Chapter 13
Shortly after the outbreak of the uprising in Poland’s capital city of Warsaw, the OKH sent schwere Batterie 638 into battle. The battery was immediately assigned to the reserve forces of the 9th Army. Although termed a battery, it consisted of only one mortar – a 600 mm calibre (!) Karl Gerät 040 – also known as a “Mörser”. This Mörser was nicknamed “Ziu”. The mortar was transported to the Warsaw District and was off-loaded at Pruszków, where there were railway facilities with heavy-capacity cranes necessary for assembling this giant mortar.
On August 16, the mortar was further transported to Warsaw and set up on a concrete floored emplacement specifically prepared for this purpose in front of a monument of General Józef Sowiński in Park Wolski (Wola Park). The foundation for this mortar, not too surprisingly, remains to this day. The other firing position was built in the vicinity of Dworzec Zachodni (West Station), south of Ulica Dworska (today: Ulica Marcina Kasprzaka) where the destroyed factories Lillpop, Rau & Loewenstein were located. For all intents and purposes, the concrete platform at this location was identical to the one in Wola Park. These firing installations clearly indicate that how and where the mortar was to be used had been carefully planned. The first targets lay in the Centre district and in the Old Town. Bombardment with the 600 mm calibre mortar did not provide the expected results because the projectiles used were designed to destroy permanent fortifications of reinforced concrete. The detonation devices were quite simply set to explode when the projectile impacted a stone-hard object, as for example, reinforced concrete. In cases where the targets were built of brick or even wood (support structure) bombardment resulted in many examples of unexploded ordnance, or so-called “duds.” Among many such projectiles, the one that hit a restaurant by the name of Adria on Ulica Moniuszko proved to be a dud. On August 18, this missile had blasted through the restaurant’s glass roof and onto its floor without exploding. Nevertheless, several people were injured and two resistance fighters were killed. The first attempt to disarm it was carried out on the morning of August 19, but failed due to a lack of the tools needed to remove the detonation-cylinder. This risky operation was undertaken by German POWs, and it wasn’t until that evening and the arrival of an expert team with specially fabricated tools (keys) in hand that the detonation-cylinder could be removed and thereafter disarmed. As it happened, it was one of the resistance fighters, Stanislaw “Pillert” Dutkiewicz, who unscrewed the bottom of the cylinder. The explosive substance was extracted and later used for the production of hand grenades. The further destiny of this disarmed projectile is interesting. Namely, the hull of the projectile lay in undisturbed peace and quiet among the ruins until June 20, 1965, when it was finally removed. Currently, it is on display at the Polish Army Museum in Warsaw.
Karl Gerät 040 Mörser nr VI “Ziu” belonged to 638 Artilleri Batteri. This photograph, taken in August 1944 shows the 600mm calibre very clearly.
“Ziu” being loaded. The gun was positioned in Wilski Park and fired towards the centre of the city.
The mortar “Ziu” also bombarded the Old Town around, among other areas, Ulica Mostowa and Ulica Miodowa. Among the targets hit in the Centre district was the Main Post Office on Napoleon Square in the vicinity of what is now Dom Chłopa and the NBP (the Polish National Bank), Ulica Wspólna, and the area around the postal terminal at the juncture of Ulica Żelazna and Aleje Jerozolimskie. In 1945, Polish engineer-troops removed a 600 mm projectile which had failed to detonate from the ruins of the Prudential Insurance Company building. In all probability, the insurgents were subjected to bombardment from the “Ziu” mortar for a total of approximately ten days, since 9th Army documentation reveals that the ammunition depot contained only 243, calibre 600 mm projectiles. During the uprising, as well as after the war, several duds were located in and around Warsaw. It therefore reasons that the Germans fired off at least some scores of projectiles. Specifically, after the war eight (8) unexploded projectiles were found.Two such duds graced the entrance to the Polish Army Museum from 1948 to 1949; until an observant Czechoslovakian realised that there lay a half of ton of explosives not more than an arms length away. Engineer troops removed the projectiles and detonated them on military land, probably in Zielonka, outside Warsaw.
This was the main post office in Warsaw. Shelling from “Ziu” destroyed the building.
“Ziu”, ready to be fired.
“Thor”, ready to fire, Warsaw, Septmeber 1944.
On September 22, 1944, the mortar “Ziu” was removed to Jüteborg in Hillersleben. The Germans drew a very well-founded, concrete conclusion from their experiences in Warsaw – Engineer Klaus Kunder from the Armament Ministry (WaPrüf ) received orders to develop a new type of detonating device for 600 mm calibre projectiles. The new detonation-cylinder, model kurze AZ 1, was more reliable. All five test-firings resulted in projectile detonation. The commander of the artillery regarded the use of the mortar in Warsaw as having been a success. The extent of German confidence in the weapon can be gleaned from a related OKH order: On August 24 1944, the next “Ziu” mortar was sent to Paris, to crush the uprising there!
“Thor”, photographed at the moment it fired.
For transporting ammunition to Karl mörsers in the combat zone, a number of Pz Kpfw IVs were modified to become so-called Munitions-schlepper PzKpfw IV Ausf F für Karl Gerät Mörser 040.
“Ziu” in the firing position in Wolski Park. To the right is an ammunition supply vehicle – Munitionsschlepper für Karl Gerät Mörser 040.
Unexploded bomb, a 600 mm concrete shell that hit restaurant “Adria”. Today this grenade can be seen at the Polish Army Museum.
Direct hit! The office building of the Prudential insurance company at the precise moment it was hit by a 600 mm mortar fired by “Ziu”.
A close-up of “Ziu”.
This house on Marszalkowska Street was destroyed by a single mortar strike from “Ziu”.
“Magda” parked in front of Pfeifers tannery.