First Test: M1 Abrams – Motor Trend Magazine

News


We’re here to tug on the horns of the Abrams M1, to find out what it’s like to be inside 60 snarling tons of killer steel. The noise, I suspect, will be awful and the controls will certainly require at least three hands. But Colonel Sam Myers suggests that the M1 drive will have much more meaning if I first get the hang of the M60A3.

The M60 is a wizened, lumpy veteran that has been in service for nearly 30 years and, according to those who know it intimately, compares to the new M1 as hell compares to heaven. All I can do is accept this as fact, because the closest I’ve ever been to the steely beast is the movies.

After a short familiarization course, which I find hard to digest, I steer the M60 noisily around The Range, slowing and “accelerating” (a relative term, since the M60’s lop speed is only 30 mph) its 750-hp diesel as the course dictates. The tank commander (TC) and the gunner brace themselves while directing me over the helmet intercom. They don’t tell me how to drive, just warn of The Range’s lethal pitfalls. It is a matter of self-preservation. These men are part of a training unit that receives more than its share of bruised ribs and wrenched backs, thanks to the efforts of beginners. In the end, they say I’ve done better than most who aspire to the task.

A diesel is a diesel, and the M60A3 engine reacts no differently from your ordinary Peugeot 505. But the thought of thrashing the bejeezus out of the $1.6-million turbine engine M1 makes the top of my head tingle. Lieutenant Robert Wentzel, the tank commander, walks us around the skirted steel unconsciously interpreting its character with admiration and affection. A veteran of the M60, he is enamored of the M1’s capability. He has a right to be. He is a young car lover who appreciates the great leaps that automotive technology has taken in the last five years. To him, the M1 represents that same sophistication; it is the Mercedes-Benz of battle tanks.

Its turbine engine produces 1500 hp and its silhouette is nearly 2 ft. lower than the M60’s. Its maintenance schedule is half that of the old model. It has the latest in laser systems and a new suspension that can be field-fixed in about one eighth the time required for the M60. The M1, he says, is a safer tank for the TC and his crew (driver, gunner, arid loader).



View 3 Photos

I follow Wentzel like a vapor trail, trying to digest his input through a brain already soaked in anticipation. He explains the function of the seven 24-volt batteries packed into the Ml’s right rear quarter and the unbelievably heavy deck plates and the side armor that will blow off in the event of a direct hit. He moves so fast there is no time to write any of it down, but it serves to underscore his union with the machine and the importance of it to his mission.

Wentzel disappears into the M1’s inner sanctum, a tiny control room in the turret that he shares with the gunner and the loader. He tells me about the onboard computer, the laser sighting system, the self-sealing ammo bins, and the camaraderie of the M1’s close-quarters crew. It is all hard gray metal, white paint, and serious business in there. The only warmth seeps from the occupants and the soft glow of indicator lights.

“Of course,” says Wentzel, “you’re probably wondering what it’s like in the driver’s seat. Miller will check you out on that.”

Intuitively I sense that 21-year-old Spec. 4 Floyd Miller, the M1’s full-time shoe, has left a 450-cubic-inch something at home in North Carolina. He knows his piece from every angle and his orientation speech is deliberately repetitive. While he covers the important things two or three times, I squat on the deck next to him, nodding like a rear window shelf mascot. No need to watch the tach or gauges, we’ll keep you checked out, he tells me. The starter is on your right and so’s the light that goes on when the engine is ready to fire. That other toggle is for the smoke machine. Now, get down in there. My stomach does a slow roll as I lower myself shakily into the manhole.

The driver’s seat is actually a recliner, a cradle that swings on a gentle arc, placing the pilot in a semi-supine position. One need only pull a left-hand lever and apply his weight to make the seat slide into place. The cockpit is small but not crampy and it has few visual indicators. The driver makes his reference points from feel, experience, and an intimacy with the steel battle slave.

The transmission is automatic, with four forward speeds and two reverse (a low and high range that shifts by itself). The gear selector is in front of the driver. With thumb and forefinger I move it easily from one detent to another on its horizontal arc. Contrary to popular belief, the tank is not guided by twin sticks or any other kind of lever; the light, power-assisted steering is controlled by Vespa-like handlebars. At either end of the tiller are rubber handgrips. Power is applied by a twist of the wrist, just like it is for a motorcycle. Close to the floor and nearly between the driver’s feet is the brake.

The aroma of diesel pervades Miller’s lair.

“How do we see where we’re going?” I ask.

“Well,” says Miller, humor dancing in his eyes, “if this were a battle condition, you’d have to use the periscope. It’ll give about 200 degrees of visibility, plus you’ve got the eyes of the TC. But this ain’t no combat, so you can just stick your head out.”

Relief washes through me like the warm rush that follows a hooker of Wild Turkey.

