Good afternoon Sam.

Thanks for the extra tank pictures. ;-)

LOL. Hey, it's catching!

It sure is.

Good morning Matt!

LOL

Yer welcome.

I think this is the tank the GI Joe MBT was based on, it looks like an M60 with an oversized turret

MBT70
Dismal Failure or Technological Marvel?

In 1963 West Germany and the U.S.A. entered into a joint development agreement to build the "Tank of the Century" . It was to include all the available state-of-the-art technologies to allow it to serve to the end of the century. It was designated as the MBT70 by the U.S. and MBT/Kpz-70 by the West Germans. From the onset, there were significant disagreements as each side endeavored to protect its own defense industries by getting as large a piece of the pie as possible. Disagreement arose over such simple matters as the type of technical drawings and whether metric or SAE treads be used on fasteners in the tank. A compromise allowed the U.S. to use SAE while the Germans stayed with metric, requiring two different sets of tools for maintenance. By 1970 the partnership broke up after completion of a few pilot models. By that time costs had skyrocketed and the U.S. Congress cut off additional funds.

Both US. and German versions were produced which differed significantly. The engine in the U.S. version used the Continental AVCR air-cooled 120° V-12 variable compression diesel developing 1470 hp designed to operate on multi-fuels. The German version used the 12 cyl. MTU MB873 Ka water-cooled multi-fuel engine developing 1500 hp, which together with its drive train could be replaced in 15 minutes. Both engines complied with NATO's policy of being multi-fueled to reduce logistical problems in time of war. There were significant differences in the main armament as well. The U.S. version was equipped with a troublesome 152mm gun/missile launcher system which fired the 152mm M409 round with a HEAT anti-tank warheads. Even this round was unique in that it used a combustible cartridge case. This launcher could also fire a missile which when launched fired off its rocket motor to reach speeds in excess of 2600 mph . It had an effective range of 5700 yds. It was guided by an IR beam controlled by the gunner. Development of this Shillelagh missile system was plagued with problems in both the M551 Sheridan and the M6OA2.

The Germans were skeptical of this system and designed a second turret equipped with the Rheinmetall 120mm gun. The MBT design included an autoloader in both versions in order to reduce crew size to 3 and reduce the height of the hull . All 3 crew members were situated in the turret with the driver in his own independent counter-rotating cupola which was designed to face forward regardless of the position of the turret. This proved to be a major problem as drivers complained of disorientation and motion sickness. One advantage of the location was that it was close to the center-of-gravity, giving the MBT70 a superior ride performance by reducing the vertical pitch input to the driver. This reduced pitch input to the driver allowed him to drive at higher speeds before the dynamic ride level he experienced exceeded the US Army's limit of 6 watts of average absorbed power in the vertical direction. This permitted cross country speeds much better than the M60A2 in tests carried out at the APG facility. In 1969, tests of the MBT70 vs. the M60A1E2 (M60A2) were conducted at APG. Both tanks were equipped with a 155mm gun/launcher. The longer barrel of the MBT70 allowed it to fire hypervelocity KE ammo. In bridging tests, vertical obstacle tests, the MBT70 was clearly superior. It was 3 times faster on the 60% grade and in the acceleration it reached 30 mph in 18 sec. vs. 43 sec. for the M60A2. Cross- country tests in various terrains showed the MBT70 to be clearly superior. In simulated combat exposure tests, the MBT70 had 1/3 less exposure time than the M60A2 and was 30% faster on a 6-mile course. The study concluded that the MBT70 was superior in every aspect tested. Its higher hp gave better speed and acceleration and its variable hydropneumatic suspension enabled it to take advantage of its powerful engine for greater speeds over rough terrain and yet crouch lower than the M60A2 in a defilade position to reduce target area. The engine and suspension appeared to be the decisive factors in the unusual record-setting performance of the MBT70 during these comparisons.

This tank was and still is very impressive. It is 29' 8" long with gun forward and only 7' 5" at normal operating height and 11' 15" wide. The thick gun mantlet and huge sloping turret are very impressive. The turret was equipped with a pop-up gun mount carrying a remote controlled 20mm cannon. Eight single-barreled smoke grenade launchers were mounted on each side of the turret.

Another innovation on this tank was the complex variable height, Teledyne Continental Model 2812 dual piston hydro pneumatic suspension system , which enabled the tank to drop its overall height to reduce its silhouette in a static firing position. It could drop to a clearance of only 4.5 inches and then to rise for cross country mobility with a maximum clearance of 28 inches. This was an engineering and mechanic's nightmare with leaks and problems. The controls permitted an adjustment of front/rear, left/right or any combination thereof.

