Main gun stabilizer revealed...

A pretty decent article on the "main gun stabilizers" of the American tanks, revealed in this Popular Science article of September, 1944. The military was pretty sure that this was no longer a "secret" which needed to be kept from the Axis powers.

See:

Popular Science - Google Books

Starting on page 82.

 

Thanks for the link Brndirt. My grandfather used to subscribe to popular science and when I was a kid I used to love reading them when I was at his house. Good memories. This particular issue has a number of interesting articles, not just the one on the tank gun stabilizer. I enjoyed the read. Thanks again for the link!

 

Glad you enjoyed the link, now if you want to "browse" the old Popular Science and Popular Mechanics magazines, here are the links to both of their archives. On the Pop Sci page, go to the bottom and start at about page 23 or so to get to the WW2 era.

Goto:

http://books.google.com/books/serial/ISSN:01617370?rview=1&source=gbs_navlinks_s

For the Pop Mech archives;

Goto:

Popular Mechanics - Google Books

These are split by decade, and somewhat easier to navigate than the Popular Science sections.

 

Brndirt1,

Thanks for posting this information. It is a very interesting article, but a shame the gyrostabilzer did not live up to its hype. It makes me think the article was published more for propaganda purposes than anything else because by the time it appeared, the Germans had plenty of opportunity to learn about the system from capture American tanks.

Duckbill

 

Without doubt it was a "puff" piece for American consumption, but that said; the crews that had the time to learn to use the "gyro" came to use it very effectively. It had been around since the sorry M3 Grant/Lee after all. Since it wasn't the easiest thing to use without intensive training, perhaps the Germans themselves found them to be of little interest when they managed to capture one that even worked.

Remember, the much touted Norden bombsight's secrets had been stolen before the war, and they never implimented that unit either. Of course it wasn't "pickel barrel" accurate in combat conditions, but it wasn't bad if the weather conditions were right. It worked quite well in the dry, still, clear air of the southwest bombing ranges. Not so good in the fog, cloud, humitity, and gusty winds of the ETO!

 

brindirt1,

I respectfully disagree with the opinion that crews that had the time to learn to use the gyro came to use it very effectively.

Certainly some Ordnance officers writing reports on the effectiveness of the gyro stabilized main gun in combat made it appear much better than it actually was, and blamed the failures with the system on poorly trained crews, or crews that had not bothered to learn how to use it. These reports were self-serving and intended to obscure the fact that the system was essentially worthless in combat. Not surprisingly they managed to leave out a few important details when claiming the gyro stabilizer worked just great when the crews were properly trained and motivated to use it.
Here are a few of those pesky little details.

n The gyro stabilizer took at least 5 minutes to spin up before it could be engaged.
n Once it was spun up, the gyro stabilizer could not be left running for extended periods of time because of wear and tear on the system.
n Before the gyro stabilizer could be used at all, it had to be calibrated. This process took a trained gun crew about 20 minutes to accomplish.
n Calibration of the gyro stabilizer had to be performed at least daily, and more often under conditions in which temperatures were very low, very hot, when they changed much during the day.
n Fine tuning the calibration could be done only when the main gun was fired.
n Depending on many variables, fine tuning might require the discharge of one to three rounds on average.
n Once the gyro-stabilizer was fine tuned for HE rounds, for example, it had to be retuned to use a round of different weight like shot or smoke.

Like I said, these are a few of the details that the Ordnance guys “overlooked” when writing their reports, and complaining about the crews not being sufficiently trained to use the gyro stabilizer. Their reports that trained crews were using it to good effect were simple fabrications. For their part, tank crews understood the gyro stabilizer was a dangerous waste of time and effort while in combat, and wisely (using the wisdom garnered only through having survived enough combat to become veterans) chose to leave the thing turned off.

((TK-525 Operation and Maintenance of the Gyro-Stabilizer. Chassis Group, Tank Department, The Armored School, Ft. Knox, KY. (2-16-44-500))

Duckbill

 

Good information, thanks for sharing "Duckbill"! Sent you some rep points since I'm out of salutes for the day. They are only worth 3 points (per salute), but the reps are up to the sender. You got more than three from me.

 

brndirt1,

TANKS for the rep points.

Duckbill

 

Where can one find that report?

 

Well I had a salute available, hopefully making up for brndirt1's shortage.

I had no idea that the early gun stabilisation systems had so many technical limitations. Now I know.

It's very easy for us children of a technological, digital society to assume that measurement and control systems were always as quick, simple to operate, and reliable as they are today. Posts like these give us some perspective.

 

Wasn't one of those who touted the effectivness of the stabalizer one Creighton Williams Abrams ? I don't think he was an ordinance officer during the war was he?

 

ickysdad,

I'll bet the Patton Museum and Ft. Knox Library have copies.

I got mine from a former Platoon Sergeant who served in a medium tank company during WWII. We had talked about the gyro stabilizer on several occassions by telephone, and a few days later an evelope arrived. In it was his original copy of the document along with a note that he had saved it after training at Ft. Knox, and wanted me to have it. I can't tell you how many tankers I've talked with about the gyro stabilizer, and they always say the same thing. It did not work as advertised.

Duckbill

 

Sentinel,

You hit the nail on the head. The WWII tankers I talk with always point out that the gyro stabilizer was a mechanical/hydraulic contraption that had no resemblance to the modern laser sighted/computer controlled systems of today. One told me that to keep the gyro stabilizer hydraulic system adjusted properly you had to turn a packing nut on the shaft from the drive motor to one of the hyraulic pumps by ear! If the motor speed slowed too much it was too tight as your turned the nut, you burned out the packing and electric motor, too loose and it leaked.

Thanks for the salute. It is much appreciated.

Duckbill

 

I have heard this before, but don't know where it comes from.

I've had the good fortune to talk with a former armor officer who served in the 4th Armored Division (perhaps the best American armored division of the war), and he said the same thing every other tanker I talked with said. The system was useless. You could not hit anything with it even if it was perfectly calibrated. According to him the 4th Armored Division did not use the gyro stabilizer in combat.

Lewis Sorley's biography of General Abrams, Thunderbolt emphasizes the general's interest in tank gunnery, and that his battlion set gunnery training records in England, but he never mentions (at least I can't find it) the use of the gyro stabilizer in combat. He does credit the speed of the M4's turret power traverse for helping defeat German tanks.

Duckbill

 

Thanks for that too, had a salute to spare today!

 

I'll have to see if I can find the bit about Abrams and the stabalizer. I know I read it on a forum which means it's far from validated but I think at least once I've seen it mentioned a source was give.

 

lwd,

Thanks for looking for the source. Let us know what you find.

Duckbill

 

I will if I find anything. So far I'm batting 0. I know some info is out there but ....