Plans of modernisation



The introduction of the first QF gun in 1897 - the French built canon de 75mm Ml. 1897 - meant a true revolution in gun design and involved a mass re-equipping of almost every army in the world. It was a formidable weapon that made every other field gun in the world obsolete: every army had to replaced its artillery park or be entirely outgunned. This re-equipment took place between 1898 and 1914 and in many countries had not been completed when World War I broke out.

The superiority of the 75mm was due to the combination of the recoil system, the trail spade, a quick-acting breech, fixed ammunition, the independent line of sight, abatage, and the use of an automatic fuze-setter. Most of these mechanisms were separately utilized prior to 1897 on various guns, but the French Army put all them together on a field gun, added a shield to protect the gunners against enemy fire and obtained a weapon that could be brought into action behind six horses and that had a rate of fire approaching twenty aimed rounds a minute.

At that time the Bulgarian artillery had only a large number of antiquated 75mm and 87mm Krupp guns of various models. They were screw-breech black-powder cannons, with no recoil mechanism and shields. Their short range, lack of shields, and slow rate of fire endangered their crews, while the black powder revealed their position. The lack of recoil mechanism caused difficulties in aiming and providing concentrated artillery barrages on enemy targets. This simply meant that the Bulgarian Artillery needed more modern weapons.


In Bulgaria the quick-firing artillery was introduced in 1904, thanks to the efforts of War Minister major general Mihail Savov. But afterwards the Artillery Committee, in spite of the low amount of the military budget, considered the hypothesis of an updating of the not QF artillery park. This problem was tackled by the Artillery Inspectors Major-Generals Nikola Ryaskov and Pantaley Tzenov in some reports to the War Ministers Lieutenat-Generals Danail Nikolaev and Nikifor Nikiforov.

General Rjaskov emphasized that the countries near Bulgaria were not only commanding QF artillery, but also trying to update their not QF guns with devices directed to speed up and improve the fire. Therefore he proposed that a spring-loaded trail spade and a quadrant should be furnished to each 87mm not QF gun and every not QF field battery should be equipped with battery telescope. It thought that this result would be achieved at the cost of 400,000 levas. In a report to the Council of Ministers he and the War Minister asked for 200,000 levas to be granted to modernize at least half of the existing not QF batteries, i.e. 162 guns.


In 1911 general Tzenov wrote a detailed report to the War Minister, stating that the whole Bulgarian not QF artillery park (324 guns) was unreliable, since one QF battery alone was able to destroy 29 not QF batteries.

In order to effectively use the great existing stock of obsolete 87mm shells, he considered necessary to introduce the following modifications in 306 – 87mm and 18 – 75mm not quick-firing guns:

1) to secure the fire control in every tactical condition, the recoil should be minimised through fixed or elastic trail spade : the adaptation of the fixed trail spade required transforming the tube and the gun-carriage into a QF system, mounting a cradle and a shield;

2) the adaptation of the chamber and tube is required in order to use a brass cartridge (single piece ammunition) instead of propelling charge and shell (the old two piece ammunition): this modification required the delivery of brass cartridges and the remodelling of the limbers and caissons of the gun system;

3) to speed up and simplify the graduation of delayed action fuze a mechanical fuze-setter should be introduced, but this required the correction of the thread of the fuze.

General Tzenov added that to make the whole not QF artillery into a real QF weapon the cost would be 14,000 levas per gun: that meant for 324 guns a total amount of 4,536,000 levas, not counting the cost of the transport of the guns to and from the factories that had to modify them, the cost of the cartridges and the cost of the adaptation of the limbers and the caissons. Moreover due to these radical modifications, the weight of the gun would rise up to 1300 kg.

In order to cut down the expenses, he considered the hypothesis to change the not QF guns in guns à tir accéléré, adding spring-loaded trail spade and adapting them to use brass cartridges. This would cost 5,000 levas per gun: that meant a total amount of 1,620,000 levas, not counting the cost of the assembly of the parts in Sofia arsenal, the cost of the cartridges and the cost of the adaptation of the limbers and the caissons.

Finally, he considered the hypothesis of supplying modern optical instruments and fuze-setter in order to improve the fire control, with an additional cost of 436,000 levas at least.

After this detailed analysis, general Tzenov suggested to use for the best the not QF guns without making any change, except the adoption of goniometric sight, quadrant elevation and fuze setter, which should be useful even if the not QF guns were assigned to the fortress battalions. Furthermore, he asked to increase successively the QF artillery, adding three QF batteries to every regiment. He thought that in this way within three or four years Bulgarian Army would be able to modernize its artillery without raising the military budget.

The War Minister, lt. gen. Nikiforov, answered that :

1)    the hypothesis of introducing modern sighting devices should be examined immediately and, in the event of a positive outcome, it should be extended to mountain artillery as well;

2)    he agreed with the proposal to gradually increase the number of the QF field batteries.


Therefore gen. Tzenov wrote both to Krupp and Schneider to propose to supply the sighting devices and fuze setters for the 54 not QF field batteries, showing precisely the requirement that the material should satisfy:

1)    the sighting devices should be equipped with goniometric sight to calculate the angle of sight and to aim the gun and might be they could be fixed firmly to the gun or removable;

2)    the goniometric sight should be graduated in millièmes and the bar sight in hectometres, with a dash every 50 m;

3)    the fuze setter should have the same thread of the fuze and should be graduated as the bar sight, with every 50 m, with the correction in combustion corresponding to 1/1000 of the height at a distance of 2000 m, it must be precise and easy and quick to use.

If interested, the two firms should sent to the Sofia Arsenal the projects of the various devices and one or two specimens for the preliminary tests. For this purpose gen. Tzenov attached to his letter: 1) a sketch of the 87mm gun, 2) a drawing, and, if necessary, also a sample of the T&P fuze, 3) the firing table of the gun.


However, nothing was implemented before the outbreak of the Balkan war. Actually, in 1912, every artillery regiment existing in peace formed another regiment armed with not QF guns (2 divisions with 3 six-guns batteries each). During the war some artillery divisions were rearmed with QF guns captured to the Turks. After the Interallied War gradually one division of every not QF artillery regiment received modern Krupp guns and in September 1915 each artillery brigade had two QF regiments and only one not QF artillery division.

Directing circles to calculate the angle of sight for not QF 87mm field guns were introduced only in 1915 with the Order on artillery Nr. 20.




Krupp 87mm field gun M. 1886

Krupp 75mm field gun M. 1886

Krupp 75mm mountain gun M. 1886

Schneider 75mm mountain gun M. 1897