WesWorld

The Argentine Armoured Development Board has issued a specfication for a new light tank for reconnaissance duties to replace the current T-2M33 tank.

The overall specs are

Weight: No more than 11.5-12 tons
Speed: No less than 30mph
Armament: at least a 37mm gun but the Italian 47mm perferred plus co-axial MG
Armour: capable of resisting small arms fire and light cannon fire over the frontal arc
Crew: At least three crewmen, radio must be fitted


The Argentine Army will submit a bid, this is still secret.


Vickers in Britain offers a variant of the Light Command Tank which will be ready for production in 1938. It is a new design with modified Horstmann suspension. The turret will mount the 37mm gun and co-axial MG. The gunner has a periscope scope on the turret roof. Weight 5 tons, crew 3, armour 11-4mm, 90hp Meadows EST petrol, 31mph.

Germany's MAN corporation has two proposals, both based on the Panzer II work for Belgium and the Netherlands.

The first proposal is the Panzer II first proposed to Belgium:
Panzer II Bel

Length 4.50 meters
Width 2.24 meters
Height 2.15 meters

Crew 3.00 men (commander, gunner, driver)

Combat Weight 9.95 metric tons

Engine: 160 hp MAN diesel, with 7 speed Renk transmission
Fuel capacity: 80 gallons diesel, for a range of 182 miles
Top speed: 29.14 mph / 46.624 km/h
Armament: 1 47mm with 60 rounds, 1 MG with 1500 rounds in turret

Chassis armor: 30mm front, 15mm sides & rear, 8mm deck, 10mm belly
Turret armor: 35mm front, 15mm sides & rear, 8mm deck


The second uses the 4.8m chassis developed for light tank usage with the more heavily armored turret adopted by Belgium and the Netherlands:
Panzer II Arg

Length 4.80 meters
Width 2.27 meters
Height 2.15 meters

Crew 3.00 men (commander, gunner, driver)

Combat Weight 11.63 metric tons

Engine: 240 hp MAN diesel, with 7 speed Renk transmission
Fuel capacity: 80 gallons diesel, for a range of 156 miles
Top speed: 37.4 mph / 59.84 km/h
Armament: 1 47mm with 60 rounds, 1 MG with 1600 rounds in turret

Chassis armor: 35mm front, 15mm sides & rear, 8mm deck, 10mm belly
Turret armor: 35mm front, 20mm sides & rear, 8mm deck

Atlantis can offer 3 designs.

AT-34 1A1 light tank
Crew: 4
Weight: 12.4 tons
Length: 5.6m
Width: 2.4m
Height: 2.35m
Engine: Roth 720R-1400 V-8, 300hp
Armament: 1x25mm
Armor: 20-6.25mm, sloped armour
Performance: 43mph, 297 miles operating range

AT-32 1A3 light tank
Crew: 4
Weight: 14.5 tons (20,000lbs/13,180 kg)
Length: 16'1"
Width: 7'7"
Height: 6'7"
Engine: Roth 668R-1200 7 cyl radial, 250hp
Armament: 1x37mm, 1x7.62
Armor: 20-6.25mm
Performance: 30mph/48km/h

AT-31 1A3 light tank
Crew: 3
Weight: 11.5 tons (11,685 kg)
Length: 5.6m
Width: 2.25m
Height: 2,25m
Engine: Roth 720R-1400 V-8, 300hp
Armament: 1x37mm, 1x7.62
Armor: 20-6.25mm
Performance: 30mph/48km/h

Vickers offers another design:

Light Tank Mk VI Tetrarch: Designed by Vickers as a private venture in 1936. New independent spring suspension uses large road wheels and flexible track steering. The 165hp Meadows petrol engine provides a top speed of 40mph on roads and 20mph cross-country. Range is 140 miles. The armour is 14-4mm thick and the armament is one 37mm and one co-axial MG. Only two crewmen are carried.

The designers at Terni had a play around with the requirements and came up with a design using techniques being developed for new Italian tanks in addition to existing technology. The hull is is based on a future Italian design with a highly sloped front and vertical sides which results in a blocky appearance but aids manufacturing. New double torsion bar suspension is used after being trialled succesfully on a number of prototypes to give a smoother ride at high speeds. The engine is the proven 300cv unit that is used on the AB34 armoured cars already in Argentine service. Very good protection is available on the frontal arc with 20mm of armour grade steel being overlaid on a mild steel base. The turret is the same as used on the existing M.25 tanks and has two crewmen along with a 47mm cannon.

