"M13 and 47mm L32 A,T,G." Topic

The Italian M13 tank has been much derided but was it an equal to British cruiser tanks in tank on tank action?
It's armour on par if not superior ?
More reliable?
A lager gun?

In many rules its gun the 47mm is equal to the 2prd and others inferior, what is your take ?
Some other rules give the 47mm a shorter range ?

Depends how much granularity you have in your rules, but the M13 was inferior in pretty much every way to the British cruisers. Slow, unreliable, poor armour quality and layout. The 47mm had marginally better armour penetration (a couple of mm, depending on ammo type) but was less accurate as the barrel was shorter and the sights weren't as good. Better HE of course.

In the march to Tobruk, Ariete lost almost all its tanks to breakdowns, and didn't have anything like the recovery capability of the Germans. 2nd Armoured Div, also equipped with M13s captured during Operation Crusader, also lost almost all its tanks to breakdowns.

Compared to Pz IIIs, the British vastly preferred to engage M13s, as they could actually penetrate the hull front, something 2pdrs with the older ammo couldn't do to a Pz III G/H. They could destroy both with turret hits.

In AHGCs old, but extensively researched, 'Tobruk' game, M13s were easy meat for all the British tanks and AT guns.

Dear Martin ,
Thank you, very interesting,

In 41 some would say that the M13 was at least equal to the Cruisers . You hear of Crusaders , A13/9 etc breaking down all the time as well. Also armour on par especially early Cruisers.

In some rules the 47mm used as a A/T/G had a better range as a free standing weapon over it being in the M13 ? That l don't understand.

The panzer 111 G had 30mm of armour, l'm.suprised the 2prd couldn't deal with that .
Would you rate the shorter 50mm in the panzer 111 as msuperior to the 2prd besides HE ?

Sorry, I wasn't clear, I meant the Gs upgraded to H standards with applique armour. Only a handful of Gs turned up in Africa and they were rapidly uparmoured. Most of them were H or G upgraded to H, and later J, with even ticker armour.

Yes, some of the early cruisers were essentially just armoured to be bullet proof, as was fashionable in the 1930s, but also in the 1940 battles the most numerous British tank was the Vickers Light, against which both the M13 and M11 were rather scary.

I'd have to check the penetration stats for the 50L42 to compare to the 2pdr. iirc they were comparable, but the 50 had a lot less armour to deal with.

Wrt the AT version of the 47mm, in WW2 and postwar, operations research has conclusively demonstrated that AT weapons, even the identical weapons as tank mounts, are at least twice as effective as vehicle mounts at destroying tanks. See eg The Stress of Battle by Rowlands.

WHY that is, is a matter of huge debate, crew size? Crew quality? Better situational awareness? tactical employment? Whatever the reason, the effect isn't in doubt, and how you might model them in Wargames rules depends. Dupuy simply doubled the combat value of AT weapons against armour in his QJM model. I suppose you might give them a longer range if you think the bigger crew can see farther.

If you can track down a copy (it is oopl, Frank Chadwicks "Benghazi Handicap" is an excellent one stop resource for wargaming the early part of the desert war, 1940 to late 41.

The scenarios are excellent and the Italians are lots of fun to play. Who doesn't like entire battalions of Cv33 tankettes?

I suppose you might give them [anti-tank guns] a longer range if you think the bigger crew can see farther.

I don't think giving anti-tank guns longer range than similar tank mounted guns is a particularly great representation of the advantages of the anti-tank guns, but I will also admit that properly presenting the real world advantages of anti-tank guns on a conventional tabletop miniature game can be challenging.

In any case, a good anti-tank gun crew (if their position is properly hidden – something not allowed by many rules) might not want to engage enemy tanks at long ranges, unless equipped with particularly powerful gun (e.g. German 88 mm). Opening fire always risks exposing your position, doing so at long range means that there is a reduced chance of hitting with the first rounds, and if you hit the chances of penetrating are reduced as the range increases. Meanwhile, the effect of HE return fire from the tanks is not dependent on range (though in case of the early war in North Africa, not every tank had effective HE ammunition). It may be better to let the tank close down to effective range before opening fire, so that it can be taken out with few shots.

