SAu 40
Contents
Description
The Canon Automoteur DE 75 mm SAu 40 was developed by SOMUA between 1935 and 1937 alongside the S.35 tank for French cavalry. It featured a redesigned hull to house a 75 mm cannon and a new commander's cupola with a machine gun. The prototype was finished in 1939 after delays in acquiring the cannon. It is uncertain if more vehicles were produced or if it saw combat action. Doctrinally, the vehicle was relegated to a support role, intended to provide cover for heavier tanks like the Char B1.
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. The tank features an APHE shell, this increases the chances of one-shots at enemy tanks. In terms of mobility, it is a pretty slow tank, and it's not very survivable either, it has a very large profile and the commander's cupola is a big weak point that can be exploited by other vehicles.
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 lose 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 MG turret, 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 34 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.
- Belly armour 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 the same engine as its predecessor, making it quite slow and unwieldy, with a very low power-to-weight ratio. In order to fulfill the task of getting into position, one should choose their route wisely and avoid risky spots as this SPG's terrible reverse speed 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. One positive of this tank's mobility, however, is that it has a decent hull traverse because of the ability to use both tracks when turning in place.
Modifications and economy
| Mobility | Protection | Firepower | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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Armaments
Main armament
As any casemate SPG, this tank's main feature is its main gun, it is also one of the rare French tanks firing APHE shells. However, the cannon has an average penetration power for its BR. And the APHE round fails to explode when targeting enemies' sides, as the round has a rather high fuse sensitivity. Another concern is its slow horizontal traverse, which makes it hard to react to fast-paced combat situations. The gun placement makes this tank quite vulnerable: being low, it exposes the SAu 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 | 0.1 | 675 | 79° | 80° | 81° | |||
Ammo racks
| 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 | 3,300 (150) | 551 | -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.
Pros and cons
Pros:
- 75 mm APHE shell gives it good single-shot knock-out potential
- Competitive reload time
- Strong armour on gun mantlet
Cons:
- Commander's turret is poorly armoured and a shot trap
- Machine gun placement makes AA use difficult
- Poor mobility due to underpowered engine
- Slow gun traverse
- Frontal armour has many weak spots due to bad sloping
- Only three crew members decreases survivability
- Large ammo rack near gunner makes easy target for ammo rack detonations
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 S.35 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 S.35's characteristic chassis with a redesigned front section of the hull to accommodate the 75 mm 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 47 mm cannon was replaced with a single 7.5 mm 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
- Videos
See also
- Vehicles equipped with a similar chassis
- Other vehicles of similar configuration and role
External links
| Société d'Outillage Mécanique et d'Usinage d'Artillerie (SOMUA) | |
|---|---|
| Tanks | |
| Medium tanks | S.35 |
| Heavy tanks | Somua SM |
| Tank destroyers | SAu 40 |
| 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 |
