Duplex Drive Shermans

The Sherman's used at the D-Day landings weren't all just the duplex drive jobbies. Many years ago (more that I care to admit) when I was in the reserves we had an old tanker Sergeant who used to talk about the special Sherman's built just for the landings that were code named "Cobra Kings". I don't remember what the model number was but it seems they were a batch made just for the D-Day landings. They were heavier that the basic Sherman because they had a whole lot of additional armor added during construction. The idea was that the up armored tanks would be a help in blasting our way through the beach head defenses. The catch was that the extra weight was very detrimental to the lifespan of the tracks and suspension parts. The reasoning was they would just be used for that breakout from the beach head and then they would be replaced by standard Shermans. He said that they found that the up armored tanks had a much higher survival rate than the "standard" models so the units that had them didn't always turn them in. He said they would rob/cannibalize parts off standard Shermans to keep the Cobra Kings rolling in the up front positions. They even robbed some standard Shermans with the later 76 mm guns of their turrets to up gun the Cobra Kings as well. He had a photograph of a tank he said was an up gunned Cobra King sitting in a ruined house somewhere in Germany in March of

1945. Snow looked to be 3 feet deep. Pretty good life span for a tank that was built to last just a couple of days.

Bill Shuey

Watched a two part special on TV recently on the National Geographic channel. Even found a flail tank diorama I want to make after seeing the cd cases on the books.....

"D Day, Machines of Invasion"

Had a great run of info and old footage of testing the funnies, and was really good to see it all. Would be worth getting a copy on video or dvd if available.

Just called up their website and finally found it (I'm on dialup, and have three other things downloading as well.......) There are several links to follow as well, a couple of them look good.....

I'd assume that some of the tanks that were modified in the field were from a range of different model tanks, the ones that were factory mods would have been made from scratch to allow the drive to the props so would possibly be same series tanks. Drive units on one of the linked sites shows they were driven off the idler wheel rather than the engine so very little factory modification was required. The blueprints that are mentioned in the show would tend to make me think they were made up to suit the original tanks at the time of construction.

Just in time before sending this is this quote from one of the linked sites: "This system of floatation resulted therefore in enormous economy of manufacturing speed as witnessed by the conversion of some2,000 tanks in this country alone, and of some 300 in the U. S. in the course of a very short period of time." which tends to make you think that several models were probably adapted as more were modified in Britain than back in the states. These tanks were not expected to last all the way to Berlin!

Weathering the tanks could prove interesting, wonder how many fishing rods to include?

Hope this helps, Peter

I saw a documentary a week ago about the DDs. What I didn't realise was the shocking fate of the DDs used initially at Omaha.

There were 27 used, and the recommendation was that they should be launched not further than 1 mile out. The trouble was that the guy in charge of the landing crafts refused to take them any closer than 3 miles as he was not prepared to put his craft in danger. The water conditions of the English Channel were very different to the Mississippi on which they were tested. The crying shame is that all 27 DDs sank with the loss of most (if not all) of the 135 crew. Not only was this a dreadful waste of brave lives but it left the poor infantry unsupported on the beach.

DDs for the English and Canadian landings were launched 1 mile out and reached the beach successfully. A german survivor recounted on the documentary, his unit's shock when they saw tanks emerge from the sea, seemingly out of nowhere.

Furthermore, the rocket ships which were supposed to pepper Omaha beach with craters so that the troops would have cover fired their rockets 1/4 mile short so that they fell harmlessly into the sea.

Cheers,

Nigel

Did some searching a week or two on Google and came up with quite a bit, like drawing for the extended periscopes and other bits. Don't see where I have those bookmarked but there is some stuff here:

Tom

The basics of what you asked are:

BOTH M4 and M4A1 were used;

They were all "mid" production variants (late production M4A1 with "big hatches" were apparently used in Operation DRAGOON, the southern landings in France later on;

All were early hatches.

As for better details, most of the websites that some of the guys have listed will give you a more complete picture of what happened.

Cookie Sewell

I think I saw the same program, very infuriating waste. Funny they couldn't attach a name. Cheers,

The Keeper (of too much crap)

Hi Bill, it sounds like the tank you are describing is the "Jumbo" Sherman. They came along a little later than D-Day but without busting out the books I don't know exactly when. Thanks for the reply though.