SAu 40

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RANK 4 FRANCE
Somua SM PACK
fr_somua_sau40.png
GarageImage SAu 40.jpg
SAu 40
AB RB SB
2.0 2.0 2.0
Research:7 900 Specs-Card-Exp.png
Purchase:10 000 Specs-Card-Lion.png
Show in game

Description

The Canon Automoteur DE 75 mm SAu 40 (75 mm Self-Propelled Gun SAu 40) is a rank II French tank destroyer with a battle rating of 2.0 (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

Armourfront / side / back
Hull40 / 40 / 34
Turret38 / 38 / 38
Crew3 people
Visibility99 %

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 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

Speedforward / back
AB41 / 6 km/h
RB and SB37 / 5 km/h
Number of gears5 forward
1 back
Weight24.0 t
Engine power
AB363 hp
RB and SB190 hp
Power-to-weight ratio
AB15.1 hp/t
RB and SB7.9 hp/t
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.

Modifications and economy

Repair costBasic → Reference
AB590 → 729 Sl icon.png
RB880 → 1 088 Sl icon.png
SB990 → 1 224 Sl icon.png
Total cost of modifications6 880 Rp icon.png
9 380 Sl icon.png
Talisman cost530 Ge icon.png
Crew training3 000 Sl icon.png
Experts10 000 Sl icon.png
Aces110 Ge icon.png
Research Aces160 000 Rp icon.png
Reward for battleAB / RB / SB
30 / 70 / 90 % Sl icon.png
112 / 112 / 112 % Rp icon.png
Modifications
Mobility Protection Firepower
Mods new tank traks.png
Tracks
Research:
460 Rp icon.png
Cost:
630 Sl icon.png
70 Ge icon.png
Mods new tank suspension.png
Suspension
Research:
390 Rp icon.png
Cost:
530 Sl icon.png
60 Ge icon.png
Mods new tank break.png
Brake System
Research:
390 Rp icon.png
Cost:
530 Sl icon.png
60 Ge icon.png
Mods new tank filter.png
Filters
Research:
580 Rp icon.png
Cost:
790 Sl icon.png
80 Ge icon.png
Mods new tank transmission.png
Transmission
Research:
1 100 Rp icon.png
Cost:
1 500 Sl icon.png
160 Ge icon.png
Mods new tank engine.png
Engine
Research:
1 100 Rp icon.png
Cost:
1 500 Sl icon.png
160 Ge icon.png
Mods tank tool kit.png
Parts
Research:
460 Rp icon.png
Cost:
630 Sl icon.png
70 Ge icon.png
Mods extinguisher.png
FPE
Research:
390 Rp icon.png
Cost:
530 Sl icon.png
60 Ge icon.png
Mods tank reinforcement fr.png
Crew Replenishment
Research:
580 Rp icon.png
Cost:
790 Sl icon.png
80 Ge icon.png
Mods new tank horizontal aiming.png
Horizontal Drive
Research:
460 Rp icon.png
Cost:
630 Sl icon.png
70 Ge icon.png
Mods tank cannon.png
Adjustment of Fire
Research:
390 Rp icon.png
Cost:
530 Sl icon.png
60 Ge icon.png
Mods new tank vertical aiming.png
Elevation Mechanism
Research:
580 Rp icon.png
Cost:
790 Sl icon.png
80 Ge icon.png

Armaments

Main armament

Ammunition101 rounds
Reloadbasic crew → aces
7.2 → 5.5 s
Vertical guidance-10° / 30°
Horizontal guidance-7° / 7°
Main article: APX (75 mm)

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) (+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

Ammunition3 250 rounds
Belt capacity150 rounds
Reloadbasic crew → aces
6.5 → 5.0 s
Fire rate1 350 shots/min
Main article: MAC 31 (7.5 mm)
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.

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
Videos

See also

Vehicles equipped with a similiar chassis
Other vehicles of similar configuration and role

External links


France tank destroyers
  AMR.35 ZT3 · SAu 40 · Lorraine 37L · ARL-44 · CA Lorraine · Lorraine 155 Mle.50 · AMX-50 Foch · SK-105A2
USA  ▄M10 GMC