Progressively thicker armor was added to hull front and turret mantlet in various improved models.
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The Soviets modified the truncated cone turret used on the BTR-70 for the BTR-80 by redesigning the mantlet.
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Later, the M4 and M4A3 were factory-produced with a 105 mm howitzer and a new distinctive mantlet in the original turret.
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The T-54 had 200 millimetre of steel armor on the turret mantlet, far greater than the Verdeja 2's maximum armor thickness of 40 milimetres.
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This would have shown the gun could not penetrate the glacis plate of the Panther at any distance, and could only penetrate the center of the gun mantlet at 100 meters.
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The gap between the turret and hull was sealed with an inflatable hose while the main gun mantlet, commander's cupola and radio operator's machine gun were given special rubber coverings.
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Design work for a new turret started in March 1941 but Nuffield was not involved until late in the year when they adapted the existing turret with a new mantlet and hatch.
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Mantelet: portable bulletproof shelter
A mantlet was a large shield or portable shelter used for stopping arrows or bullets, in medieval warfare. A mantlet could be mounted on a wheeled carriage, and protected one or several soldiers.
A short sleeveless cloak or cape; A portable screen or other covering, especially as used to protect the approach of soldiers engaged in a siege
Detached fortification preventing direct access to a gateway; low outer wall.
A mobile wooden protective shield on wheels.
A large shield or portable defensive hoarding used in the field. Also known as pavise and setzscild.