Jorsch

Builder:	New Admiralty, St. Petersburg
Keel laying:	March 23, 1874
Launch:	August 5, 1874
Commissioning:	1874
Period of service:	1874-1907
Displacement:	305.5 t
Length:	29.6 m
Width:	8.69 m
Draft:	2 m
Drive:	1 steam engine 1 screw 240 PSi
Speed:	9.4 kn
Range:	Autonomy 40 hours
Crew:
Armament:	Guns: 1878: 1 × 11-inch M1867 cannon 1 × 16 mm Gatling 1890s: 1 × 11-inch M1877 cannon 2 × 44 mm Engström system 1900: 4 × 87 mm cannon

Jorsch (Russian: Ёрш, German: Kaulbarsch) was the name of a sea-going gunboat of the Imperial Russian Navy . The boat was the type ship of a series of several gunboats, which is referred to as the Doschd class (Russian: Дождь, German: rain) after the first keeled boat.

history

Project

The boats were intended as a supplement to the coastal defense of the Baltic Sea , which was based on armored gunboats, the tower frigates of the Admiral Spiridow class and the coastal fortifications of the Kronstadt fortress . In peacetime, the boats should be used in port service and for hydrographic tasks.

The development of the project was provided by a commission chaired by Rear Admiral Stepan Stepanowitsch Lessowski (Степан Степанович Лесовский). The British gunboat Sketch was used as a model . In contrast to the model, which had a hull made of iron, the commission specified the wooden construction, only parts that were particularly stressed such as the ammunition load and the planking in front of the cannon should be made of metal. It was hoped that this construction method would result in less damage in the event of ground contact in the rocky shallow water of the eastern Baltic Sea. The displacement was also increased in order to be able to install a 280 mm cannon as the main armament. The draft was limited to 1.83 m. Since the projected speed should be at least eight knots, a machine output of 240 HP was calculated for the project. In the final meeting, the commission decided on steam engines from the British company John Penn and Sons from Greenwich .

The boats had a very flat keel, the midship coefficient was 0.8, and the overall fullness was 0.58. The ratio of the length to the width of the boat hull was 3.4. The hull was divided into five compartments by four watertight bulkheads. The boat was 280 mm high and 229-280 mm wide bilge keels of oak .

The 280 mm model 1877 cannon built by the Obuchow works was chosen as armament . The weapon was installed on a pivot mount developed by Andrei Alexandrovich Popov . The carriage was submitted to the Naval Technical Commission in 1874 and confirmed without changes. The mount was manufactured by the Obuchow works. For reloading, the weapon lay below the deck. An auxiliary steam engine moved four threaded spindles over two shafts, which raised the platform with the weapon for firing. On the platform, the weapon stood on a slideway that was inclined by 4.5 ° and was 2.235 m long. The recoil was compensated by the movement of the cannon on this slide. In addition, the pipe return was dampened by a pneumatic pipe brake. The platform was rotatably mounted on a pin and thus enabled side straightening. The platform was rotated using cables, the auxiliary steam engine served as the drive source. In October 1874, the construction was tested in a sharp shot, the tests were overall satisfactory. The elevation range was between −2 ° and + 10 °, the side alignment range was 17 °. The pipe return was normally 1.422 m, a maximum of 2.133 m was possible. The platform had a total length of 5.486 m. The weight of the gun carriage with weapon was around 40 t.

The fittings, the deck of the forecastle, the watertight bulkheads, the walls of the powder chamber and the ammunition load were made of sheet steel with a thickness of 9.5 to 11.1 mm. The planking of the hull was made of larch wood with a thickness of 76 mm. The reinforcement at the level of the waterline, the so-called barghout (Dutch, Russian: Бархоут), consisted of oak wood with a thickness of 114 mm. The deck was planked with 76 mm thick pine.

construction

On October 8, 1873, the representative of the Imperial Russian Navy in England, Rear Admiral Iwan Fjodorowitsch Lichatschow (Иван Фёдорович Лихачёв) ordered the steam engines, and a shortened delivery period of six months was agreed.

Construction of the boat began on December 3, 1873 on the slipway for wooden ships of the New Admiralty shipyard in St. Petersburg , but the official keel-laying did not take place until March 23, 1874. The hull was completed by the end of April, but the launch was delayed due to problems with the delivery and installation of the machinery, fittings, rudder equipment, anchors and cisterns. Some of the equipment was supplied by John Penn and Sons , and some came from the Russian Ishorsky factory. In June / July the machinery and armament were delivered and installed in four deliveries. The launch finally took place on August 5, 1874.

testing

The stand test took place on August 31, 1874. With mostly installed equipment, the draft at the bow was 1.1 m and at the stern 1.74 m. A first test drive between St. Petersburg and Kronstadt and back was carried out on September 28, 1874. A maximum speed of 5 knots could not be exceeded. On October 17th, a test drive to the Tolbuchin lighthouse took place with wind force  9 and swell force 7. Even on October 19, the projected speed could be achieved in calm seas, although the best stokers in the Baltic fleet were assigned to the corvette Bojarin (Боярин) and the clipper Isumrud (Изумруд) for this voyage , and high-quality coal from Newcastle was also used came.

After a test shooting in rough seas, which caused the boat to heel, the planking of the forecastle was reinforced and the mounting of the carriage revised.

As a result of the tests, it was proposed to change the contours of the hull in the bow area and to move the carriage with the cannon to midships. In addition, the steam output of the boiler system should be increased and the output of the steam engine increased. The commandant of the boat, Kapitan-Leitenant A. O. Blank (А. О. Балк), suggested an extension of the boat by 4.5 m. To compensate for the increased displacement, the number of pieces of equipment made of iron should be reduced or their cross-section reduced.

In the years 1874–76 further changes were made. Additional pumps were installed and the design of the hatch covers changed. The grille above the weapon was replaced with removable wooden planks. Furthermore, a speed controller was installed to prevent the steam engine from revving up if the propeller emerged from the water in rough seas.

commitment

In 1892 the boat was reclassified as a coastal defense gunboat. It was primarily used for training purposes in the Baltic Sea. In 1907 it was deleted from the fleet list.

Individual evidence

1. ↑ all information according to Melnikow
2. ↑ Side elevation and top view of the mount
3. ↑ In the literature, October 8, 1874 is occasionally given as the date of the order, but October 8, 1873 appears more likely in the overall view of the process.

Web links

• History, drawings and technical data of the boat (Russian)
• image

literature

• Л. И. Амирханов: Артиллерия российских мониторов , Гангут, Санкт-Петербург 1998 (LI Amirchanow: Artillerija rossijskich monitorow ) (Russian)
• Р. М. Мельников: Канонерская лодка “Ёрш” , “Судостроение”, 1986. № 7 (RM Melnikow: Kanonerskaja lodka “Jorsch” ) (Russian)