french light tank ERAC, MBT power in a compact tank

[CaID 8,996]

 

i would like to suggest the Engin de Reconaissance Amphibique Chenillé or also called ERAC

 

 

the ERAC was a french light tank designed for the reconnaissance duty in all terrain. alternative to the AML-60, this vehicles was featuring a very light weight, the amphibious capacity and a heavy fire-power. designed in 1961, the vehicles was tested in 1963 was intended to be a light tracked armoured reconnaissance vehicles with amphibian capacity. the vehicles was ultimately rejected, the reason is not know but it was most likely economical as the performance on the test was pretty good.

 

Firepower

the gun was a 105mm D1090 who was using HEAT rounds with 400mm of penetration. most likely using the G heat rounds also known as OCC 105 F1  which was also used in the AMX 30. this the rest related to the fire-power is still well known. the gun have a elevation of -8° + 15 which is pretty standard on the french tank. the rotation was initially slow, under powered by the transverse engine it was reaching 8°/sec but was eventually increased to a rotation of 24°/sec after they concluded the tank had electricity to space for a more powerful transverse engine. the tank carry 15 rounds in the turret and 15 rounds in the chassis giving it a total of 30 rounds for the 105mm . the coaxial been a 12.2mm M2hb but a 20mm M621 was also consider which is a feature choice for France and fallow the idea of the AMX 30.

the gunner sight have a night vision for fighting in the night.

at some point, there was a AFV version planned with a 20mm and HOT ATGM.

 

OCC 105 F1 (HEAT)

standard Heat round for the CN-105 F1, it was also know as Obus G.

 

projectile weight :  10.95 kg

projectile velocity : 850 m/sec

 

penetration

400 mm at any-distance, angle 0°

 

Mobility
the vehicles is powered by a 180 hp engine but it was also proposed to mount a 200/220 depending of the fuel and could provide up to 260 hp if you overfeed it. the vehicles. weighting 9 tonnes in his final stage, it was having a track large of 380 mm which led to to a pressure of 0.475 km/cm² which is pretty light for a tank. this allow it to perform particularly well in the mud and snow. the transmission imported from the M113, was completed by a automatic converter "high low" and a gearbox offering 5 speed and . the speed reaching 70 km/h and also theoretically 75 km/h would make this tank a very fast one, capable to match in mobility with the fastest tanks of the game. the power-weight ratio reaching 20.0 hp/tonnes the very high ratio for great mobility. the tank is also perfectly amphibious powered by 2 propeller inside of the chassis. this allow a speed of 10 km/h in the water which on his own is pretty good.

 

 

Protection

the armour in mainly made of aluminum with a thickness offering a fair protection. the turret who is made of steel, dispose of a 15mm gun-shieldand the turret itself made of aluminum is 15mm thick at the front and 12mm at the side. this shall make it a bit vulnerable to the HMG on the side but the front shall be capable to the the HMG hit. the chassis is a bit better protected at the front with 60mm at the nose and 30nm on the side. the rear and roof have 15mm. this give a bit better protection than most amphibious vehicles of his kind but not outstanding them. the crew of 3 men include a gunner and commander in the turret and a driver in the hull. the vehicle was designed to be more compact than the PT-76. it was actually just a bit smaller.

 

hull made of aluminum

turret  made of steel

Armour	Front	Sides	Rear	Roof
Hull	60 mm (23°) nose 15 mm (79°) top	30 mm	15 mm (23°) bottom 15 mm (79°) top	15 mm
Turret	15 mm Turret front 15 mm Gun mantle	12 mm (22°)	12 mm (9°)	8 mm
Cupola	30 mm	30 mm	30 mm	8 mm

 

additional photos

Spoiler

 

Specifications (PT-76 model 1)
Mass	9 t
Length	6.95 m (gun forward) 5.02 m (hull)
Width	2.55 m
Height	2.08 m
Crew	3 (driver, commander/gunner,loader)
Armour	aluminium 60mm - hull front 30mm - hull side 15mm - hull rear and top 20mm - bottom 45mm - turret front 30mm - turret side and rear 8mm - turret top Steel 15mm - gun mantlet.
Main armament	105mm D1090 (30 rounds)
Secondary armament	12.7mm M2HB (500 rounds) *mounted or 20mm M621 (300 rounds) *proposed
Engine	180 hp (220 planned)
Power/weight	20 horsepower / tonne
Suspension	torsion-bar
Ground clearance	440 mm
Fuel capacity	250 L (55 imp gal; 66 US gal)
Operational range	370–400 km (230–250 mi) 480–510 km (300–320 mi) with external fuel
Maximum speed	70 km/h on road, 9.8 km/h swimming

source

French archive (i apology if this seem to be a mess, there is like 6 different documents about it) thanks to @Colasix to have provide the documents

