Cheap Shots

I can’t imagine any circumstances in which I would have voted for Mike Dukakis for President back in 1988. Well, maybe if someone gave me a pre-frontal lobotomy perfomed with dull swiss army knife and a dirty spoon. Maybe. I never liked him, and he stood against pretty much everything I stood for politically. But I always thought he got a raw deal one time.

When he was running for President, he faces an opponent with military experience and a great deal of foreign policy background- George H.W. Bush. Bush had been a Naval Aviator in WWII and had served in  a wide variety of positions including Director of Central Intelligence and of course, two terms as Vice President under Ronald Reagan. Dukakis was the Governor of Massachusetts, but had little defense or foreign policy background(Dukakis did serve in the Army from 1955-57). In order to bolster his defense “bona fides” he took part in a photo op riding in an Army M-1 Abrams Tank. The result was this infamous photo.

Dukakis was mercilessly mocked for the photo. The Bush campaign ran ads of the photo to make the point that Dukakis was not fit to be Commander-in-Chief. Many people credit this for shifting the tide in the election from favoring him to favoring Bush (I think Willie Horton might have had more to do with it).  It bacame the prime example of a PR stunt backfiring.

Here’s why I think he got a raw deal. He looked goofy. Well, I’ll let you in on a little secret. Everyone in a tank helmet looks goofy. I do. Oh, Lord, don’t I know I look goofy. The thing is, the helmet wasn’t designed as a fashion accessory, it was made to keep you from cracking your skull open when the tank bounces around.

We’ve seen several cases where politicians since then have been mocked for wearing helmet, to include John McCain, Joe Lieberman and Obama with the bike helmet (I’ll admit, I love Slu’s P-Shops of the bike helmet). George W. Bush has been mocked for being photographed in a flight suit on an aircraft carrier (if he hadn’t taken the helmet off before photos, he would have been screwed).

I’m glad Dukakis lost the election, I just feel bad that he had to take that cheap shot.

Dragon Tales

One of the jobs I had when I was a young troop was Dragon Gunner. By the time I was a Dragon Gunner, they were pretty long in the tooth and not very highly thought of. But think about this: back before you could buy a pocket calculator, the Army had fielded a guided missile that could reach out and destroy a tank over half a mile away, and yet was small enough and light enough for one man to carry.

The Dragon, or M47 Medium Anti-Armor/Assualt Weapon, was first issued in 1975. It was a man portable guided missile that used wire guidance technology called SACLOS-Semi-Automatic Command Line of Sight. Basically, when the missile was launched, it trailed to very thin coppper wires behind it. It also had a flare in the rear of the missile. The sight unit tracked the flare and saw if the flare was in the crosshairs or not. If the missile was not in the cross hairs, the sight sent a signal by way of the wires for the missile to go up, down, left, or right. All you had to do to guide the missile was keep the crosshairs on the target. But that is easier said than done. Dragon gunners spent a lot of time practicing this skill. Since the missile cost about $10,000, they didn’t let us shoot all that many for practice. Usually, a device that fired a powerful blank cartridge was used. One of the other things that made it tough to aim was the launch itself. The missile used a small rocket to propel itself out of the launch tube.

[youtube=http://youtube.com/watch?v=xu7HjKR4I3U]

That’s a missile being shot from a test stand. In real life, it looks pretty much the same and it takes practicee to avoid flinching. If you flinch, you tend to point the sights at the dirt. The missile quickly obeys and flies right into the dirt. That’s not what you want.

If you look closely at the photo above, you’ll see a bunch of dimples on the side of the missile. These are the rocket motors that fly it to the target. Since the back end of the missile is taken up by the wire spool, the flare and the starter motor, the engineers had to put the sustainer motors somewhere else. Also, they had to figure out a way to control the missile in flight. They came up with an unusual method. There are 32 pairs of motors on the missile. While the Dragon is flying, it is spinning like a bullet. Pairs of motors will fire, sounding like a “pop” to boost it on its way. If the missile is not in the crosshairs, other pairs of motors will fire to push it back onto the right path.

Here’s a video that demonstrates the launch and if you listen closely, you’ll hear the pop-pop-pop.

