The IJN Yoshino was a Ishikari-class Battlecruiser, built to a wildly different design as a result of wartime shortages.
Due to a bombing of the factory where the 12in Guns were being produced for Yoshino and her sister IJN Nantai, both ships were scheduled to be converted into Carriers.
However, just as work started on converting Yoshino, the decision was made to equip the Yoshino with 18.1in Guns from the cancelled Yamato-class Warship #111. The 6 guns had suffered severe casting flaws near the tip of the guns, and were scheduled to be scrapped.
However, in desperate need for capital ships, the decision was made to modify the Yoshino to be equipped with the excess guns, cutting the flawed tips off.
Equipped with what was essentially a howitzer, the Yoshino spent most of her service life in port, being deployed to provide island bombardment.
Approximately 85% completed by the time the barrel factory was bombed, the Yoshino was not an optimal candidate for a carrier conversion. However, with no other option, the Yoshino was being prepared to be converted into a light carrier, with a hanger essentially welded to her deck.
On January 1, 1947, work began in preparing in the modification of her barbettes to plate over. However, at this time the decision had been made to scrap the 6 ruined 18.1in barrels that had been intended for the now cancelled Yamato-class Warship #111 which had suffered a casting error to the ends of the barrels during the cooling process.
With the barrels located next to the drydock Yoshino was being constructed in, a young naval officer named Isoroku Maeda suggested that the end of the barrels be cut off, and instead be mounted on the Yoshino. With the strategic importance of a converted Yoshino being drastically limited due to her nearly completed state, the decision was made to follow through.
The 18.1in guns from the Warship #111 had suffered cracks in the very edge of the barrels, rendering a high chance of the barrel exploding. Pumping the "good" area of the barrels with cutting fluid, and using a blocker, the last 3.7m (12.1ft) of the normally 21.13m (69.4ft) long guns were cut off, leaving the guns 17.43m long (57.1ft).
This gave the guns a caliber of 38. While the turrets for Yoshino had never been completed, the turrets destined for the Nantai had been completed.
Modifying the turrets, the Gun Cradles from the 12.1in guns were removed, and the tunnel for the central barrel plated over with 10in thick of armor.
The wing tunnels were greatly modified, allowing not only the 18.1in guns to fit, but also allowing a greater elevation of 55 degrees.
The Barbettes for the turrets would also be raised, allowing the elevation machinery of the gun cradles from Warship #111 turrets to elevate the additional 10 degrees. The overall thought process was the conversion of the Yoshino into essentially a floating mortar, and the need for greater gun elevation was needed.
The overall changes to the elevation machinery was minimal, with only an additional 5 degrees of movement being added. Since the gun cradles already allowed for 5 degrees of gun depression, the gun cradles were simply rotated 5 degrees so that the normally negative 5 depression was in fact zero'd.
While the meant the guns could not depress, it did allow for less modifications to be made. However, this additional elevation also allowed for the use of the 18.1in "San Shiki" AAA Shells as being much more effective as a closer range screen.
Commissioned in 1948, the Yoshino was quickly mocked for being an incredibly ugly ship, not only due to the already strange appearance of the Ishikari-class Battlecruisers, but also the very odd short guns.
She quickly received the nickname "Shorty" during her firing trials. Taking the unofficial but effective role of the battleships of land bombardment to the extreme, the Yoshino was rarely deployed from her home port in Nagasaki, instead being deployed for land bombardment.