Mk.VIII (533 mm)

Description

The Mk.VIII torpedo is a British 21-inch (533 mm) torpedo mounted on many destroyers and motor torpedo boats in the British tech tree. Other 21-inch British torpedoes include the Mk.V (533 mm) and the Mk.IX (533 mm).

General info

The Mk.VIII torpedo has a diameter of 533 mm, a length of 6.579 m, and weighs 1,566 kg. Without the Torpedo Mode modification installed, it can travel at a maximum speed of 84 km/h for 4.57 km. With it installed, the maximum range is increased to 6.40 km, but the maximum speed is reduced to 76 km/h.

Torpedo characteristics
Torpedo Mode	Mass (kg)	Maximum speed in water (km/h)	Travel distance (km)	Depth stroke (m)	Arming distance (m)	Explosive type	Explosive mass (kg)	TNT equivalent (kg)
No	1,566	84	4.57	1	50	TNT	327	327
Yes	1,566	76	6.40	1	50	TNT	327	327

Effective damage

The Mk.IX torpedo carries a 340 kg TNT warhead, which is fairly middling compared to other torpedoes. Destroyers and other smaller vessels can be destroyed by a single hit, but cruisers, especially heavy cruisers, may be able to survive multiple hits, depending on where the hit occurred.

Comparison with analogues

Compared to all other ship-launched torpedoes in the British tech tree:

• Mark XII: An 18-inch torpedo, the Mark XII has a lower maximum speed (69 km/h), has a lower maximum range (3.2 km), and has a much smaller explosive mass (176 kg TNT equivalence). With the Torpedo Mode modification installed on both, the Mark XII has a slightly lower maximum speed (74 km/h) and has a much lower maximum range (1.37 km).

• Mark XV: An improved Mark XII, the Mark XV has a larger explosive mass (385 kg TNT equivalence); but it has a lower maximum speed (61 km/h) and has a lower maximum range (3.2 km). with the Torpedo Mode modification installed on both, the Mark XV has a much lower maximum speed (54 km/h) and has a lower maximum range (5 km).

• Mk.V (533 mm): The earliest of the British 21-inch torpedoes, the Mk.V has a lower maximum speed (74 km/h) and has a smaller explosive mass (305 kg TNT equivalence). With the Torpedo Mode modification installed on both, the Mk.V has a much higher maximum range (12.35 km), but it has a much lower maximum speed (46 km/h).

• Mk.IX (533 mm): A further development of the 21-inch torpedo, the Mk.IX has a much higher maximum range (9.6 km) and has a larger explosive mass (340 kg TNT equivalence); but it has a lower maximum speed (67 km/h). With the Torpedo Mode modification installed on both, the Mk.IX has a much higher maximum range (12.35 km), but it has a much lower maximum range (56 km/h).

Compared to common torpedoes mounted on destroyers and cruisers among other nations:

• Mk.15 (533 mm): The Mk.15 has a higher maximum range (5.5 km); but it has a slightly lower maximum speed (83 km/h) and has a smaller explosive mass (224 kg TNT equivalence). With the Torpedo Mode modification installed on both, the Mk.15 has a much higher maximum range (9.15 km), but it has a lower maximum speed (62 km/h).

• G7a (533 mm): The G7a has a larger explosive mass (358.4 kg TNT equivalence) and has a higher maximum range (6 km); but it has a slightly lower maximum speed (81 km/h). With the Torpedo Mode modification installed on both, the G7a has a much higher maximum range (14 km), but it has a much lower maximum speed (56 km/h).

• 53-38 (533 mm): The 53-38 has a slightly lower maximum speed (82 km/h), has a lower maximum range (4 km), and has a smaller explosive charge (300 kg TNT equivalence). With the Torpedo Mode modification installed, the 53-38 has a much higher maximum range (10 km), but it has a much lower maximum speed (56 km/h).

• Type 93 Model 1, Mod 2 (610 mm): The Type 93 Model 1, Mod 2 has a higher maximum speed (91 km/h), has a much higher maximum range (20 km), and has a much larger explosive mass (627.2 kg TNT equivalence). There is no Torpedo Mode modification available for the Type 93 Model 1, Mod 2.

• Type 93 Model 3 (610 mm): The Type 93 Model 3 has a higher maximum speed (91 km/h), has a much higher maximum range (15 km), and has a much larger explosive mass (998.4 kg TNT equivalence). There is no Torpedo Mode modification available for the Type 93 Model 3.