One trick favoured by ATG crews (not necessarily easy in North African desert) is to use terrain to shield the gun position so that there are only limited arcs of fire. Thus, when the gun opens fire, there will be only limited number of guns able to spot it and to return fire. Those selected arcs of fire however need to be chosen careful so that the enemy has to traverse them to get past the positions of the ATG unit.

Tanks may have the same gun but like the Tiger, the tanks maximum charge is less for the tank as the recoil absorption is less able than the gun carriage.

In addition tanks will have to estimate range, anti-tank guns will generally be surveyed in so the actual ranges can be found relative to terrain features. In addition some anti tank guns will have better range finders so again better first shot accuracy. Another benefit in some cases is a bigger crew so a higher rate of fire.

Atg have higher rof. Better spotting, awareness. An atg could also have a spotter off to one side with bones correcting any range mistakes so better 2nd round accuracy. Better first round if they have surveyed.

The best reference source of which I am aware would be – "Tank Combat in North Africa" by Thomas Jentz.

Jentz provides data suggesting that the Italian 47mm was an effective and accurate anti-tank gun for that period of the war. The Type 35 fired an uncapped AP/HE; the Model 39 fired a ballistically capped AP/HE.

Jentz gives comparative accuracy values for the British 2-pounder versus the Italian 47mm-32 Model 39 as follows -

Weapon – - – -100m – - – 500m – - -1000m – - – 1500m
2-pounder – - 100% – - – 67% – - – 26pct – - – 12%
47-32 M35 – - 100% – - – 95% – - – 46% – - – - 17%
47-32 M39 – - 100% – - – 95% – - – 52%

Recommend that you snag a copy of this book (really not very expensive – see ADDALL used book site), because I'm only scratching the surface here. For example, the British 2-pounder solid shot AP had shatter problems versus German face-hardened applique armor; Jentz shows 0 penetration ability in the case of frontal hits upon the hull and superstructure of the MkIIIH and upon the superstructure of the MkIVE.

It's complicated …..

B

Thank you Blutarski,

So that data shows the 47mm as more accurate.
What about penetration, which one is superior?

Cheers

hi Khazi,
Again, data per Jentz, "Tank Combat in North Africa"

ARMOR PENETRATION – Italian Type 47-32 gun
versus rolled machinable quality homogeneous plates of BHN values 210-245 @ 30 degrees.

Range (yards)- -100 – - 500 – - 1000 – - 1500
M35 AP/HE – - – 55mm – -43mm – -31mm – - 23mm
M39 AP/HE/BC – -39mm – -35mm – -30mm – - 25mm

- – -

Also per Jentz
TABLE 4.1.6 – RANGE IN METERS AT WHICH THE 47mm M.39 COULD PERFORATE THESE TARGETS AT A SIDE ANGLE OF 30deg.

Light Tank Mk.VI

FRONT
Gun Mantlet – - – 1200
Turret- – - – - – 1200
Superstructure- – 1200
Hull- – - – - – - 1200

SIDES
Turret- – - – - – 1200
Superstructure- – 1200
Hull- – - – - – - 1200

REAR
Turret- – - – - – 1200
Upper Hull- – - – 1200
Lower Hull- – - – 1200

Cruiser Mk.I

FRONT
Gun Mantlet – - – 1200
Turret- – - – - – 1200
Superstructure- – 1200
Hull- – - – - – - 1200

SIDES
Turret- – - – - – 1200
Superstructure- – 1200
Hull- – - – - – - 1200

REAR
Turret- – - – - – 1200
Upper Hull- – - – 1200
Lower Hull- – - – 1200

Cruiser Mk.IIA

FRONT
Gun Mantlet – - – 600
Turret- – - – - – 1200
Superstructure- – 1200
Hull- – - – - – - 1200

SIDES
Turret- – - – - – 1200
Superstructure- – 1200
Hull- – - – - – - 1200

REAR
Turret- – - – - – 1200
Upper Hull- – - – 600
Lower Hull- – - – 1200

Cruiser Mk.IVA

FRONT
Gun Mantlet – - – 600
Turret- – - – - – 800
Superstructure- – 1200
Hull- – - – - – - 1200

SIDES
Turret- – - – - – 1200
Superstructure- – 1200
Hull- – - – - – - 1200

REAR
Turret- – - – - – 1200
Upper Hull- – - – 1200
Lower Hull- – - – 1200

Cruiser Mk.VI

FRONT
Gun Mantlet – - – 0
Turret- – - – - – 700
Superstructure- – 700
Hull- – - – - – - 1000

SIDES
Turret- – - – - – 700
Superstructure- – 1200
Hull- – - – - – - 1200

REAR
Turret- – - – - – 1200
Upper Hull- – - – 1200
Lower Hull- – - – 1200

2-pounder later.

