# Light tanks for the beligerents



## tomo pauk (Apr 19, 2012)

Hi, all,
The light tanks were produced used on large scale during the ww2, many times doubling as the 'front line' tanks, helping out the infantry, in the teeth of the AT guns. How would the light tanks looked if you were calling the shots? The upper limit is 15 tons prior 1942, 20 tons from 1942 and on, each country using only 'domestic' engines weaponry, along with historical suspension set-ups. If the tank can be used as a platform for different kinds of AFVs, it scores extra points )

EDIT: I agree that in 1939/40 the 15 ton tanks were in 'medium' category, so the category of 'under 10 tons, prior July 1940' is added


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## davebender (Apr 19, 2012)

1935. German Army specification for a 15 ton tank with main gun up to 5cm in size.
The Panzer III won the competition.

This tank gets my vote. How many other 15 ton light tanks had potential for upgrade to a 22 ton MBT by 1940?


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## Vincenzo (Apr 19, 2012)

imho 15 tons it's too high for a light early in the war
Pz II 10 tons
L 6 7 tons
Type 9598 7.5 tons
Tetrarch 7.5 Tons
T-26 10 Tons
T-60 6 Tons
T-70 9 Tons


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## davebender (Apr 19, 2012)

The 10 ton Panzer II performed well for a vehicle of that size and it was dirt cheap, costing only about 50,000 RM. The relatively powerful 2cm KwK30 or KwK38 autocannon was effective against both soft targets and light armor. Frontal armor was upgraded to 30mm during 1940 which is pretty good for a vehicle of that size. The same chassis could be used for a low cost 10.5cm SP howitzer or 7.5cm SP AT gun.


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## Shortround6 (Apr 19, 2012)

Light tanks, for the most part were a waste of resources. They were popular because they were cheap and/or could be built in factories that could not build "medium" tanks. Once in combat, while they did perform good service at times, it was usually at a high cost both in tanks and crews. The only real role they had in the European Theater was as tracked reconnaissance vehicles when the terrain/weather bogged wheeled vehicles. Asia was a bit different as the Japanese never had much beyond light tanks and had rather weak anti-tank guns so US Light tanks could perform there ( they also fit better in the landing craft). Using light tanks as a chassis for other types of AFV's also presents problems. Just because a certain size gun could be mounted or was mounted on a light tank chassis doesn't mean is was really a good idea. It may have been better than no tracked chassis under that gun but that may not be saying much. Small chassis restrict gun crew numbers and room to operate which affects rate of fire, small chassis also mean restricted ammunition storage which either means restricted engagement times or bombardments or extra tracked chassis to keep an adequate supply of ammo on hand. Needing 6 chassis for 4 barrels to have a decent supply of ammo doesn't look so good compared to 4 medium chassis for 4 barrels and about the same total amount of ammunition. 

The British had a good light tank for helping the infantry, it was called the Valentine.


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## Shortround6 (Apr 19, 2012)

davebender said:


> 1935. German Army specification for a 15 ton tank with main gun up to 5cm in size.
> The Panzer III won the competition.
> 
> This tank gets my vote. How many other 15 ton light tanks had potential for upgrade to a 22 ton MBT by 1940?



Again with the superior German designs? The 1935 15 ton "design" went through at least 3 different suspensions and 3 transmissions by the time the "E" went into production in Dec of 1938 about 70 total of the A, B, C and D models were built. 

15 toms was firmly in the medium category in 1935. 

The MK II shows the limits of the "light" category rather well. Unless the enemy offers up softballs like the British Light tank MK VI or some of the early Russian light tanks (t-37/38 or T-40) it's role quickly became tracked reconnaissance or a desperation attempt to make up numbers. 
30mm armor was darn near useless against anything heavier than 20mm cannon or those short French 37mm guns.


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## psteel (Apr 19, 2012)

15 tons is too big for light tank before WW-II. I would agree 10 tons good mark. I would vote for Cz tanks of this weight range.the T-35 and then T-38. Also good as medium tanks in a pinch and later excellent for SPAT vehicles ; SP infantry gun vehicles and further evolution into Assault gun like "Hetzer" design and 13 ton Weapons Carrier like "Waffentragger" .


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## Vincenzo (Apr 20, 2012)

the Pz 35 38 were used as medium tank (despite they weighted around as a Pz II).
also the M3 Stuart (13 tons early models, called light tank from US) were initially used as cruiser tank


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## davebender (Apr 20, 2012)

That depends on when they were built. Prior to 1941 light tanks such as the Soviet BT-5 ruled the battlefield. Heavier tanks existed during the 1930s but they were relatively few in number.


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## tomo pauk (Apr 20, 2012)

I've set the limits in order to cut down on the number of categories, but, upon the popular request, I'll ad another category (and edit the opening post here accordingly): under 10 tons, prior July 1940.


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## Vincenzo (Apr 20, 2012)

Tomo i known this is your thread, so sorry
no italian tanks used v/s allies weight more 15 ton, a model used vs germans weight around 16 tons, as september '43
Japanese common medium tank until the end was Type 97 a 15 ton, the maybe used Type 1 in late '44) is a 17 tons
Pz 3538 were used as medium tank in Barbarossa
as writed before M3 Stuart were used as cruiser tank in fall 41 i think also in winter 41/42.
in the 30s all tank with a gun are medium, also a Pz II, july 1940 maybe a minim date for take the 10 tons as light previously are medium


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## tomo pauk (Apr 20, 2012)

No problems, Vincenzo 

Different countries had different categorizations, so it's my intention to call all the tanks that fit under these weight/time categories as 'light tanks'. The designs' particular for this thread should, however, be connected at the best possible layouts, rather that at the real ones. 
Maybe it would be cool if we had polls that cover the real lights, though.