“One more thing,” Miller warns, serious again. “Make sure to duck when the main gun comes around!”

My stomach does a slow roll in the other direction.

“Put the helmet on and check out your hookup with the TC.” The TC is always in the driver’s ear and in order for him to respond, he must push a small red button on the steering handlebars.

“We’re ready to roll,” Miller announces, as he uncoils from his crouch over the manhole.

“Can you hear me okay?” says the disembodied voice.

“Yup.”

“Can you hear me okay? Uhh…press the intercom button so I can hear you. “

“Crank her up and let’s get it,” urges the voice of the leader.

Freeze. How do we start this thing again? Come on, son, you’re a tanker now. Get with it.

Wentzel repeats the procedure before I have time to ask. I engage the switches and the big turbine whirrs easily to life. When you’re standing outside, the engine sounds like a gigantic vacuum cleaner, billowing waves of blast furnace heat with virtually no smoke. But in the driver’s foxhole, insulated by tons of metal, there is very little noise and no vibration.

Before we move an inch, Wentzel implores us to test the brakes. They’re hairy, he says, and will stop this load on a dime. He’s right, these things are touchier than the binders on a ’60 Lincoln. But when pressed lightly, they are faultless. The voice says to slide the selector to “D” and pull back on the throttle. Pull back hard. For a second, nothing happens. Then we lunge forward in a great whoosh of engine and brown talc. Compared to the diesel, the turbine’s power is very linear and very smooth. Shift the transmission to high; that’s the ticket. That way I only have to concern myself with steering, throttle, and, infrequently, the brake.

In one respect, the turbine is like the diesel. If power is diminished, there is a short lag until the turbine spins faster and builds it up again. Once the driver knows this, he can keep power at a usable level and still have nearly instantaneous wide-open throttle when he needs it.

Although the M1 has nearly 2 ft. of suspension travel, one cannot go slamming it into any ditch or string of humps as he might a Renault R5 Le Car. There is a finesse involved, one that comes not from driving the M1 but from that talent which marks the driver as being sensitive to the machine. After a few minutes practice and advice from the others, I have the tank moving well enough to craftily run a long dinosaur spine with nearly perfect rhythm, applying just enough steering and power to “float” the tank over the humps without disturbing its occupants.

Under full throttle, the turbine comes on like Godzilla, sending the transmission through its shift pattern and changing gears like a drag racer. The power is so clean, so pure, and so abundant that it can make one become almost manic. Then you remember that there are 60 tons along for the ride and you imagine the feeling of an elevator loosed from its cable, say 60 stories up with you in it, and discretion prevails.

The M1’s steering is very light and there is virtually no road feel as we ordinarily perceive it. An extremely low profile (for tanks, anyway) has established the M1’s center of gravity directly under the TC’s gluteus maximus. Couple this with ponderous weight and wide track and you have a vehicle that is nigh impossible to roll over. Really fast turns are out, but the M1 will take a new heading pretty much on command. An abrupt about-face requires that the monster be stopped. The rest is easy: Crank the handlebars all the way over, touch the brake, and pull on the power. The tank does the rest.

Although the driver is all but swallowed by sheets of olive-drab plate, the front of the M1 falls away rapidly, allowing safe and accurate nose-in parking. But parallel parking is out; nobody makes a rearview mirror large enough. The driver must rely on the temperament of the TC and his own peripheral vision because the great elephant-head turret blots out everything else. Here’s a for-instance: During the end of our run with the giant weevil gone berserk, a hoard of Russky tanks gets too close for comfort. We lay down a smoke screen to evade them, forgetting in our zeal to shut the fuel dump switch. We can’t see the smoke, but Wentzel and Miller can. A toggle next to the ignition must first be pulled out, then flipped to make the smoke machine work. When you do this, about a gallon of raw fuel hits the turbine’s 950-degree exhaust manifold, issuing a copious cloud of pure white smoke big enough to swallow 10 tanks.



View 3 Photos

On another part of The Range is a perfect place for high-speed time trials. The road is flat but interrupted in places by gouges deep enough to derail a speeding tank. Miller has driven us there, over some tricky terrain. He wheels the M1 like he’s driving a Corvette, backpedaling the throttle at just the right moment and then spurring it on as fast as his nerves will allow. He works the brake like it’s part of his body.

“She’ll do about 50 wide open,” drawls Miller. “And that’s with the governor. Without the speed control we’ve hit 70!” We whine down the straight with the turbine howling at our backs. Because the M1 has a such a large frontal area, it tends to reduce the air blast to your face to about half what it would be if you stuck your head out a car window. I’ll tell you, son, there’s nothing like it. The sun in your face, the wind in your hair, and bullets up your nose. Perched in the turret, I watch Miller charge straight at a long, vicious rut. At the last moment he smoothes the tank cleanly around and announces that the big girl is pounding her rubber-covered tracks as fast as she can. We all whoop when he lets a bucketful of fuel hit the exhaust. As he backs off the throttle and the tank slows almost to a stop, the spew begins to creep up over us.