B

Fantastic information thanks.
Can't wait to see 2,prd .
Cheers

Thanks. Good information there, and I also would like to see how the 2 pounder would have stood up against its North African opponents.

My sense is that is a head on fight the M13 would have done well enough against all of its early to mid-1941 opponents except for the Mathilda. 1942 was a different story.

However a tank is more than its gun, armor and engine. It is also its visibility, its range finding ability, intra and inter-tank communications. It is how big a target, its crew training and logistics train and how and where the tank is being used.

The comment about M13 breakdowns falls into this. If your army is retreating then a minor mechanical issue or minor combat damage can mean a lost tank. If you are pushing a tank to perform at levels beyond what it was designed for, or cannot stop to take care of minor maintenance, you are going to have tanks dropping by the wayside. The British Crusaders had their share of breakdowns too.

Hi Bill N,

If your army is retreating then a minor mechanical issue or minor combat damage can mean a lost tank.

I quite agree. Both Italian tanks and early pre-war design British light tanks and cruiser tanks proved mechanically unreliable in the inhospitable operational conditions found in North Africa. The Germans mentioned problems with dust and sand overpowering their engine dust filters.

I also have read (somewhere, don't recall) that the great majority of British tanks losses in the Greek campaign occurred during the retreat – the result of abandonment after irreparable track/suspension breakages suffered as a result of the terribly rocky/stony condition of Greek roads.

B

Two-pounder data, and some other stuff
(same source – Jentz)

This is more complicated than the Italian data.

Two-pounder gun armor penetration tests of the era were conducted against IT80 specification homogeneous (BHN 300-321) armor plate at a striking angle of 30 degrees. Wartime British testing standards defined "perforation" (henceforth referred to as "penetration" for the sake of terminological consistency). A successful "perforation/penetration", according to Jentz, was defined as "80 percent success" – where "in four out of five cases of the shot hitting that plate at the critical velocity, at least 20 percent of the shot would have passed through the plate as a free missile.

ARMOR PENETRATION – 2-Pounder AP-Shot @ Vo 2600 fps
Range (yds) – - IT80 plate – - – -IT60 plate
100 – - – - – - – 55mm – - – - – - -49mm
500 – - – - – - – -47mm – - – - – - -40mm
1000 – - – - – - – 37mm – - – - – - -29mm
1500 – - – - – - – 27mm – - – - – - -19mm

ARMOR PENETRATION – 25-Pounder AP-Shot @ Vo 1550 fps
Range (yds) – - IT80 plate
100 – - – - – - – 70mm
500 – - – - – - – 62mm
1000 – - – - – - -55mm
1500 – - – - – - -49mm

Jentz Note
When attacked by the ordinary British armor-piercing shot, face-hardened armor was much superior to homogeneous armor. A 60mm plate offered a resistance equal to 85mm of homogeneous armor when attacked by a 2-pounder gun at normal and 100-yard range.

[U]RANGE IN YARDS AT WHICH 2-POUNDER AP-SHOT (2600 fps) COULD PERFORATE THESE TARGETS AT A SIDE ANGLE OF 30 deg.[/U]

TARGET VEHICLE – - M13-40 – - – PzII A-C

FRONT
Gun Mantlet – - – -600 – - – - – - – - 500
Turret – - – - – - 600 – - – - – - – - 500
Superstructure – - 1300 – - – - – - – -1100
Hull – - – - – - – 800 – - – - – - – - 500

SIDES
Turret – - – - – - 1400 – - – - – - – -1800
Superstructure – - 1600 – - – - – - – -1800
Hull – - – - – - – 1600 – - – - – - – -1800

REAR
Turret – - – - – - 1400 – - – - – - – -1800
Upper Hull – - – - 1600 – - – - – - – -1800
Lower Hull – - – - 1400 – - – - – - – -1800

