Siege and fortress artillery
In 1885, after
the defeat of
To equip the fortress
artillery with modern weapons, in 1890, on request of the Prime Minister
Stefan Stambulov, the government announced funds to buy 150mm Krupp long
guns. The order was assigned to the Artillery Inspection that sent to
These guns were intended for use on a wooden platform, the carriage being connected to a pivot plate on the platform. The platform consisted of three layers of posts connected by bolts, on which also a shield was fastened. Even if they were not true quick-firing guns, a recoil buffer was connected from the platform to the trail and wooden wedges behind the wheels were used for counter-recoil. These wedges both took up the recoil and made the task of manhandling the howitzer back into position easier. According with some Western sources, two of these guns were later equipped with steel wheels type Bonagente, in order to increase their mobility and allow them to fire without being mounted on the platform. This is confirmed by a picture.
In 1891 major Nyagul Tzvetkov was sent to the German firm Grusonwerk
This kind of
guns were sold in significant numbers to various countries (Romania, Denmark,
Belgium, Switzerland, Chile) both in 57mm, 53mm and 37mm calibre. In summer 1891 Grusonwek started a tour aimed at publicizing their new
guns in the Balkans. Exhaustive tests
with a 53mm gun were carried on at
On 25 May 1892
the Artillery Committee and the Committee for the defence in a joint session considered
what kind of quick-firing gun was most suitable for the close defence of the
forts of Slivinitza, Belogradchik and
In the same
years major Kalin Najdenov was sent in
1896 War Minister Racho Petrov along with some officers came to
On 30 July
The Bulgarian government would have preferred to keep on buying Krupp guns, since they had served as the standard guns in use by the Army since the beginning. Nevertheless to appease the French Foreign Minister Gabriel Hanotaux, who had intervened directly in support of the French firm, it agreed to place a smaller order : on 10 February 1897 Schneider-Canet obtained a command for 24 siege guns, 24 heavy howitzers and 18 mountain guns for 1,250,000 levas. Schneider had to supply both the guns and their ammunition and equipments (cast iron shells, steel shells, steel shrapnel, propellant charges of black powder for guns, vent-sealing tubes of Bulgarian model, double effect fuzes for fortress guns and percussion fuzes for field guns).
It was only
after that the contract had been signed, that the loan was issued in June
1897, and 3 million levas were made available for arms order. In this manner
Schneider scored its first success in
The planning and the manufacture of the French artillery pieces lasted from 1898 to 1900. They were tested under the control of some representatives of the Bulgarian Artillery Committee that required the introduction of alterations, when the pieces were still in the factory. To make the howitzers more movable, major Kalin Najdenov suggested to remove the platform planned by Schneider, and designed a special field wheeled carriage, which rendered them suitable for immediate service on any kind of ground without being necessary to construct a firing platform. In such a way the howitzers could be drawn by horses or oxen and placed in firing position quickly and easily. The carriage was provided with a trail spade that in ordinary ground prevented almost completely the carriage from recoiling. The recoil of the barrel in the cradle was absorbed by a hydraulic recoil cylinder, the return being secured by a compressed air run-out gear. Also the sight was improved, graduating it.
innovative heavy howitzer resulted from the conversion was presented to the
Paris International Exhibition in 1900. Unfortunately it was delivered hastily and without appropriate tests,
and after being employed for two or three years the howitzers showed some
major faults : in particular during the return in battery, the compressors
let flee air and after 4-5 shots they broke down, forcing some pieces to
interrupt firing. On 26 November 1904 the Artillery Committee examined the
howitzers, suggested some improvements and subsequently commanded to
Schneider the accessories required to modernize them on the basis of the Bulgarian plan. They were built in
The improvements introduced were :
– the replacement of the air brakes with hydro-pneumatic ones, that prevented the leak of the air;
– the introduction of special gears for small lateral correction, that enabled to fire more easily and rapidly;
– the adoption of dual sights equipped with goniometers, that enabled to aim easily from covered positions;
– the introduction of elevating gears that enabled to put the barrel in horizontal position rapidly, when the howitzer was loaded;
– the addition of a movable trail spade and of devices to fixe the howitzer during the march and joint the traversing lever with the carriage trail.
In 1907, when the howitzers were finally fully upgraded, the fortress battalions carried several drills to test the weapons and train the troops. On the basis of the lessons learned, further improvements were introduced, this time to the 120mm siege guns. In order to increase their field of fire, an extension was added on the right or on the left side of the firing platforms. In addition to protect the guns and the crews from the shrapnel bullets they were covered and surrounded by a shelter, the so-called “veranda”, that proved to be very effective during the siege of Odrin.
the beginning of the 20th Century the Bulgarian siege park could
field 109 artillery pieces, including the outdated Russian guns and mortars.
The general Staff intended to share the fortress guns among
To manage this threat, in 1906 the budget of the Bulgarian War Ministry assigned a considerable sum to increase the amount of the heavy artillery. Then the Artillery Inspection proposed to buy 24 – 150mm heavy and 48 – 120mm field howitzers, but the Chief of the General Staff, major general Radko Dimitriev thought more urgent to buy mountain guns instead of heavy howitzers. The purchase of field howitzers dragged on, because the French firm Schneider-Canet at that time had not 120mm howitzers and proposed a 105mm light howitzer. In 1911, after a long debate, the Bulgarian Government ordered 36 howitzers instead of 72, as originally planned.
In 1909 Major General Georgi Vazov published a Brief instruction on the operation and the attack against fortresses (Кратко упътване за действие против крепостите и атаката им), where he presented a detailed introduction to the siege warfare and to the gradual or regular attack to a fortress. Unfortunately his text did not penetrate into the Bulgarian Army, and was studied only by the Engineers, to whom it was mainly addressed.
In the spring
of 1911, lt.col. Stefan Slavchev, head of the Sofiyski Fortress Artillery Battalion,
gave some lectures on the vital
importance of the Odrin stronghold in a war against the
Unfortunately at the beginning of the Balkan War, nothing had been done to fulfil his plan. Also the request carried out jointly by the Artillery Inspection and the General Staff in 1910 to obtain funds to form a siege park composed of 300 modern artillery pieces was not accepted. To have an increase of its heavy artillery, the Bulgarian Army had to wait until the fall of Odrin in March 1913, when a large amount of fortress guns was captured and immediately adopted. Thus the major part of the fearful quick firing 150mm howitzers and 105mm guns of the Turkish Army became the top of Bulgarian Artillery.