WWII Russian Soviet S-51 Self-Propelled Heavy Gun 203mm Howitzer at 1-56 scale

This listing started as most of my work does by a request for a model not currently available. Intrigued by the idea of balancing the massive Soviet 203mm B4 strategic gun on the hull of a heavy tank I decide game on.  I spent most of February & March 2021 developing the files and I have since then sold numerous copies of the printed vehicle. It is a long print but one refined over time and does generally print reliably and assemble with normally minimal adjustment and application of green stuff.

The S-51 was a Soviet Experimental Heavy Self-Propelled Gun designed by TsAKB to meet the need of offensive operation undertaken by “Red Army” forces from 1943 onward. The strategic 203mm howitzer was the mainstay of Soviet long range artillery but it was exposed to counter battery fire and unarmoured versus direct fire encounters with the Germans. Reliant on being towed this heavy gun was not suited to supporting the intended swift breakthrough of enemy lines. By the autumn of 1943 TsAKB had created a prototype which combined the mobility of the KV-1S hull with the proven fire power of the M1931 B4 203mm howitzer.

The S-51 had a very long hull and an open topped fighting compartment. The front, side and rear of the hull had 75 mm, 60mm and 30 mm of armour respectively. The hull had a driver’s compartment and could seat one out of the 10 crews required, with the engine and transmission being located in the rear of the hull. The hull also had a bottom hatch for emergency escape and a number of small hatches for access to the other modules of the vehicle.

The S-51 was armed with a modified 203 mm howitzer M1931 (B-4). The gun was mounted at the front of the vehicle with gun shields. The elevation of the gun was 0 to +60 degrees, and the gun traverse being 4 degrees to either side. The vehicle had 12 rounds of ammunition that could be HE and/or armour piercing shells. The shells and propellant charges were placed behind the gun shields of the vehicle.

During transport, the gun shields were let down and the barrel of the howitzer was turned to the centre of the hull

In February 1944, the S-51 underwent factory testing. It was transferred to the artillery testing ground before completing the factory tests due to the great interest in the heavy self-propelled gun project.

However, many flaws in the S-51 were discovered during the trials. When the gun was elevated to a high angle and fired, the gun would sway and the recoil would push the tank back. When the gun was elevated at a low angle and fired, the recoil would be so strong that the crew would fall over, which could be deadly in battle. Overall, it was deemed that the KV-1S chassis was unsuitable for conversions into SPGs.

Due to these problems, the S-51 did not enter mass production

Despite truly only being a concept prototype vehicle I did get a request to design this vehicle and it has been printed numerous times in plastic for Ebay customers at 1/56 and 1/72 scale since March 2021. I have recently reworked some parts to assist in printing the model in resin for an Ebay customer in November 2022, though I still printed the hand rails in plastic.

This listing will provide vehicle files at the 1/56 scale to print in both plastic and resin:

Bracing frame, sits on the rear deck.

Gun Barrel

Gun Mount

Gun Mount Sub frame

Gun shield comes as left and right shield both upright and laying down in the travel position

Gun shield brace needed only for the laying down version of the shield

Hull for plastic printing

Hull for resin printing, it is semi hollow and has drain holes covered by the Bracing Frame

Hand Railing Set

Left Right Track assembly

Shell Locker.

The supported files are intended for resin printing and were done using Chitubox.

For results in plastic similar to the obvious plastic listing photos select a layer height of 0.1mm.

These models were design by Neal Bowskill Copyright March 2021. No printing of these files for commercial gain is permitted.