Sunday, April 17, 2016

Tank Commander Exposure in Combat Mission

With the release of's (BFC) Combat Mission: Final Blitzkrieg (which utilizes the second generation Combat Mission (CM) game engine), there has been a bit of discussion about the modelling of tank commander exposure in that game system. There seem to be two main of points of contention at present
  • how often should tank commanders expose themselves to enemy fire
  • how effective should fire directed at them be
Those issues will be resolved by BFC in their own community, but largely absent from the online discussion so far has been a reference to available evidence.

Evidence - Rate of Exposure

On the face of it, casual histories answer the question of how often tank commanders exposed themselves to enemy fire, and why, very simply. This primer on German tank crewmen of the Second World War sums up the situation in typically vague terms:
At the rear of the turret sat the commander. At safe distances, he would stand on his small seat, so that his upper body was exposed in the cupola, and observe the battlefield with binoculars. When the enemy was near and in combat situations the turret hatch was battened down, and the commander observed the battlefield through small episcopes set into the cupola surface.(1)
A survey of tank operations mentions:

The interior of an (Armoured Fighting Vehicle - AFV) is cramped and dark, with hard metal edges wrapping around the crew and passengers. Visibility is provided through a mixture of periscopes (and) vision slits...Even with the most advanced systems, the crew will have a distinct sense that there are things going on out there that might harm them and that they cannot see.
 One response to this vulnerability in the past has been for the tank's commander to direct combat standing up from an open turret. This has its advantages - the commander gains a complete perspective of the battlefield, being cognizant of all threats, including those from the air. He can also spot enemy infantry attempting to creep up on his tank.(2)

And a primer on U.S. tank crews in the Second World War suggests that in U.S. units, there was an additional advantage to the commander exposing himself to enemy fire:

Above the commander's hatch was a .50 cal. Browning heavy barrel machine gun. This was intended for anti-aircraft protection, but in fact was much more often used for self-defense of the tank and for attacking ground targets that did not warrant the use of the main armament...The .50 cal. heavy machine gun was very destructive, and proved to be extremely effective in attacking enemy infantry and trucks; the 4th Armored Division placed a great deal of emphasis on its use. Gen. Bruce Clarke later recalled:
I told my men that the greatest thing on the tank was a free .50 cal. in the hands of the tank commander. We were not able to fight from tanks with the tank commander buttoned up - that has never been successfully done. [Buttoned up] he can't hear or see and so pretty soon he unbuttons. Now if he's got a free .50 cal. machine gun, all he has to do is press his thumb and he can pick out a dangerous spot. It may be a bazooka flash or something. He can throw a burst there without even thinking about giving an order.
On the early M4, the .50 cal. machine gun was mounted on a pintle that was attached to the commander's hatch. On later tanks with the all-vision cupola, it was fitted to a pintle behind the commander's hatch, very awkward for the commander who had to expose himself to use the weapon. On the M4A1 (76mm) and M4A3 (76mm), both of which had the large round loader's hatch with pintle, units often moved the machine gun to the loader's side due to its more convenient mounting. Other units came up with their own improvised solutions. On (Creighton) Abram's (Sherman tank), he had a .30 cal. machine gun mounted in front of the cupola for his personal use.(3)

Early Sherman variants had the AAMG on a pintle behind the commander's turret, requiring a crewman to expose himself in order to fire it.

 The turret used on 76mm Sherman tank variants (T23 turret) had two round hatches, the commander's (with armored glass vision blocks and a round hatch) and the loader's (with split hatch). A pintle can be seen at the rear of the loader's hatch. (Image from:

The introduction of a larger round hatch on the loader's side of the turret was not an intentional move to enable the loader to access an anti-personnel weapon; crew concerns about emergency exit had been raised since the original Shermans which had no loader-side hatch at all. A small oval hatch was added at first, since "(c)ombat reports had indicated that the early hatches were inadequate for emergency exits, especially in the turret." The introduction of the oval hatch meant "the loader didn't have to wait for the commander and gunner to leave before he could get out."(4)

The Regimental History of one Canadian armoured regiment had a copy of the Tank Standing Orders that regiment used during combat in Italy and Northwest Europe. The document is reproduced online here. One of its provisos shows that Commonwealth tank commanders were expected, under penalty of court martial, to fight with commanders able to expose themselves quickly where necessary:
20. HATCHES ETC. Crew commanders will NOT close both turret flaps except under very heavy mortar fire when the situation does not demand unrestricted vision. Drivers and co-drivers hatches will not be fastened. Safety belts will NOT be used. 

