G7 (500 mm)

Description

In 1906, the Imperial German Navy initiated the development of larger 50 cm torpedoes, leading to the creation of the G/7 model. This torpedo featured a new explosive filler, a mix of TNT and hexanitrodiphenylamine, that enhanced thermal stability and allowed for a heavier warhead within the same space as in the older torpedoes. The G/7 was quickly adopted, Moltke and Kaiser classes being among the first to be equipped in winter 1913/1914 and the rest of the modern capital ships by the end of the first half of 1914. During the First World War, it was adapted for use in submarines, despite challenges in handling a 7 m-long torpedo within confined spaces. Although the G/7 was extensively used throughout the war, it was eventually surpassed by newer designs. Post-war developments led to further modifications, culminating in the G7a, which featured an increased diameter along with numerous other developments.

The G7 is available only as a fixed launcher on a capital ship, making it very difficult to use and relegating it primarily to close-range, opportunistic pot-shots at enemies with limited mobility. Still, though, the torpedo offers a capable warhead and good speed, making it able to reach and cripple its target much more reliably than most of the foreign analogues.

Vehicles equipped with this weapon

• SMS Derfflinger

General info

A typical World War One-era torpedo carried by capital ships. It lacks swivel mounts or torpedo modes, which makes it a very opportunistic weapon.

Effective damage

The nearly 250 kg TNT-equivalent warhead is not enough to breach most torpedo bulges, but it is still a large warhead, capable of inflicting significant damage on most vessels, potentially sinking them outright if the magazine is hit.

Comparison with analogues

The closest direct analogues are torpedoes carried by other capital ships from the World War One, such as:

• Bliss-Leavitt Mk.1 - lower speed, shorter range and a much smaller warhead
• Wet-heater torpedo Pattern 1912 - 40% of the warhead size and half the range, but significantly higher speed
• Mark I torpedo - 40% of the warhead size, lower speed but significantly longer range
• Mark IV torpedo - first superior torpedo on the list, with comparable warhead size and speed, but significantly longer range
• Type 43 torpedo - 60% of the warhead, lower speed, but double the range
• Whitehead A 110/450 - Smaller warhead, lower speed, and exactly the same range
• 1909R torpedo - Worse speed, range and warhead

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
G7		500	1,365	TNT	249.6	69	4.00
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

Currently, the torpedo can only be found on fixed mounts on a WW1-era battlecruiser. Like other similar torpedoes, it should primarily be used for ambushes, targeting ships with impaired manoeuvrability, or in close-range engagements. The fact that only a single torpedo can be launched in any given direction severely limits its usage in battles, making it an extremely situational weapon. If your approach is to engage enemies primarily at very long range, it may be preferable not to load the torpedoes at all, to avoid the risk of them exploding after a direct hit.

Pros and cons

Pros:

• Good speed
• Decent size of the warhead

Cons:

• Below-average range

History

In 1891, the Imperial German Navy transferred all official torpedo development to its Torpedo Werkstätte (torpedo factory), and in 1906 ordered a series of large (größere), 50 cm, torpedoes in two lengths: 6 meters, named G6, and 7 meters - the G/7 (Größere 7, also named "G7" in many sources).

The Torpedo Werkstätte adopted a new explosive filler for the warhead - a mix of TNT and Hexanitrodiphenylamine (also known as HND, Hexanite, or simply: Hexa), which did not directly improve the explosive power but had a greater specific weight than the previously used wet guncotton (1.6 for TNT+Hex vs. 1.2-1.3), allowing designers to pack more explosive mass into the warhead. An additional benefit of the new mixture was its greater thermal stability. This was proven on 19 August 1915, when the bow torpedo room of the battleship SMS Moltke, filled with G/7 torpedoes, was hit by torpedoes from the submarine HMS E1, and none of the torpedo warheads inside detonated.

The G/7 was a steam wet-heater torpedo with two gyroscopes, allowing it to reduce dispersion from 2% of its predecessor down to 1%.

The following variants of the G7 were built:

• G/7 - 200 kg warhead, 4000 m @ 37 kts (68.5 km/h) or 9300 m @ 27 kts (50 km/h)
• G/7* - 200 kg warhead, 4500 m @ 35 kts or 9200 m @ 28.5 kts
• G/7** - 195 kg warhead, 5000 m @ 35 kts or 10,300 m @ 28.5 kts
• G/7*** - 195 kg warhead, 5000 m @ 35 kts or 10,700 m @ 28.5 kts
• G/7 AV - AV stood for Anwärmvorrichtung (preheater), a dedicated version for submarines adopted during the Great War

The torpedo was quickly adopted; in the winter of 1913/1914, all vessels of the Moltke and Kaiser classes, as well as the newly launched SMS Seydlitz and the light cruiser SMS Rostock, were the first to be fitted with the new G/7 torpedoes. Within the next several months, all capital ships built since 1908 were fitted with the G/7. Additionally, in 1915, the 1st, 5th, 7th, and 8th Torpedo-boat flotillas (Torpedobootsflottille) began using the G.7 after refits. Finally, the G/7 was adapted for use in submarines - although very difficult to handle in the cramped interior of a U-boat and requiring modifications to the launch tubes - between February 1917 and the end of July 1918, a total of 90 G/7 AV and 203 G/7** were launched by U-boats, scoring 45 and 84 successful hits, respectively, with the G/7 AV having a notably higher hit rate (50% to 41.3%).

In total, 765 G/7 torpedoes in all variants were ordered by the Imperial German Navy.

The planned successor for the G/7 was the 60 cm H/8 torpedo, nicknamed the "Supertorpedo." It had a 210 kg warhead and a range of 12,000 m @ 30 kts, a significant improvement over the G/7***. It entered service in 1915, but due to the ongoing First World War, its adoption was limited, and to this day, it is unknown whether it was ever used in combat.

After the end of the First World War, development of the G/7 was taken over by the TVA (Torpedo-Versuchsanstalt), starting in 1923. By that time, the G/7 was already a 10-year-old design, vastly surpassed by the latest designs such as the French Model 1923DT.

Post-war development:

• G 7s - A variant with a design goal of reaching 40 kts in a short-range setting. It had a modified shape, new propellers, and a new, higher-pressure engine cooled by seawater. One hundred units were built for a testing campaign starting in November 1926. It never entered service.
• G 7v - Further development of the G/7s with a new valve control. Validated only on a test bench.
• G 7v* - A 1928 follow-up with a new boiler able to sustain pressure of 200 atm, new pistons, and other minor improvements. Very limited production, only 30 units made by August 1934

By that time, most of the development costs were covered by the Spanish military, which demanded that the torpedo diameter be increased to 533 mm / 21 inches, making it compatible with existing launch tubes. This change required a significant redesign of the entire torpedo. The new variant was designated G7 a and its development continued into the famous World War Two torpedo.

Media

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

See also

Links to the articles on the War Thunder Wiki that you think will be useful for the reader, for example:

• reference to the article about the variant of the weapon;
• references to approximate analogues by other nations and research trees.

External links

• [NavWeaps] Torpedoes of Germany Pre-World War II
• [Wikipedia deutsch] G7 (Torpedo)
• [Truppendienst] Wie der Torpedo entstand
• Naval Weapons of World War One: Guns, Torpedoes, Mines, and ASW Weapons of All Nations by Norman Friedman
• Die Torpedos der deutschen U-Boote by Eberhard Rössler, pages 39-59