Akashi is the only ship in Japanese Navy designed and built as a construction ship. While the big hitters get all the attention, she's a very important logistic ship.
Before Akashi was constructed, the Japanese Navy modified the captured Russian steam ship Manchuria and operate her as the repair ship Kantou. But this ship sank in an accident in 1924.
Now they wanted a real repair ship.
But, ignoring budget, the (② Plan) was approved in 1934 and finally construction was started in Sasebo Shipyard in January 1937. Construction was finished on July 31st 1937.
Her hull design was a flat-deck type (all the exposed deck from bow to stern was made into a single deck). This gave her more space internally and three large cranes were installed on the deck.
There were 17 workshops in her hull and they worked on everything from milling to finishing. For this, they had 144 units of the latest machine tools imported from Germany that even facilities on the mainland didn't have. Thanks to this, Akashi had a very high repairing capacity.
During the war, Akashi's sister ship Mihara was planned in the "Improved Circle-5 Plan", but because the situation worsed, her construction was halted.
There is this episode of Akashi. In 1940, the crew of Akashi were welcoming the new year on the sea. They wanted to make mochi, but they didn't have a mortar nor a mallet.
So they decided to make that equipment themselves. But instead of a chisel and plane, they used their large sized lathe and as result the wood became soft and easily chipped
Nobody realized this when they were pounding the mochi. Only when the mochi was done did they realize that it was filled with wooden chips.
But because it was a new year celebration, they ate the mochi with tears from their eyes. ( what a tough crew isn it.
Another story is when the submarine i-156 got stranded on Miyakojima. Akashi tried to pull the submarine, but even after moving all the submarine's cargo to Akashi, the submarine still wouldn't budge.
Then, the light cruiser Jintsuu made a circular course at high speed and let the large wave she caused wash over the submarine. Following the timing of the wave, Akashi finally managed to dislodge the submarine.
(from Recollection of Repair Ship Akashi).
Back to the story.
With her equipment, Akashi became the mobile factory of the Combined Fleet and the vital point of the fleet's repair.
While going to Truk, she performed repair on Mogami who had been damaged in the Battle of Midway on the sea. After she arrived, she performed repair on Chitose, Ootaka, Murasame, Chikuma, Teruzuki, Amatsukaze, Sendai, Agano, Akizuki, Kumano, Yakaze and many others. Imagine the long line of patients waiting to meet the doctor.
Of course this was also known to the enemy and there were orders that put her destruction at a higher priority than even Yamato.
She was heavily damaged in an air raid on Truk in February 1944, forcing her to retreat to Palau. Then on March 30th, she hit the bottom after receiving 13 bombs from an air raid on Palau.
After losing Akashi, damaged Japanese ships in the southern front were forced to return to the mainland for repairs. This separated the southern front which had fuel but couldn't do repairs and the mainland which could perform repairs but didn't have enough fuel. Japan had essentially lost it's ability to continue the war.
In modern day, Akashi's name was inherited by JMSDF ocean observation ship (JS Akashi, AGS-5101). Want know more about akashi? See wikipedia of course http://en.m.wikipedia.org/wiki/Japanese_repair_ship_Akashi
