From mid-1957 until December 1960, the carrier underwent a massive refit and reconstruction in the Netherlands. The work was carried out by Verolme Dock in Rotterdam, and cost US$27 million. The most visible change was the installation of an 8.5-degree angled flight deck. The size of the angle required that an accessway be built around the starboard side of the island superstructure; the weight acting as a counterbalance for the flight deck's portside overhang. Combined with the fitting of a more powerful steam catapult, stronger arresting gear, reinforced hangar elevators, and a mirror landing aid, these modifications permitted the operation of jet aircraft up to in weight. The carrier's island superstructure was replaced, and a lattice mast was fitted to support the new fire control system and radar suite. The ship's boiler capacity was increased, and internal electricity was converted to AC through the installation of four turbo generators and one diesel generator.