The Gundlach Periscope, usually known under its British designation as Vickers Tank Periscope MK.IV, was a revolutionary invention by Polish engineer

Rudolf Gundlach Rudolf Gundlach (1892–1957) was a Polish military engineer, inventor and tank designer. He headed the design division of the Armored Weapons Technical Research Bureau (''Biuro Badań Technicznych Broni Pancernych''). He held the military rank ...

, manufactured for Polish 7TP tanks from the end of 1935 and patented in 1936 as the ''Peryskop obrotowy Gundlacha''. It was the first device to allow the

tank A tank is an armoured fighting vehicle intended as a primary offensive weapon in front-line ground combat. Tank designs are a balance of heavy firepower, strong armour, and battlefield mobility provided by tracks and a powerful engine; ...

commander to have a 360-degree view from his

turret Turret may refer to: * Turret (architecture), a small tower that projects above the wall of a building * Gun turret, a mechanism of a projectile-firing weapon * Optical microscope#Objective turret (revolver or revolving nose piece), Objective turre ...

with a single periscope. By rotating the periscope and allowing the tank commander to look backwards through the second

eyepiece An eyepiece, or ocular lens, is a type of lens that is attached to a variety of optical devices such as Optical telescope, telescopes and microscopes. It is named because it is usually the lens that is closest to the eye when someone looks thro ...

, he no longer had to change position to look behind the turret. Early tanks had small turrets and fixed seating, without an independently rotating cupola, and so the commander wasn't easily able to move himself to another rear-facing periscope. On 14 June 1935 it was officially adopted by the

Polish Army The Land Forces () are the Army, land forces of the Polish Armed Forces. They currently contain some 110,000 active personnel and form many components of the European Union and NATO deployments around the world. Poland's recorded military histor ...

, as reversible periscope G wz. 34. The design was first used in the

TKS The TK (TK-3) and TKS were Poland, Polish tankettes developed during the 1930s and used in the Second World War. Design and development The TK (also known as the TK-3) tankette was a Polish design produced from 1931 based on the chassis of the ...

tankette A tankette is a tracked armoured fighting vehicle that resembles a small tank, roughly the size of a car. It is mainly intended for light infantry support and scouting.

, then in 7TP light tank. Shortly before the war it was given to the

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories and Crown Dependencies. * British national identity, the characteristics of British people and culture ...

and was used in almost all tanks of

WWII World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

, including the British

Crusader Crusader or Crusaders may refer to: Military * Crusader, a participant in one of the Crusades * Convair NB-36H Crusader, an experimental nuclear-powered bomber * Crusader tank, a British cruiser tank of World War II * Crusaders (guerrilla), a C ...

, Churchill, Valentine, and

Cromwell Oliver Cromwell (25 April 15993 September 1658) was an English statesman, politician and soldier, widely regarded as one of the most important figures in British history. He came to prominence during the Wars of the Three Kingdoms, initially a ...

and the

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, p ...

M4 Sherman The M4 Sherman, officially medium tank, M4, was the medium tank most widely used by the United States and Western Allies in World War II. The M4 Sherman proved to be reliable, relatively cheap to produce, and available in great numbers. I ...

. After the German and Soviet attack and fall of Poland in 1939 it was copied entirely from captured 7TP and TKS Polish tanks and later used by the

Soviets The Soviet people () were the citizens and nationals of the Soviet Union. This demonym was presented in the ideology of the country as the "new historical unity of peoples of different nationalities" (). Nationality policy in the Soviet Union ...

for their tanks (including the

T-34 The T-34 is a Soviet medium tank from World War II. When introduced, its 76.2 mm (3 in) tank gun was more powerful than many of its contemporaries, and its 60-degree sloped armour provided good protection against Anti-tank warfare, ...

and

T-70 The T-70 is a light tank used by the Red Army during World War II, replacing both the T-60 scout tank for reconnaissance and the T-50 light infantry tank for infantry support. The T-80 light tank was a more advanced version of the T-70 with ...

). As a part of Polish-British pre-war military cooperation, the patent was sold for one zloty to

Vickers-Armstrong Vickers-Armstrongs Limited was a British engineering conglomerate formed by the merger of the assets of Vickers Limited and Sir W G Armstrong Whitworth & Company in 1927. The majority of the company was nationalised in the 1960s and 1970s, w ...

. It was produced as the Vickers Tank Periscope MK.IV (pictured), and built into all British tanks (Crusader, Churchill, Valentine, Cromwell). After the fall of Poland, Germany, USSR and Romania captured some equipment, allowing them to copy the invention. In USSR the Gundlach periscope was known as MK-4 (harking to the British designation, as Russian sources openly confirm that it was copied from samples acquired with British-supplied tanks) and implemented in all tanks (including the T-34 and T-70). At the end of World War II this technology was adopted throughout the world and used basically unchanged for almost 50 years, until it was replaced by electronic devices.

References

* {{cite book , first1=Grzegorz , last1=Łukomski , first2=Rafał E. , last2=Stolarski , title=Nie tylko Enigma... Mjr Rudolf Gundlach (1892–1957) i jego wynalazek , trans-title=Not Only Enigma... Major Rudolf Gundlach (1892–1957) and His Invention , year=1999 , location=Warsaw-London , lang=pl , isbn=
1938 US patent 2130006 "periscope for armored vehicles"
Armoured fighting vehicle vision and sighting equipment History of the tank Military equipment of Poland Polish inventions