Suddenly there are headlights in front of us, streaming through another, larger plume of dust. It is a string of armored personnel carriers probably bent on a more serious mission.

“Fun time,” clucks Wentzel. He barks an about-face and Miller wheels the M1 around on its axis.

“Okay, Miller, let ’em get a little closer and then lay one down!” The attack force clanks busily toward us, and soon we can see the features of the men jouncing along in the first armored vehicle.

The M1 surges through its gears, its turbine commanding a huge clot of dust. The open-top carriers are about SO yd. away when the white cloud gobbles them up.

We don’t know what psychic alleys one must pass through to become a tank lover, a gourmand of overweight machinery and claustrophobic quarters, but we know that he must be a little bit taken by the same madness that spurs a stuntman or high steel worker. What they do is ultimately a defiance of death, and through it one must somehow perceive one’s invulnerability.

This was only play for us and, at the time, so it was for the tank commander and his driver. But if they let it, the fear of real business could lurk as close to them as their dogtags. Tomorrow they could face the Russian frontier. But these men are betting against it. You can feel it in their eyes.

The Abrams M1: A new champ takes the field

As the Army’s primary ground-combat weapon, the Abrams M1 tank satisfies three requirements: It is capable of tremendous firepower; it is extremely mobile; and it presents, by sheer sound, a shock deterrent to the enemy. It was designed by the men who would use it rather than by a committee. The tankers and their mechanics love it. Some of the people in Lima, Ohio, feel the same way.

For the time being, all M1s are built at the Chrysler defense plant in Lima with civilian labor, under the auspices of the military. When the M60A3 is finally phased out of production in the Detroit tank plant, the sites will have a combined production of 150 M1s per month.

According to Colonel Sam Meyers (who is a ringer’ for Robert Duvall’s Colonel Kilgore in “Apocalypse Now”), the M1 can tangle with everything the Russians can send against it, including the new T-80 tank and its eventual offspring. The M1 will remain contemporary for at least 10 years, and has been designed accordingly. It is protective of its crew by nature. It has special armor plate, some of which will blow off during a direct hit so that the crew doesn’t take the brunt of the explosion. The fuel cells and main gun ammunition are compartmentalized, away from the crew. The M1 also has automatic fire detection and fire extinguishing systems as well as a solid-state digital computer and laser range finder. With 1500 smokeless horsepower on tap, the M1 gunner can fire accurately on the run, even while the driver takes evasive action. An improved suspension system consisting of seven road wheels, torsion bars, and rotary shock absorbers at the first, second, and last road wheels, is vital to the tank’s superb (for a tank) handling. By design, the suspension members are easy to repair in the field.

The M1’s firepower is formidable. At the core is the 105mm main gun (55-round magazine). There are two 7.62mm machine guns: One pivots coaxially next to the 105, while the other is lor the loader (11,400 rounds). Finally, there’s the tank commander’s weapon for all seasons, a .50-caliber kidney-disturber with 1000 rounds in the kitty.

The suspension system rolls out with rubberized road wheels and rubbercleated tracks. Jounce travel of 15 in. has been built in. Down-time in the field has been pared to the bone. A broken torsion bar, which is as long as the tank is wide, can be replaced in about 30 minutes; in the old M60, the same job look four hours.

As the driver turns the handlebars, a lot of silent hydrostatic activity is produced underneath. Tanks are steered when one track is made to go faster than the other — one is braked while the other is accelerated, and the tank turns on its axis to face a new direction. In M1 terms, this is a crude way to steer. The M1 has a system of planetary gears and wet clutches that transfers power from one side of the tank to the other, starting and stopping the tank’s tracks on demand. But there is so much fluid and componentry in between ground and handlebars that “road” feel is nonexistent.

The M1 is braked through two compatible, yet separate, systems that are capable of inducing .4-g deceleration. To lasso 60 storming tons in a mud field, you need much more than ordinary 4-wheel discs: You need the hydromechanical wonderfulness of oilcooled wet-plate discs. A series of them keeps the Abrams from reeling in too much territory with a light, almost car-like feel.

The M1 is accustomed to extremes. It was subjected to cryogenics to develop a cold-start system good down to -65 degrees, and it will keep running in the gummy sweat of a 125-degree rain forest. The tank has logged 35,000 miles in austere, dusty places. This used to be a problem with early models because the turbine tended to suck enough grit to make it stop working. Amphibious behavior is also an M1 capability. It can slither into something 7 ft. deep, engine compartment submerged, and the crew and powder will stay dry. The out-the-door sticker on this tanker’s dream is $1.6 million and rising. There will also be an upgraded version when 1984 rolls around. By then it will be called the M1E1, and will have the latest in main guns: a 120mm smoothbore cannon that will most likely fire more than conventional armor-piercing high explosives.

