Although this particular Thornycroft dates from 1940, it is a good example of what these depth charge throwers looked like. The round can fitted into the half-circle atop the thrower is the depth charge, which was launched from the deck of the ship.
From the Wikimedia Commons caption: "Depth charge thrower from INS Haifa (K-38) in the Clandestine Immigration and Naval Museum, Haifa, Israel. Comment : This is a British Thornycroft depth charge thrower with depth charge loaded. INS Haifa was originally the British Hunt class escort destroyer HMS Mendip, completed 1940."
By User:Bukvoed. - Own work, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=1437448
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