SAu 40

SAu 40

Lorraine 37L

SAu 40

Lorraine 37L

France

I Rank

Battle rating:

AB	RB	SB
1.7	1.7	1.7

Class:

Tank destroyer

Research:5 900

Purchase:6 300

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Description

The Canon Automoteur DE 75 mm SAu 40 (75 mm Self-Propelled Gun SAu 40) is a rank I French tank destroyer with a battle rating of 1.7 (AB/RB/SB). It was introduced in Update 1.75 "La Résistance". It distinguishes itself by its very tall cupola and thick gun barrel. This tank is equipped with APHE rounds, a rare feature in the French tech tree.

As it was developed from the French S.35, this tank shares many of its characteristics such as the ~40 mm thick cast hull bolted onto the chassis, which is barely a widened version of its original. The track system is mostly the same as on the S.35, with 25 mm plates covering the roller wheels. As for the hull, it's a widened variant of the S.35's hull with two 8 mm grilles over the engine compartment and doors on the side.

General info

Survivability and armour

As this tank is based off the S.35, it shares many of its attributes when it comes to armour. A slight angle can defeat most shots this tank will take at this BR, this is useful to know when getting into position: from a distance and not showing neither side nor front to the enemy, you should be safe. As for frontal armour, its 40 mm overall thickness is not strong enough to withstand anything bigger than AA fire. But, a thing to consider with this weird pattern is its "bouncy" behaviour, principally around the gun mantlet: complex angles may just bounce some shots, making them loose some energy before hitting the main armour, this feature is peculiarly distinctive at gun's height.

The main weakness of this tank is its very tall commander's cupola, which makes it quite easy to spot and destroy, as it is thinner than the main armour. Any APHE penetrating this area will knock out the tank's commander, thus disabling its only MG and some shrapnels may even damage or incapacitate the driver, disabling this tank for good. A way to avoid getting spotted too easily is buying camouflage for the front cupola area, making it look more like a bush popping out a hill than a tank's turret. Try to hide the tank's lower hull part as it is only 35 mm thick.

Armour type:

• Cast homogeneous armour (hull, turret)
• Rolled homogeneous armour (side skirts, engine vents, exhaust pipes)

Armour	Front (Slope angle)	Sides	Rear	Roof
Hull	40 mm (0-73°) Front glacis 34 mm (1-54°) Lower glacis 60 mm (spherical) Gun mantlet 34 mm (cylindrical) Top - Turret base	40 mm (20-46°) Top - Front 34 mm (43-63°) Top - Roof junction 34 mm (cylindrical) Top - Turret base 40 mm Top - Centre and rear 40 + 25 mm Bottom	34 mm (26°) Upper plate 34 mm (4) Centre plate 34 mm (29-33°) Lower plate	20 mm (9-15°) 8 mm (14°) Engine vents
MG turret	38 mm (15-38°) Turret front 38.5 mm (5°) + 25 mm Machine gun mantlet	38 mm (16-38°)	38 mm (23-32°)	20 mm (8-17°)
Cupola	34 mm (spherical)			34 mm

Notes:

• Suspension wheels are 15 mm thick while tracks are 20 mm thick.
• Turret underside is 20 mm thick.
• Turret ring is 30 mm thick.
• Hull underside above the tracks is 12.7 mm thick.

Mobility

Game Mode	Max Speed (km/h)		Weight (tons)	Engine power (horsepower)		Power-to-weight ratio (hp/ton)
	Forward	Reverse		Stock	Upgraded	Stock	Upgraded
Arcade	41	6	24	270	363	11.25	15.13
Realistic	37	5		168	190	7	7.92

While being mounted on a widened S.35 hull, the heavier SAu 40 has about 70 HP less than its predecessor, making it quite slow and unwieldy. In order to fulfill the task of getting into position, one should choose its route wisely and avoid risky spots as this tank's awful reverse speed and hull turning rate makes it quite bad at hasty retreats. Mobility with the SAu 40 is an issue. It is arguably what makes this tank hard to master as it does not allow for good map placement.

Armaments

Main armament

As any casemate SPG, this tank's main feature is its main gun...kind of. With average penetration rates for this BR with a maximum of 73 mm at point-blank ranges (comparably, the Russian SU-76M penetrates 80 mm with its basic APHE shell and up to 135 mm with APCR shots). While being one of the rare French tank shooting APHE shells, increasing its one-shot potential, this round noticeably fails to explode when flanking enemies as this round takes 25 mm of steel to detonate. Another concern being its slow horizontal traverse, which makes it hard to react to fast-paced situations. This gun placement makes this tank quite vulnerable: being low, it exposes the SOMUA 40 to enemy fire when popping up a hill.

