Not quite, the XM291 was actually a dual-caliber system. You could swap the 140mm tube out for the 120mm tube. I believe the 120mm tube was actually rated at around 1,000lbs lighter in comparison to the M256 overall.
The reason they wanted it to be a dual caliber tube is because they wanted to be able to retain the ability to use existing stocks of 120mm ammunition.
I’m pretty sure the 120mm version of the XM291 was even used on the 120mm M8 Enhanced Capabilities Demonstrator
That’s exactly what i’ve said, while the XM291 is dual-caliber system, TACOM had to hide the further development of the 140mm gun tube from 1991 and onwards, because the congress no longer wanted to give money for the 140mm gun tube and ammo development, only for the 120mm gun tube.
Just to clear it up for some ppl, some documents like the Finite Element Stress Analysis for Component Advanced Technology Test Bed (CATTB) suggests that the CATTB uses the 120mm gun tube but that’s not true, LW 120 is the “nickname” of the 140mm gun tube.
Correctly, the M8 Thunderbolt used the XM291, but with a shorter 120mm L/44 gun tube. Watervliet designed and tested with the ATAC System Demonstrator (Thumper) 3 different 120mm gun tubes for the XM291, L/56 (Long tube), L/44 (Short tube) and one between these two lengths (Medium tube).
The CATTB only ever used the XM291 with the 140mm gun tube, while Thumper tested 3 different 120mm gun tubes manned and the 140mm unmanned.
I will write an article about the CATTB and the Thumper with correct information since every single article, blog or website lacks information about them, the CATTB in some aspects is even more advanced than the Abrams X.
so one square meter is about 10.8 square foot. so 5.7x10.8=61.56lbs per square meter. 61.56lbs is about 28kg, so my estimation of 30 kg per square meter for only the kevlar wasn’t that far of :)
granted i added extra steel and mounting weight to that which probably would not be necessary.
but i’m a bit confused how they then got 1250lbs (about 567kg) as a total for just the turret.
that would mean an area of 567/28=20.25 square meters, for just the turret. that does not sound correct at all. lets say, 2m tall cylinder with 1m radius. that gives an area of roughly 2m length and 2m width and 2m height (which seams reasonable in my head).
the lateral area of a cylinder: 2πrh gives 2 x π x 1 x 2=4 x π= about 12.6 square meters to cover ALL the walls. lets say you want the roof as well, add π x r^2=π x 1= about 3.14.
so a total of 15.7 square meters.
admittedly larger than i thought but still only 3/4 of their total.
rough calculations done in head gets me to about 8-9square meters for the upper turret.
i looked further and the basket is 1.2m radius and about 1.2m high. so (again roughly) 9 square meters.
which makes things make more sense, a total of 18 square meters (from head-math). but then you probably don’t have liner everywhere since it has to be mounted around some stuff.
but yeah, bigger than i thought.
Another photo from book. It said:
Armor
Composite armor, similar to the British Chobham. The composite includes steel, depleted uranium sheets, ceramics and synthetic fibers. is the equivalent of 560 mm of steel armor on the front of the hul
yes. its text. sarcasm and text don’t go together and this forum is full enough of misinformed people that many might believe that you actually think what you write is true.
I said the v3 service date started in 2020, Ayeflyingcowboy said it started in 2018. He denied everything i showed him continuing to clam it was in service in 2018. What am i misconstruing? The service date is 2020.
