[2023] Hull Armor of the M1 Abrams

A lil somethin somethin: You can find the details for this event on the announcement page here.

We’ve seen a lot of topics regarding the armor of the Abrams series of tanks, more specifically the presence of DU (depleted uranium) armor, and so we’d like to share our data on the subject.
Most sources on radiation safety clarify that the only threat to personnel is posed from armor packages in the cheeks of the turret. The M1A2 Abrams in War Thunder has uranium armor in the turret cheeks.


Source: The Medical NBC Battlebook, USACHPPM, 2011.[apps.dtic.mil]

We’re aware that several experimental vehicles of an unspecified modification of the Abrams were equipped with reinforced DU armor in the hull. However, even though armor was reinforced on these experimental variants, we have no sources that clarify which specific versions of the Abrams these were, and as such can’t confidently state that any of the Abrams versions we have in War Thunder received this specific hull armor reinforcement.


A section from a document describing the use of DU in five machines located in army schools. Source: Nuclear regulatory commission renewal license application for DU armor.[www.nrc.gov]

The documents presented in the reports we currently have don’t provide clear evidence of DU armor being present on the M1A2 SEP V1 or M1A2 SEP V2 modifications. A significant increase in mass which would accompany strengthening the armor with high-density fillers is also not observed in the SEP V1 or SEP V2 versions.


Weight changes of different M1 Abrams modifications. Source: An Independent Assessment of the 2040 Battlefield and its Implications for the 5th Generation Combat Vehicle (5GCV), Department of the Army Office of the Assistant Secretary of the Army, 2023[asb.army.mil]

Additionally, a significant weight increase from such an armor package would lead to overloading the first pair of torsion bars, which already are under an increased load on the M1 series due to the placement of the frontal armor being positioned significantly far towards the front of the hull, as well as the large armored fuel tanks either side of the driver.

The implementation of low-density mass-efficient fillers would inevitably require an increase in size, which is not observed on the serial modifications of the M1 Abrams.


An M1 Abrams series hull armor package demonstration with an additional armor screen that greatly increases the armor’s resistance. Source: "Svenskt pansar igår, idag och imorgon" by Rickard O. Lindström.[www.docdroid.net]

Therefore, the lack of reliable information regarding the increase of frontal hull protection in tandem with the lack of observable evidence (such as a significant increase in weight or size), does not allow us to assume that the frontal hull armor was strengthened with DU packages on the versions of the Abrams we have in game.

We’d also like to leave a comment on the sources that players cite as evidence about the use of depleted uranium for the M1A2 SEP.

Боевые машины Уралвагонзавода. Танк Т-72 (Combat vehicles of Uralvagonzavod. Tank T-72)
This book cannot be considered a reliable source, especially for modern Western vehicles. The authors wrote this book shortly after the SEP came into service, the written information is more speculation and guesses on their part. This book also contains errors for the characteristics of Soviet tanks in comparison to other open source data available.

MATERIALS LICENSE from U.S. NUCLEAR REGULATORY COMMISSION
Licenses to work with depleted uranium in the hull of the M1 Abrams series of tanks may apply to those experimental vehicles, for example 5 vehicles located at the tank school. These documents do not describe whether there was depleted uranium in a particular modification of the tank.

M1 Abrams Main Battle Tank, Owners' Workshop Manual
This publication does not directly indicate that the M1A2 SEP or M1A2 SEP V2 had depleted uranium armor added to the hull. Only general words that the changes achieved on the M1A1SA were implemented on the M1A2 SEP V2. In addition, this source is secondary; other independent secondary sources are also needed.

The Army's Future Combat Systems Program and Alternatives
Only the use of third-generation uranium armor is mentioned, but there’s no confirmation that this armor was located in the body of the M1A2 SEP, and what exactly the “third generation” consisted of.


Main changes with the M1A2 SEP modification. Source: The M1A2: Current and Future Program Plans, US Army Armor Center, 1997[apps.dtic.mil]

If we consider other projections, possible changes to the armor of the Abrams over its various modifications may not have directly resulted in an increase in the actual protection of the armor itself. These changes could rather have been aimed at increasing the armor filler’s survivability upon impact (which is an element not currently modeled in the game). Because of this, without hard numbers and solid facts confirming a tangible increase in protection, we can’t alter the protection currently offered by the armor on the M1 series.

However, this is not the end of our attention on the Abrams, as we’ll continue to look at all declassified and publicly available information we can regarding its protection — we fully appreciate the discussion. If in the future an increase in protection can be validated and corroborated from available sources, we’ll take action on it.

Thank you to everyone in our community for your attention on this topic and for all of the discussions you’ve brought forward, we hope that this devblog has managed to provide useful information and clarify our outlook on the Abrams currently.