While the Dragon was a pretty impressive weapon for its day, it had its problems. Its range was only 1000 meters. That’s right about the maximum range of the machine guns mounted on all the vehicles it was shooting at. Since it took 10 seconds  for the missile to fly that far, the bad guys had a fair chance of spotting you and shooting quite a few bullets at you while you tried to guide the missile. They didn’t even have to hit you. If they made you flinch, you’d miss the target. That was the other big problem. You had to keep the crosshairs on an often moving target. Even heavy breathing was enough to make this difficult. Getting shot at didn’t help. Still, it was better than no anti-tank weapon at all.

With these shortcomings in mind, the Army developed the replacement for the Dragon. The Javelin has twice the range, is faster, has a better warhead, and has a fire and forget capability. Once the Javelin gunner fires, he can duck for cover or start reloading while the missile guides itself to the target.

[youtube=http://www.youtube.com/watch?v=8VdRnY-TUb4]

Just a little Air Force love

It is a given that the folks in the Army like to make fun of the Air Force as “the country club” and not really being a military service. An old joke holds that the very first thing built on a new Air Force base is the golf course. They know if they blow all the money on luxury items, sooner or later Congress will fund the runways. I’m not immune to this, having made fun of the wing-wipers once or twice myself.

There is, however, a small slice of the Air Force that Army folks admire, almost without reservation. Close Air Support is a mission the Air Force doesn’t like, never has, and probably never will. But the folks in the Air Force that actually do end up with the job are commited to doing it as good as anyone in the world. The epitome of close air support is the A-10.

[youtube=http://youtube.com/watch?v=mJSk2Xc3Eq4]

At the end of the Vietnam war, the Air Force had relied heavily on two planes for close air support- the A-1 Skyraider, and the A-7 Corsair II. While both were excellent aircraft, neither were optimum aircraft for the post-Vietnam close air support role. The A-1 was a piston engined airplane of WWII design. They were just plain worn out. Even worse, it was a Navy design. That didn’t set well with the upper echelons of the Air Force. The A-7, on the other hand, was a relatively new design, with excellent range and load-carrying capacity. But it too had two major flaws. Again, it was a Navy design. Second, it wasn’t optimized for the close air support role. It had been designed for long range strike. The Air Force began a to design a new aircraft totally dedicated to close air support.

The major problem facing the Air Force in Western Europe in the 1970s was the same as the Army- the colossal numbers of Soviet tanks. The prime mission of any close air support aircraft would be killing tanks. Historically, the best weapon an airplane could use to kill tanks was a gun. The 20mm Gatling gun in use wouldn’t be enough though. A bigger gun was needed. And a bigger gun was got. The GAU-8 Avenger. This huge 30mm Gatling gun fired armor piercing rounds that could penetrate the armor of any tank. But it was huge. The airplane that carried it would actaully have to be designed around the gun.

The A-10 was designed around the gun. In fact, the nose wheel of the plane is offset to one side to make room for the gun and to make sure that the firing barrel is on the centerline of the aircraft.

In addition to the big gun, the A-10 has lots (and lots and lots) of hard-points under its wings to hang additional weapons, including missiles, bombs and rockets.

Another prime concern when the A-10 was being designed was survivabilty. The front line is a dangerous place. Planes flying close air support have to get down low and in close. That means that every bad guy with a gun gets to take a shot at you. Republic, who designed and built the A-10, had seen many of their F-105s lost in Vietnam to relatively minor damage. They were determined that wouldn’t happen with the A-10. Airplanes are made of panels of aluminum about as thick as a beer can. So is the A-10. But the pilot sits in a “bathtub” of titanium armor, so he won’t be injured by flak. The engines are mounted to reduce the chance of a heat-seeking missile hitting the aircraft. Rather than risking losing control from hydralic leaks, the airplane has a backup system of pushrods to handle the flight control surfaces. The wheels don’t even retract all the way into the plane. This way, in a belly landing, they can still support the plane.

The A- 10 isn’t a very fast jet. It only goes about 400 miles an hour. That’s about the same as a WWII fighter. The joke in the Air Force is that A-10 pilots don’t wear a wristwatch, they carry a calendar. But it is the best plane in the world for close air support. In service since the late 1970s, A-10s have been the angel on the groundpounder’s shoulder in Desert Storm, The 1999 Air War in the Former Yugoslavia, Afghanistan and Iraq. With its excellent manueverability, lethal weapons and great survivability, the A-10 has not only been the plane for close air support, it has also served as a Forward Air Controller, helping planes like the F-15E and F-16 locate and destroy targets to support the troops on the ground. Currently, the Air Force is upgrading the A-10s to help them do this job well into the future.

