HMS Trenchant (S91)

<tr valign=top><td>Commissioned:</td><td>January 14 1989</td></tr>

<tr valign=top><td>Draught:</td><td>31.2 ft (9.5 m)</td></tr><tr valign=top><td>Propulsion:</td><td>Rolls-Royce PWR1 nuclear reactor
2 × GEC turbines
1 × shaft pump jet 15,000 hp (11 MW)
motor for emergency drive
emergency retractable propellor
2 × W H Allen turbo generators 2 MW
2 × Paxman diesel alternators 2,800 hp (2.1 MW)</td></tr>

<tr valign=top><td>Sensors and processing systems:</td><td>Ferranti/Gresham Dowty DCB/DCG
Type 2072 hull-mounted flank array passive sonar
Plessey Type 2020 or Marconi/Plessey Type 2074 hull-mounted active and passive search and attack sonar
Ferranti Type 2046 towed array passive search sonar
Thomson Sintra Type 2019 PARIS or Thorn EMI 2082 passive intercept and ranging sonar
Marconi Type 2077 short range active classification sonar
Kelvin Hughes Type 1007 I band navigation radar
Pilkington Optronics CK34 search periscope
Pilkington Optronics CH84/CM010 attack periscope
Type 2076 sonar from 2004</td></tr><tr valign=top><td>Electronic warfare and decoys:</td><td>2 × SSE Mk8 launchers for Type 2066 and Type 2071 torpedo decoys
RESM Racal UAP passive intercept
CESM Outfit CXA<bt>SAWCS decoysd from 2002</td></tr><tr valign=top><td>Armament:</td><td>5 × 21 in (533 mm) torpedo tubes
Spearfish torpedoes (originally Tigerfish torpedoes) with 20 reloads
UGM-84 Harpoon submarine-launched cruise missile
Mines
UGM-109 Tomahawk from 2004</td></tr>