Cromwell Mk IV (A27M)

An excellent British tank of the later War years, the Cromwell is perhaps less well known than much hardware of the Western Europe Campaign.

Let’s take a look at a very useful design.

I’ll have to start by admitting the whole development process of British armor is a bit bewildering to me (not that American armor makes a great deal more sense!).  
The Cromwell was a cruiser tank, that means it was designed for speed and mobility; breakthrough operations as opposed to infantry support. As a later wartime design it benefited from a lot of practical experience, but at the same had many cobbled together features.  The first big difference from previous cruiser tanks was reasonably heavy armor, three inches in front.  That’s about 50% more than a Sherman, with a lower profile.  But the armor was in vertical slabs with no angle, which made for roughly equal protection (the Sherman had a better chance of deflecting hits, while the Cromwell was more likely to be hit square).
But that extra armor means extra weight, and a reliable, powerful engine initially posed a problem. Working from a damaged Merlin, with no supercharging and other changes to facilitate tank use, the Tank Board came up with the Meteor engine.  This was rated at about 600 hp, which meant plenty of reliable power.  Many early production Cromwells would get Meteor engines rebuilt from Merlins, until Rover was contracted to deliver new-build engines.  The powerful Meteor could push the 27 ton tank up to 40 mph.
The gun was also problematic, the six pounder was originally intended but was no longer considered enough by forces in Italy.  The 17 pounder simply wouldn’t fit.  But British troops were mostly very happy with the American 75, especially since it had interchangeable armor piercing and high explosive ammunition.  The basic American gun wouldn’t quite fit either, but it was discovered that the 6 pounder could be bored out to fire the same ammunition.  This actually came to be considered a better gun than the American 75, with a better rate of fire and superior armor penetration.


It entered service late in 1943, but didn’t see combat until Normandy.  It was used by six different divisions during the European Campaign, but I believe only the 7th Armored Division had it as the main tank in every Armored Brigade.  It was always backed up by Sherman Fireflys for heavy anti-armor support.  Overall it was rated comparable, or slightly superior to a Sherman or Panzer IV.  It was obviously faster than either, with good armor and a good gun.  Its only real knock being lower mechanical reliability; road tests showed it required slightly more than twice the service of a Sherman, but that’s still considered good performance.


Late in the War, a larger redesign of the Cromwell with the 17 pdr entered service as the Comet.


This particular tank served with the 7th Armored Division, Summer 1944.  It is from the Tamiya kit.

The Cromwell was about equal to the Sherman, which was more numerous in British armored formations.
Thick armor was bolted and welded to the frame. Apart from a superficial resemblance to rivets I’ve not heard of the same sort of complaints or failures with this application.
Late War British Armor. Notice both cruiser tanks, Cromwell and Crusader, use Christie suspension.
The Panzer IV, foreground, was roughly equal to the Cromwell. Panther, behind, could be more of a problem.

About atcDave

I'm 5o-something years old and live in Ypsilanti, Michigan. I'm happily married to Jodie. I was an air traffic controller for 33 years and recently retired; grew up in the Chicago area, and am still a fanatic for pizza and the Chicago Bears. My main interest is military history, and my related hobbies include scale model building and strategy games.
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7 Responses to Cromwell Mk IV (A27M)

  1. jfwknifton says:

    Thanks for a very informative article. You certainly know a lot more about British tanks than i do!

  2. Ernie Davis says:

    It seems funny that, given their advantages in industrial capacity the Allies still seemed to have a “stop gap” mentality on a lot of things, armor most especially. The constant tradeoffs and compromises to get the various tanks in the field in sufficient numbers led to, as you note Dave, a lot of confusion about just who was in charge of that herd of cats.

    • atcDave says:

      Yeah I’m not sure why that was? Obviously US and Britain both came up with some decent hardware, but the process always seems chaotic. I suppose it starts with a conflict between what they want, what the actual need will come to be, and what is buildable.
      And to be fair, I don’t think aircraft design is any smoother, just that I’m a lot more familiar with it.

    • Ernie Davis says:

      At least with the Brits and tanks it always struck me that they were perpetually seeing which gun they could wedge in to the tank they already built or had. Can’t fit the 17 Pdr, well how about a 6? Not effective? Well what about the Yank 75? You know if we put a longer turret and redesigned the recoil I bet we could fit the 17 Pdr on a Sherman. Not a bad notion, then we can put a modified 6 on the Cromwell and deploy them together while we redesign the turret to take the 17.

  3. Pingback: Cromwell Mk IV (A27M) – faujibratsden

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