Retro Apache Pr0n…

When I put up my post on the Apache development, I asked BillT from Castle Argghhh! to take a look and let me know if I’d made any colossal blunders. As I fired off the email, I knew in my bones he was going to come back with a word about the Apache’s daddy, the venerable AH-1 Cobra. How did I know this? Bill is a retired Army Aviator (in fact, I believe he’s a Master Aviator), with combat time in Vietnam and long experience in attack and scout aviation. My request was like asking the owner of a ’64 Mustang to give me his thoughts on the new Dodge Magnum. Sure, he’ll help, but you know he’s gonna want to talk a little Mustang.

Almost from the first helicopter, people had the bright idea to arm them. Everyone in the Army knows to seek the high ground, and how much higher can you get than in a helicopter? But the concept was easier than the implementation. Early helicopters had little power, and were only able to lift relatively small loads. Think back to the opening shots of M*A*S*H. Not a lot of room there for lifting heavy stuff. Early helicopters were powered by piston engines. You could use a bigger engine to get more power, but the weight of the engine increased faster than the improvement in power. It wasn’t until the invention of the gas turbine that lightweight, powerful helicopters became a reality.

A gas turbine is a jet engine that transfers its power to a drive shaft, instead of pushing air out the back. The first practical gas turbine powered helicopter was the UH-1B Iroquois, far better known as the Huey. Early in the Vietnam war, Huey’s began to be used to ferry troops to the battle, saving time that would otherwise be spent walking in the woods. Unfortunately, the VC learned that they could predict where the Huey’s would land, and soon began laying ambushes for them. The Huey’s were tough, capable birds, but they can only take so much damage. What was needed was an escort to keep the VC’s heads down while the Huey’s landed and offloaded their troops. The Army quickly developed an armed version of the Huey, equipping it with machine guns and 2.75” rockets, just the thing to discourage the VC from shooting at the transports.

While the new gunship escorts were a great improvement over nothing, they still weren’t perfect. The extra weight of the guns, rockets and ammunition actually left the escorts slower than the transports.

The Army and Bell Helicopter took the parts of the helicopter that they liked, such as the rotor, transmission and basic engine, and developed a specialized gunship. By using a more powerful version of the basic engine (and not many aviators will ever complain about having more power) and using the smallest possible body, they were able to introduce a chopper that was both faster than the transports and more heavily armed than previous gunships. The AH-1G would be the Army’s primary gunship in the Vietnam war. Over 1,000 were produced.

Armed with two 6-barreled 7.62mm Mini-guns and 2.75” rocket pods, the AH-1G Cobra had plenty of firepower to suppress the VC when transports were landing or taking off at an LZ. In addition, they were used to provide close support for troops on the ground. In fact, some units were used primarily for this and were designated Ariel Rocket Artillery Battalions. Many a grunt blessed the familiar “Whop-whop-whop” sound of a Cobra overhead.

After the Vietnam War, the Army turned its attention back to Western Europe. The Army was in bad shape and facing a truly massive Soviet army. With budgets tight, forces demoralized and equipment obsolete, how would the Army be able to defeat the Soviets and prevent them from conquering Western Europe. The Army had a large supply of Cobras on hand, but rockets and Mini-guns were next to useless against tanks and armored personnel carriers. The answer lay with the TOW missile. TOW stands for Tube Launched, Optically tracked, Wire-guided missile. With a range of 3000 meters and a warhead capable of destroying any tank, the 70 pound missile gave the Cobra the firepower it needed to be useful on the battlefields of Europe. A new 20mm three barreled cannon was also added to deal with targets like trucks.

[youtube=http://www.youtube.com/watch?v=e1_Tg1p5Xw0]

With this new, powerful anti-tank weapon, Army aviators began thinking beyond the front lines. By using the mobility of helicopters, they could search out and attack Soviet formations behind the front lines, before they were attacking our troops. In conjunction with the evolution of what would become AirLand Battle doctrine, the concept of “Deep Strike” came to be accepted. No longer would aviators be thought of as glorified truck drivers or simply flying artillery, but as Cavalry in the tradition of JEB Stuart and Nathan Bedford Forrest.