The turret was fully stabilized; the tank was equipped with a laser range finder, a ballistic computer, environmental control / life support system, night sights, spaced armor and advanced power train. The quality control assurance and reliability were set at a standard never before realized.

The MBT70 embodied such excellent safety features as spaced armor to defeat incoming rounds, with bulkheads, fireproof doors and blow-out type sections in the ammunition storage area to minimize crew injury when a hit was received. Self-sealing fuel tanks were also included. The MBT70 could travel 400 miles on 400 gallons of fuel, ford an 8-foot deep stream and climb a 70% grade or cross a 9-foot trench. The combat weight was 105,273 Ibs. or 52.6 tons.

The first prototypes were presented simultaneously in both Germany and the U.S.A. in July 1967. Technical problems abounded and delays and costs skyrocketed. At that time the cost of a single MBT70 was estimated at U.S. $1 million, whereas an M60A2 cost about $220,000. Congress grew increasingly restive after spending more than $400 million in R&D and in 1969 denied any further funds. The Army made a valiant attempt to salvage the program with the XM803 less expensive version incorporating many of the desirable features of the MBT70. Six were to be built. Instead, an MBT70 was converted to XM803 specifications and this prototype still exists at Fort Knox, Kentucky.

When the joint project disintegrated, both countries began to work on austerity versions of the Main Battle Tank to utilize some of the advanced technology developed. The American prototype was designated initially as the XM815 but later designated as the XM1 which eventually became the M1 Abrams.

The Germans developed the Leopard 2(AV) which was sent to Aberdeen where it was evaluated versus the XMl prototypes. In January 1977, the U.S. formally announced it had selected the XMl over the German Leopard 2 prototype, not an unexpected decision.

Was the MBT70 born premature? The technology employed was new and experimental with major design flaws and overruns. The problems encountered incorporating so many new systems widened the gap between the partners. Joint ventures always result in differences between the partners and this one was no different. Some differences were minor, but others were major such as the American insistence on using the ill-fated Shillelagh system while the Germans wanted the flexibility of a projectile firing cannon. Interestingly, the Rheinmetall 120mm cannon was later adopted for the Abrams M1A1 tank. This program showed what a modern tank would cost. The XM1 program that followed cost more than the projected costs of the MBT70, even without all the high tech features.

The MBT70 on this web site and the specimen exhibited at Aberdeen are still very popular with visitors. Thomas M. Tencza

Plus I scared the hell out of the dogs

Your coffee and booze!!!!!! I don't think I'd survive.

LOL. And I was thinking that is what it was missing. Sure would make it go down easier, or at least I wouldn't care. ;-)

Here's an engineer's explanation for how the thing works.

The raised portion of tha barrel is a bore evacuator. As the round passes it, ports in the barrel pressurize the cylinder around the barrel. As the round exits the barrel, the pressure in the evacuator is released by angled ports that point toward the muzzle. The flowing gas from the evacuator pulls propellant gases away from the breach and keeps them from entering the turret.

Good afternoon tanker, thanks for answering PE's question. I'm starting to like these things.

I think the M109 SP howitzer has a bore evacuator.

M1A1 / M1A2 ABRAMS MAIN BATTLE TANK, USA

The M1A1/2 Abrams main battle tank is manufactured by General Dynamics Land Systems (GDLS). The first M1 tank was produced in 1978, the M1A1 in 1985 and the M1A2 in 1986. 3,273 M1 tanks were produced for the US Army. 4,796 M1A1 tanks were built for the US Army, 221 for the US Marines and 555 co-produced with Egypt. Egypt has ordered a further 200 M1A1 tanks with production to continue to 2005. 77 M1A2 tanks have been built for the US Army, 315 for Saudi Arabia and 218 for Kuwait. For the M1A2 Upgrade Program, over 600 M1 Abrams tanks are being upgraded to M1A2 configuration. Deliveries began in 1998.

M1A2 SYSTEM ENHANCEMENT PACKAGE (SEP)

In February 2001, GDLS were contracted to supply 240 M1A2 tanks with a system enhancement package (SEP) by 2004. The M1A2 SEP contains an embedded version of the US Army's Force XXI command and control architecture; new Raytheon Commander's Independent Thermal Viewer (CITV) with second generation thermal imager; commander's display for digital colour terrain maps; DRS Techologies second generation GEN II TIS thermal imaging gunner’s sight with increased range; driver's integrated display and thermal management system. The US Army planned to procure a total of 1150 M1A2 SEP tanks but the US Army has decided to cancel future production of the M1A2 SEP from FY2004.

