President Patton Armor

Though the Russians are noted for building impressive tanks, an important aspect was numbers fielded. A Nazi King Tiger could dispatch six Soviet T-34’s for every loss. One Soviet response was to build 50,000 T-34/76mm’s just as the Americans fielded a comparable number of M-4 Sherman tanks.
 
Forty writes the 32-ton T-34/85mm carried a crew of five freeing up the tank commander to better guide movement and spot targets. The 85mm ZiS S53 main gun is very comparable to the famous Nazi 88mm and effective to 1000-meters. An aluminum 500-horsepower V12 diesel pushed the T-34 to 34 mph for 186-miles before needing to re-fuel. The T-34 stood nine-feet tall and had up to 90mm of armor compared to the M4 Sherman’s 50mm (143). In the historic Korean War, the T-34 proved well protected against the 2.36-inch M-1 bazooka and 57mm recoilless rifle.
 
Forty illustrates the Joseph Stalin III, the last Soviet heavy tank of World War Two, which didn’t see combat, but was displayed at the Potsdam conference ON September 7, 1945. The frontal armor of the JS III sloped to each side as well as down towards the front. The pointy glacis plate gave it the nickname ‘Pike’ after the large infantry spear that carried all before it (181).
 
Forty continues, the JS III boasted a 122mm D-25 cannon, which could penetrate 230mm (nine-inches) of opposing armor, and thick frontal armor. Despite that, the Joe Stalin III was only nine-feet, seven-inches tall and 46 tons. The low stature meant that the Soviets didn’t need to re-bore railroad tunnels and the JSIII was a smaller target on the battlefield than the ten foot tall Sherman. Russian tank crewmen were the shortest ten-percent of recruits. The JS III only carried 28-rounds for the main gun. The ammunition was carried in two parts which reduced the rate of fire to two per minute in the cramped turret (181).
A 520 horsepower V12 diesel propelled the JSIII at 23 miles per hour for 130-miles. Small internal fuel capacity was offset by large drums of fuel on the back deck of the tank. Stalin fielded 2,311 of his namesakes.
 
Forty tells us the Soviets invented the Main Battle Tank with the T-54 in 1948. The 35-ton T-54 combined the capable 100mm D10 main gun with a speed of 30 miles-per-hour and range of 250-miles (224). GDW relates the 100mm BR-412AP shell could penetrate 135mm (five-inches)of armor at 1000-meters (17). At seven-feet, 10.5-inches tall, the T-54 was even lower than the T-34. Crew size was reduced to four by using an automatic loaded. Tales of one-armed former Russian tankers are likely exaggerated. Maximum armor thickness of 203mm was over twice that of the sturdy T-34 and comparable to the American M-26/M-45.
 
Patton may have faced ‘only’ 8,000 T-54’s in late 1949. The T-54 lack gun stabilization until 1955 and developed a reputation for the magnesium engine catching fire on its own. This may be due to a lack of an early break-in oil change to remove metal shavings from new engines.
The Soviets transported infantry on the backs of their tanks during World War Two (The Great Patriotic War) and have not fielded battle taxis with overhead cover in 1949.
 
President Patton’s tanks were distinctly advanced in the matters of fuel, gun caliber and armor. Many tankers are concerned with the volatility of gasoline in combat. A bigger issue for Division commanders is diesel engines in tanks provide twice as much range. The ‘Red Ball Express’ was a herculean effort to transport fuel from Normandy beachheads to the front lines, which used quite a bit of fuel and manpower to operate. Lack of fuel led General Eisenhower to reduce fuel to General Patton in favor of British General Montgomery’s Market Garden campaign.
 
Historic tanks are rated by gun caliber, President Patton’s tanks are uniformly 105mm M4 howitzer. One Sherman tank in four was fitted with a 105mm at Normandy as a replacement for the M-7 Priest self-propelled gun. The M-7 was not adequately armored for the direct fire role against bunkers encountered in Italy. The WWII era 105mm M67 High Explosive Anti-Tank (HEAT) round had a penetration of 140mm (5 ½ inches). This was comparable to most other guns used on the Sherman. The British 17 pounder (75mm) achieved 186 mm penetration (7-inches) by use of a tungsten sabot round.
 
HEAT (high explosive anti-tank) rounds are also called shaped charge or hollow charge rounds. The explosive in a HEAT round has a dense metal cone (usually copper) with the wide mouth facing the target. The back is packed with high explosive. The igniter is at the rear and as the blast wave pushes forward, the cone is compressed into a high density pellet of hot metal traveling at thousands of feet per second. The hole it makes in armor is quite similar to long rod penetrators but remains as effective at all distances.
 
The front of the HEAT round has an aerodynamic cap that also holds the electric detonator switch for better standoff distance from the target armor.
 