UPDATE:

BillT was kind enough to give me his thoughts on the subject (see comments) and better yet, send pictures!

Why are we here?

More than one US Army soldier in the Cold War looked at his map of Western Europe and wondered why the US Army, the anchor of the Nato Alliance, was stationed at one of the least likely invasion routes. The geography in the north of Germany is generally flat or low rolling hills, quite suitable to armored forces attacking from Poland and East Germany, where the bulk of the Soviet army was stationed.

In the south, the terrain was far more mountainous, with numerous chokepoints where attacking forces could be blocked, trapped, and destroyed. The primary Warsaw Pact Forces there were the Czech Army.

Given the importance of this terrain, why was the vast majority of the US Army in Europe stationed in the south, rather than in the north where the heaviest attack could be expected? The answer is a historical accident from 1940, and shows the tyranny of logistics over tactics.

In the summer of 1940, Nazi Germany was triumpant. They had conquered all of Western Europe from the Baltic to the Mediterrenian Sea. The only countries not under the Nazi thumb were a compliant Spain and tiny Portugal, both neutral countries, and that defiant lion, The United Kingdom. Following the fall of France in June 1940, the British Army was forced to retreat at Dunkirk and return to England. The British evacuation there will long live in the annals of history as a magnificent feat, but it was still a defeat.

The remains of the British Army were in bad shape. Most of their equipment had been abandoned in France. Just twenty miles away lay the victorious Wehrmacht. Already the German Army was laying plans for an autumn invasion of England. The British Army quickly moved to the southeast of England to defend against this planned invasion.

The Battle of Britain, where the Luftwaffe and the Royal Air Force fought a desparate struggle for command of the skies, took place over that summer and fall of 1940. The Germans knew that air superiortiy was needed for a successful invasion. They failed to achieve it. Still, the British were obliged to maintain a defense in southeast England lest the Germans try. While here, they began the process of re-equipping and rebuilding.

After the entry of the United States into the war in December 1941, Churchill and Franklin (and more importantly, their military staffs) both agreed that eventually, there would have to be an invasion of France across the English Channel. The US began moving forces into England. Since the southeast of England was full of British troops, most US forces were based in the west.

When the time for the invasion came, the decision was made to land in Normandy. Here is where the tyranny of logistics raised its ugly head.  Looking at the map below, we see that the US forces, stationed in the west, would be forced to land on the western side of the Cotentin Peninsula. The size of the invasion fleet was just too large to swap positions while at sea. The British would land in the east and the US to the west. When they broke out of the beachhead and wheeled to head east, that would place the British to the north and the US to the south.

After the invasion of Normandy, further US and French forces would invade southern France near Marseille, reinforcing the US position in the south.

While military planners would have preferred the heavier, larger, and more mobile US forces to attack across the north of Europe, while the smaller, less mobile British Armies made a supporting attack in the south, the delay, cost and confusion of trying to switch their positions made this impossible. Moving the forces might have been just barely possible, but there was no way to even attempt to move their huge logistical tails. The die was cast and the stage was set in stone. The disposition of forces would remain all the way across Europe to the defeat of Nazi Germany in May of 1945.

With the defeat of the Nazis, the vast majority of the Allied armies were demobilized and went home. Because so much of the German society had collapsed, however, significant occupation forces had to remain. Germany was divided into zones of occupation, with zones for the Russians, British, Americans, and French. Mostly these zones were where the forces had halted at the end of the war.

When the Iron Curtain fell across Europe in 1947, the Western Allies began to reinforce their positions in Europe, eventually forming NATO in 1949 (the Warsaw Pact wasn’t formed until 1955). By this time, it was too late to shift major forces to better suit the terrain, again primarily because of logistics. There was a political factor here though. If the US had tried to reposition major forces outside the US zone, the Soviets would have been able to protest that we were not abiding by the terms of the agreement. In fact, they could have argued that they should be able to move outside their zone as well, perhaps into the British or US zones. We certainly didn’t want that. Even after West Germany regained its sovereignity in 1955, it was logistically impossible to switch the positions of the major forces.

