Serge

Question of crew survivability after penetration and how to improve it was there at least ever since late 60s, or early 70s, based - among other things - on experience of Yom Kippur war of 1973 as it was percieved, because it was expected that WW3 would resemble something like that in intensity of fire and losses.

One could also look at M1 Abrams with its ammunition compartment and blow-off panels, - and some people did that IRL in late 80s during Bradley's survivability upgrade (A2) development. Infamous Col. Burton was involved in that, and also he - and Hunnicat , as well as some US Senate hearings and some reports - they do mention "Advanced Survivability Test Bed", a Bradley with compartmentalized ammunition and most of its fuel  on the outside, and Burton said that there was s question of whether it was possible to put TOW in some compartment away from the crew too.
 
Another thing about Bradley, and another one reason for ASTB mentioned by Burton was that in US Army' own studies on what to expect on the battlefield agains Soviets, infantry carriers like Bradleys and M113 were expected to suffer from enemy fire of all sorts - including tank 115/125mm KE rounds, including tank CE rounds, and also all ATGMs - completelly different from an idea that tank is №1 target for another tank and in battle IFV should not worry about being targeted by enemy tanks untill enemy tanks have destroyed all friendly tanks.
So one of the reasonable questions about ERA armor for A2 Bradley (providing protection against RPGs only, IIRC) was - that it is not nearly enough against all other treats expected on battlefield of war that could be called "pece-keeping" only in very special sense. Thus one needs measures to increase crew survivability after penetration.
/added another screenshot about ASTB - from Hearings of 1987/

Very interesting vehicle with impressive UFP LOS armor thickness even at preliminary project stage

OBM vol.3 p.342 says it was able to withstand some 122mm KE round, and provided protection against 600mm CE.
The thing is - there is a difference between drawings of preliminary project (p.227), and another drawing (p.341), with later having more sloped armor at around 74 degrees

which leads to even more impressive LOS thickness of 90,7 cm,
however I wish there was some better source for that than my measurements using those drawings scaled by their T-64 type roadwheels and 5TDF engine.
 
...
This thing also had sight cover doors, unlike some other russian vehicles of not-so-distant-past:

...
It also had some sort of periscopic device for commander (which, obviously, was located in hull and had rather limited observation via perisopes in his hatch)
here, protruding on the starboard side of the vehicle:

inside:


Upd:
btw, btvt.info's web version of OBM vol.3 article on 287 has same image in somewhat different quality. Upscaled:



And another thing i should've remembered earlier. Btvt.info's article on soviet ERA development history, among other things, talks about ERA which was tested in 1968 with 3 vehicles in mind - obj. 434 (T-64A), obj 775 and obj. 287. For some reason i've always forgot about 287.
Anyway, that article has this drawing of 287 ERA UFP (as anyone can see,  in very bad quality):

and it says that shape of composite armor UFP+LFP is also shown, and that it was taken from drawing of obj.287-50-assembly2. And that this ERA-hull configuration was tested against Falanga ATGM (IIRC 500mm CE) and was also able to protect against up to 800 mm CE treats. (Which leads to a question of whether composite armor version was tested, and able to withstand, against same treats or not)
Anyway, it shows that angle in question is 75 degrees,
and that alone would lead an UFP of 90+130+30mm to having a LOS thickness of about 96 cm.


...
Another interesting feature of 287 is that people in 1940s-1960s were not satisfied at all 
with the way all that slat armor and other means designed to increase standoff distance from shaped charge weapons
also increase vehicle's dimensions and could be torn away by obstacles.
So both in US and USSR there were some developments on how to fold those things when there are no imminent danger. Gill armor on T-72 is rather well-known, and described there https://thesovietarmourblog.blogspot.com/2017/12/t-72-part-2-protection-good-indication.html in length (in part "GILL ARMOUR")
but there were other things which were proposed, tested, and apparently rejected - and 287 got two of those.

There were some thin presumably metal sheets which look similar to some of the prototypes which were tested in early 60s and later apparently lead to "gill armor"


and even earlier 287 had some netted armor - made using steel wire -

which by the way was also proposed for preliminary project of Obj. 432 in 1961

 

https://andrei-bt.livejournal.com/1186187.html

 
 

I guess one has to ask Czech, Slovak or Polish army about that - whether they are unstable or not. Those armies have - for 40 years - Dana Vz.77 SPH on Tatra chassis, which is 2.5 meters wide when measured by wheels, exactly like KAMAZ truck. And its 3.3 meters high when measured from the ground to turret's top

BTW, reportedly Soviet Union borrowed some Danas in mid 80s for tests, and later even bought about 120 of them, although several years later during withdraval of Soviet army from former WarPac countries all those Danas were moved to Kazakhstan and later (in mid-late 90s) their turrets were scrapped.
 

Ever since early 80s Soviet Army also tried to develop some 8x8 howitzer on tactical truck chassis of its own, under designations of 2S21 Msta-K and 2S26 Pat-K, using Ural-5233, Kraz 4R-3120 (also known as ChR-3120) and KrAZ-6316 trucks as chassis. And while KrAZ trucks turned out to be 2,8 meters wide (they were originally intended to be 2.5 meters wide, but it turned out that it's impossible if one also wants some very wide tires for lower soil pressure and better trafficability), Ural truck was ~2.5 meters wide, when measured by wheels. Using those they made at least 4 different prototypes:

Ural-5233:



KrAZ chassis:



...
It seems to me that in case someone seriously wanted howitzer on tactical truck chassis, in Russian army of last 28 years, there was only one reasonable 2.7-3-meters-wide option - BAZ trucks.

