Shortly after the Warsaw uprising outbreak, OKH ordered the Schwehrer Batterie 638 to crush the insurgents. The Batterie will be part of the 9. Armee
Despite being labelled Batterie, i twill only include one Mortar -600mm caliber – Karl Greät 040, also called Mörser. This one ‘s name is “Ziu”, son of Odin in the North Germany mythology . Transported by train to Pruszkow station where it is reassembled.
On August the 16th, the M örser is fieled on a concrete structure in the Parc Wolski. The concrete structure is still visible nearby the general Jozef Sowinski’s statue..
A second firing position will be prepared close to the Western station, south of Ulica Dworsa.
“Ziu” will shell the old town and the city center for 10 days.
For the German High Command, several changes are planned to increase the efficiency of the Mörser. The short barrel –Kurze AZ I -is definitely adopted as more accurate than the “long one”. A new detonator is developed, exploding on impact, whatever the surface of the target is.
The OKH is so satisfied with “Ziu” that they decided to dispatch it against Paris uprising in order to crush the Resistance..