Turkish B.a.K. guns

Taking advantage from the studies carried out by German factories at the beginning of 20th century and from their production of a little number of experimental anti-aircraft guns, in 1912 Ottoman Army bought two 75mm Krupp B.a.K. guns. They had the same performances, but they were not all the same pattern of guns. One of them had a calibre of 75mm L/28, while the others had a longer barrel (L/30). They were sent to Odrin in order to defend the fortress by enemy’s balloons, dirigibles and planes. In 1913 the Bulgarian Army captured these two guns. They were the first real anti-aircraft guns of the Bulgarian Army, since during the Balkan war it had used regular field artillery guns to fire on air targets. In October 1915 they formed the 1^st Anti-aircraft Section.

But what kind of guns did the Turks buy in 1912?

The Bulgarian sources offer little explanations with regard to their identification. The История на зенитната артилерия…, pp. 16-17 give only some technical data, but not even a picture of them. However it had a drawing of a 75-мм балонно оръдие “Круп”, обр. 1912 г., showing something like a platform gun, similar to Pferdebespannte 7,7 cm Sockelflak L/27. But the calibre was different and, unlike what happened to other experimental anti-aircraft guns, Krupp did not manufacture any gun of this pattern in 75 mm calibre. In fact, while some of the anti-aircraft guns offered by Krupp to the German Army were simply 75 mm export guns rebored, this platform gun was an original attempt to change the standard German field gun in an anti-aircraft gun. Moreover among the various pattern of anti-aircraft guns designed by Krupp before World War I, nothing could be identify with the guns bought by the Turks.

From 1908 to 1914 Krupp manufctured three different kind of experimental anti-aircraft guns:

- guns on platform (77mm L/27, 77mm L/35 and 105mm L/35);

- guns on field carriage (65mm L/35, 75mm L/28.4, 75mm L/30 later rebored to 77mm, 77mm L/27);

- guns borne on lorry (71mm L/30, 75 L/30 guns, both later rebored to 77mm).

After long useless inquiries, the solution of the puzzle came from an unexpected source. In 1914 the Belgian military mission sent to Odrin published a detailed report, where, listing the artillery pieces employed by the Ottoman Army in the fortress, it offered also a brief description of the Turkish ant-aircraft field gun:

“7.5 cm field anti-aircraft gun Krupp. We saw two artillery piece of this kind; the hubs of the axle are articulated; for the shooting, the wheels are turned on the side of the chase, to allow, for the pointing in direction, the revolving of the gun around a pivot laid out on the spade of the trail-end. Arc of fire, horizontal : 360°; vertical : 70°” .

This description matches exactly with the second kind of Krupp experimental anti-aircraft guns. Moreover the technical data of one of them – 7,5 cm Räder B.A.K. L/28,4 mit abschwenkbaren Rädern - matches with the data of the Turkish anti-aircraft gun according with the История на зенитната артилерия, and with the brief description that it offers at p. 16 (and that I had been not able to understand before).

This gun was derived from a 65mm L/65 guns manufactured in 1908. On 21 November 1911 it was registered (Deutsches Patent Nr. 260826) and in September 1913 the German review “Artilleristiche Monatshefte” gave a detailed account of it.

The other gun was probably the 7,5 cm Räder-B.A.K. L/30 mit abschwenkbaren Rädern, although according with La Flak 1914-1918, vol. 1, p. 48, it seems that it was introduced only in 1914. It is possible that the Turkish Army, pressed by the war against Italy, where the aircraft was used as weapon for the first time, bought all the anti-aircraft guns that Krupp could offer at that time.

Experimental anti-aircraft guns designed by Krupp before World War I
Guns borne on lorry
7,1 cm B.a.K. auf Kraftwagen L/30	1911	later rebored to 77mm
7,5 cm B.a.K. auf Kraftwagen L/30	1913	later rebored to 77mm
7,7 cm B.a.K. auf Kraftwagen L/27	1914
Guns on field carriage
6,5cm Räder-B.a.K. L/35 mit abschwenkbaren Rädern	1908
7,5 cm Räder-B.A.K. L/28,4 mit abschwenkbaren Rädern	1912
7,7 cm Räder-B.A.K. L/27 mit abschwenkbaren Rädern	1912
Pferdebespannte 7,7 cm Sockelflak L/27	1913
7,5 cm Räder-B.A.K. L/30 mit abschwenkbaren Rädern	1914	later rebored to 77mm
7,5 cm Räder-B.A.K. L/30 mit Vordersporn und Schwanzschiene	1914	later rebored to 77mm
Guns on platform
7,7 cm Ortsfesteflak L/35	1909
10,5 cm Ortsfesteflak L/35	1909