Blast Effects On Tanks
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I was really surprised the first time I went to M-60A1 gunnery as a TC. Blast effects from the main gun can be pretty nasty when you are outside the tank. I got caught retrieving 'brass' between two tanks on a slab at Fort Knox once when both of them fired. That was an eye-opener especially since I didn't have my ear plugs in.

The first time my tank fired a main gun round with me as TC and my hatch open it felt a little like someone had patted me on the top of the head. I even looked up. Before that I had been a Sheridan crewman, and there was never any doubt when a conventional round was fired from the main gun of one of those.

The M-60 was heavy enough and closed up enough to protect the crew pretty well from most blast effects even with both turret hatches open. Naturally there are very few drivers who want their hatches open when the gun fires over the front.

What was really strange was firing main gun at night from a 'blade' tank. I don't know how much extra weight that dozer blade and the hydraulics added, but the blade was in the right place to reduce any 'rocking' caused by firing forward. On one occasion when we were firing practice rounds it seemed like I actually had trouble telling when we fired unless I saw the breech go back, and in red light conditions that wasn't always easy. Maybe I'm exaggerating because I should have been able to tell from the shell case hitting the floor.

Anyway, it really isn't quiet inside a tank, but you're kind of in your own little world where outside noises don't intrude unless they are very loud. Even without a blade mounted 50+ ton vehicles are hard to rock and if you are moving an explosion might have to be pretty close before you notice it, depending on the size of the explosion, of course.

There must be some kind of limit, though. When the gun fires the muzzle blast is what, fifteen feet away? The Hoffman charges that were used to simulate the gun firing during training exercises were supposed to be the equivalent of 1/4 stick of dynamite. The result was hardly noticeable. A full stick of dynamite at that distance might be. Its not experimentation that I would like to be involved in, though. "Okay, we're going to simulate a 2000 bomb 10 feet away. Ready?"

Interesting that someone mentioned tanks firing at tanks, though. Especially in Zumbro's book about tanks in Vietnam there are a number of instances mentioned where one tank would have to use it's coax to clear bad guys off of another one. Their sponson boxes must have looked like Swiss cheese if they actually did that.

I'm not sure what things are like for drivers if they have their hatches open. I don't remember ever being in the driver's seat when a tank fired. I suspect tht most tank drivers avoid having their hatches open when the gun fires, especially Sheridan drivers. The Sheridan has a relatively short gun tube, and fires a relatively large round, 152mm, so that might be uncomfortable.

I remember one occasion in Germany, though, where I gave my driver an unpleasant surprise. I had only been in the unit for a few days and we were out for some kind of training with Hoffman devices mounted. The Hoffman device is supposed to simulate the muzzle blast signature of the main gun. It's a cluster of 9 heavy metal tubes in a frame that mounts on the gun tube near the mantlet, right above the driver's hatch. We were driving through a wooded area and the driver got a little close to a tree. M-60A1 are considerably taller than Sheridans, and I didn't realize that I need to duck until the tree limb was too close for me to escape unscathed. Somehow I managed to survive getting crushed up against the back of the cupola. I don't really remember now whether I fired the Hoffman devices in anger or not. I think not. That tree limb had small branches and maybe one hit the 'salvo' switch on the Hoffman control box. It fired all 9 charges at once. The driver got very upset about it. I wasn't really in the mood to listen to him because I felt that my recent brush with the tree had been at least partially his fault. I had problems with a driver at Fort Hood who used to like to drive under trees with low branches, but I think that most drivers who have a little experience avoid doing that. TCs need to maintain their situational awareness, but that requires looking around a lot. If you are bringing up the rear of the unit, as I was, the place where you are supposed to direct most of your attention is towards the rear of your tank. The only long term driver I had in Germany apparently kept that in mind because he stayed close to the trees when they were available, but never ran me into a limb.

My thanks yet again to Rory.


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