75 mm APX					Turret rotation speed (°/s)					Reloading rate (seconds)
Mode	Capacity	Vertical	Horizontal	Stabilizer	Stock	Upgraded	Full	Expert	Aced	Stock	Full	Expert	Aced
Arcade	101	-10°/+30°	±7°	N/A	5.3	7.3	8.9	9.8	10.4	7.15	6.33	5.83	5.50
Realistic					3.6	4.2	5.1	5.6	6.0

Ammunition

Penetration statistics
Ammunition	Type of warhead	Penetration @ 0° Angle of Attack (mm)
		10 m	100 m	500 m	1,000 m	1,500 m	2,000 m
Mle1910M	APHE	77	75	66	57	49	42
Mle1917	HE	10	10	10	10	10	10

Shell details
Ammunition	Type of warhead	Velocity (m/s)	Projectile Mass (kg)	Fuse delay (m)	Fuse sensitivity (mm)	Explosive Mass (TNT equivalent) (g)	Ricochet
							0%	50%	100%
Mle1910M	APHE	570	6.4	1.2	14	90	47°	60°	65°
Mle1917	HE	577	6.13	0.0	0.1	675	79°	80°	81°

Ammo racks

Ammo racks of the SAu 40

Full ammo	1st rack empty	2nd rack empty	3rd rack empty	4th rack empty	5th rack empty	Visual discrepancy
101	84 (+17)	66 (+35)	42 (+59)	18 (+83)	1 (+100)	No

Notes:

• As they are modeled by sets of 3 or 4, shells disappear from the rack only after you've fired all shells in the set.
• Flank racks empty: 18 (+83) shells

Machine guns

7.5 mm MAC 31
Mount	Capacity (Belt)	Fire rate	Vertical	Horizontal
MG turret	3,250 (150)	1,350	-9°/+20°	±180°

The small calibre of the MAC 31 machine gun makes it largely ineffective against all armoured vehicles but the ones with an open compartment. It still can be used to ping targets as a rangefinding help or to mow down minor obstacles blocking your line of sight. The turret is slow, which also negates the possibility of tracking low-flying aircraft with it.

Usage in battles

The SAu 40 behaves as a classical casemate SPG as it should provide its teammates with superior firepower from medium to far distance, behind the frontlines where it will be harder to flank. As this is its purposed role, this tank has some issues accomplishing it. The first being its relatively low penetration and shell velocity, which makes long range engagements (>750 m)a bit hard to manage. The second being bad mobility, which complicates the task of positioning.

Act as a classical SPG while keeping in mind your slow pace. There is nothing very much interesting nor special you can do with this tank.

Modules

Tier	Mobility		Protection	Firepower
I	Tracks		Parts	Horizontal Drive
II	Suspension	Brake System	FPE	Adjustment of Fire
III	Filters		Crew Replenishment	Elevation Mechanism
IV	Transmission	Engine

Pros and cons

Pros:

• Firepower
  • 75 mm APHE shell with explosive filler gives it good single-shot knock-out potential.
  • Competitive reload time
  • Depression and elevation angles are acceptable.
• Armour is quite thick on all sides.
• Gun mantlet armour is strong

Cons:

• Commander's turret is badly designed.
  • Tall turret with an exposed turret base.
  • Turret-mounted MG does not allow for shooting down planes.
  • Weak, unslopped armour makes it a shot trap
  • Makes it easy to spot while bringing no tactical advantage.
• Poor mobility
  • Engine is underpowered
  • Turret traverse is slow
  • Guns traverse is even slower
• Frontal armour has many weak spots due to bad sloping
• Only three crew members decrease the survivability.
• Huge ammo rack near gunner makes it easy to target and cause detonation.

History

The SAu 40 self-propelled gun was developed by the SOMUA company between 1935 and 1937 as part of the same order the French cavalry placed for the S35 tank.

The two tanks combined were intended to equip light mechanized divisions of the French army and support the larger "battle tanks" (chars de bataille). The vehicle inherited the S35's characteristic chassis with a redesigned front section of the hull to accommodate the 75mm APX cannon. In addition, the rotating turret on top of the fighting compartment was redesigned to a commander's cupola and moved to the side of the vehicle, but the turret's 47mm cannon was replaced with a single 7.5mm machine gun.

The body of the SAu 40 was ready by 1937, but it couldn't be immediately completed. Because the cannon was not yet ready to be installed on the chassis, SOMUA engineers had to wait nearly 2 years before the cannon was finally made available. It wasn't until 1939 that the fully assembled prototype was completed, and orders for mass production were received in October of the same year.

Whether or not any additional vehicles other than the prototype were built or if the vehicle took part in active fighting is unknown.

-From Devblog

Media

Skins

• Skins and camouflages for the SAu 40 from live.warthunder.com.

Videos

SAu 40, French, Tier-2, Tank Destroyer - Angry Nerd Gaming

SAu 40 Tank Review - NUSensei

The Shooting Range #77 - Pages of History section at 00:31 discusses the SAu 40.

See also

Vehicles equipped with a similiar chassis

• S.35

Other vehicles of similar configuration and role

• Sav m/43 (1944)

External links

• [Devblog] SAu 40 - The Ugly Duckling
• [Wikipedia] SOMUA_S35 - Projects

France tank destroyers
Lorraine 40t derivatives	CA Lorraine · Lorraine 155 Mle.50
ATGM	MEPHISTO · AMX-10M
Other	AMR.35 ZT3 · Lorraine 37L · SAu 40 · ARL-44 · ELC bis · AMX-50 Foch · AuF1
USA	▄M10 GMC · ▄M36B2