Canona Antimagnetica
The Canona Antimagnetica ( CAM ) was a device with which magnetic mines were detonated well in advance of a ship approaching them.
It was developed by the Italian professor GM Pestarine and was originally intended for wooden vehicles up to 300 tons, but could also be used on smaller iron ships. The system consisted of two large iron rods laid cross-shaped on the upper deck, weighing a total of 90 t, which, similar to the "cross winding" in a VES system , were alternately polarized and flowed through . This shifted the ship's magnetic field so far in front of the bow that mines with a simple magnetic detonator detonated about 40 m in front of the bow.
The Canona Antimagnetica had significant advantages over the VES system developed by the German Navy , which was still used on high-sea barrier breakers . So you needed z. B. no heavy and raw material-demanding core stowage of scrap iron in the front part of the ship and also no complex wrapping of the ship's hull with copper cables. The system was also only installed on deck, which made installation and repairs much easier.
Since the navy needed small barrier breakers to keep port entrances, estuaries and - when German inland waterways were also occupied with magnetic mines in the course of the Allied air offensive - also inland waterways, the Canona Antimagnetica, bought from Italy, was initially used on these ships.
The positive experiences made with it ultimately led to the development of the slightly modified, approximately 70-80 t heavy German cross pole device (KPG), later also called cross pole device. A number of naval ferry boats (MFP) and naval artillery lighters (MAL) of type II were equipped with this, which then operated as barrier breakers.