135 mm/45 O.T.O. Mod. 1937 (135 mm)

Stern port battery of 135 mm/45 O.T.O. Mod. 1937 on RN Etna

Description

Write an introduction to the article in 2-3 small paragraphs. Briefly tell us about the history of the development and combat using the weaponry and also about its features. Compile a list of air, ground, or naval vehicles that feature this weapon system in the game.

Vehicles equipped with this weapon

• RN Attilio Regolo
• RN Comandante Margottini
• RN Conte di Cavour
• RN Duilio
• RN Etna

General info

Tell us about the tactical and technical characteristics of the cannon or machine gun.

Ship	Front		Sides		Top		Elevator
	Tickness (mm)	type	(mm)	type	(mm)	type	(mm)	type
RN Conte di Cavour RN Duilio	120	RCA	80	RCA	60	RHA	100	RCA
RN Etna RN Attilio Regolo	20	RHA	6	RHA	6	RHA	0	—
RN Comandante Margottini	12	AfA	12	AfA	12	AfA	0	—

Available ammunition

135 mm APHEBC Perforante shells pictured in-flight, with the aft battery of RN Etna firing in the background. Note the white tracer characteristic for armour-piercing shells.

The choice of shells is typical for the Italian pre-WW2 guns, limited to HE and AP against surface targets and HE-TF against aircraft. It's adequate for nearly every situation a warship can encounter.

• 135 mm HE Dirompente - Universal high-explosive round, great against frigates and torpedo boats alike, to a degree also useful against enemy destroyers, or to ignite heavier warships on fire.
• 135 mm APHEBC Perforante - The shell of choice against enemy cruisers, or to reach the ammo racks on destroyers. It lacks penetration to deal with some of the heavy cruisers or all of the battleships/battlecruisers, so against them the HE rounds would be a better choice.
• 135 mm HE-TF Contro-aerea - Time-fused high explosive shell, able to counter enemy aircraft through shrapnel. Use Distance fuse set accuracy crew skill to increase the probability of fusing in the perfect spot for the kill - however, even with the skill maxed-out, shells still can explode ± 100 m away from a target at 5000 meters range, which is more than enough for the aircraft to avoid taking any damage. Still - it's by far the best round to use against enemy airplanes.

Penetration statistics
Ammunition	Type of warhead	Penetration @ 0° Angle of Attack (mm)
		1,000 m	2,500 m	5,000 m	7,500 m	10,000 m	15,000 m
135 mm HE Dirompente	HE	23	23	23	23	23	23
135 mm APHEBC Perforante	APHEBC	171	139	100	73	56	45
135 mm HE-TF Contro-aerea	HE-TF	23	23	23	23	23	23

Shell details
Ammunition	Type of warhead	Velocity (m/s)	Projectile mass (kg)	Fuse delay (s)	Fuse sensitivity (mm)	Explosive mass (TNT equivalent) (kg)	Ricochet
							0%	50%	100%
135 mm HE Dirompente	HE	825	32.42	0	0.1	1.8	79°	80°	81°
135 mm APHEBC Perforante	APHEBC	825	32.73	0.01	6	1.47	48°	63°	71°
135 mm HE-TF Contro-aerea	HE-TF	825	32.42	0	0.1	1.8	79°	80°	81°

Comparison with analogues

135 mm is a fairly unusual calibre, thus the comparison will be made with the guns of relatively similar calibre used as either primary guns on cruisers, or secondary guns on battleships/battlecruisers. Pure destroyer guns are intentionally skipped.

HE

Cannon		Sample Ship	Ammo	Calibre (mm)	Muzzle Velocity (m/s)	Sustained rate of fire (rounds/min)	Targeting speed (°/s)		TNT Equivalent (kg)	Penetration @ 0° Angle of Attack (mm)
							Horizontal	Vertical		1,000 m	5,000 m	10,000 m
	135 mm/45 O.T.O. Mod. 1937	RN Etna	HE	135	825	7.5	9.5	9.5	1.8	23	23	23
	5 inch/38 Mk.12 (127 mm)	USS Atlanta	HE	127	792	15	21	13	3.22	36	36	36
	150 mm/45 SK L/45 (150 mm)	SMS Elbing	HE	150	835	7	4.2	4.2	1.6	21	21	21
	130 mm/55 pattern 1913 (130 mm)	Imperatritsa Mariya	HE	130	823	8	3.4	3.4	3.9	37	37	37
	140 mm/50 3rd Year Type (140 mm)	IJN Sendai	HE	140	840	6.2	8.0	8.0	3.15	35	35	35
	138.6 mm/55 model 1910 (138.6 mm)	Lorraine	HE	139	840	6	4.2	4.2	4.41	36	36	36

AP/SAP

Cannon		Sample Ship	Ammo	Calibre (mm)	Muzzle Velocity (m/s)	Sustained rate of fire (rounds/min)	Targeting speed (°/s)		TNT Equivalent (kg)	Penetration @ 0° Angle of Attack (mm)
							Horizontal	Vertical		1,000 m	5,000 m	10,000 m
	135 mm/45 O.T.O. Mod. 1937	RN Etna	APHEBC	135	825	7.5	9.5	9.5	1.47	171	100	56
	5 inch/38 Mk.12 (127 mm)	USS Atlanta	SP Common Mk.46	127	792	15	21	13	0.9065	150	95	56
	150 mm/45 SK L/45 (150 mm)	SMS Elbing	APCBC	150	835	7	4.2	4.2	0.99	238	153	93
	130 mm/55 pattern 1913 (130 mm)	Imperatritsa Mariya	SAPBC	130	823	8	3.4	3.4	1.67	178	115	71
	140 mm/50 3rd Year Type (140 mm)	IJN Sendai	mod 1 SAP	140	855	6.2	8.0	8.0	2.21	115	81	54
	138.6 mm/55 model 1910 (138.6 mm)	Lorraine	SAPBC	139	790	6	4.2	4.2	2.93	73	47	34

Usage in battles

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Pros and cons

Summarise and briefly evaluate the weaponry in terms of its characteristics and combat effectiveness. Mark pros and cons as a list.

Pros:

Cons:

History

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Media

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See also

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• reference to the article about the variant of the cannon/machine gun;
• references to approximate analogues by other nations and research trees.

External links

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• other literature.