 She temporarily mounted an imported Heinkel aircraft catapult atop the third turret between 1930 and 1933 . It was transferred to the cruiser Krasnyi Kavkaz when Sevastopol began the first stage of her reconstruction in November 1933 . This was based on that done for her sister Oktyabrskaya Revolyutsiya , but was even more extensive . Her rear superstructure was enlarged and a new structure was built just forward of it which required the repositioning of the mainmast forward . This did not leave enough room for a derrick , as was fitted in Marat , and two large booms were fitted to handle aircraft while the existing boat cranes remained in place . The mast had to be reinforced by two short legs to handle the weight of the booms and their loads . Her false bow was reworked into a real forecastle like those fitted to her sisters . All twenty @-@ five of her old boilers were replaced by a dozen oil @-@ fired boilers originally intended for the Borodino @-@ class battlecruisers . The space saved was used to add another inboard longitudinal watertight bulkhead that greatly improved her underwater protection . 