The power pack never needs an oil change, and it operates on No. 2 diesel (though jet fuel, leaded gas, or marine diesel will do in a pinch). The turbine-powered M1 can churn up at least 12,000 hideous miles without an overhaul. When the power pack must be taken out, it can be done in one hour (compared to four hours for a diesel) without special tools. All maintenance points are easy to reach, and the AGT 1500 has a modular construction that permits the replacement of individual sections instead of the entire engine.

Since Avco Lycoming is only on the threshold of tank turbine development, it is conducting a 30-month program it hopes will reduce battle-condition fuel consumption by 10%. In short, it will try to make more power more efficiently through improved components, better air flow, maximized internal heat buildup, and additional turbine cooling. The result should net 1750 hp — though the difference between “should” and “will” may be only a function of defense budget decisions yet to come.

The M1 power pack: 1500 hp and no pistons

A monstrous machine needs an engine of monstrous capability, so as the diesel powerplant reached its potential, the turbine engine and its inherent advantages could not be overlooked. Though the M1 is built by Chrysler, a company with considerable turbine experience, its gas turbine engine was developed by the Lycoming Division of Avco, located in Stratford, Connecticut.

Officially the engine is known as the AGT 1500. It is capable of 1500 hp at 3000 rpm (speed measured at power output shaft), twice that of a reciprocating engine. Although the AGT 1500 parallels other turbines in method of operation (simply, a vaned wheel is made to revolve by the product of combustion), it is a free-power turbine, which helps deliver more usable power to the drive sprocket. The AGT 1500 also possesses a recuperator. The recuperator recovers much of the exhaust gas that would be wasted in ordinary turbine operation, thus contributing to the M1’s overall economy.

The 1500 turbine has two idle speeds. “Normal” idle, 750 rpm, is used whenever the tank is not on maneuvers. In the field the turbine operates at “tactical” idle, which is 1300 rpm and closer to the turbine’s peak speed. The momentary throttle lag we complained about on The Range was due to a normal idle setting. At peak speed in low gear, when torque multiplication reaches 20:1, the turbine delivers an incredible 210,000 lb-ft. of torque to the drive sprocket! Power is transmitted directly, through a series of reduction gears, to log-sized halfshafts that connect to the sprockets.

The gas turbine weighs 2500 lb. but its bulk is compact, measuring 66 x 39 x 33 in. These dimensions make it a perfect mate for the smaller and more streamlined profile of the M1. If you were a mechanic, you’d never use “engine” or “turbine” to describe the powerplant. In that endless military jargon, the turbine is known as the power pack. And the keepers of the M1 tank love it.

M1 Abrams
General
Vehicle type Rear-engine, rear-drive, 4-pass, 3-door tank
Base price $1,600,000
Options on test vehicle None
POWERTRAIN/CHASSIS
Engine type Gas turbine
Bore & stroke N/A
Displacement N/A
Pressure ratio 13.6:1
Fuel system Single electronic fuel injector
Recommended fuel No.2 diesel
Emission control None
Valve gear None
Horsepower (SAE net) 1500 at 3000 rpm
Torque (lb-ft, SAE net) 3900 at 1500 rpm
Power-to-welght ratio 25 hp/ton
Transmission 4-speed automatic
Final drive ratio 4.30:1
Suspension, f/r Torsion bars, rotary shocks/torsion bars, rotary shocks
Steering type Hydrostatic, power assis
Turning circle, curb to curb 25.9 ft (pivots within its own length)
Brakes, f/r (N/A)/Oil cooled, wet-plate disc
Wheels 25 in. forged aluminum w/steel wear plates
Tires Goodyear solid rubber
DIMENSIONS
Wheelbase 251.8 in
Track, f/r 137/137 in
Length x width x height 384.5 x143.8 x 93.5 in
Ground clearance 19 in
Curb weight 121,300 lb
Weight distribution, f/r 69,820/51,480 lb
CAPACITIES
Fuel 498 gallons
Crankcase 7 gallons
Cooling system 7 gallons (engine); 14 gallons (transmission)
FUEL CONSUMPTION
U.S. Army “flat” road 1.85 gallons per mile
U.S. Army cross-country 3.50 gallons per mile
Driving range 280 miles at 30 mph, level surface
TEST RESULTS
Acceleration
0-20 mph 6.1 sec
0-30 12.5
0-40 22
0-45 31
0-50 45.0 (approx. )
Top speed 50 mph (governed)



Source link

Products You May Like

Leave a Reply

Your email address will not be published. Required fields are marked *