Thus , Smeul was the only one of her class to retain her original armament of two 37 mm revolving guns .
They had a crew of 20 and drew 2.13 meters ( 7 feet ) of water , carrying 7 tons of coal .
Smeul was the only one of her class to retain her original armament of two 37 mm revolving guns .
They had a crew of 20 and drew 2.13 meters ( 7 feet ) of water , carrying 7 tons of coal .