 27. DISCIPLINE. Failure to obey these orders will be treated as a court-martial charge.
A Canadian Sherman in action at Ortona. Commonwealth units often removed the AAMG altogether, but the exposure of the commander is obvious. Vision-block cupolas did not appear on the majority of types employed in Commonwealth units and only late in the war for certain American Sherman types.
The use of the .50 as an anti-infantry weapon seems not to have been considered by Commonwealth tank crews:
As well as the 75mm main gun and the two .30 calibre machine guns, Shermans came from the factory with a .50 calibre machine gun mounted on the commander's hatch for anti-aircraft use. While this was sometimes replaced with another .30 calibre gun, in the Canadian Army tank commanders were discouraged from exposing themselves to air attack. There were specific anti-aircraft units whose job it ws to shoot down enemy aircraft and it was believed that commanders had enough to do in commanding their tank without engaging in gunfights with aircraft.(5)
Crew Survivability

The question of survivability is a separate issue. Roger Lucy provided some hints in a forum conversation at - suggesting that Operational Research seems to have focused on what killed tanks with comparatively less emphasis on how crewmen were killed. One report is held by the Laurier Centre:

Medical Research Council Team for Survey of Casualties Among Tank Personnel - Casualties among tank crews in 11 armoured division in operational veritable 27 Feb - 4 Mar 45

and this is available online;

Injuries to Tank Crews: A Guide to the Data-base and the Data Forms

There is certainly scope for additional research. Library and Archives Canada has this for example:

RG24 Series C-1, Reel C-5254
File: 8676-9-8 , Access code: 90
File Title: Casualties - Royal Canadian Armoured Corps 

Other Models

Player complaints that crew commanders are killed too often are difficult to justify without understanding what the historical situation was. Other games like Advanced Squad Leader may be a guide as they also model crew exposure's benefits and drawbacks. In ASL, a tank suffers a penalty to direct fire against enemy targets with the main armament when the commander/crew is not exposed ("Buttoned Up" or BU). When "Crew Exposed" (CE) the tank receives a bonus to its movement. Enemy fire against the exposed crew is possible, and they are given protective bonuses equal to infantry behind a stone wall or in hard cover in a building.

The effects of crew casualties are temporary inability to perform any actions ("Stun") and a permanent loss of crew exposed bonuses. How often do tank crews expose themselves to enemy fire in ASL? One often-cited article regarding tank warfare in ASL suggests rather unhelpfully that:
Whether or not to remain CE probably comes down to personal preference, though the primary consideration involves any hazards invited by doing so.(6)
However, good advice in the conclusion of the article applies in CM as much as ASL:
...(K)eep your eye on the prize. Your goal ultimately is to win the scenario; so even though your stated object is to defeat the enemy's armor, do not let yourself become side-tracked from the Victory Conditions solely to engage his armor. Strategy is dictated by the Victory Conditions - though, if tanks are involved on both sides, they will almost inevitably come to grips with one another. However, do not let yourself become distracted!
... it must seem that the "successful" tank commander adopts a primarily defensive posture during an armored battle. In fact, by following the Rules of Engagement and through judicious use of mobility, a tank tends to behave very much like a hunter stalking its prey...Likewise, the successful tank commander waits for the enemy to move into his sights, or carefully moves into an advantageous position to destroy the target. Conservative play is the by-word here, since the DEFENDER will almost always hold the upper hand initially during an Engagement. Whatever the case, allow the enemy to make the first mistake while you wait to take immediate advantage. Above all, patience is the virtue which most distinguishes the successful tank commander.
Another article on fighting armor in ASL, equally unhelpfully says: "The often difficult decision of "CE or not CE" is taken away from you (when providing one-man turret tanks in the order of battle)" but does not discuss the actual decision making process.(7)

About the only thing that ASL can offer is that in that game system, deciding to button up or expose the commander is a highly individual and subjective choice to make.


It would seem tank crews in the Second World War were not only encouraged to fight with the commander exposed, but may have even preferred to do so. Canadian regulations in at least one case actually required the commander to at the least keep one of the turret hatch halves open except under heavy mortar fire "when the situation does not require unrestricted vision."

The use of turret machine guns seems to have varied by nationality, certainly on the Allied side, and possibly only late in the war when U.S. 76mm armed tanks were provided with turrets/hatches that permitted a greater flexibility of weapons employment.

Combat Mission player's perceptions that tank commanders are too easily eliminated may have some basis of truth, though more research into historical casualty rates may be useful. At the very least, though, the rate of exposure in the game seems consistent with the references cited above. Being exposed offered very real dividends, tank commanders often took these risks in order to achieve these benefits, and CM at least seems to model this realistically given the absence of more definitively defined references.


1. Williamson, Gordon. Panzer Crewman (Osprey Publishing Ltd., Botley, Oxford, UK, 2002) ISBN 7-84176-328-4 p.27 
2.McNab, Chris and Hunter Keeter. Tools of Violence: Guns, Tanks and Dirty Bombs (Osprey Publishing, Botley, Oxford, UK, 2008) ISBN 978-1846032257, pp.99-100
3. Zaloga, Steven J. US Army Tank Crewman 1941-45: European Theater of Operationss 1944-45 (Osprey Publishing Ltd., Botley, Oxford, UK, 2004) ISBN 1-84176-554-6 pp.20-21
4. Culver, Bruce. Sherman in Action (Squadron-Signal Publications, Carrolton, TX, 1977) ISBN 0-89747-049-4 p.30
5. Guthrie, Steve. The Sherman in Canadian Service (Service Publications Ltd., Ottawa, ON, 2002) ISBN 1-894581-14-8 pp.15-16 
6. Bakken, Bruce "Panzer gegen Panzer" ASL Annual 93'a (The Avalon Hill Game Company, Baltimore, MD, 1993)
7. Olie, Dave "What To Do If You Have A Tin Can" ASL Journal Issue 1 (Multi-Man Publishing, Gambrills, MD, 1999)