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## davebender (Apr 20, 2012)

Why bother? APCs like the 8 ton Sd.Kfz. 251 3/4 track were arguably superior to any "tank" weighing less then 10 tons.


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## Vincenzo (Apr 20, 2012)

superior for? is halftracked so has not same mobility (maybe worst sometime, maybe best othertime), as not gun turret so in less tactical flexible, as less armour and as you told is a APC or also AFV so is an other thing.


as possible layout, taking out, the 1939/40 campaign. i think we can put a limit a 10 tons from '41 to spring 42, up slowly to reach 20 tons in '45 (minim winter 44/45)


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## Shortround6 (Apr 20, 2012)

APCs are big targets with open tops that cry out for air burst artillery fire.


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## Shortround6 (Apr 20, 2012)

The problem with light tanks is like the saying " In the land of the blind the one eyed man is king".

They are great as long as you opponent has no tanks and little or no anti-tank defenses. Which was often the case in the 1930s or even into 1939/40. After that they get a lot less useful real quick.

They stayed useful for limited purposes but many countries kept them in production way too long and spent way too much time, money and effort on new designs or modifications well after decent mediums were available in large numbers. It some cases in may have been a case of not quite knowing what to do with them but "if countries A,B and C have them then by golly we should too."


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## tomo pauk (Apr 20, 2012)

No takers? 
The light tank was deemed to be a good thing even by Cold war armies, many of them building and/or operating them. No light tanks should find itself going against the established front line, I agree with that. Anyway, since those were built operated in ww2, why not proposing something that is better than what was fielded, yet suited to be produced at the factories unfit to build 30+ ton 'proper' tanks. We don't have to call them 'light'. 'Tanks' will do


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## davebender (Apr 20, 2012)

*Sd.Kfz.250/9*
6 tons.
15mm frontal armor. 
.....Similiar to Panzer II prior to 1940.
2cm KwK38 autocannon plus 7.92mm MG. Turret mounted.
.....Similiar to Panzer II.
Height slightly over 2 meters.
.....Similiar to Panzer II.

leichtes Schützenpanzerwagen (2 cm) (Sd. Kfz. 250/9): German Halftracked Armored Car « Catalog of Enemy Ordnance






Vehicles such as this small 3/4 track can perform scouting missions similiar to a light tank at less then half the cost. This particular vehicle is factory made. However similiar conversions were made in field workshops almost from the beginning of the war.


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## psteel (Apr 20, 2012)

Shortround6 said:


> APCs are big targets with open tops that cry out for air burst artillery fire.



I don't know, but this sounds like a wargameing mentality? All the available historical evidence points to APC being essential part of succses with any operational manuevuer. They do have to be used properly.


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## Shortround6 (Apr 21, 2012)

psteel said:


> I don't know, but this sounds like a wargameing mentality? All the available historical evidence points to APC being essential part of succses with any operational manuevuer. They do have to be used properly.



They do have to be used properly. And using them properly does not include trying to use them like or instead of tanks. 

Tanks were capable of overrunning infantry positions for most of the war. It got a lot costlier with infantry hollow charge anti-tank weapons but tanks were bullet proof 360 degrees and from above. SP guns and half- tracks were not. German light armored cars were fitted with anti-grenade screens over their open turrets for a reason and even Mr Benders picture of the German Sd.Kfz.250/9 shows the anti-grenade screens. 
APCs in WW II were NOT supposed to over run the target position but transport the infantry to a close distance and then support them with the vehicle mounted gun/s.


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## Shortround6 (Apr 21, 2012)

tomo pauk said:


> No takers?
> The light tank was deemed to be a good thing even by Cold war armies, many of them building and/or operating them. No light tanks should find itself going against the established front line, I agree with that. Anyway, since those were built operated in ww2, why not proposing something that is better than what was fielded, yet suited to be produced at the factories unfit to build 30+ ton 'proper' tanks. We don't have to call them 'light'. 'Tanks' will do



The post war "light tanks" were built for special purposes for the most part. The Russian PT-76 was an amphibious reconnaissance vehicle. The British Scorpion was also a reconnaissance vehicle, more of a tracked armored car. The French AMX-13 was more of a tank destroyer than a tank and was supposed to be air transportable. In few, if any, cases were they simply a cheap regular tank unlike many light tanks of the 1930s or early WW II.


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## yulzari (Apr 21, 2012)

If we start off by seeing the 'light' tank as a comparative not an absolute then it must exist by virtue of being lighter than it's companions in the same army. Therefore it must fulfill a different role to them. A MBT is to engage then enemy in a firefight. A light tank can have value in only two ways. Firstly as a reconnaissance machine to use tracked mobility. Small size and light weight assist in this role. It needs only to be armed to cope with infantry or IFVs as the weight and size of an anti MBT gun would restrict it's mobility. The other role is to (poorly) substitue for MBTs either where MBT's weight and/or size preclude their use. For example on narrow mountain roads or using low strength bridges. 