Under the Firepower Enhancement Package (FEP), DRS Techologies has also been awarded a contract for the GEN II TIS to upgrade US Marine Corps M1A1 tanks. GEN II TIS is based on the 480 x 4 SADA (Standard Advanced Dewar Assembly) detector.

M1 ABRAMS ARMAMENT

The main armament is the 120mm M256 smoothbore gun, developed by Rheinmetall GmbH of Germany. The 120mm gun fires the following ammunition: the M865 TPCSDS-T and M831 TP-T training rounds, the M8300 HEAT-MP-T and the M829 APFSDS-T which includes a depleted uranium penetrator. Textron Systems provides the Cadillac Gage gun turret drive stabilisation system.

The commander has a 12.7mm Browning M2 machine gun and the loader has a 7.62mm M240 machine gun. A 7.62mm M240 machine gun is also mounted coaxially on the right hand side of the main armament.

DEPLETED URANIUM ARMOUR

The M1A1 tank incorporates steel encased depleted uranium armour. Armour bulkheads separate the crew compartment from the fuel tanks. The top panels of the tank are designed to blow outwards in the event of penetration by a HEAT projectile. The tank is protected against nuclear, biological and chemical (NBC) warfare.

One L8A1 six-barrelled smoke grenade discharger is fitted on each side of the turret. A smoke screen can also be laid by an engine operated system.

FIRE CONTROL AND OBSERVATION

The commander's station is equipped with six periscopes, providing 360 degree view. The Raytheon Commander's Independent Thermal Viewer (CITV) provides the commander with independent stabilised day and night vision with a 360 degree view, automatic sector scanning, automatic target cueing of the gunner's sight and back-up fire control.

The M1A2 Abrams tank has a two-axis Raytheon Gunner's Primary Sight- Line of Sight (GPS-LOS) which increases the first round hit probability by providing faster target acquisition and improved gun pointing. The Thermal Imaging System (TIS) has magnification x10 narrow field of view and x3 wide field of view. The thermal image is displayed in the eyepiece of the gunner's sight together with the range measurement from a laser rangefinder. The Northrop Grumman (formerly Litton) Laser Systems Eyesafe Laser Rangefinder (ELRF) has a range accuracy to within 10m and target discrimination of 20m. The gunner also has a Kollmorgen Model 939 auxiliary sight with magnification x8 and field of view 8 degrees.

The digital fire control computer is supplied by General Dynamics - Canada (formerly Computing Devices Canada). The fire control computer automatically calculates the fire control solution based on: lead angle measurement; bend of the gun measured by the muzzle reference system; velocity measurement from a wind sensor on the roof of the turret; data from a pendulum static cant sensor located at the centre of the turret roof. The operator manually inputs data on ammunition type, temperature, and barometric pressure.

The driver has either three observation periscopes or two periscopes on either side and a central image intensifying periscope for night vision. The periscopes provide 120 degrees field of view. The DRS Technologies Driver's Vision Enhancer (DVE), AN/VSS-5, is based on a 328 x 245 element uncooled infrared detector array, operating in the 7.5 to 13 micron waveband. A Raytheon Driver's Thermal Viewer, AN/VAS-3, is installed on the M1A2 Abrams tanks for Kuwait.

PROPULSION

The M1 is equipped with a Honeywell AGT 1500 gas turbine engine. The Allison X-1100-3B transmission provides four forward and two reverse gears. The US Army has selected Honeywell International Engines and Systems and General Electric to develop a new LV100-5 gas turbine engine for the M1A2. The new engine is lighter and smaller with rapid acceleration, quieter running and no visible exhaust.

Since today is Treadhead Tuesday, I guess the obvious choice would be a "Tank Buster" aircraft.

Air Power
A-10/OA-10 "Thunderbolt II"

The A-10 and OA-10 Thunderbolt IIs are the first Air Force aircraft specially designed for close air support of ground forces. They are simple, effective and survivable twin-engine jet aircraft that can be used against all ground targets, including tanks and other armored vehicles. The primary mission of the A-10 is to provide day and night close air combat support for friendly land forces and to act as forward air controller (FAC) to coordinate and direct friendly air forces in support of land forces. The A-10 has a secondary mission of supporting search and rescue and Special Forces operations. It also possesses a limited capability to perform certain types of interdiction. All of these missions may take place in a high or low threat environment.

