The Object 187 (Объект 187) was a Soviet experimental main battle tank developed between the late 1980s and middle 1990s. It remains a relatively unpublicized development because of high levels of secrecy surrounding the project. The tank was fitted with cutting-edge systems and structural solutions, losing many of the traditional shortcomings of Soviet tanks. Originally the design was intended to be only a temporary solution before the development of new combat platforms. Object 187 was a parallel project to Object 188, the T-90 tank. It was based on the T-72B, with a heavily modified turret. A particularly notable feature was the rejection of the T-64 hull design. The redesigned layout took up more space, but positively affected ergonomics and protection from the glacis plate. Due to lengthening of the hull's nose section, the driver's position was lower, with his optics attached to the roof of the hull, unlike in the T-64 and its derivatives. This remedied a notorious weak spot of the T-64 design - the section between the turret and the hull. The same solution made it possible to arrange armoring at more rational angles of inclination as a countermeasure to modern sub-caliber armour-piercing rounds. The tank was fitted with a new welded turret, unlike traditional cast ones, fabricated using steel Rolled Homogeneous Armour (RHA). Work on the welded turrets of Object 187, Object 188 (T-90) and the future T-80UD was carried out practically simultaneously. The turret of Object 187 was characterized by an imposing overall size, especially in the rear section. The 902A "Tucha" grenade launcher was fitted for deploying smoke and aerosol screens, and snorkel equipment was also installed. Several types of power plants and transmissions were tested on the different modifications, including a gas turbine engine. The most promising of the power plants in the course of tests proved to be the 1200 hp А-85-2 engine. It was installed in a longitudinal configuration, similar to the T-34. A new undercarriage and hydraulic shock absorbers substantially increased dynamic abilities. During testing some of the Object 187 prototypes were fitted with the 125 mm 2A46M smoothbore gun of the T-80B. Planned primary armament of the tank though was the ballistically improved 125 mm 2A66 (also known as D-91T) smoothbore gun. Together with the tank gun, a new uranium-cored sub-caliber armor-piercing APFSDS rounds were developed called Anker-1 and Anker-2, as well as new HEAT shells, and GLATGM missiles. The 2A66 had a different appearance to the 2A46M. A muzzle brake was installed primarily to keep a clear line-of-sight for the missile guidance system, while also decreasing effective recoil from the more powerful new gun. The barrel was strengthened, with chamber volume increased to accommodate the larger round and incremented charge. The tank was equipped with the most advanced fire control system of the time. Something similar began to appear more widely on tanks in the late 1990s. The 2A66 was based on the 2A46M as a transitional version between the 2A26 gun and the new generation 2A82 smoothbore gun. The 125 mm 2A82 was tested earlier (late 1970s) on the experimental tank Object 785. Object 785 was also tested with a 130 mm rifled gun. While Object 187 was in development work on yet another experimental tank was also in progress. The Object 187 used composite armour for the turret and the hull front, and RHA for the rest of the tank. The passive armour was supplemented by the new Malakhit explosive reactive armour, a prototype of the present Relikt, and by the Shtora active protection system. It also had a CBRN protection system. Maximum physical thickness of the passive armour was up to 950 mm. It possibly consisted of special materials including ceramic or high density uranium alloys.
There weren't many Object 187 pics so they might not be accurate.