As for a weight, I would point to the Scimitar at @ 7 tonnes and PT76 at 14 tonnes as differing approaches that could be used as a guide. The PT76 sacrifices size to amphibious mobility and the Scimitar seeks to restrict size whilst adequate firepower. Equally the PT76 was designed to operate principally in the western USSR whilst the Scimitar was optimised for NW Europe which partially explains their differences.

Now the WW2 belligerents could not really use aluminium armour and amphibious armour would have been too bold a step to rely on. So we would be looking at a steel tank of the Scimitar class armed with something that can suppress infantry or an antitank gun so either a heavy machine gun with a good rate of fire and ammunition capacity or something that can use worthwhile HE. I would suggest that @ 50mm is the absolute minimum calibre for single shot HE and 0.5" for a heavy machine gun.

Given the weapons etc. available for WW2 belligerents to choose from an automatic 20mm cannon might be a useful compromise.

Thus I would suggest something in between the Vickers Light VI and Pz II or about T60 in size, 20mm automatic cannon, with a low ground pressure and excellent rough ground performance. 

Or you could use more and cheaper (in cost, resources but necessarily life) armoured cars. I once postulated (for a certain limited budget dry but varied country) an army solely using Staghound armoured cars (suitably modified as APCs/supply vehicles, lightly armoured MBTs, A/A, ARV/engineers SPGs, for all roles. I think the principal problems were matching MBTs at range, mission kill vulnerability to mines and a large enough artillery gun (and that could be dealt with by towed artillery with the Staghound as prime mover.) I remember suggesting the limited budget air force could be best spent on good artillery, mobile A/A and light spotter/recconnaisance aircraft of the Auster/Cub class and small STOL transports of the Antonov 2 class rather than a few fighters that would last about 4 hours if they weren't destroyed on the ground: but I digress.


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## Shortround6 (Apr 21, 2012)

Everything is a trade off. If you want a tank to be amphibious then the hull volume must be enough to support it's weight in water (displacement). this leads to a a larger than needed or wanted hull for dry land operations. You can use detachable floats or screens but they take time to install and discard. The PT-76 could use it's guns while swimming I believe, which cannot be done with flotation screens. 

Armored cars can be lighter than tanks because they don't have the the heavy track systems. As a rough guide they have half the rolling resistance of a tank and so need less power. 

Heavy machine guns and even 20mm cannon have problems as the main armament for a light tank. The Heavy Machine guns generally are limited in ammo supply ( they are NOT a secondary anti-personnel weapon) and the striking power is usually insufficient for armored targets any heavier than the vehicle that mounts them. 
Not all 20mm are created equal.

The Russians built over 6000 T-60 light tanks but stopped in 1942 because they really weren't very good. Too light at about 6 tons it's armor wasn't good enough against even light AT weapons. The Russian 20mm wasn't particularly high powered. It was also belt feed which made changing types of ammo not the easiest chore. Especially with the one man turret crew who had plenty of other things to do. The 70hp engine also meant it was under powered and it could not keep up with T-34s cross country which rather limited it's usefulness also.

The Russians also churned out over 8000 T-70s before realizing it wasn't the best idea either. You have a choice, send the T-70s into the middle of the battle with their one man turret, limited vision, low rate of fire and almost impossible to co-ordinate tactics/movement or stand back 500-2000yds and pound the enemy positions with SU-76s, in fact the SU-76s can fire HE to well over 10,000 yds. The Su-76 can't overrun positions but it was a much more useful vehicle. 

This is the problem with light tanks, they can't carry enough armor to keep them safe _OR_ they can't carry a gun big enough to really hurt the enemy (Matilda I) _AND/OR_ they can't go fast enough _AND/OR_ they can't carry a big enough crew to make the most of the weapons they do carry. 

By the time the Americans came up with a satisfactory "light" tank it weighed about 20 tons (the M-24) and still didn't have very good protection. The "bow" gunner was a waste of space and weight so perhaps the tank could have been a bit smaller.


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## psteel (Apr 21, 2012)

Shortround6 said:


> They do have to be used properly. And using them properly does not include trying to use them like or instead of tanks.
> 
> Tanks were capable of overrunning infantry positions for most of the war. It got a lot costlier with infantry hollow charge anti-tank weapons but tanks were bullet proof 360 degrees and from above. SP guns and half- tracks were not. German light armored cars were fitted with anti-grenade screens over their open turrets for a reason and even Mr Benders picture of the German Sd.Kfz.250/9 shows the anti-grenade screens.
> APCs in WW II were NOT supposed to over run the target position but transport the infantry to a close distance and then support them with the vehicle mounted gun/s.



Use of the SPW was not intended to over run infantry positions, but to route infantry independantly to reach the Panzer units position and give them infantry cover.

Having said that SPW in recon units would over run/prob any enemy position it came upon as part of their recon mission. That is a vital role for light armor.

As the war progresses and mass production gets underway, this years 'tank' becomes next years 'light tank', so as much prodution as possible can remain uninterupted.


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## davebender (Apr 21, 2012)

Which war are you talking about?

Light tanks such as the BT5 ruled battlefields in Spain and China during the 1930s. The same light tanks wouldn't last long vs well equipped infantry during the 1940s.


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## Shortround6 (Apr 21, 2012)

They wouldn't have lasted long against "well equipped infantry" in 1940 let alone later. But open topped vehicles wouldn't have lasted long against well trained but _poorly_ equipped infantry in 1940. It doesn't take much special equipment to shoot down into an open topped vehicle, terrain permitting, let alone an open backed one. Gasoline bombs may or may not take out a tank but put one into an open topped vehicle? 