German and U.S. military officials had planned, then canceled, a demonstration this week of the Bundeswehr’s Puma infantry fighting vehicle, as the U.S. Army surveys candidates for its Next-Generation Combat Vehicle program.  A German Army spokesman confirmed that an event had been scheduled at the Munster tank-training area for Jeffrey White, a deputy to U.S. Army acquisition chief Bruce Jette. White ended up canceling because of a scheduling conflict, the spokesman told Defense News.

Laser warning 

Picture is from czech military magazine(ATM), so it's possible that BAE could offer CV90 in that configuration for Czech Army. 

Forgot to post this earlier. Mk4 with MCT-30(v2).
 
 
 

 
 

£1.5bn is missing from the scheduled AFV budget according to reports and a Journalist has confirmed this with the MoD. However the MoD are quoted as saying that it isn't cut but "re-prioritised".
WCSP is speculated at £1.4-1.6bn and the final decision date should be this year. Hence why many think that WCSP has finally been cut.

The other possibility is L-ATV for MRV-P (Multi-Role Vehicle - Protected) Group 1 has been rejected by the Treasury.
L-ATV was selected by the Army without a competition on the belief that its $250,000 base price and massive US purchase meant that even with required modifications it would still be cheaper to buy and run than any other competitor.
However after some testing its rumoured to be too cramped for needed equipment. The modifications to make it UK road legal (right-hand drive) and desired protection levels have dramatically risen the average price to buy and run. Nearly all the work would be done in the US leaving little for UK industry.
Previously the Treasury wouldn't fund Piranha V for FRES UV in 2008 because for such a large deal the MoD hadn't negotiated export or IP rights. So the Army went to GD and demanded exclusive rights to Piranha V. Got told no and collapsed the deal. 

And read it once more. 
Just in case...

And read it once more. 
Just in case...

new DTR issue http://defencetechnologyreview.realviewdigital.com/#folio=1
with those renders:

@SH_MM If I had to guess, maybe it's kind of like why Uranium alloys won out in the US for penetrators? Abundance and ease of manufacturing. Staballoys are easier to extrude and turn on a lathe than Tungsten alloys, they can also be drawn and cold rolled with less difficulty. WC and WHAs are often both sintered into a near-net shape because of the difficulty of machining them. Comparing between Oak Ridge's guide to machining depleted uranium and Midwest Tungsten Service's machining guide for their MT series heavy alloys, with a density of 17 g/cm3, the tungsten alloy requires a higher spindle speed, a slower feed rate and a slightly shallower depth of cut on roughing. In the worst case for both metals (slowest spindle speed, slowest feed rate, shallowest cut depth), you can turn tungsten at about half the rate of Uranium on a lathe.
 
1" Uranium bar Roughing: 573 RPM, 0.012"/rev feed, 0.050" cut depth = 1.080 in3/min metal removal rate
 
1" WHA bar Roughing: 764 RPM, 0.008"/rev feed, 0.030" cut depth = 0.576 in3/min metal removal
 
WHA lets you go significantly faster than uranium on finishing however, again comparing the worst case scenarios for both metals we get
 
1" Uranium bar Finishing: 1050.423 RPM, 0.002"/rev feed, 0.002" cut depth=0.013 in3/min metal removal
 
1" WHA bar Finishing: 954.930 RPM, 0.004"/rev feed, 0.010" cut depth=0.120 in3/min metal removal
 
This is why WHA penetrators are manufactured as close to the finished shape as possible while Uranium penetrators can afford to be further off from the complete shape.
 
Tungsten Carbide is an absolute bitch to machine too, requiring specialized inserts like Polycrystalline Cubic Boron Nitride and cutting rates during roughing that approach the finishing speeds of Uranium
 
There is also another difference between the two materials that's worth noting, how they interact with the actual cutting tool. Uranium is frequently compared to austenitic steel in Oak Ridge's literature, described as being susceptible to work hardening and built up edges. Tungsten on the other hand varies between class 4 alloys which behave like a highly abrasive version of grey iron with a risk of chip hammering, to the less dense class 1 and class 2 alloys whose behavior is closer to Uranium.

As far as I am aware, Sweden was only inspired by the US to test DU armor themselves.
 
Original:
" Inspirerade av den valda skyddslösningen i den amerikanska stridsvagnen M1A1 DU där Chobhampansaret uppgraderats med skikt av utarmat uran, gjordes provskjutningar i Sverige även mot denna typ av material. Resultaten visade på möjligheten att nå bättre skyddsprestanda om volymen och inte vikten var gränssättande. "
 
English:
" Inspired by the american armor solution in the M1A1 DU main battle tank, in which the Chobham armor was upgraded with layer of depleted uranium, a test was conducted in Sweden of this type of material. The results showed that if was possible to increase armor protection if volume, but not the weight was the limiting factor. "
 
In short, they tested a home made armor, and concluded it was only worth it if volume was the constraint, not the weight. 
 
Source:
http://www.ointres.se/strv_2000.htm

Reactive liquid armor when?

It's add-on armor.

The USMC has their first JLTV now.