Here is an argument against the M1A2 SEPV3 having DU hull armor (or even any hull armor improvement beyond the M1A2) supporting Gaijin’s claim in [Development] Hull Armor of the M1 Abrams - News - War Thunder.
First, start with Gaijin’s favorite source: FMV’s comparative briefing “Skyddsnivå – utvärderingsunderlag strv Ny, 1994” produced when Sweden tested replacement tanks
This image suggests that the M1A2 hull has the same kinetic protection of 350mm as the 1980 original M1 Abrams (same case in game).
Next, consider the following images:
Using data from these images (in U.S. short tons) and subtracting the turret combat weight from that of the full vehicle to get combat weight of the hull:
- M1A2: (68.4-26.9)*0.9=37.6 (metric tons)
- M1A2SEP V3: (73.6-31.5)*0.9=38.2
It is then argued that the 600kg increase in hull combat weight is unlikely to be enough to accommodate DU hull or perhaps any upgrade in armor that would improve protection against kinetic rounds significantly than the M1A2 in all SEP variants.
How valid does this argument seem? It seems to exclude the possibility of DU hull considering the weight increase from M1A1 to M1A1DU of 2.4t. Although, the sources in the discussion here M1a2 SepV2 missing hull armor // Gaijin.net // Issues, the U.S. removed restrictions on storage and transportation of radioactive M1 hulls near the time of the sepv3’s introduction and there might be hull armor upgrades (even TrickZZter acknowledged this).
Gaijin’s argument of “overloading the first pair of torsion bars” sounds made up and unbased from seeing M1SEPV3 test vehicles running around with hull ballots and carrying mine-plows. There does not seem to be much information regarding m1 suspension capabilities.
Also, Gaijin’s reasoning here “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. 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.” is not necessarily true.
Find any ceramic composite armor analysis and the result could vary in a large range depending on the materials used, i.e. this graph in Performance of Ceramic-Composite Armors under Ballistic Impact Loading | Journal of Materials Engineering and Performance:
99.9% alumina with about half the areal density of zirconia achieves double the ballistic limit velocity against the same same projectile and for the armor setup (same ceramic thickness).
It is not possible to conclude that there is no improvement in kinetic protection just from no increase in volume and minimal increase in weight of the armor package.
M1 hulls have approximately 700mm of physical thickness, the in game KE protection of 350mm of equivalent RHA gives a 0.5 thickness ratio, which is quite low for modern composite armor (due to the massive presence of air in early M1 hull armor designs). Yet, all the next-gen armor upgrades all refer to the M1 front as a whole and never specifies for the hull and it is unlikely to find any declassified information regarding M1 hull armor composition to motivate Gaijin to make a change…