That is the difference between a tank and an SP gun or open halftrack. The tank has overhead protection and even if it loses a track it can still fight 360 degrees while waiting for help.


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## davebender (Apr 21, 2012)

Not all half track versions had open tops.
Not all tanks or tank destroyers had closed tops.

If you want the Sd.Kfz.250/9 or similiar vehicle to have a closed top then build it that way. Just as Czechoslovakia did when they put a top on the Sd.Kfz.251 and renamed it an OT-810.


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## Vincenzo (Apr 21, 2012)

a vehicle w/o closed and armored tops is not a tank imo


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## Shortround6 (Apr 21, 2012)

davebender said:


> Not all half track versions had open tops.
> Not all tanks or tank destroyers had closed tops.
> 
> If you want the Sd.Kfz.250/9 or similiar vehicle to have a closed top then build it that way. Just as Czechoslovakia did when they put a top on the Sd.Kfz.251 and renamed it an OT-810.



What tank had an open top??

Some tank destroyers had open tops and some did not but tank destroyers are not tanks. SP guns on tank chassis are not tanks even if they have a 360 turret. An "AA tank" is not a real tank but a specialized SP gun. 

You can close the top on an a WW II half track, that doesn't make it a tank either. Czechs also used a more powerful engine to drive their version. Armored roof is good for .2-.25 ton without hinges, supports, etc. Frontal armor of the halftracks was only good against rifle caliber bullets. Side armor was iffy against rifle caliber bullets depending on range, type of bullet and location of hit.


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## yulzari (Apr 22, 2012)

I certainly agree Shortround6 that a light cannon or heavy machine gun are anti materiel weapons and a co-axial medium machine gun of the 7.7mm class is worthwhile for antipersonnel use.


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## tomo pauk (Apr 22, 2012)

Prior the 1940 (under 10 tons), the armor would need to protect vs. LMG fire. The off-the shelf engine is a must, mounted along the driver so the last 2/3rds of the tank is free. The 37mm cannon was possible to fit in many tanks under 10 tons historically, the 20mm cannon should be a better choice vs. 'soft' targets*. Maybe a high-angle mounting, so the windows at higher floors can be attacked, or even the planes? A 3 man crew. After 1940, a conversion into SP artillery, AAA ond/or APC seem just natural. 
German Pz-II fits the bill (apart from the powerplant layout), Brits can use Horstman suspension, there was plenty of under-100 HP engines to choose, if they can fit 2pdr - way cool. If not, maybe purchasing 25mm from the French, or 20mm Oerlikon. Besa 15mm could give the Germans Italian light competition some worries.
French can adopt 20mm HS, one of two 25mm designs (AT, AAA), or low velocity 37mm. Soviets can adopt 37mm (from the 30's ATG) + 20mm combo for production. Sweden produced some interesting designs, and the Germans have adopted the Czech light tank as the Pz-38(t).

*Italians managed to mount their 47mm on the 6500 kg vehicle, StuG-like; wonder if the turret would be able to hold it, being tailored to fit under 10t limit, total.


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## psteel (Apr 22, 2012)

Well prepared infantry positions vs. armor were-at best-a mid war to late war phenomena. They rarely figured in early war clashes. Most war mechanized clashes were mobile attacks were operational considerations/decisions actions were paramount not tactical limitations of one weapon over another. In that regard, light tanks and open APC were fine, even preferable to heavier tanks. Since their consumption of supplies and maintenance was much less than heavy tanks were.

This all just sounds like tactical war gaming mentality. Tactical considerations come at the end of a very long line of other considerations.


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## Shortround6 (Apr 22, 2012)

37mm guns are all over the place as far as gun power goes. French actually had 2 different 37mm guns. The first used the same ammo (cartridge case) as the WW I trench gun a pretty poor armament by WW II despite being used by the thousands. There were two AP rounds for it. One was a 'HOT' load but used a light projectile. This is the 21 cal. gun the 33 cal. gun used a heavier projectile at a higher velocity and wasn't that far off the German 37mm. 

The big machine guns and auto-cannon have a problem with feeds. Some Modern guns have a dual feed that can be switched from one belt to the other in 1-2 seconds allowing for both HE and AP to readily available. No such thing in WW II. Large magazines are awkward to handle in small turrets (and need a lot of turret above the gun). While the German 20mm AA guns used 20 round magazines the tank versions used 10 round magazines. They also feed from the side and not the top. The 15mm BESA gun (used in the Lt. tank MK VIC) used 25 round belts in British service and I don't believe there was an HE round for it. Even if there was, taking out a part used belt and fitting a new one would have been a difficult task inside a small turret. 
The French 25mm guns (AT, AAA) used different ammo. With a projectile weigh a bit less than half a 37mm round a single shot 25mm gun does not have impressive HE capability. An automatic 25 mm gun is approaching the weight of a good 37mm gun and more importantly the breech is much bulkier which affects turret size and thus armor weight. 

Dual purpose (AA) armament is not a good idea either. Tanks don't have good vision if they have a closed top and if the top is open they are not a tank. The higher elevation usually means a bigger turret or deeper hull. Rate of traverse is also none to good for an AA weapon.