The A/OA-10 aircraft was specifically developed as a close air support aircraft with reliability and maintainability as major design considerations. The Air Force requirements documents emphasized payload, low altitude flying capability, range and loiter capability, low speed maneuverability and weapons delivery accuracy. The A-10 is slow enough to be an observation plane. This greatly increases the A-10's effectiveness at protecting ground troops.

The A/OA-10 is a single place, pressurized, low wing and tail aircraft with two General Electric TF-34-100/A turbo-fan engines, each with a sea level static thrust rating of approximately 9000 pounds. The engines are installed in nacelles mounted on pylons extending from the fuselage just aft of and above the wing. Two vertical stabilizers are located at the outboard tips of the horizontal stabilizers. The forward retracting tricycle landing gear incorporates short struts and a wide tread. The nose wheel retracts fully into the fuselage nose. The main gear retracts into streamlined fairing on the wing with the lower portion of the wheel protruding to facilitate emergency gear-up landings.

The A-10's survivability in the close air support arena greatly exceeds that of previous Air Force aircraft. The A-10 is designed to survive even the most disastrous damage and finish the mission by landing on an unimproved airfield. Specific survivability features include titanium armor plated cockpit, redundant flight control system separated by fuel tanks, manual reversion mode for flight controls, foam filled fuel tanks, ballistic foam void fillers, and a redundant primary structure providing “get home” capability after being hit.

All of the A-10's glass is bulletproof and the cockpit itself is surrounded by a heavy tub of titanium. Titanium armor protects both the pilot and critical areas of the flight control system. This titanium "bathtub" can survive direct hits from armor-piercing and high explosive projectiles up to 37mm in size. The front windscreen can withstand up to a 23mm projectile. Fire retardant foam protects the fuel cells which are also self sealing in the event of puncture.

The redundant primary structural sections allow the aircraft to enjoy better survivability during close air support than did previous aircraft. Designers separated all of the crucial battle and flight systems. The wheels can roll in their pods, which lets the plane perform belly landings without significant damage to the aircraft. Dual engines are mounted away from the Warthog's fuselage; if one is destroyed, the other can propel the craft to safety. Dual vertical stabilizers shield the hot exhaust from Russian-designed heat seeking missiles. The A-10 has two hydraulic flight control systems, backed up by a manual flight control system. This redundancy allows the pilot to control a battle damaged aircraft, even after losing all hydraulic power. Furthermore, redundant primary structural and control surfaces enhance survivability. Lastly, the long low-set wings are designed to allow flight, even if half a wing is completely blown off. No other modern aircraft -- including the F-16 -- can survive such punishment. The wings themselves are set low to allow for more weaponry to fit beneath the aircraft.

The General Electric Aircraft Armament Subsystem A/A49E-6 (30 millimeter Gun System) is located in the forward nose section of the fuselage. The gun system consists of the 30mm Gatling gun mechanism, double-ended linkless ammunition feed, storage assembly and hydraulic drive system. The General Electric GAU-8/A 30mm seven barrel cannon, specifically designed for the A-10, provides unmatched tank killing capability. The gun fires armor-piercing projectiles capable of penetrating heavy armor. It also fires a high explosive incendiary round, which is extremely effective against soft skinned targets like trucks. The cannon fires at a rate of 4,200 rounds per minute. The A-10's maneuverability, teamed with the gun's accuracy, allows the pilot quick reaction with lethal effects. Other weapons include the AGM-65 Maverick and AIM-9 Sidewinder missiles.

Thunderbolt IIs have Night Vision Imaging Systems (NVIS), compatible single-seat cockpits forward of their wings and a large bubble canopy which provides pilots all-around vision. The ACES-II ejection seat safely operates from 518 miles per hour down to zero speed and zero altitudes.

Avionics equipment includes communications, inertial navigation systems, computer-aided fire control and weapons delivery systems, electronic countermeasures, target penetration aids and self-protection systems. The A-10 employs both electronic and infrared countermeasures against enemy weapons systems. The weapons delivery system incorporates a heads-up display that provides the pilot with references for flight control and weapons employment. The weapons delivery systems include head-up displays that indicate airspeed, altitude and dive angle on the windscreen, a low altitude safety and targeting enhancement system (LASTE) which provides constantly computing impact point freefall ordnance delivery; and Pave Penny laser-tracking pods under the fuselage.