– - -

TARGET VEHICLE – - PzIII F/G – -PzIII H

FRONT
Gun Mantlet – - – -200 – - – - – - – - 200
Turret – - – - – - 800 – - – - – - – - 800
Superstructure – - 900 – - – - – - – - 0
Hull – - – - – - – 700 – - – - – - – - 0

SIDES
Turret – - – - – - 1000 – - – - – - – -1000
Superstructure – - 1300 – - – - – - – -1300
Hull – - – - – - – 1300 – - – - – - – -1300

REAR
Turret – - – - – - 1000 – - – - – - – -1000
Upper Hull – - – - 1500F/1000G – - – - 1000
Lower Hull – - – - 1800F/1300G – - – - 0

- – -

TARGET VEHICLE – - PzIV D – - – PzIV E

FRONT
Gun Mantlet – - – -200 – - – - – - – - 200
Turret – - – - – - 900 – - – - – - – - 900
Superstructure – - 900 – - – - – - – - 0
Hull – - – - – - – 800 – - – - – - – - 200

SIDES
Turret – - – - – - 1600 – - – - – - – -1600
Superstructure – - 1800 – - – - – - – -800 (see note below)
Hull – - – - – - – 1800 – - – - – - – -800 (see note below)

REAR
Turret – - – - – - 1600 – - – - – - – -1600
Upper Hull – - – - 1800 – - – - – - – -1800
Lower Hull – - – - 1800 – - – - – - – -1800

NOTES
> The PzIV D with additional armor (applique kits) could be penetrated at the same ranges as the Pz IV E. Those side areas without the additional 20mmm side armor could be penetrated at 1800 yards.

> Additional protection was afforded by sections of spare track carried across the hull front of virtually all Pz II, III and IV and sometimes across the superstructure front.

SPECIAL NOTE – I REALLY recommend acquiring a copy of "Tank Combat in North Africa" by Thomas Jentz. Used copies are not very expensive. I'm only reproducing a fraction of the information Jentz covers in the book.

Enjoy …

B

The crusader was not quite as bad as it's reputation. There was some bad luck involved in the early problems.
The crusader 3 was more reliable with the excellent 6 pdr and more successful than earlier ones.

Hi Andy,
Fair comment. I'm guessing that the Mk III missed the author's cut-off date. "Tank Combat in North Africa" covers the period through Battleaxe (June 1941). I think that the Mk III was only just being introduced to the desert campaign at that time.

Does that make sense?

B

Yes, sorry. The MK3 was later and ( as usual ) I wondered off the original subject.

I came across this:
With few exceptions the British (all gun types) were used to engage Italian armor at the farthest possible distance, 1000 meters and way over that, shooting as quickly as possible. Clearly by doing so they waived accuracy and a degree of hitting power, but they thought they would compensate for that with a murderous rate of fire which would overwhelm the opponent, avoid damage to themselves by not allowing the Italians to get close, cause damage in any case given the known brittleness of Italian tanks, and possibly scare them off.

Conversely, Italian 47/32 gun crews were instructed to engage enemy armor at about 400 meters, thus maximizing hitting power and favoring accuracy over brute force barrage. This meant Italian tanks had to keep moving forward or stand fast under 2-pdr broadsides for several minutes without replying to enemy fire, until British tanks got within range. That required steel nerves and inevitably damage and losses were often suffered in the process.

Recent analysis shows that Italian tactics was probably not the most effective, at least in the early stage of the war. Because the 47/32 had some more penetration power than the 2-pdr *at long range* (32 mm at 1000 meters vs. about 25 for the 2-pdr). In fact at 1000 meters the 47/32 could still penetrate the front armor of an A-10 cruiser, whereas theoretically at that distance the 2-pdr could not defeat the M11 or M13's 30 mm thick front plates.

I think the brittleness of the armor should not be underestimated because even hits from long range that does not penetrate will affect the crew and equipment for a morale check. That should be included in the rules.

Wolfhag

The 2pdr elevation in early British tanks was controlled by the gunners shoulder. The idea being he could act as a sort of manual stabiliser for shooting on the move.
This made shooting at range harder. No fine correction based on observed fall of shot that elevation controls would offer.

Don Featherstone's Tank Battles in Miniature suggested a range guessing mechanic to model the usual practice of "straddles" used at range.

Andy wrote

I wandered off the original subject.

IMO, if the discussion does not wander off the original topic, it's not really a properly thought-provoking thread.

;-)

B