Spoiler

blob:https://imgur.com/4164fb69-daf5-43ad-b8fe-ec1dc2e6bede

 

Edited May 24, 2022 by CaID

[kurururocks 210]

Open for discussion

[ThomasElsass67 305]

+1, and you already made the research for Gaijin! ^^

[CaID 8,996]

9 minutes ago, ThomasElsass67 said:

+1, and you already made the research for Gaijin! ^^

and i first i just wanted to get the geneal details of the tank. as the only online source was very limited and inaccurate
https://www.chars-francais.net/2015/index.php/engins-blindes/chars?task=view&id=798

 

but it was @Colasix who did most work. i only read the papers he found and wrote the suggestion

 

we are still missing the disposition of the vehicles inside, like how is the engine placed and where is the ammo. i suppose we can go with guess work a bit

[Abaddon75 460]

9 minutes ago, CaID said:

and i first i just wanted to get the geneal details of the tank. as the only online source was very limited and innacurate
https://www.chars-francais.net/2015/index.php/engins-blindes/chars?task=view&id=798

it would be good to point out there is 3 prototypes here, or I miss a pieace of info and that's the same one with a different side skirt, rear, and wheels/tracks

Edited April 23, 2022 by Abaddon75

[CaID 8,996]

15 minutes ago, Abaddon75 said:

it would be good to point out there is 3 prototypes here, or I miss a pieace of info and that's the same one with a different side skirt, rear, and wheels/tracks

as the rear is different from certain picture, i can only assume they had mounted the H.S 103 engine who was a multi-fuel engine proving 200 to 220 hp depending of the fuel it was using and could be over-feed to reach 260 hp

 

but the weight would rose to 9.4 tonnes from the evaluation of the project. still it would give a better mobility with 23.4 hp/tonnes

 

but for the other prototype, i do not think any of them was built. save fore the wood mock-up

[Abaddon75 460]

first pic has a straight side skirt and a square butt, thin tracks separated in their middle, twin wheels

second pic to fifth one : new butt, new sideskirts witha little hump at the rear, same wheels and tracks, but the later are enlarged.

last pic : pointy butt, new wheels and tracks and same side skirt as the previous one.

Wheels and tracks are not a big deal to modify I guess, also they always have 5 of them with similare space between them, so the chassis didn't changed to much except for the engine deck and some litlle details.

[CaID 8,996]

11 minutes ago, Abaddon75 said:

first pic has a straight side skirt and a square butt, thin tracks separated in their middle, twin wheels

second pic to fifth one : new butt, new sideskirts witha little hump at the rear, same wheels and tracks, but the later are enlarged.

last pic : pointy butt, new wheels and tracks and same side skirt as the previous one.

Wheels and tracks are not a big deal to modify I guess, also they always have 5 of them with similare space between them, so the chassis didn't changed to much except for the engine deck and some litlle details.

such different are often related to the polishing of the design during the prototype stage. the only concern i have is the engine deck as it's a good indicator that the engine was changed at some point. and the documents do state that they was studying the potential installation of a new engine. but if they did, which one is what?

the photos was taken online and not from the archives, the archive had little pictures outside the one in the sources. eventually we might get them, but for now we can go with what we have.

[Milocat 4,857]

+1 for sure, would love to see this.  

[Jan_Gustl_WT 1,746]

+1 every additon to the french tech tree is always welcome!

[CaID 8,996]

i updated some information about the velocity

we found a new document with specification of the muzzle velocity which is 850 m/sec with the HEAT rounds. it also give a 2nd confirmation that the penetration reach 400mm, (it indicate 375 to 400mm)

that give a better velocity than expected as i was assuming the velocity would be around 700 m/sec due to the comparison to the AMX mk.61 who also use the same rounds.

[cervotoc123 129]

+1 sounds great to me

[Colasix 25]

ERAC's mockup

 

[KilianL 865]

I absolutely love this and I hope we get it soon to bolster the rank V 

 

Id love to yeet it in some rivers in some maps

[_TheCrimsonKing_ 504]

+1!!