Thanks for the positive feedback, everyone!
Now onward to Projekt 1125.
As explained before, this is the lighter sister-class of Projekt 1124, with a displacement around 30 tons. This secondary design was meant to have a shallower draft and serve in a wider array of waterways.
Compared with the Projekt 1124, this version had a shorter hull and replaced the aft gun turret with an MG position, while a thrid MG was installed in front of the (now single) tank turret.
Its evolution over the course of the Second World War was similar to that of Projekt 1124:
It started out with a low hull, cut-down bow and T-28 turret:
After tests showed, as for Pr.1124, that the bow was inadequately wet, the forward hull profile was modified for the main production variant.
The BK-114 shown below is an example of that series configuration: Built in 1938-39, it was part of the first batch to see combat on the Western front, successively in the Dnepr flotilla, the Baltic fleet and the Danube flotilla, before being sunk by artillery fire near Antonovka on the Dnepr in September 1941:
Once trial by fire showed the inadequacies of the original weapons fit, a lot of boats were submitted to various refits with what weapons were available at the time.
As for Pr.1124, some were outfitted with multiple rocket launchers, although the heavy M-13M Katyusha was of little use on such a light hull.
For example, the BK-14 below was refitted with T-34 turret and M-8M small-caliber MRL mount in 1944. This boat would end up having a distinguished career on the Western front, fighting all the way from Stalingrad to Berlin, then soldiering on until being transferred to the DOSAAF in 1956.
In parallel, other boats saw their anti-aircraft capacities improved, such as the BK-92 seen here with a DShK hevy machine-gun on an AA pintle mounted in an armored bucket over the engine room, in addition to its T-34 turret. This boat entered service in late 1942 in the Volga flotilla, then transferred to the Dnepr flotilla, following the offensive westwards through Belarus until being heavily damaged and sunk by artillery fire in Pinsk in July 1944.
As for Pr.1124, new boats built from 1942 onward started showing the second standard configuration with a single T-34 turret and armored DShK mountings. At the same time, the forward MG turret was often removed as it interfered with the fire arc of the gun turret.
The BK-93 below, carrying the new T-34 turret along with the rarer original single-tube DShKM turret, was launched and put into service in 1942 before joining the Dnepr flotilla in 1943. This was another of the boats serving through the fighting on the Western front from Stalingrad to Berlin, and was removed from service as a river gunboat only in 1958.
Further boats produced between 1943 and 1946 used the same general weapons fit with the same variations in MG mounts as Pr.1124.
One significant difference appeared in 1944 when, in a move strangely not replicated on Pr.1124, some boats started being equipped with open mounts for DShK MGs with anti-aircraft capability. This mount, standard on any seagoing ships, traded armor protection for a higher elevation and turn rate to engage fast-flying fighter-bombers.
The BK-241 here shows that final configuration with 2 twin DShKMs in open AA mounts. Built in Perm in 1942-43, this boat followed combat operations from the Caspian flotilla to the Black Sea Fleet to the Danube flotilla, within which it fought in Iasi-Chisinau, Budapest and Vienna.
More to follow!