Larger merchant ships were equipped with an assortment of guns during the Battle of the Atlantic and were known as Defensively Equipped Merchant Ships, distinct from the Armed Merchantmen operated by the Royal Navy such as HMS Rawalpindi. They provided limited protection from an attack from the air:
At 7.50 a.m. on March 25th Captain B.L. Leslie’s Beaverbrae was bound from Liverpool to Saint John, New Brunswick, the winter terminal of the Canadian Pacific Line. She was a fine ship of 10,000 tons with a speed of fifteen knots, one of a class of five ships of advanced design built in 1928. It was not yet fully light, and out of cover of heavy clouds typical of March in the North Atlantic the ship was suddenly attacked by a Condor from under three hundred feet, firing cannon and machine guns.
The attack took them by surprise, but the DEMS [Defensively Equipped Merchant Ships] gunner standing by on the poop got off a burst at the aircraft with a stripped Lewis as it passed overhead and before its bombs hit the ship. Two heavy bombs hit the after deck, exploded below and caused devastating damage. The mainmast and its housing and most of the derricks housed in trestles on the after deck disappeared entirely. A wide crater was smashed in the steel deck and a huge hole in the port side shell plating. Every steam-pipe in the engine-room was fractured and some of the men in the engine-room and stokehold were badly scalded, though no-one was killed. Fire was soon raging in the ship.
The ship’s gunners ran to action stations. The crews of the 4-inch and 40 mm Bofors on the poop found difficulty getting to their guns along the damaged after deck, but the two Hotchkiss and the stripped Lewis on the bridge were fully manned by officers and cadets ready for the Condor’s second attack. They opened up on him as he swept over them and could see their tracers passing through the aircraft. This time his bombs fell wide. He missed them again on a third attack, and by the time he came in again the Bofors crew had reached their gun. Their first burst made the Condor pull away, and he did not return. But Beaverbrae was doomed. More fires had started, the flames overcame her, and she had to be abandoned.