It is a fair guess that more than one US general, looking at the defense of Western Europe during the Cold War, cursed the fates that places the Allies in the positions they held. In fact, a large part of the development of AirLand Battle Doctrine was about flipping this geographical disadvantage on its head, and finding a way to use manuever to hide behind the terrain of southern Germany and strike into the flank of any Soviet attack to the north.

Apache Pron and YouTube

Believe it or not, the Army didn’t spend millions upon millions of dollars developing the Apache just so you could watch clips of it smokin’ jihadis on YouTube. Mainly because YouTube didn’t exist when they came up with it.

After the end of the Vietnam war, the Army found itself with old, obselescent and poorly maintained forces facing a massive Soviet Army in Western Europe. The need to recapitalize and re-equip the forces was great, but the defense budget was tight. Military spending was unpopular and the mood in the country was fairly isolationist. The Army was one of the least trusted institutions in the country. The leadership was faced with a problem familiar to managers and leaders everywhere- a huge task and very little in the way of resources.

The development of the Apache took place in this arena of limited budgets, and was a product not only of the state of the art in aerospace engineering, but also of changing ideas of how best to fight a war. As the development began, The 1973 Yom Kipur war showed just how violent and intense an armored battle could be. It also showed just how effective Soviet weapons could be. We tend to treat them with scorn now, but they were very effective in the Sinai, and fit in very well with the Soviet view of how to fight. Partly as a result of the 73 war, and a very comprehensive study of history, the Army developed the doctrine of Active Defense, which would later evolve into the AirLand Battle Doctrine. AirLand Battle was the governing view of “how to fight” from roughly 1982 to the end of the Cold War. It’s effectiveness can be seen in Desert Storm. The equipment that the Army bought in the 1970s and 1980s was designed with this doctrine in mind as well as the constraints of budget and engineering.

Doctrine drove the development of equipment. The Army looked at how it wanted to fight, then decided what it needed to fight that way. Knowing that there was a very limited pool of money, the were ruthless in aiming for what the NEEDED versus what they WANTED. This eventually boiled down to what became known as “The Big Five”: The M-1 Abrams tank, the M-2/M-3 Bradley Fighting Vehicle, The UH-60 Blackhawk transport helicopter, the Patriot air defense missile system, and of course, the AH-64 Apache attack helicopter.

The big problem facing US commanders on the ground in Western Europe was being outnumbered. A US division could expect to face up to nine Soviet divisions. The rule of thumb is that the attacker should bring three times the troops as the defender. The problem for the Soviets was that there wasn’t enough space to get all nine divisions into the fight at the same time. There just weren’t enough roads to move the divisions and supply them. Their answer was the “echelon attack”. The first echelon of three divisions would attack. If they broke through, fine. If not, they would pull back slightly while keeping pressure on the US forces. The second echelon would then pass through and make its attack. If that didn’t work, the third echelon would then take its turn. During each attack, they could expect to wear down the US division to the point that it collapsed. The question for the US was how to counter this. The answer was-timing. If the US could delay the follow up attacks by the second and third echelons, the US division would be in a position recover from the first attack, and even counter-attack to upset the Soviet efforts. The question became “how do we delay and disrupt the follow on echelons?” Artillery and rockets didn’t have enough range to reach that far behind the front. The Air Force would do its part by concentrating on targets like bridges, supply and fuel depots, and command posts. That left a middle ground from roughly 25-100 miles behind the front lines that the Army needed to be able to attack.

The solution was the attack helicopter and deep strike. Attack helicopters had been around almost as long as helicopters themselves. Previously, however, they had always been used in close support of the ground forces, like flying artillery, and tied to the units they were supporting.  Anyone who has seen Apocolypse Now remembers the choppers coming in over the beach and laying waste to the bad guys. The new concept was for the helicopter to act more like Cavalry, raiding deep behind enemy lines, popping up where least expected. Think JEB Stuart in the Civil War. Rather than one or two helicopters providing support to an infantry battalion, an entire battalion of helicopters (18 birds) would slip past the first echelon and attack the second and third before they could even get to the fight. They would sow confusion, concentrate on taking out commanders and headquarters, force the Soviets to react to us, rather than having us react to them. By carefully choosing when and where they attacked, they could influence not only when, but where the follow on echelons attacked. For instance, if the Soviets planned to attack by crossing a river, the helicopters could concentrate on attacking bridging vehicles, forcing the Soviets to choose another path.