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## Shortround6 (Apr 22, 2012)

psteel said:


> Well prepared infantry positions vs. armor were-at best-a mid war to late war phenomena. They rarely figured in early war clashes. Most war mechanized clashes were mobile attacks were operational considerations/decisions actions were paramount not tactical limitations of one weapon over another. In that regard, light tanks and open APC were fine, even preferable to heavier tanks. Since their consumption of supplies and maintenance was much less than heavy tanks were.
> 
> This all just sounds like tactical war gaming mentality. Tactical considerations come at the end of a very long line of other considerations.



Try telling that to the German 4th Panzer Division in Poland, just for starters. Yes, they used what they had and performed on an operational level but is was part of the learning curve that taught them NOT to use unsupported tanks in built up areas. The Polish campaign also taught them that 14.5-15mm armor was not protection enough against 7.92mm Anti-tank rifles let alone heavier weapons. 
APCs could get the troops closer to the battle than trucks could, air burst artillery shells at the time were time fuses and required direct observation of the target by artillery observers and good gun crews. This was _NOT_ a new technique as Shrapnel shells in WW I were _ALL_ airburst with time fuses. Firing on approach routes or map firing on roads, road junctions and the like _without_ direct observation to correct the time of flight and fuse settings meant impact fuses and here is were the open APCs offered very good protection compared to trucks. Granted the APCs could cover ground faster than men on foot but then they are a bigger target too. The APCs offered a mobility that kept the infantry in reach of the tanks. By that I mean the infantry was not stuck on different road or in a different village in trucks that could not keep up with the tanks cross country.


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## psteel (Apr 23, 2012)

Sounds like tactical war gaming mentality. Again the tactical considerations were ALWAYS secondary to operational considerations, which were mostly secondary to strategic requirements. The speed of the panzer assault was so swift in the first couple of years, there was little or no time to do anything other than establish a hasty defense with little depth. The Panzers and what armored infantry they had; all enveloped the opponent making such defenses’ moot while artillery fixed the opponent in place. There are ALWAYS exceptions, but those should never divert the basic operational plan. Tweaking the AFVs in-between campaigns is always advisable and was done by all sides whenever possible. Doesn't mean the previous design was inferior, just that it is good enough to keep pace with developments.


Air bursting artillery was the exception, not the rule in WW-II. The vast majority of the artillery was ground burst, and certainly not in a fluid battle clouded by "fog of war". Yes in a prepared set piece determined attack this was possible but not in fluid battle situation. The situation you are describing is idealized late war allied tactics with total air superiority and information superiority, and has little bearing on the rest of the war.


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## Shortround6 (Apr 23, 2012)

If the tactics don't work then the operational plan won't work and then the strategic plan goes in the toilet. The Germans won in Poland but it was not the walk over some people think it was. There were very few armored "clashes" as the Poles had very little armor and much of it was even worse than the German light tanks. Hundreds of cheap light tanks or tankettes that meet pre-war "strategic requirements" failed miserably in combat and were unable to conduct operations as their owners wanted. 

How many German tanks were lost or knocked out in the Polish campaign? 

The "Idea" that vehicles with lighter armor and even with open tops would have done any better, even if available in somewhat greater numbers, doesn't seem to be the lesson learned. 

Some countries "tweaked" such light armor right out of production between campaigns. It took a while to work through existing inventory though. 

Air burst artillery was the standard for short range tactical artillery use in 1914. It may have been replaced by the machine gun but it certainly was not a new or unknown technique. While it was not used on top of friendly positions as they were being overrun it could certainly be used against the enemy before the forces mixed. Air burst in early WW II does require a trained observer with eyes on the target with what is now know as a "real time link" ie voice radio or telephone to the gun battery. Trying to use air burst on a dust cloud behind a hill or stand of trees will be ineffective and that is where the impact fuses come in ( impact fuses are also the choice against any sort of dug in target, if you are trying to damage the fortifications) Code messages take too long to de-code. Artillery use did change in all armies during the war and more in some armies than others. Improved communications between observers and batteries and between batteries and art HQTRs made for much faster response times and for more flexible concentrations. Improved communications as much to improve artillery performance as any new gun or shell. 

Too heavy a tank does no good. if you can't load it on ships or get it ashore it doesn't do any good and if it can't cross a river on existing bridges or on army temporary bridges it does't do any good. However, if an army was going to mechanize and go to tanks restricting it's tanks to weight that the existing trucks and temporary bridges ( which were designed for horse drawn artillery and supply wagons or, at best, trucks) means to great a sacrifice in actual combat ability. Early tanks did have a powerful morale effect. But building tanks that cost thousands of dollars if not tens of thousands of dollars that can be taken out by AT rifles costing hundreds of dollars is not sound planning. At least build tanks that require the opponent to come up with 37-50mm AT guns that need vehicles of their own to move them. 20lb rifle vs 900lb AT gun?


