Project 641

NATO: Foxtrot

Type	SS
Soviet designation	PL
NATO reporting name	Foxtrot
Country	USSR
Displacement (t)	2,475
Length (m)	91.3
Beam (m)	7.5
Draft (m)	5.1
Height (m)	11.8
Max speed submerged (kn)	16.0
Max speed surfaced (kn)	16.8
Max safe depth (m)	250
Endurance (days)	90
Diesel-electric	Yes
Titanium hull	No
Class year	1957

Sensors

Sonar (5)

Name	Type	Platform	Passive range (km)	Active range (km)
Beresta	ssp		—	—
MG-10 Kola	Cylindrical	sub	0.9	—
MG-13	Active Intercept		—	—
MG-200 Arktika	Hull	sub	—	1.3
NEL-5	Echo sounder	sub	—	—

Radar (3)

Name	NATO name	Air search	Surface search	Fire control
ARP-53		—	—	—
Flag	Snoop Plate	—	Yes	—
MRP-10 Nakat		—	—	—

Launchers (3)

Name	Tubes	Fire control	Max launch depth (m)
533mm Torpedo Tube (forward) 6 Leningrad-641 100 1962 - 1963: 4 x 53-61 , 2 x 53-61 , 8 x SAET-50M , 2 x SAET-50M , 6 x SET-53 , 2 x SET-53 1964 - 1964: 4 x 53-61 , 2 x 53-61 , 8 x SAET-50M , 2 x SAET-50M , 6 x SET-53M , 2 x SET-53M 1965 - 1968: 4 x 53-65 , 2 x 53-65 , 2 x SAET-50M , 8 x SAET-50M , 6 x SET-65 , 2 x SET-65 1969 - present: 4 x 53-65K , 2 x 53-65K , 8 x SAET-50M , 2 x SAET-50M , 6 x SET-65M , 2 x SET-65M
533mm Torpedo Tube (aft) 4 Leningrad-641 100 1962 - 1964: 4 x 53-61 1965 - present: 4 x 53-65
Signal Ejector	2	—	200

Extendable devices (7)

Name	NATO name	Capabilities	Max depth (m)	Max speed (kn)
ARP-53 RDF	—	Direction finder	—	6.5
Flag Radar	—	Radar	—	6.5
MRP-10 Nakat ESM	—	ESM	—	6.5
PA-10 Attack periscope	—	Periscope (attack)	—	6.5
PZN-10 Search periscope	—	Periscope (observation)	—	6.5
RDP	—	Snorkel	—	6.5
VAN-S Radio antenna	—	Radio (LF, MF, HF), Radio navigation	—	6.5