What is it used for?

[Niume]

Does anyone know what purpose does the steel beam has? Is it a ice breaker or a ram of some sort?
https://www.part.lt/img/c6195c5b6fe7cbef0034c1ed60b2fd02446.bmp (https://www.part.lt/perziura/c6195c5b6fe7cbef0034c1ed60b2fd02446.bmp)

[La vache]

That is a "Klappspier" for GBT (Geräuschboje Turbine) against acoustic mines


http://parow-info.de/f/Krake/H-GBT.gif