12.8 cm FlaK 40/1 – towed version – case report

      Development of the gun began in 1936, with the contract being awarded to Rheinmetall Borsig. The first prototype gun was delivered for testing in late 1937 and completed testing successfully. The gun weighed nearly 12 tonnes in its firing position, with the result that its barrel had to be removed for transport. Limited service testing showed this was impractical, so in 1938 other solutions were considered.

Flak 40 in early method of transport… Not practical, at all!!

While the FlaK 40 was typically utilized on its static carriage system, production was already under way of six “mobile” versions, these mounted atop multiple-axle transport carriages to help content with the massive weapons weight over distances. Despite their mobile classification, these examples still proved heavy and cumbersome to maneuver with any great haste. It came to be that the weapon was eventually dismantled between two loads for transport but even this method was equally time consuming and impractical, forcing the Germans to revert back to the original single-load process for transporting the weapon.

A very effective final type of the 12.8 cm Flak 40/1 with the box-shaped carriage center section and four swivel arms on the corners. Notice the kill markings and cammo… A lethal weapon, no doubt!

Due to the heavy nature of the weapon system as a whole, the FlaK 40 was eventually settled as a static gun emplacement along few – though critical -airspace routes throughout the Reich. Berlin and Vienna were two such locales protected FlaK 40 guns and even then some of these weapons had specially constructed towers designed to manage their weight and take on even greater vantage points.

Flak 40/2 twin version in a flak tower in Berlin Notice the color of the cammo

To compensate for the FlaK 40s limited tactical value, engineers eventually managed a railcar variant that supplied only limited additional mobility.

12,8cm Flak 40 railcar prototype

Drawing of railcar for 12,8cm Flak 40

As the Allied bombing campaign (day and night) was taking an ever increasing toll on German war-making capacities, a twin-gun variant was also developed and these were designated as “12.8cm FlaK 40 Zwilling”. These were essentially the same class of weapon though completed with two side-by-side 128mm gun barrels, appropriate fire control systems and dual loading facilities all fitted to the original mount. Production of this form also began in 1942 to which some 34 examples were available by February of 1945. Again, the sheer weight and complexity of these systems made their availability limited and, thusly, they were utilized strictly around key Reich centers.

12.8 cm Flakzwilling 40/2, the most commonly known variant of the Flak 40. These guns were used in the AA defenses of Berlin and Vienna

      The eventual solution was to simplify the firing platform, based on the assumption it would always be securely bolted into concrete. The total weight of the Flakzwilling twin-gun mount system reached 26.5 tonnes, making it practically impossible to tow cross-country. In the end, this mattered little since by the time the gun entered production in 1942, it was used in primarily static, defensive applications. There were four twin mounts on the fortified anti-aircraft Zoo Tower, and they were also on other flak towers protecting Berlin, Hamburg, and Vienna.

12,8cm Flakzwilling 40/2 in the Zoo AA tower – Berlin

It is claimed that during the Battle of Berlin the guns on the Zoo Tower were used successfully to support ground forces, “where the heavy 128 mm shells obliterated Soviet armor, especially when hit from the side”. The rush to capture the Reichstag led to dozens of tanks being destroyed. Approximately 200 were mounted on railcars, providing limited mobility.

      The gun fired a 27.9 kg shell at 880 m/s to a maximum ceiling of 14,800 m. Compared with the 88 mm Flak 18 & 36, the FlaK 40 used a powder charge four times as great.

• 12.8 cm Flak 40 – static version: most commonly used version, on a static pedestal stand.

12,8cm Flak 40 with full crew in a flak tower. Notice the static pedestal stand – right view Reich area – Germany – December, 1943.

12,8cm Flak 40 with full crew in a flak tower – left view Reich area – Germany – December, 1943.

• 12.8 cm Flak 40/1 – towed version: With the four-axle special trailer 220 (Sd. Ah. 220), the 12.8cm Flak 40/1 could be moved in one load in the pulling force. The Sd. Ah. 220 consisted of two identical two-axle trailers, between which the anti-aircraft gun was suspended. The set had a total weight of 27t.

• 12.8 cm Flakzwilling 40/2: The 12.8 cm Flak 40 ordnance on a static dual mounting with a total weight of 26 tonnes, capable of firing 20 rounds per minute. Used mainly on flak towers. Production started in 1942 with 10 twin sets produced, another eight in 1943, and in February 1945 a total of 34 were available.

12.8 cm FlaK 40 Zwilling mount on the Flakturm Tiergarten – Berlin 1945

• 12.8 cm PaK 40: A derivative anti-tank gun, rejected in favour of the Krupp 12.8 cm Pak 44, used to arm the Sturer Emil prototypes.

12,8 cm VK30.01 Selbstfahrlafette auf (H) “Sturer Emil”