The Army’s first attempt at a purpose built attack helicopter was the AH-56 Cheyenne. It was not a success. It was primarily designed to serve as an escort for transport helicopters, but the ability to fly fast for long distances also helped inspire the deep strike concept. After the failure of the Cheyenne, development of the Apache began in earnest. What was wanted was a long range helicopter that could survive considerable small arms fire, and packed a large punch, able to defeat any known enemy armor. The helicopter needed to be able to operate day  or night, or in bad weather. This lead to the development of the Apache’s TADS/PNVS (Target Aquisition and Designation System/Pilots Night Vision System). This used infrared sensors to allow the gunner to spot enemy vehicles and “paint” them with a laser designator. The pilots night vision system used was mounted above the TADS and moved separatley. This allowed both crewmembers to use night vision, even while looking in differnt directions. One of the “good ideas” incorporated was to allow the 30mm cannon to point where the pilot was looking. While the gunner was using the TADS to fire Hellfire missiles at enemy tanks, the pilot could engage any threats that got in close.

The Hellfire missile was developed in concert with the Apache. It has a range of about 5 miles so the Apache is outside the range of most anti-aircraft missiles and guns it would encounter. It’s warhead was large enough to defeat any known armor and since it was laser designated, it could be guided by the helicopter firing it, another helicopter, or a scout on the ground. The 30mm chain gun gave the Apache to engage soft targets like trucks without spending an expensive Hellfire missile. It also gave it good self-defense against troops and anti-aircraft guns. In addition, 2.75″ rockets could be used to attack soft targets and troops.

The best known use of the Apache performing a deep strike was on the opening night of Desert Storm. A force of eight Apaches, supported by four Air Force MH-53Js, attacked two Iraqi radar stations on the border to open up a corridor for Allied strike planes to slip through unobserved. Less well known were several deep strike missions performed by the Apaches of the VII Corps to attack Republican Guard brigades and “fix” them in place to be destroyed later by ground forces. They were so successful, by the time they were done, there was little left of the units to be destroyed.

Ironically, the Army has abondoned the deep strike mission for the Apaches. This is partly because there is little chance of US forces being so greatly outnumbered. Another major factor was the deep strike mission against the Medina Division on March 24, 2003. Thirty-three Apaches attacked the Medina Division near Karbala. Having learned their lesson in Operation Desert Storm, the Medina Division laid a clever “flak trap” that shot down one Apache, and damaged almost all the others. All the damaged Apaches were able to make it back home, but several were damaged beyond repair. The high cost of the mission wasn’t worth the results.

If you made it this far, many thanks. Here’s the payoff-

[youtube=http://youtube.com/watch?v=UOIsDJsH1kw]

A personal favorite:

[youtube=http://youtube.com/watch?v=jXvEy8leKpM]

And one more:

[youtube=http://youtube.com/watch?v=Og_qqzuj6xY]

Flying Tanks (yes, really)(well, sorta)

No, we aren’t going to drop a 70-ton M-1A1 tank using parachutes. But that doesn’t mean we haven’t had airborne tanks. I wouldn’t call any of them huge successes, but our main topic today, the M551 Sheridan wasn’t a complete flop, either.

[youtube=http://www.youtube.com/watch?v=50cpPAVoxJQ]

Airborne forces got their start in WWII. We’ve all seen the movies of paratroopers jumping into Normandy. One problem they had was a shortage of ways to defeat German armor and take out targets like bunkers and pillboxes. The bazooka went a ways toward this, but a tank would help a lot. The US and the British developed a very light tank called the M22 Locust that could be landed by glider or transported by plane. Arriving in service too late to see combat in WWII, it was also badly undergunned.

After WWII, the Army still tried to come up with lightweight tank for the airborne forces, but had little success. To have any success defeating armor meant a bigger gun. A bigger gun meant a heavier vehicle, and heavier vehicles couldn’t be airdropped. That was pretty much the state of affairs until missile technology entered the picture.