L12/38
Crew: 3
Weight: 12,020kg
Length: 4.92m
Width: 2.20m
Height: 2.22m
Engine: 300hp Isotta-Fraschini L1506
Armament: 1 x 47/32, 1 x 8mm Breda
Armour: 30 - 10mm
Performance: 45mph top speed, 180mile range
P/W: 25hp/ton Ground Pressure: 9.5psi

The Commander of the Mechanised Corps, Maj. Gen. Antonio Miguel Barbera has annouced a new TOE for the Armoured Forces.

His intial plan of centralising the armoured units into a Brigade and having reduced regiments with heavy tanks and self-propelled guns attached to the Infantry Corps was rejected by the High Command owing to costs.

Instead all armoured regiments will now have eight companies, two light companies for scouting, four fast companies for anti-tank duties and exploitation and two heavy companies for support work.

Armoured Regiment Organization (1938 TOE)

Regimental Staff Headquarters Company
1 Motorised Signal Company
1 Motorised Radio Company
1 Mapping Company
1 Military Police Company (9 LMG)
2 Motorised Pioneer Companies (9 LMG)
2 Bridging Columns

Armoured Car Reconnaissance Battalion
Battalion Headquarters Company (3 C-4M35 AC)
4 Armoured Car Reconnaissance Companies (two 9 C-3M35 AC each, two 9 C-4M35 each)
1 Motorised Signal Company

2 Tank Battalions
Battalion Headquarters Company (3 tanks)
4 Armoured Companies (12 tanks each) (1 light, 2 fast and 1 heavy tank company)
1 Motorised Signal Company

1 Support Company Headquarters (3 tanks)
1 Support Company (12 SPGs)

Antiaerea Artillería Company
Antiaerea Artillería Staff Platoon
1 Observation Platoon
3 Batteries (four truck-mounted 20mm each)

Anti-Tank Company
Staff Platoon
1 Observation Platoon
2 Batteries (four 37mm each)

Quartermaster Battalion
4 Motorised Supply Companies
1 Repair Workshop
1 Field Bakery
1 Field Butcher Company
1 Field Post Office

Medical Battalion
1 Motorised Medical Companies
1 Ambulance Company
1 Field Hospital


The tank chosen to fulfil the heavy requirement is the Vickers Valentine which can easily accomodate the excellent Italian 47mm gun and has armour thick enough to withstand most anti-tank guns. Around 120 will be brought during 1938 alongside the new light tank type.


In the first round of the Light Tank contest the following were rejected;

Vickers Light Comman Tank: Too small, armour too weak
Vickers Tetrarch: Two crew, cannot be armed with 47mm and thin armour
AT-32: Too heavy, no 47mm gun

Following the next assesment the next to be rejected were;
AT-31: Not as well armoured as the better AT-34, 37mm gun
Panzer II Bel: Not enough growth compared to the longer Panzer II Arg and also slower.

This leaves the following to go into the final round;

Panzer II Arg, good growth potential, excellent armour and firepower with 47mm gun
AT-34: Sloped armour worth investigating, fast, poor armament but four crew is an asset
Terni L12/38: Very advanced, meets critera but is heavy, potential problems with suspension, sloped armour noted, very fast
T-4M38: Designed by Army, meets spec in terms of protection, firepower and speed and very long range

[Actually, the Pz II has a fair amount of sloped armor, it's just not as heavily sloped like some. The chassis front and upper sides and the turret front, sides, and rear are all sloped at 30 degrees.]

I don't see the L12 as being particularly advanced it's all existing technology; engine already exists and works fine in other similar vehicles; transmission already exists from the S25 series; turret already exists as is; suspension is new but has been trialled on prototypes. The frontal armour is heavily sloped and with high quality armour offers very good protection on the frontal arc. Elsewhere its slab sided which compromises protection a bit but makes it easier to build. Speed is probably a little optimistic, ride quality would be pretty poor at that point. I'm not sure on the drawing either, it just doesn't look quite right yet.

RA, compared to the British tanks offered it looks postively sci-fi!

I know all the main components are proven and tested and offer excellent commonality.

It's a tough choice between the Pz II Arg and the L12/38 and my own T-4M38 (a designation that will be applied to whichever tank wins.