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## tomo pauk (Apr 23, 2012)

Shortround6 said:


> 37mm guns are all over the place as far as gun power goes. French actually had 2 different 37mm guns. The first used the same ammo (cartridge case) as the WW I trench gun a pretty poor armament by WW II despite being used by the thousands. There were two AP rounds for it. One was a 'HOT' load but used a light projectile. This is the 21 cal. gun the 33 cal. gun used a heavier projectile at a higher velocity and wasn't that far off the German 37mm.
> 
> The big machine guns and auto-cannon have a problem with feeds. Some Modern guns have a dual feed that can be switched from one belt to the other in 1-2 seconds allowing for both HE and AP to readily available. No such thing in WW II. Large magazines are awkward to handle in small turrets (and need a lot of turret above the gun). While the German 20mm AA guns used 20 round magazines the tank versions used 10 round magazines. They also feed from the side and not the top. The 15mm BESA gun (used in the Lt. tank MK VIC) used 25 round belts in British service and I don't believe there was an HE round for it. Even if there was, taking out a part used belt and fitting a new one would have been a difficult task inside a small turret.
> The French 25mm guns (AT, AAA) used different ammo. With a projectile weigh a bit less than half a 37mm round a single shot 25mm gun does not have impressive HE capability. An automatic 25 mm gun is approaching the weight of a good 37mm gun and more importantly the breech is much bulkier which affects turret size and thus armor weight.
> ...



Okay, so for the French the 37mm L33 should be the choice? I now that the AT and AAA 25mm rounds were not the same; if they can properly shove in the AAA cannon, the HE fire is impressive, the AT properties would be better than of 20mm cannons, so the Pz-II, -38(t) and lesser tanks would be in jeopardy. Should be fine even if the elevation is only suited for the fire vs. ground targets only.
The tanks were operated perhaps 1% of the war time buttoned up. The parallelogram-operated AAA sight is a must, to replicate barrel elevation for the gun aimer that has it's head above the roof. The rate of traverse for eg. German 20mm flak was not that great either, though some foresight to design a dual purpose tank would be fine. The 20mm would be perhaps the biggest gun that fits for an under-10 ton tank. 

The 20mm auto-cannon could use the magazines attached from below, so the turret top wouldn't interfere.


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## Vincenzo (Apr 23, 2012)

actually japanese light tanks (~7 tons) had a 37/45 gun. 

( i not mention the T-70 and its 45 because it's too near to 10 tons)


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## Shortround6 (Apr 23, 2012)

In a ground or Sp AA mount the gunner/s are only trying to move the weight of the gun, cradle/upper mount. In a DP tank turret they would also be trying to move all the turret armor unless you can supply power traverse. Unless you have really thin armor this is going to be a ton or more. 
Some guns didn't take well to firing on their sides or upside down. 

The best of the 10 ton "class" of light tanks was the Czech t-38. 

With a 10 ton limit there are a number of trade-offs that have to be made. Consider the French light tanks, the Renault R-35 and the Hotchkiss R-39. Their armor was about as good as it was going to get on a light tank, 30-45mm which means that they were good against just about all AT-rifles, a fair degree of protection against weaker 37mm guns and were some what "shell proof", that is, resistant to HE shells fired by 75-80mm field guns. The nose fuses on the HE shells would either crush and fail to detonate or would detonate on contact and explode the shell with the main body of the shell not in good contact with the armor. Such hits could damage the tank, some times severely, but could not achieve the same percentage of kills that AP shot could. 
The penalty for such good armor was a small size that restricted them to a two man crew. The man in the turret commanded the tank ( directed the driver) picked out targets, selected the gun (cannon or MG) loaded the cannon with appropriate ammo, aimed and fired the cannon, loaded the MG as needed, watched out for his platoon leaders signals, and so on. French tanks were rather an exception to the 1% buttoned up figure. While they were not buttoned up on the march, the commander frequently sitting on a seat formed by a fold down hatch in the rear of the turret, the tank could NOT be fought with the commanders head sticking out of the rear hatch or the cupola hatch. He would be too far away from the gun sight and the turret/ firing controls. Leaving a hatch open might give him better ventilation but it darn little for vision. BTW a similar restriction would apply to anybodies one man turret vehicles, some gave the commander a bit more vision that others. 
Getting back the French tanks, they were also short and narrow. It kept the target size down and the armor thickness up but also limited their ability to be used as a chassis in other roles. Yes, they were used as gun tractors, supply vehicles and even to a limited extent as chassis for self propelled guns, but they were far from ideal because their small size meant a very limited storage capacity inside. 
The German MK II offered more volume, it had a third man plus a radio set, both transmit and receive. The extra size meant thinner armor for the same weight. It also had a one man turret, latter versions got a cupola with six (?) vision blocks so the commander had a better idea of what was going on outside, but again he could not aim the guns and have his head outside the tank at the same time. Early versions gave the commander a periscope with rather limited vision. Some tanks had periscopes that turned, better in some ways but trying to maintain oreintation could be a problem. Turret is turned 30 ^ to line of travel and the periscope is turned another 30^ and try to tell the driver where to go? 
Wiki has an interior shot of a Russian t-26 turret (I am on an I-PAD at the moment and cutting and pasting is a real b**ch).
The T-26 is another tank that was limited in armor protection in part due to size vs weight. 15mm armor is great a against Rifle caliber bullets and even the lighter AT tank rifle and 12.7-13mm machine gun ammo. It is NOT shell proof and is an easy mark for the lightest of real anti-tank guns. One of the criteria for the T-34 was it should have "shell proof" armor and since the HE shell doesn't really care that much about slope that should give you an indication as to what was wanted.

There is also a difference between a tank commander having his head/shoulders sticking out of a hatch ( not buttoned up) and having part of the roof missing or large gaps in the roof or turret front. 

