This is the massive bridge of Takao on 21 December 1939 after her Modernisation. Her upper bridge has been reduced in height and a tripod replaced the quadruped foremast. The new twin 25mm AA mount is shown abreast of the funnel and twin 13mm machine guns have been added to sponsons on either side of the bridge. Notice the 610mm torpedoes swung outboard. To reduce the threat to the ship by accidental explosion of one of their warheads, doctrine called for them to be swung outboard in this fashion before going into battle.
This is Chokai, photographed in 1940. Chokai was originally slated to receive the same modernisation that was given to Takao and Atago in 1940 but the refit was cancelled in order to ready the fleet for war. As a consequence, the upper levels of the bridge retained their initial appearance in large measure. The horizontal yardarm on the foremast is another feature of the unmodernised Chokai and Maya; Atago and Takao after modernisation had yardarms which slanted upwards.
On 1 May 1938 Takao was at Yokosuka awaiting her Modernisation. This photograph shows her appearance on that day with RDF shack mounted inside the quadruped foremast and totally inadequate 7.7mm machine gun abreast of the forward funnel.
On 14 July 1939 Takao ran full power trials after her Modernisation refit. Even with the addition of an upper torpedo blister to improve stability and lessen draft, the wake would still swamp the lower row of scuttles if they were open. Her new tripod foremast and relocation of her mainmast to just forward of No 4 barbette are clearly shown. During these trials Takao hit 34.25 knots at 133,100shp on the measured mile.
Since the cruisers of the Takao class were newer than the Myokos, they received very few alterations early in their careers. In August 1933 new HA directors were installed. As a result of the typhoon damage to Myoko in September 1935, the Takao class also received hull strengthening plates from May to September 1936, Takao and Maya also received heavier lattice cranes to the mainmast for aircraft handling, to replace the pole derricks originally fitted. In Maya blast screens for the searchlight towers were removed and new searchlights fitted. Further minor modifications were made in 1937 and 1938. In May–June 1937 Takao received the new searchlights, a shortened foremast and added a radar room inside the quadruped foremast. From October 1936 to July 1937 Chokai received the same treatment, as well as replacement of the Vickers 40mm guns by quadruple Hotchkiss 13.2mm guns and the new lattice crane. Maya received the radar room and AA replacement in December 1937 to January 1938. Other than hull strengthening plates, Atago did not receive these modifications.
By 1937 plans were underway to thoroughly modernise the Takao class, scheduled from 1938 to 1939 for Takao and Atago, with Chokai and Maya to follow in 1940 to 1941. Takao underwent modernisation from May 1938 to August 1939 and Atago from April 1938 to October 1939, but war intervened before Maya or Chokai could be taken in hand. Thereafter ships of the Takao class could be easily identified as to which group they belonged.
FIRST MODERNISATION (TAKAO AND ATAGO 1938–1939)
The main details are given in the summary table. The four Type 96 twin 25mm guns were positioned on either side of both funnels and the two Type 93 twin 13mm on bridge sponsons (replaced by twin 25mm mounts in the fall of 1941). New gun platforms for the planned twin 127mm (5in) were added but the new guns were not actually installed until March and April 1942 in unshielded mounts. Two four-charge depth charge racks were added to the stern. The upper bridge was rebuilt to reduce topweight and received new range finders. The aircraft deck rails were changed to match the pattern already installed on the Myoko class, along with the heavier catapults. After the refit one Type 94 ‘Alf’ three-seat and two Type 95 ‘Dave’ two-seat floatplanes were carried, but the Type 0 ‘Jake’ replaced the ‘Alf’ in November 1942 and the Type 0 ‘Pete’ replaced the ‘Dave’ in 1942.
The torpedo bulge was enlarged along the same lines as those in the modernised Myoko class, so Takao and Atago had torpedo bulges that were visible above the waterline while Maya and Chokai did not. The new torpedo bulges greatly increased stability: revised design draft was 6.41m but at trial displacement of 14,838 metric tons, the draft was 6.32m. New bilge keels were also fitted.
When it was clear that Maya and Chokai could not receive the same modernisation, a few less extensive changes were made in 1941. The twin torpedo mounts were adapted to receive the newest model of 610mm torpedo. The new heavier catapults were also installed, although they initially received the same complement of floatplanes as Takao and Atago. The quadruple 13mm machine guns on either side of the aft funnel were replaced by Type 96 twin 25mm mounts and twin 13mm machine gun mounts were added on either side of the bridge.
After the Dutch East Indies operations, Maya and Chokai had the twin 13mm guns on the bridge replaced by twin 25mm guns and two additional twin 25mm mounts were placed on either side of the forward stack. They also received the two depth charge racks at the stern, as previously fitted to Takao and Atago. At the end of the Guadalcanal campaign, in February 1943 the Takao class was slated for their First Wartime Modification. Takao and Atago were refitted from July to August 1943 with additional light AA of two triple 25mm mounts on either side of the mainmast, Type 21 radar and bridge wind baffles. Maya and Chokai received two additional twin 25mm mounts on either side of the mainmast, Type 21 radar and wind baffles from August to September 1943.
The Takao class cruisers, less Maya, received their Second Wartime Modification in the same time period as the ships of the Myoko class. Atago from November to December 1943 and Takao from November 1943 to January 1944 received the same treatment, but Chokai, at Truk, only had ten single 25mm guns added. Maya, however, received a unique refit: she was rebuilt as an anti-aircraft cruiser from December 1943 to April 1944 at Yokosuka. No 3 203mm gun turret and the existing AA armament was removed, and replaced by the new battery shown in the table. Her torpedo armament was also brought up to standard and a centreline depth charge rail added. She was equipped to handle two new Model 11 Zuiun floatplanes but only carried two ‘Jakes’. After these changes, standard displacement rose to 13,350 tons and trial to 15,159 tons. It was planned to give Chokai the same conversion as Maya but this plan was shelved.
By the summer of 1944 the four ships of the Takao class presented three distinctly different appearances, with Takao and Atago substantially identical, Maya unique in her AA configuration, and Chokai the only unit retaining her pre-war appearance with single 120mm mounts, twin torpedo tubes and no above-water torpedo bulge. The Third Wartime Modification for the Takao class was conducted in June and July 1944. Takao and Atago continued to be twins with each receiving an additional four triple and twenty-two single 25mm gun mounts. Maya received an additional eighteen single 25mm mounts. Chokai had the fewest changes, with twelve extra single mounts, as she did not have the additional stability conferred by enlarged torpedo bulges. This was the last appearance for the ships of the class, as Atago, Maya and Chokai were sunk during the Battle of Leyte Gulf. Although Takao managed to limp back to Singapore after being torpedoed in the Palawan passage, she was not repaired. She remained an immobile AA platform and survived the war. She was the last of the Japanese heavy cruisers, as she was not scuttled until 26 October 1946, almost four months after Myoko.