In the interests of fairness the Argentine Army releases its design. Note this design features only very few sloped surfaces, this is a basic OTL Pz II type tank under the surface. Torsion bar suspension is used.

Vehicle Name T-4M38
Vehicle Type Light Tank

Length 4.50 meters
Width 2.25 meters
Height 2.10 meters

Crew 3.00 men
Passengers 0.00 men

Weight Breakdown
Crew Weight 0.54 metric tons
Passenger Weight 0.00 metric tons
Miscellaneous Weight 0.07 metric tons
Armor Weight 4.11 metric tons
Armament Weight 0.36 metric tons
Ammunition Weight 0.45 metric tons
Engine Weight 0.72 metric tons
Fuel Weight 0.16 metric tons
APU Weight 0.00 metric tons
Energy Bank Weight 0.04 metric tons
Transmission Weight 0.40 metric tons
Amphibious Equipment Weight 0.00 metric tons
Suspension Weight 0.71 metric tons
Track Weight 1.40 metric tons
Road Wheel Weight 0.14 metric tons
Applique Armor Package A 0.00 metric tons
Applique Armor Package B 0.00 metric tons
Cargo Payload 0.00 metric tons

Mobility and Performance Breakdown

Engine 175.00 horsepower
Fuel Capacity 50.00 gallons
Maximum Hull Speed (water) 5.93 MPH

Baseline Upgraded (A) Upgraded (A+B)
Combat Weight 9.12 9.12 9.12 metric tons
Growth Capability (Transmission) 6.28 6.28 6.28 metric tons
Growth Capability (Suspension) 0.88 0.88 0.88 metric tons
Ground Pressure 5.76 5.76 5.76 PSI
Power/Weight Ratio 19.18 19.18 19.18 hp/metric ton
Top Speed 34.77 34.77 34.77 MPH
Operating Range 248.37 248.37 248.37 miles


Armament Breakdown
Hull Turret
Rifle Calibre MGs 0.00 1.00
HMGs 0.00 0.00

Hull Turret Total
ATGMs 0.00 0.00 0.00 rounds stowed
Rifle Calibre 1,600.00 800.00 2,400.00 rounds stowed
HMG Calibre 0.00 0.00 0.00 rounds stowed

Calibre (mm) # in Hull # in Turret Rounds (hull) Rounds (Turret)
Cannon/Gun 1 47.00 0.00 1.00 48 8


BASELINE PROTECTION LEVELS
KE (mm) HEAT (mm) KE Resistance HEAT Resistance
Front Hull Armor 32.18 30.06 Resistant to 20x110mm Hispano Penetratable by Virtually Anything
Side Hull Armor 18.45 15.00 Resistant to 7.62 Penetratable by Virtually Anything
Rear Hull Armor 12.53 12.53 Resistant to 5.56 Penetratable by Virtually Anything
Top Hull Armor 10.00 10.00 Resistant to 5.56 Penetratable by Virtually Anything
Hull Floor Armor 8.00 8.00 Penetratable by Virtually Anything Penetratable by Virtually Anything

KE (mm) HEAT (mm) KE Resistance HEAT Resistance
Front Turret Armor 38.20 31.06 Resistant to 20x110mm Hispano Penetratable by Virtually Anything
Side Turret Armor 37.47 30.46 Resistant to 20x110mm Hispano Penetratable by Virtually Anything
Rear Turret Armor 24.98 20.31 Resistant to 12.7 Penetratable by Virtually Anything
Top Turret Armor 12.30 10.00 Resistant to 5.56 Penetratable by Virtually Anything

Looking at it, the ground pressure is VERY low. One of the flaws in TS is that it over-estimates the amount of track on the ground, so if you use a historical track width it will give you an unrealisticly low ground pressure. You may want to shrink the width of the track until you get a ground pressure similar to that of the historical vehicle, then increase the width of the vehicle until you get back to where you have the same width as the historical vehicle.

I suspect you're using the original TankSharp spreadsheet which includes many, many errors. I tried to have a go at fixing it and gives more reasonable results. An example sheet is here for the L12 design. There were lots of problems with the maths in the spreadsheet itself, like only accounting for one side being armoured, but the errors almost cancelled each other out. I eventually sorted it out and got towards something more reasonable.

The picture of the L12 can always be changed.

Actually, he's using TS 0.71, which has a whole different set of errors than TS 0.6 had.

