The two - inch thick transverse bulkhead fore and aft protected them from raking fire .
Gromoboi 's casemates were 4.7 inches ( 119 mm ) thick , with two - inch backs and 1 - inch ( 25 mm ) roofs .
The two - inch thick transverse bulkhead fore and aft protected casemates from raking fire .
Gromoboi 's casemates were 4.7 inches ( 119 mm ) thick , with two - inch backs and 1 - inch ( 25 mm ) roofs .