The 1st Separate Tank Brigade is one of the Ukrainian Ground Forces’ main armored elements. The most widely-known contribution of the Brigade was during the defense of Chernihiv at the beginning of the 2022 full scale invasion.
Recently, very little information has been made available about the unit’s status and position, potentially meaning it is being reconstituted or that vast amounts of manpower and equipment have been moved to other Brigades.
Analysis/Notes
Tank Battalions are the main combat element of Ukrainian Tank Brigades. Generally three compose a Brigade, though it's possible (but unconfirmed) that the 1st Tank Brigade received a fourth Battalion, later attached to Mechanized Brigades.
They all seem to be equipped with T-64 variants, ranging from T-64Bs to standard T-64BVs and even upgraded T-64BM Bulats in unspecified numbers.
Several T-72B3s were captured by the Brigade and at least one was put back into service.
One Mechanized Battalion is also part of the 1st OTBr's maneuver element and has been seen utilizing BMP-1 IFVs.
Two additional Rifle Battalions complete the main fighting force of the Brigade but essentially no information is publicly available on these.
The Brigade's Artillery Group has the standard composition of two Artillery Battalions ("divizions") equipped with 2S1 Gvozdika (122mm) and 2S3 Akatsiya (152mm) self-propelled guns, a Rocket Artillery Battalion employing BM-21 Grad MLRS and an Anti-Tank Artillery Battalion (likely using MT-12 Rapira guns).
The Anti-Aircraft Defense Battalion has been seen using the standard 9K35 Strela-10 and 2K22 Tunguska vehicles, possibly complemented by ZU-23-2 anti-aircraft guns.
The Engineer Battalion uses UR-77 Meteorit mine-clearing vehicles and GMZ-series minelayers.
Sources
1st Tank Brigade Facebook, UA Wikipedia
1st Tank Battalion T64BM Bulat
MANPADS Platoons: Stinger, Igla
1st Mechanized Battalion Flag, BMP-1
Anti-Aircraft Defense Battalion: Strela-10, Tunguska, ZU-23-2