2 man turrets could come two ways. Gunner and commander/loader and commander/gunner and loader. The latter meant you needed fewer "skilled" tank men but it also meant poorer tactical co-operation between tanks or the units. Again the benefits of operating "unbuttoned" are rather diminished by the commander having to spend so much time with his head inside the turret in order to do his "second" job. T-34s could operate unbuttoned with that big hatch folded up but with the tank commander operating as the gunner it didn't really add anything to the ability of the tank. 
3 man turrets are were the ability to operate unbuttoned really show up. 
The Czech tank is about the only light tank to have that ability. A few British light tanks do but that is because they are armed with Machine guns and the commander is not needed every few seconds while firing to reload the gun. Of course the 12.7 Vickers can't really hurt anything heavier than a MK II either.


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## tomo pauk (Apr 23, 2012)

Actually, a simple 'like' would not be enough; great post really 

About the DP tank - the Flakvierling weighted 1500 kg; 'my' 2-barreled 30mm (with splinter-proof aimer position, and 100 rds) was also being capable to be aimed manually, with decent speed. Granted, a power traverse is a better thing.


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## yulzari (Apr 23, 2012)

Perhaps we need to revisit why one would want light tanks if you can have heavier more combat capable ones. What would they need to fight? If a light tank is part of an army with period MBTs then it only needs to fight infantry and individual anti tank guns in order to progress it's reconnaissance duties. If it meets stronger opposition then it's duty is to run away and report that. 

WW2 British higher formation reconnaissance policy was to mix low visibility small scout vehicles with supporting support fire from larger ones and to have a small organic infantry element. A lightweight mobile all arms arrangement.

Light tanks were the reconnaissance arms of armoured regiments; having superior mobility to the battle tanks to find the main strength of the enemy. But then to leave engaging that main enemy to the larger battle tanks once the enemy had been found and their positions understood.

I fear that we are trying to make a more combat capable light tank where a larger one would be more suitable, not a light tank that can do a light tank's duties better.


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## psteel (Apr 23, 2012)

You've got it the wrong way around; operational requirements define what tactical capabilities you need to pursuit. Tactical requirements will ALWAYS be secondary to operational requirements. Fixating on specs of Tanks will not help if you can't find or give battle to your enemy in a fluid battle. You need recon forces to find the enemy and apply force where it’s needed the most to break your enemy. Airburst in WW-I is irrelevant since this was mostly static warfare. It was not until late in the WW-II that allied 'called in' artillery was able to deliver timely barrages with fuse set ammo to burst overhead. It was the exception rather than the rule. 

Germans tried to get around this by bouncing shells ahead of target in the hopes it would burst over the target. That took allot of skill that was in short supply at the lower ranks as the war progressed. It takes allot of planning to establish artillery fire patterns on an enemy position and can't be done in a fluid battle without great difficulty. Which again requires high skill levels, something in short supply for most armies as the war progressed? Therefore it is not relevant either.
Generalizing from a specific case [the occasional Polish AT ambush] to a broad war-wide case, a is flawed approach. Better to go the other way and look at data and distill that into basic lessons.


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## Shortround6 (Apr 23, 2012)

Light tanks changed from _being_ period MBTs to being reconnaissance vehicles in about 1-3 years depending on army. Or changed from infantry support tank to reccon or security vehicle in that time. The German, British and Russian armies used light tanks in 1939-41 to make up numbers and "flesh out" units when there were not enough medium/cruiser tanks. They suffered rather badly doing this and were assigned reccon duties as more of the larger tanks showed up. Some armies didn't quite get the message. The U.S. Built about 25,000 of the M3, M5, M8 family. Many of them after they had no clear role or at least built way more than needed for the roles they could play.


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## tomo pauk (Apr 24, 2012)

Shortround6 said:


> ...
> 
> 2 man turrets could come two ways. Gunner and commander/loader and commander/gunner and loader. The latter meant you needed fewer "skilled" tank men but it also meant poorer tactical co-operation between tanks or the units. Again the benefits of operating "unbuttoned" are rather diminished by the commander having to spend so much time with his head inside the turret in order to do his "second" job. T-34s could operate unbuttoned with that big hatch folded up but with the tank commander operating as the gunner it didn't really add anything to the ability of the tank.
> 3 man turrets are were the ability to operate unbuttoned really show up.
> The Czech tank is about the only light tank to have that ability. A few British light tanks do but that is because they are armed with Machine guns and the commander is not needed every few seconds while firing to reload the gun. Of course the 12.7 Vickers can't really hurt anything heavier than a MK II either.



I'd like to return on this part.
Those '99%' of the time the tank was operating (un-buttoned), would exclude fighting vs. ground targets? The tank still can be attacked by enemy air force, being miles from the front line. A tank crew can have its DP gun elevated somewhat, ready to pounce an enemy plane - something like US tanks had (HMG), but better. Commander will be buttoned up when it's time to engage ground targets, or when the enemy ground fire is judged as incoming. 
The magazine-fed 20-25mm (for under-10 tonner; 30mm for German under-15 tonner?) might be the best solution for a two men turret of a light tank. Aimer can have between 10-60 shots to dispose with the enemy, prior re-loading, plus the MG, if the target is suitable. If we're going for a two men crew and a single shot weapon, maybe it's the best if both crew members can load the gun. Not as good as 3-men turret, that's for sure.



yulzari said:


> Perhaps we need to revisit why one would want light tanks if you can have heavier more combat capable ones. What would they need to fight? If a light tank is part of an army with period MBTs then it only needs to fight infantry and individual anti tank guns in order to progress it's reconnaissance duties. If it meets stronger opposition then it's duty is to run away and report that.
> 
> WW2 British higher formation reconnaissance policy was to mix low visibility small scout vehicles with supporting support fire from larger ones and to have a small organic infantry element. A lightweight mobile all arms arrangement.
> 
> ...



