Jeeper704 Posted February 12, 2013 Share #126 Posted February 12, 2013 Great variety of types here...even a cast hull M3 Lee! One of many color photos of the Demonstration Regiment (check the markings on the front of the tanks). That is why you see so many different types of vehicles together. Erwin Link to comment Share on other sites More sharing options...
Jim Baker Posted February 18, 2013 Author Share #127 Posted February 18, 2013 Read more: http://www.histomil.com/viewtopic.php?f=335&t=12802&start=40#ixzz2LGz8kUkS Ah, thanks Jim. It looks more like 1-1.5 feet thick measured perpendicular to the armor surface. A bit more reasonable since concrete weighs roughly 145lbs per cubic foot. This M4A3E8's Concrete Armor was issue by the 12th Armored Division in January - February 1945. To further protect the Sherman from German anti-tank weapons, the 12th's ordnance officers decided to develop a local expedient using concrete applied over the glacis plate and the hull sides with steel rebar for internal reinforcement. You will also frequently see steel plates cut from destroyed US and German vehicles welded onto critical areas of the Sherman for the same purpose. Link to comment Share on other sites More sharing options...
Big Al Posted February 19, 2013 Share #128 Posted February 19, 2013 Thanks Jim. I love field-expedient stuff like that. On the subject of composite armor, I think I read somewhere that Patton (or maybe another officer, memory is fuzzy) issued an order telling his men to stop loading up the outsides of their tanks with sand bags because they reduced mobility and increased ground pressure. Have you ever heard of that? Link to comment Share on other sites More sharing options...
Jim Baker Posted February 19, 2013 Author Share #129 Posted February 19, 2013 Yes, Patton hated to see all the sandbags because he thought it was unnecessary and it also added weight to the suspension. But then when you look at 14th AD tanks, they are easy to spot because they were almost all covered in sandbags in the same fashion. They all looked nearly identical. Here is Patton after allegedly chewing out a tank crew for it's use of sandbags. This is supposed to a 14th AD Sherman. Link to comment Share on other sites More sharing options...
Jim Baker Posted February 19, 2013 Author Share #130 Posted February 19, 2013 This is a 14th AD Sherman. Most of them looked like this one. Link to comment Share on other sites More sharing options...
Jeeper704 Posted February 19, 2013 Share #131 Posted February 19, 2013 Another 14th Armored Sherman. In Rittershofen, March 1945. Erwin Link to comment Share on other sites More sharing options...
Jeeper704 Posted February 19, 2013 Share #132 Posted February 19, 2013 And another one. They make really good studies of both the tank type used and the added protection. Erwin Link to comment Share on other sites More sharing options...
Jeeper704 Posted February 19, 2013 Share #133 Posted February 19, 2013 Ma Maj. Gen. A.C. Smith, CG, 14th Armored Div., U.S. Third Army, walks along site where Combat Engineers are building a bridge to span the Isar River near Moosburg, Germany. 5/30/45 Tank is marked 14th Armd Div, 47th Tank Bn, tank C5 (From an internet site) Erwin Link to comment Share on other sites More sharing options...
Sabrejet Posted February 19, 2013 Share #134 Posted February 19, 2013 All very well for the General to (allegedly) chew out his crews out for overloading their tanks with sandbags and downgrading their performance. He didn't have to ride around in them dodging 88's and Panzerfausts!! Link to comment Share on other sites More sharing options...
Jim Baker Posted February 19, 2013 Author Share #135 Posted February 19, 2013 I'm not saying the General was right or wrong, and as you say we were not crew members trying to protect ourselves. But try to remember one of the Shermans advantages (and they were few) was it's speed and handling. Some of these guys were not just adding sandbags, they were adding sandbags filled with concrete as seen in this photo. Imagine the weight increase with a concrete "wrap" around that tank. Link to comment Share on other sites More sharing options...
Big Al Posted February 19, 2013 Share #136 Posted February 19, 2013 The weight increase is actually pretty easy to figure out. Lets say the filled dimensions of a concrete-filled bag are 3' x 1.5' x .75'. You multiply those together and you get 3.375 cubic feet per bag. From there you multiply by 145 (concrete's weight per cubic foot) and you get roughly 490 pounds per bag. Multiply that by the number of bags packed in the frame on the side of a Sherman tank (lets say 36), and you get 17,640 pounds, or almost 9 tons of dead weight hanging off of one side of the vehicle. Combined with the weight of the bags in the frame on the opposite side, it would be akin to cutting an M8 Howitzer Motor Carriage in half and welding each half to the sides of the Sherman. With those kinds weights added to the vehicle, I am surprised that the practice was done at all. Link to comment Share on other sites More sharing options...
Jim Baker Posted February 19, 2013 Author Share #137 Posted February 19, 2013 Nice talking to someone smart!! But in my case, that is most everyone.... That kind of weight would be detrimental to the operation of the vehicle. Maybe the crews only used the concrete filled bags in certain areas of the vehicle, like steel applique armor. I'll keep an eye out in my histories and see if it is mentioned. Seriously, thanks for doing the ciphering there. Very interesting. Do you have figures for the weight of sand in the bags? Link to comment Share on other sites More sharing options...
