There have been a number of 18-inch torpedoes in service with the United States. These have been used on ships and submarines of the US Navy. American "18-inch" torpedoes were actually 17.7 inches (45 cm) in diameter, beginning with the "Fiume" Whitehead torpedo of 1890.
Ship classes that carried 18-inch torpedoes include:
| Name | Country | In service date | Platform / target | Dimensions | Warhead | Propulsion | Performance |
|---|---|---|---|---|---|---|---|
| "Fiume" Whitehead torpedo |  US
|
1894 | Surface / Surface | Diameter: 17.7 in (45 cm) Length: 140 in (360 cm) Weight: 845 lb (383 kg) |
54 kg (119 lb) Guncotton |
Compressed air | Speed: 26.5 kn (49.1 km/h) Range: 800 yd (730 m) |
| Mark 4 (Bliss-Leavitt) | US |
1908–1922 | Submarine / Surface ship | Diameter: 17.72 in (450 mm) Length: 197 in (5,000 mm) Weight: 1,500 lb (680 kg) |
Vertical Turbine | ||
| Mark 6 (Bliss-Leavitt) | US
|
1911–1922 | Surface / Surface ship | Diameter: 17.7 in (45 cm) Length: 204 in (520 cm) Weight: 1,800 lb (820 kg) |
Turbine | Speed: 35 kn (65 km/h) Range: 2,000 yd (1,800 m) | |
| Mark 7 (Bliss-Leavitt (Short) | US
|
1917 | Submarine / Surface ship | Diameter: 17.7 in (45 cm) Length: 144 in (370 cm) Weight: 1,036 lb (470 kg) |
281 lb (127 kg) TNT |
Turbine | Speed:35 kn (65 km/h) |
| Mark 7 (Bliss-Leavitt)(long) | US
|
1912–1945 | Submarine & Surface / Surface ship | Diameter: 17.7 in (45 cm) Length: 204 in (520 cm) Weight: 1,682 lb (763 kg) |
326 lb (148 kg) TNT |
Turbine | Speed: 35 kn (65 km/h) Range: 3,500 yd (3,200 m) or 6,000 yd (5,500 m) |
| Whitehead torpedo Mk.1 (short) | US
|
1894–1913 | Surface / Surface ship | Diameter: 17.7 in (45 cm) Length: 140 in (360 cm) Weight: 845 lb (383 kg) |
118 lb (54 kg) Guncotton |
Air-flask Brotherhood pattern engine | Speed: 26.5 kn (49.1 km/h) Range: 800 yd (730 m) |
| Whitehead torpedo Mk.1 (long) | US
|
1894–1922 | Surface / Surface ship | Diameter: 17.7 in (45 cm) Length: 197 in (500 cm) Weight: 1,160 lb (530 kg) |
220 lb (100 kg) Guncotton |
Air-flask Brotherhood pattern engine | Speed: 27.5 kn (50.9 km/h) Range: 800 yd (730 m) |
| Whitehead torpedo Mk.2 (short) | US
|
1896–1913 | Surface / Surface | Diameter: 17.7 in (45 cm) Length: 140 in (360 cm) Weight: 845 lb (383 kg) |
118 lb (54 kg) Guncotton |
Air-flask Brotherhood pattern engine | Speed: 27 kn (50 km/h) Range: 800 yd (730 m) |
| Whitehead torpedo Mk.2 (long) | US
|
189?–1922 | Surface / Surface | Diameter: 17.7 in (45 cm) Length: 197 in (500 cm) Weight: 1,232 lb (559 kg) |
132 lb (60 kg) Guncotton |
Air-flask Brotherhood pattern engine | Speed: 28.5 kn (52.8 km/h) Range: 1,500 yd (1,400 m) |
| Whitehead torpedo Mk.3 | US
|
1898–1922 | Surface / Surface | Diameter: 17.7 in (45 cm) Length: 140 in (360 cm) Weight: 845 lb (383 kg) |
118 lb (54 kg) Guncotton |
Air-flask Brotherhood pattern engine | Speed: 26.5 kn (49.1 km/h) Range: 800 yd (730 m) |
| Whitehead torpedo Mk.5 | US
|
1910–1922 | Surface & Submarine / Surface | Diameter: 17.7 in (45 cm) Length: 204 in (520 cm) Weight: 1,452 lb (659 kg) |
200 lb (91 kg) Guncotton |
Heated Air-flask Brotherhood pattern engine | Low: 27 kn (50 km/h) Range: 4,000 yd (3,700 m) Medium: 36 kn (67 km/h) Range: 2,000 yd (1,800 m) High: 40 kn (74 km/h) Range: 1,000 yd (910 m) |
