Military Council of Armoured and Mechanized Forces of the Red Army
April 1st, 1944
To the commander of the 2nd Ukrainian Front, Marshal of the Soviet Union, comrade Konev.
The heavy IS and ISU-152 regiments sent to your disposal contain the first batch of tanks and SPGs of this type.
Both the tanks and SPGs have a series of small technical omissions. In addition, there is not yet sufficient experience regarding their use and application in combat.
IS tank and ISU SPGs are meant primarily to combat heavy enemy tanks and SPGs, as well as artillery, pillboxes, and dugouts in the depth of enemy defenses. Heavy regiments of both vehicles should be used as a part of tank and mechanized corps.
In battle, their place is in the second echelon. Medium tanks must protect their flanks from sudden attack by enemy tanks. In addition, each heavy tank and each SPG is guarded from tank destroyer groups by submachinegunners. Submachinegunners are included in the regiments (one company) at a ratio of five submachinegunners per tank or SPG.
At first, it is desirable to use these regiments on terrain that is suitable for tanks and accessible without great effort and, most importantly, take any measures to ensure that these tanks do not fall into enemy hands.
Keep in mind that the regiments do not have their own reconnaissance elements. As a rule, the unit that the regiment is cooperating with should provide scouts.
Tanks armed with 122 mm guns and SPGs armed with 152 mm guns can fire from either standstill, short stops, or ambushes at a range of 1.5-2 km. Tanks armed with 85 mm guns open fire during motion, from standstill, short stops, or ambushes from 1.2-1.5 km.
Since tanks with 122 mm guns and SPGs with 152 mm guns have small ammunition racks, it is necessary to arrange timely resupply in battle and use their ammunition wisely.
I especially ask you to give directions regarding timely technical inspection and correction of breakdowns in these vehicles.
In order to study the usage and combat characteristics of these tanks and SPGs, I send Lieutenant-General Taranovich and a group of officers. Please provide them with assistance.
Inform me of your impressions regarding the advantages and drawbacks of IS tanks and ISU-152 SPGs.
Commander of the Armoured and Mechanized Forces of the Red Army, Marshal of the Armoured Forces, Fedorenko
Member of the Military Council, Lieutenant-General Biryukov."