The A-10/OA-10 have excellent maneuverability at low air speeds and altitude, and are highly accurate weapons-delivery platforms. The A-10 has half the turning radius of the Air Force's other primary CAS aircraft, the F-16. After initially leaving a target, the A-10 can turn around and hit the same target again, all in around 7 seconds. Due to its large combat radius, the Thunderbolt II can loiter for extended periods of time, allowing for the coordination required to employ within yards of friendly forces. They can operate under 1,000-foot ceilings (300 meters) with 1.5-mile (2.4 kilometers) visibility. Using night vision goggles, A-10/ OA-10 pilots can conduct their missions during darkness. The A-10s highly accurate weapons delivery system makes it effective against all ground targets including tanks and other armored vehicles.

The aircraft is capable of worldwide deployment and operation from austere bases with minimal support equipment. Their short takeoff and landing capability permit operations in and out of locations near front lines. In addition to its survivability, the A-10 has the ability to land on unimproved airfields and be flown and maintained near Army ground troops. Highly effective and efficient in combat, the A-10 is capable of sustaining operations on unimproved airfields near ground troops -- keys to success in conducting small operations against hostile forces. The A-10's rapid re-fueling and re-arming capability allows it to operate from forward bases close to the front lines. It is also capable of refueling in the air.

Specifications

Primary Function

A-10 -- close air support, OA-10 - airborne forward air control

Contractor

Fairchild Republic Co.

Power Plant

Two General Electric TF34-GE-100 turbofans

Thrust

9,065 pounds each engine

Length

53 feet, 4 inches (16.16 meters)

Height

14 feet, 8 inches (4.42 meters)

Wingspan

57 feet, 6 inches (17.42 meters)

Speed

420 miles per hour (Mach 0.56)

Ceiling

45,000 feet (13,636 meters)

Maximum Takeoff Weight

51,000 pounds (22,950 kilograms)

Range

800 miles (695 nautical miles)

Armament

One 30 mm GAU-8/A seven-barrel Gatling gun;

up to 16,000 pounds (7,200 kilograms) of mixed ordnance on eight under-wing and three under-fuselage pylon stations, including infrared countermeasure flares; electronic countermeasure chaff; jammer pods; 2.75-inch (6.99 centimeters) rockets; illumination flares and:
MK-82 (500 pound bomb)
MK-84 (2000 pound bomb)
MK77 incendiary
10 MK20 Rockeye II (4 - 6 standard load)
10 CBU-52 (4 - 6 standard load)
10 CBU-58 (4 - 6 standard load)
10 CBU-71 (4 - 6 standard load)
10 CBU-87 (4 - 6 standard load)
10 CBU-89 (4 - 6 standard load)
CBU-97
10 BL755 (4 - 6 standard load)
AGM-65 Maverick missiles
GBU-10 laser-guided bomb
GBU-12 laser-guided bomb
AIM-9 Sidewinder missiles

MK	AGM	CBU	CBU	CBU	2.75	GBU	AIM	LUU	LUU	30
82	65	87	89	97	RX	12	9	1	2	MM
12							2			1000
	4						2			1000
6	2						2			1000
	2	4					2			1000
		6					2			1000
	2		4				2			1000
			6				2			1000
				6			2			1000
	2				14		2	8	8	1000
	4				14		2	8	8	1000
	2					4	2			1000

Systems

AN/ALE-40
AN/ALQ-119

Crew

One

Date Deployed

March 1976

Unit Cost $FY98
[Total Program]

$13 million

Inventory


                A-10   OA-10
Active force      72      72
Reserve           24      12
ANG               64      30

Battle-Damaged A-10

The images below are of an A-10 Thunderbolt II which took part in Operation Iraqi Freedom. According to an ACC news article, during a mission over Baghdad, this aircraft encountered enemy fire. Despite suffering visibly significant battle damage, the aircraft was nonetheless capable of being sucesssfully flown home.

All information and photos Copyright of Global Security.Org

My guess would be they put them on anything that has an enclosed crew position.

Much obliged CT.

All 3 crew members were situated in the turret with the driver in his own independent counter-rotating cupola which was designed to face forward regardless of the position of the turret. This proved to be a major problem as drivers complained of disorientation and motion sickness.

Okay, I'm confused. If the idea was to have the driver always face forward, why would he need to be in his own rotating cupola. Why would it rotate? What am I missing in the explanation. (no wonder they got dizzy)

Thanks for any enlightenment.

Thanks for the MBT-70 history! I remember I got a kick out of the "crouch" feature, but that system would have been a nightmare to try to maintain.

Air filters for what system?

Good afternoon, Snippy! Tanks are way cool. You know you're hooked when you enjoy following a diesel truck because the smell reminds you of an M60A1.

The Abrams.