Why Didn't the Tiger Tank Use Sloping Armor?

The Tiger I specifically did not employ sloping armor, primarily due to its design philosophy and operational requirements. Here are some key reasons:

Design Philosophy

The Tiger I was designed with the intent to provide heavy firepower and protection. The engineers prioritized thickness and vertical armor to withstand hits from enemy anti-tank weapons rather than the angled armor seen in other tanks like the Soviet T-34. This design philosophy led to a focus on maximizing defensive capabilities against direct hits from larger caliber shells.

Manufacturing Constraints

The complexity of sloped armor would have increased production difficulties. The German war industry was already facing challenges in producing tanks efficiently, and maintaining a simpler design helped streamline manufacturing processes. Complex sloped armor would have required additional manufacturing steps and potentially less reliable outcomes.

Weight Considerations

The Tiger was already a very heavy tank, weighing over 54 tons. Adding sloped armor could have increased its weight further, which might have impacted its mobility and operational effectiveness. Every ton of additional weight would have reduced the vehicle's speed and fuel efficiency, making it less practical for the battlefield conditions of the time.

Combat Doctrine

German armored doctrine at the time emphasized the use of heavy tanks in a support role, often in combination with infantry and other support units. The Tiger was meant to engage enemy tanks and fortifications directly, where thick vertical armor was deemed more effective for direct frontal protection. The emphasis on close combat and heavy firepower influenced the design choices made by German engineers.

Existing Design

The design of the Tiger I was already well underway before the advantages of sloped armor had been fully recognized in tank development. The Soviet T-34’s success in highlighting these advantages came too late for the Tiger I, which was already in production by then. This premature release meant that the Tiger I design had to adhere to the manufacturing and operational constraints that were set at the time.

Despite the known advantages of sloping armor, which include deflecting incoming rounds and increasing effective armor thickness, the Tiger I design choices reflected a different set of priorities that emphasized heavy direct frontal protection.

The Myth of Sloped Armor

People often believe that sloping armor is more beneficial because of the perceived increase in effective thickness. However, the line of sight thickness is exactly the same for a given height and weight of armor. In that sense, sloped armor doesn't inherently help with weight reduction.

Additionally, the effectiveness of sloped armor can be variable. Small caliber shells get deflected upwards within the armor and thus experience an effective thicker armor. However, large caliber shells experience a slightly thinner armor due to their nature. Sloped armor by itself often isn't sloped enough to significantly alter this effect. It requires the additional factor of the bearing angle of the tank to be effective.

Historical Context

During World War I, sloping armor was already known and implemented on battleships. Incoming rounds on a battleship usually come at steep angles, so both main-belt and deck armor would be sloped with respect to the incoming shell.

Early German tanks, being focused on mobility and firepower with armor as an afterthought, had relatively thin armor. Armor thicknesses of 20mm to 30mm in early German tanks meant that sloping the armor may not have provided much additional protection or could have even worsened the situation for these early models.

Practical Concerns

Sloped armor brings its own set of practical challenges. For example, on a boxy tank, it can become very difficult to make the roof dismountable so that crew members can access the inside compartment for maintenance tasks such as exchanging the gearbox or drivetrain. This would require significant modifications, increasing the complexity of the design and potentially leading to weaker points in the armor.

Weight distribution is also a significant issue. Sloping the armor down from the hatches to the front of the tank places the center of weight further back, which can negatively impact the tank’s stability and maneuverability. In contrast, a thick armor plate in front of the hatches keeps the center of weight closer to the front, improving weight distribution and overall performance.

Finally, it can be problematic to make bow machine ports and driver vision slits with sloped armor. These features can create weak points in the armor, making the tank more susceptible to hits. This is one of the reasons why the British stayed with vertical armor on the Cromwell and Churchill tanks, allowing them to create a stable and reliable driver position with a thick plug that is stable upon being shot. Sloped armor, in contrast, does not provide the same level of protection and ease of access.

Therefore, while sloping armor has its advantages, practical concerns and the weight and mobility considerations of the Tiger I delayed its adoption. The perceived advantages of sloping armor may not have been as enormous compared to the practical problems and operational constraints faced at the time.