Instead of using a solid shot to penetrate enemy armor, the plan was to use High Explosive Anti Tank (HEAT) rounds. These use a warhead that focuses the explosion to “burn through” enemy armor. The velocity of the round doesn’t matter to the penetration. The effectiveness of a HEAT round is directly related to the diamater of the warhead. The larger the better. But that takes us back to the problem of weight. The solution was to sacrifice muzzle velocity and accept a slow flying round, since the velocity on impact didn’t matter. This made the gun effective at short ranges. Unfortunately, the problem of long range defense against tanks was still there. The Army solved this by using the same gun as a launcher for a guided missle. After a protracted (and not terribly successful) development, the gun and missile combination was finalized. The gun was a 152mm bore (about 6″) that could fire HEAT rounds for short ranges, and the MGM-51 Shillelagh guided missile.

The gun/missile combination was mated to a lightweight, aluminum hull (or chassis, if you will) that was capable of both being airdropped from a C-130 and of swimming. Production started in 1966 and vehicles soon began to equip the 11th Armored Cavalry Regiment in Vietnam, and other units soon thereafter.

While the system worked to some extent, most of the users weren’t very happy with it. The aluminum armor was easily penetrated, and vulnerable to mines. The Sheridan was also prone to breakdowns. By the mid-70s, most Cavalry units had phased it out. The 82nd Airborne Division, however, had nothing to replace it and so held on to theirs until 1996. The 82nd actually airdropped eight of them during the invasion of Panama, and deployed 51 of them to Operation Desert Shield/Desert Storm.

By the late 1970s, the Army had several hundred relatively new, but obsolete Sheridans on its hands. It had also just opened the National Training Center at Fort Irwin, near Barstow, CA, and needed lots of armor to simulate a Soviet regiment attacking across Western Europe. Many Sheridans were modified with sheet metal and fiberglass to give them a distinctive, somewhat Soviet look to play this part. They served very honorably in this role until 2003 when they were replaced by highly modified M-113s.

Update:

Because there were few enemy tanks in Vietnam, and the recoil of HEAT rounds tended to damage electronics on board, Sheridans deployed to Vietnam had their missile guidance packages removed. In addition to the HEAT round, they carried a cannister anti personnel round. You’ve seen a shotgun shell before. Now imagine one six inches across and about 2 1/2 feet long. This was a fearsome weapon when the VC or NVA attacked Sheridan units.

Tank Battles

I wrote earlier about bringing enough gun to the fight, but not too much. A prime example of this was the M-1 Abrams tank.

When this tank debuted, people were aghast at the cost. What they didn’t realize was it was acutally the result of an extreme cost cutting program. For 20 years, the Army had been cooperating with Germany to develop a sucessor to the M-60 series of tanks, but each iteration had become too complex and too costly. The Army finally decided that they would develop a tank using technology shared with the Germans rather than develop a tank to be used by both countries.

One of the sticking points was the main gun. The standard US tank gun was the 105mm M68. The Army thought this was sufficient to defeat current and projected Soviet armor (and were pretty much right).

The Germans had developed the excellent 120mm smoothbore, and wanted both countries tanks to use it. Our Army resisted for a couple of reasons. The biggest was cost. The new gun would have to be license produced here, with associated setup costs. Even more expensive would be providing stocks of ammunition for the gun. The Army had a huge stockpile of 105mm ammunition already. Buying an entirely new stockpile in the tight budgets of the 1970s wasn’t an attractive option.

In the end, the 105mm won-sort of. The decision was to place the M-1 into production with the 105mm, but make provision to add the 120mm in the future. As it turned out, for various reasons, this was a lot harder than anyone expected. Still, partly as a sop to our German allies, and partly over concern about the ability of the 105mm to defeat future Soviet armor, the 120mm was adopted for the M1A1 that entered service in 1988.

One disadvantage of the 120mm was a reduced ammo load. An M-1 with the 105mm carries 55 main gun rounds. An M-1A1 carries 40. As it turns out, however, few tanks will shoot their entire basic load in a single battle. In fact, not a single tank in Desert Storm fired its entire basic load.

Tankers, ever wonder why the coax on your tank has that massive 4000 round load? Because that’s where the designers originally wanted to put the 25mm M242. The only reason it didn’t make it into the final design was cost. Leaving the 25mm out saved about $100,000 just for the gun, and made the fire-control system simpler, and hence cheaper.