Name	Country of origin	Diameter (mm)	Mass (kg)	Explosive type	TNT equivalent (kg)	Max speed (km/h)	Max range (km)
12.75 inch Mark 44		324	235	HBX	54.4	56	5.49
12.75 inch Mark 46		324	235	TNT	44.5	91	7.30
18 inch Mark XII		450	702	TNT	176	74	1.37
18 inch Mark XV		450	817	Torpex	395.2	61	3.20
18 inch Type 38 No.2 B		450	663	Shimose	104.5	59	2.00
18-inch Mk.7		450	720	TNT	93	59	3.65
21 in Mk.8		533	1,252	TNT	146	50	9.14
21 inch Mark I		533	1,270	TNT	102	56	11.00
21 inch Mk.20 Bidder		533	821	TNT	89	37	11.00
21 inch Type 43 (1910)		533	1,187	Shimose	143	50	8.00
45-36NU		450	951	TNT	200	76	4.00
53-38		533	1,615	TNT	300	82	4.00
53-39		533	1,780	TNT	317	94	4.00
53-56		533	2,000	TNT	400	93	8.00
53-57		533	2,000	TNT	306	83	18.00
53-65		533	2,070	TNT	300	126	12.00
Bliss-Leavitt Mk.1		533	680	TNT	91	50	3.66
C/06D		450	810	TNT	122.6	50	5.90
G6c		533	1,008	TNT	160	50	5.00
G7a		533	1,528	SW39a	358.4	81	6.00
H/8		600	2,160	SW39a	268.8	67	6.00
LT 1A/1		450	812	TNT	250	74	2.00
Mark 35		533	803	Torpex	196	50	13.71
Mk.8-3 C/D		533	1,373	TNT	174.2	50	12.35
Mk.13		569	884	TNT	178	56	5.21
Mk.15		533	1,559	TNT	224	83	5.50
Mk.16		533	1,766	Torpex	915.2	85	6.40
Mk.IV		533	1,454	TNT	234	65	7.30
Mk.IX		533	1,693	TNT	340	67	9.60
Mk.IX**		533	1,693	Torpex	587.2	76	10.00
Mk.V		533	1,736	TNT	305	74	4.57
Mk.VIII		533	1,566	TNT	327	84	4.57
1909R		450	716	TNT	144	61	2.00
Model 1919V		550	1,358	Picric acid	261.8	80	2.00
Model 1923DT		550	2,100	TNT	308	72	9.00
1926V		400	674	TNT	144	81	2.00
L3		550	910	TNT	200	46	5.00
Pattern 1910		450	665	TNT	100	54	3.00
Pattern 1912		450	810	TNT	100	80	2.00
R.G.F. Mark VI**		450	700	TNT	134	56	5.49
S.I.170/450X5,25		450	860	TNT	170	76	4.00
S.I.270		533	1,715	TNT	270	74	4.00
S.I. 250/533,4X7,5 Tipo A		533	1,781	TNT	250	76	4.00
S.I. 270/533,4X7,2 Tipo I		533	1,700	TNT	270	89	4.00
S.I. 270/533,4X7,2 Tipo M		533	1,715	TNT	270	93	4.00
S.I. 270/533X6.84 Tipo L		533	1,700	TNT	270	93	4.00
Seal DM2A1		533	1,370	TNT	250	61	20.00
SET-40		400	550	TNT	80	54	8.00
SET-53M		533	1,480	TNT	100	54	14.00
SET-65		533	1,740	TNT	205	74	16.00
SET-72		400	730	TNT	80	74	8.00
Type 2		450	1,000	Type 97	448	72	3.00
Type 6		533	1,432	Shimose	223.3	65	7.00
Type 8 No.2		610	2,362	Shimose	380.6	70	10.00
Type 43		450	663	Shimose	104.5	48	5.00
Type 44 No.2		450	750	Shimose	121	65	4.00
Type 54 model 3		533	1,600	TNT	100	44	6.00
Type 72 mod.1		533	1,760	TNT	300	120	10.00
Type 89		533	1,660	Type 97	384	83	5.50
Type 90		610	2,540	Type 97	480	85	7.00
Type 93 Model 1, Mod 2		610	2,700	Type 97	627.2	91	20.00
Type 93 Model 3		610	2,800	Type 97	998.4	91	15.00
W.200/450X5,75		450	930	TNT	200	81	3.00
Whitehead A 110/450		450	936	TNT	110	56	4.00

Usage in battles

The Mk.VIII is a fast torpedo, sporting an above-average top speed of 84 km/h with the Torpedo Mode modification and a top speed 76 km/h without. However, its maximum range is small, 4.57 km with and 6.4 km without the Torpedo Mode modification. Its warhead is also only average, at 327 kg TNT.

For motor torpedo boats and other smaller vessels, the Mk.VIII should be used without the Torpedo Mode modification, where the lower maximum range is insignificant in the often short-range engagements, and the higher maximum speed is helpful in making it more difficult for the enemy vessel to evade. On destroyers, the Mk.VIII should be used with the Torpedo Mode modification, since close-range encounters are much less common, and the increased maximum range provides more strategic usefulness, especially in Encounter and Enduring Confrontation game modes, though in this aspect, its small range of 6.4 km leaves much to be desired.

Pros and cons

Pros:

• Above average maximum speeds

Cons:

• Short maximum range

History

The 21-inch Mark VIII torpedo was designed in 1925. It had a diameter of 21 inches (533 mm), a length of 21 feet 7 inches (6.579 m), weighed 1,566 kg, and carried a 340 kg TNT warhead. The Mark VIII was the first British torpedo to utilise the burner-cycle engine, an advancement in torpedo technology at the time. In the burner cycle engine, pressurized air was heated and combined with atomised fuel, and then injected and ignited into the combustion chamber at top dead centre (when the piston is furthest away from the crankshaft). Powered by this, the Mark VIII could maintain a speed of 40 knots (74.1 km/h) for 4.57 km.

An improved version Mark VIII** was also developed, which increased the top speed to 45.5 knots (84.3 km/h) and introduced a low-speed setting at 41 knots (75.9 km/h) for 6.4 km. As originally designed, the Mark VIII** carried a 327 kg TNT warhead, though this would be replaced by a 365 kg Torpex warhead in later productions.

The Mark VIII entered service and production in 1927. The Mark VIII** was the primary version used during World War II, mounted on motor torpedo boats and the O-class submarines, as well as any succeeding submarine classes. It remained in service within the Royal Navy as late as 1982, when HMS Conqueror sunk the Argentinian light cruiser ARA General Belgrano during the Falklands War, and would continue to remain in service with other minor navies even further.

Media

Excellent additions to the article would be video guides, screenshots from the game, and photos.

See also

• Mk.V (533 mm)
• Mk.IX (533 mm)

External links

• NavWeaps - WWII Torpedoes of the United Kingdom/Britain