Big Al Posted February 19, 2013 Share #138 Posted February 19, 2013 The reason I know that stuff is because I work for my father who is a structural engineer. He does a lot of concrete design and I have learned a lot from him. As for the weight of sand, dry sand weighs 100 pounds per cubic foot. From there it is the same formula that I used to figure the concrete. Link to comment Share on other sites More sharing options...
Jim Baker Posted February 20, 2013 Author Share #139 Posted February 20, 2013 I'm going to bookmark this page. As soon as I write that down and save it somewhere, I will forget where! It's still sinking in just how much weight these guys were adding to their tanks. Link to comment Share on other sites More sharing options...
Big Al Posted February 22, 2013 Share #140 Posted February 22, 2013 It is astounding. I guess it really shows how desperate the situation was in France. I wonder how badly that stuff affected the service lives of engines and running gear. Anything on that anywhere? Link to comment Share on other sites More sharing options...
Jim Baker Posted February 22, 2013 Author Share #141 Posted February 22, 2013 Not that I have noticed. But I will be looking for it now. If anywhere, I would say probably in a history of the 14th AD since they seemed to have done this consistently. I read "Death Traps" and Cooper took about every shot he could have at the Sherman, but I don't recall anything in the book. Link to comment Share on other sites More sharing options...
Jeeper704 Posted February 22, 2013 Share #142 Posted February 22, 2013 For one thing, it also proves how much a Sherman could take or handle. It could be that they used the concrete filled sandbags on the front of the tank and "normal" sand filled ones on the sides? Nevertheless it sure is a lot of weight to carry around. Just thought it might be a temporary addition? For street fighting only maybe? Once they were out of the small cities and villages, maybe they took it back off? Just an idea. Apart from the adding of concrete filled sandbags, I also noticed the 14AD marked their unit designation on the barrel of most of their tanks. Erwin Link to comment Share on other sites More sharing options...
etienne Posted February 22, 2013 Share #143 Posted February 22, 2013 The weight increase is actually pretty easy to figure out. Lets say the filled dimensions of a concrete-filled bag are 3' x 1.5' x .75'. You multiply those together and you get 3.375 cubic feet per bag. From there you multiply by 145 (concrete's weight per cubic foot) and you get roughly 490 pounds per bag. Multiply that by the number of bags packed in the frame on the side of a Sherman tank (lets say 36), and you get 17,640 pounds, or almost 9 tons of dead weight hanging off of one side of the vehicle. Combined with the weight of the bags in the frame on the opposite side, it would be akin to cutting an M8 Howitzer Motor Carriage in half and welding each half to the sides of the Sherman. With those kinds weights added to the vehicle, I am surprised that the practice was done at all. You're right about the density of concrete but I think you overestimated the size of the bags ... my own calculations lead me to about 50 liters, and 100kg = 220 lbs when filled with concrete. My experience is that it's very difficult to handle a sandbag heavier that 50kg / 110 lbs ... and I handled some When counting sandbags on one side, I have a guesstimate around 25 so the final weight should be around 2500 kg / 5500 lbs per side. Link to comment Share on other sites More sharing options...
Sabrejet Posted February 22, 2013 Share #144 Posted February 22, 2013 The already high gas consumption must have rocketed with all that excess weight...not so much miles per gallon, but gallons per mile!! Link to comment Share on other sites More sharing options...
Big Al Posted February 22, 2013 Share #145 Posted February 22, 2013 You're right about the density of concrete but I think you overestimated the size of the bags ... my own calculations lead me to about 50 liters, and 100kg = 220 lbs when filled with concrete. My experience is that it's very difficult to handle a sandbag heavier that 50kg / 110 lbs ... and I handled some When counting sandbags on one side, I have a guesstimate around 25 so the final weight should be around 2500 kg / 5500 lbs per side. Thanks etienne. I was just guessing from what I could see in the photos as far as the sandbags sizes and the numbers per side are concerned. What are the true filled dimensions of a filled sandbag? Link to comment Share on other sites More sharing options...
etienne Posted February 22, 2013 Share #146 Posted February 22, 2013 Thanks etienne. I was just guessing from what I could see in the photos as far as the sandbags sizes and the numbers per side are concerned. What are the true filled dimensions of a filled sandbag? Considering the dimension of a Sherman tank, those used by the 4th AD were 20"x12"x10" ... in line with what I used to have when in the french army, and even if it's not very large, I can say that full of sand, it's rather heavy Link to comment Share on other sites More sharing options...
Jeeper704 Posted February 22, 2013 Share #147 Posted February 22, 2013 14th Armored Division, you mean? Erwin Link to comment Share on other sites More sharing options...
Jim Baker Posted February 23, 2013 Author Share #148 Posted February 23, 2013 Link to comment Share on other sites More sharing options...
Jeeper704 Posted February 23, 2013 Share #149 Posted February 23, 2013 They sure are making it smooooooth .... 105mm HOW Sherman? Erwin Link to comment Share on other sites More sharing options...
Sabrejet Posted February 23, 2013 Share #150 Posted February 23, 2013 So no lights, klaxon, or travel support for the gun tube and limited traverse for the bow mg! The lesser of two evils I suppose? Link to comment Share on other sites More sharing options...
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