5 305 1956 - 1959: 4 x Mk 16 Mod 1 , 8 x Mk 37 Mod 0 1960 - 1966: 4 x Mk 16 Mod 1 , 0 x Mk 37 Mod 0 , 8 x Mk 37 Mod 1 1967 - 1970: 4 x Mk 16 Mod 7 , 8 x Mk 37 Mod 2 , 0 x Mk 37 Mod 3 1971 - 1973: 12 x Mk 48 Mod 1 1974 - 1976: 12 x Mk 48 Mod 2 1977 - 1982: 12 x Mk 48 Mod 3 1983 - 1987: 12 x Mk 48 Mod 4 1988 - present: 12 x Mk 48 Mod 5 ADCAP
Missile Launcher 16 — 125 1974 - 1978: 16 x Poseidon C-3 1979 - present: 16 x Trident C-4
Signal Ejector	2	—	305

Towed devices (2)

Name	Type	NATO name	Towed decoy	Capabilities	Cable (m)	Depth (m)	Speed (kn)
BRA-8 (Imp.)	Trailing buoy	—	—	Receive, Radio (VLF, LF, Radio navigation)	450	396 – 61	3.0 – 12.0
Floating wire VLF (SUBTASK IV)	Trailing wire	—	—	Receive, Transmit, Radio (VLF, LF, MF, HF, Radio navigation)	549	91 – 37	2.3 – 9.0