text:  The turret was first used in naval combat on the USS <unk> in 1862 , with a type of turret designed by the Swedish engineer John Ericsson . A competing turret design was proposed by the British inventor <unk> <unk> with a prototype of this installed on HMS <unk> in 1861 for testing and evaluation purposes . Ericsson 's turret turned on a central spindle , and <unk> 's turned on a ring of bearings . <unk> offered the maximum arc of fire from the guns , but there were significant problems with their use in the 1860s . The fire arc of a turret would be considerably limited by masts and rigging , so they were unsuited to use on the earlier ocean @-@ going ironclads . The second problem was that turrets were extremely heavy . Ericsson was able to offer the heaviest possible turret ( guns and armour protection ) by deliberately designing a ship with very low <unk> . The weight thus saved from having a high broadside above the waterline was diverted to actual guns and armour . Low <unk> , however , also meant a smaller hull and therefore a smaller capacity for coal storage — and therefore range of the vessel . In many respects , the <unk> , low @-@ <unk> <unk> and the broadside <unk> HMS Warrior represented two opposite extremes in what an ' <unk> ' was all about . The most dramatic attempt to compromise these two extremes , or ' <unk> this circle ' , was designed by Captain <unk> <unk> <unk> : HMS Captain , a dangerously low <unk> turret ship which nevertheless carried a full rig of sail , and which subsequently capsized not long after her launch in 1870 . Her half @-@ sister HMS Monarch was restricted to firing from her turrets only on the port and starboard beams . The third Royal Navy ship to combine turrets and masts was HMS <unk> of 1876 , which carried two turrets on either side of the centre @-@ line , allowing both to fire fore , aft and broadside . 
  