 SS Ben @-@ my @-@ Chree was chartered by the Royal Navy on 1 January 1915 and she began her conversion into a seaplane carrier at the Cammell Laird shipyard in Birkenhead the following day . Part of her aft superstructure was removed and replaced by a hangar , aft of her rear funnel , that housed four to six seaplanes . The aircraft were lifted in and out of the water by derricks fore and aft . A dismountable 60 @-@ foot @-@ long ( 18 m ) flying @-@ off platform was installed forward of her superstructure ; it was equipped with a trolley and rails to allow a seaplane to take off . 