The catch was that many countries were ill capable to build tanks above certain tonnage, and even the most industrialized nations relied to 6-15 ton tanks to double as MBTs. Poland, Japan, Italy - they all made their mark in ww2, yet anything above 15 tons was almost impossible for them to churn out in significant numbers. It was judged that even a 'bad' tank is better than no tanks at all, all belligerents were thinking in those lines. Eg. the German offensive vs. West in 1940 was won, among other stuff, by light tanks. 
Light tank (disregarding the operator's nomenclature) was in great demand, for fighting, and prior 1943 it was comprising the bulk of the tanks in use, worldwide. So a better combat capable light tank would come in handy. Once it's past it's prime, it can serve as recon, os a pltform for other duties.


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## psteel (Apr 24, 2012)

As I said before the Germans learned that ‘this year’s MBT is next year’s recon unit. This worked well for the Panzer Regiments and Battalions. Mean while the need to fight for information forced the Divisional SPAH battalions to shift from using only wheel Armored Cars to using a mix of armored cars and Panzer grenadiers on SPW in order to fight for territory they reconnoitered. Since the Germans built there combat units on an organic format, these SPW units included Infantry gun/SPWs and PAK/SPWs along with Flame APC Mortar APC units. 

However there was always a need to give a basic amount of armor to the far more numerous infantry divisions and korps, otherwise the Panzer Korps would have to be constantly diverted to fur fill defense tasks and provide basic ‘combined arms’ for these divisions. This could not be done my mass production of medium tanks, but a sufficient investment in light tank chassis used as cheap Panzer Jagger through the middle of the war and later Jag Panzer AFVs.


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## tomo pauk (Apr 25, 2012)

> As I said before the Germans learned that ‘this year’s MBT is next year’s recon unit.



Maybe this should not be taken literally?


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## Shortround6 (Apr 25, 2012)

Not in any way, shape or form. 

The Pz I was never intended to be a MBT, even though it was used as one. with only a radio receiver and no transmitter it may have helped beef up a recon unit but could not perform good recon on it's own ( singly or in a group) and had a number of liabilities with few vertues. As noisy as most other tanks, not very fast, limited obstical climbing or ditch crossing capabilities, no great range.
The Pz II was an interim MBT or training vehicle depending on who you believe. While noisy, slow, and short ranged it at least had a radio transmitter, a bit better ditch crossing ability, better armor and a better gun set up. Even it's one machine gun was better than the Pz I dual machine guns making it a much better though far from ideal recon vehicle. 
The Pz III was rarely, if ever, assigned to recon units no matter how old it got and the same could be said of the Pz IV. Some adhoc missions may have included them though. 
Using old light tanks for recon means more fighting for the same information. The British liked armored cars for recon because, while obstacle and ditch crossing ability are minimal, they were much quiter and could sneak around better, they were also faster and many British cars, like many German ones, could be driven at high speed in reverse to get out of trouble. 
The clatter of all metal tank treads would alert the dumbest lookout that something was up. Modern tracked recon vehicles often use not only rubber pads on the tracks but rubber bushing between the track links. 
The Germans did find in Russia that between the snow and the mud there were times that even an 8 wheeled armored car would get bogged down and a tracked vehicle would not. So there are certain circumstances that make one vehicle better than the other. Neither type was best at all times. The Russian's finally figured that if you were going to have to " fight for information" you might as well do your recon with T-34 tanks, rather than light tanks that would have to pulled back at first contact anyway.


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## psteel (Apr 25, 2012)

All Panzer units assigned the lesser Panzers lesser models to both their Regimental and Battalion Recon platoons.


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## tomo pauk (Apr 26, 2012)

I've just checked out: the Pz-38(t) was featuring a 2-men turret, not 3-men one.


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## psteel (Apr 26, 2012)

tomo pauk said:


> I've just checked out: the Pz-38(t) was featuring a 2-men turret, not 3-men one.



Yes but when the Germans got them they removed some ammo from the turret and 'shoe-horned' a loader in its place.


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## Vincenzo (Apr 26, 2012)

that was the Pz 35 that was 1 man turret


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## Shortround6 (Apr 27, 2012)

The Czech Pz 35 had a two man turret in German service. It is claimed that originally the turret was crewed by one man but the basic design leaves questions unanswered. It the commandeer gunner Is on the left side and the machine gun is on the other side of the 37mm gun from him how does he aim and fire (not to mention reload) the machine gun in it's independent traverse and elevating mode in the ball mount? Th hull machine gunner is also on the left side of the tank and would have to squeeze between the commander and the driver in order to reach the right side of the turret in order to take over the machine gun?

Captured French Somua 35s and Renault 35s had one man turrets. 

I have reread Wiki's description of the Czech Pz38(t) And it makes little or no sense. It says the Germans added a loader and deleted 18 rounds of ammo, but says the commander had to aim and fire the gun, which I don't doubt given the size of the turret and the position of the commanders cupola and the gun sight. But if the commander is aiming and firing what is the other turret crewman doing? ONLY operating the turret machine gun when it was not coupled to the main armament? If he was loading the main gun why do you need ANOTHER loader?


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