Patton knew the shaped charge warhead had great potential. The 90mm M-20 super bazooka of 1944 was effective against 280mm (eleven-inches) of armor. The twisting imposed by rifled cannon distorts the penetrating jet of HEAT rounds. Patton’s research with cone geometry, cone material, standoff probes or explosives have improved the 105mm howitzer HEAT penetration to 200mm by 1949.
 
One reason for the 105mm howitzer in the heavy tank is crew survivability. Many WWII Sherman tanks would survive several hits on the way from Normandy to Berlin. It was the crew that would be washed out with a fire hose. Besides reducing the enthusiasm of tanker recruits, infantrymen replacements have less training and practice before combat in a tank.
 
Some M26 Pershing tanks were outfitted with 105mm howitzers in 1945. Tanks-encyclopedia tells us the 105mm weighed only 1,140-pounds while the 90mm gun weighed 2,260-pounds. The gun mantlet was increased from 4.5 to eight-inches thick to balance the turret. The turret was thickened to five-inches in front and sides as well. A post war study indicated that 90% of disabling hits on tanks were on the top three feet of the tank. The thicker armor of the 105mm turret was just the ticket for improved tank and tanker survival.
 
The heavy tank also benefited from the 105mm M-4 gyro stabilizer which, with a trained crew, allowed accurate firing on the move. The shorter barrel also would allow easier traverse movement in urban terrain and forests.
 
Upgunning the M24 Chaffee light tank to the 105mm M4 howitzer would provide benefits of ammunition commonality in a mixed tank unit where the Chaffee’s were relegated to scouting. The bigger gun would give stronger impact in airborne operations where the Chaffee might meet larger enemy tanks without the support of their big brothers. Fewer rounds at hand are a tradeoff.
 
Patton was concerned about the heavier recoil of the 105mm howitzer on the 18-ton chassis. The Chaffee might mount a muzzle brake and/or take advantage of the howitzers semi-fixed ammunition to reduce the number of charges below the maximum of six. The more modern example is the 20-ton Cadillac-Gage Stingray light tank firing the high velocity 105mm L7 NATO round once used by the M1 Abrams heavy tank.
 
Most artillery dating from the French 75mm fire with the barrel stationary, in battery. The barrel recoils back as the shell rushes downrange and is slowed by hydraulic cylinders and returned to the start position.
 
A soft recoil system starts with the barrel in a rear position. When fired, the barrel is allowed to travel forward and the propellant is ignited while the barrel is moving forward. Recoil must first slow the barrel to a stop before pushing it back to the starting position where it is retained.  
 
The President Patton M4 Dumbo tank is the most numerous in his tank park despite the rear-engine, front drive that raises the height if the turret. The PPM-4 is improved with diesel power train and improved armor suite based on historic battle damage.
 
Where the standard M4A1 has a maximum 75mm turret armor, the PPM4 inherits the heavy turret and applique glacis armor of the M4A3E3 ‘Jumbo’ assault tank. Chamberlain writes the Jumbo turret had 150mm (six-inches) of frontal armor (118). The heavier weight is carried on wider tracks. Eliminating the bow machine gunner adds stowage for the main gun above the standard 66 rounds of 105mm. The 50mm smoke grenade launchers are life savers when disengaging from the enemy.
 
The PPM-47 main battle tank gains great mobility by using a gas turbine electric drive. Electric transmissions are used in locomotives and heavy equipment because of the full torque electric drives provide at zero revolutions per minute. The U.S. Army tested diesel electric drives, in the 1940’s, but found the hydromatic transmission to be lighter weight and more reliable when paired with diesel or gasoline engines. The Abrams gas turbine, of the late 20th century, enjoys the smaller size and greater horsepower to weight ratio of the gas turbine but uses a transmission adapted from a helicopter.
 
Diesel electric transmissions suffer from the diesel’s slow 900 rpm. A gas turbine running at 3600 rpm pushes four times as much power from the same size alternator. The President Patton M-47 increases crew protection by mounting the engine up front. This was seen in a post-war Chrysler proposal. This allows an escape hatch to the rear, rather than dodging torsion bars under the tank’s hull.
 
Leg infantry and armored infantry units ride armored fighting vehicles adapted from WWII Sherman tanks. The turrets are removed and hulls are fitted with steel fragmentation resistant roofs. Fifty-caliber Browning machine guns provide anti-aircraft and anti-materiel performance. Super bazookas provide self-defense against tanks and can also be used against bunkers.
 
Air transported units get modified M-18 Hellcats capable of fifty-mile-per-hour speed. Some anti-tank capability is maintained with a recoilless rifle. The recoilless rifle can reach out a thousand yards with equal effectiveness due to shaped charge shells.

Next month will discuss President Patton's aircraft.  Rick