I must admit I don't put too much store by Tanskharp, I just use it as a guage rather than plucking figures from thin air or just always copying real tanks.

With corrections, it can be fairly accurate, I can get very close to historical numbers for most things (top speed can be a bit high) for a lot of historical vehicles. Top speed, though, is easily fixed by installing a governor (historically common even into the present day) and so on. If it's corrected, it allows reasonable numbers for a-historical vehicles, which given WW's proliferation of producers is a good thing.

Maj. Gen. Antonio Miguel Barbera and the Technical Board have a requirement for a light tank-destroyer, a turretless armoured vehicle able to be used as a moble AT gun. The gun would be the 47mm and armour must be thicker than the light tank and certainly proof from 20mm cannon fire on the frontal and side arcs.

The Board wishes to see submissions based on the Pz II Arg chassis and the L12/38. A version of the T-4M38 has already been drawn up as a casemate type (think mini StuG or Skoda S1d). The best chassis for both requirements will be chosen as the winner for the light tank contest for commonality.

The Atlantean design although fast and modern is rejected because of the weaker 25mm mount and inability to mount a 47mm gun.

In response to the requirement, the designers at Terni added a small sloping superstructure in place of the turret, actually increasing the available space inside. More armour was added to the vehicle, with the side plates being thickened to 30mm. Another increase in protection was achieved by the sloping plates that make up the superstructure, in place of the vertical faces of the previous turret. Due to the extra armour, the weight of the vehicle has increased, and the performances revised downwards.

The designers felt that a variety of other weapons could also be accommodated. The 75/18 howitzer is interchangeable with the 47/32 and could be mounted in the turret or fixed emplacement. Due to the greater space available in the self propelled gun, it was also thought possible to fit a longer 75/32 gun which has better performance.


S13/38
Crew: 3
Weight: 13,400kg
Length: 4.92m
Width: 2.20m
Height: 2.22m
Engine: 300hp Isotta-Fraschini L1506
Armament: 1 x 47/32, 1 x 8mm Breda
Armour: 40 - 10mm
Performance: 40mph top speed, 160mile range
P/W: 23hp/ton Ground Pressure: 10.5psi

MAN proposes the following pair of vehicles (based on the StuG II design already done for the Heer but with the larger engine used on the Panzer II Arg):

JadgPanzer II Arg

Length 4.80 meters
Width 2.27 meters
Height 1.95 meters

Crew 4.00 men (commander, gunner, loader, driver)

Combat Weight 11.64 metric tons

Engine: 240 hp MAN diesel, with 7 speed Renk transmission
Fuel capacity: 80 gallons diesel, for a range of 156 miles
Top speed: 37.4 mph / 59.84 km/h
Armament: 1 47mm with 60 rounds, 1 MG with 1200 rounds in chassis front

Chassis armor: 40mm front, 20mm sides, 12.5mm rear, 8mm deck, 12mm belly


Sturmgeshutz II Arg

Length 4.80 meters
Width 2.27 meters
Height 1.95 meters

Crew 4.00 men (commander, gunner, loader, driver)

Combat Weight 11.94 metric tons

Engine: 240 hp MAN diesel, with 7 speed Renk transmission
Fuel capacity: 80 gallons diesel, for a range of 156 miles
Top speed: 36.4 mph / 58.7 km/h
Armament: 1 75mm with 45 rounds, 1 MG with 1200 rounds in chassis front

Chassis armor: 40mm front, 20mm sides, 12.5mm rear, 8mm deck, 12mm belly

Damn its sooo hard to choose! You guys have both designed very good tanks that fulfill what I had in mind.

My own tank is losing favour (production capacity lacking due to the Leopard programme, needs new 175hp engine) and so the choice is down to two.

S13/38:
Plus points: Growth capability, capable of being armed with 75mm guns, better armour, spacious inside, uses standard engine parts we already use, already an Italian customer.
Minus points: Is higher than Pz II not much else wrong

JdPz and StuG:
Plus points: retains all advantages of Pz II, good armour, already developed vehicle in German use, both variants essentially identical, lower tactical height
Minus points: not quite as fast as S13, new engines for the Army, never brought German tanks before (but other arms)

I think both are very good and although I should probably logically go for Italian designs something just draws me to the smaller and lighter Pz II.

So therefore the Pz II Arg will become the T-4M38, TG-2M38 and TG-3M38.