Operation Oyster Bay, referred to by most non-Mesans as the Yawata Strike and by treecats as the Day of Sorrow, was a massive military assault on the Manticore System and the Yeltsin's Star System by the Mesan Alignment Navy.
It was carried out in February 1922 PD after a long phase of planning and preparation, and was a terrible blow to both star systems.
The Alignment originally intended to strike in the Republic of Haven as well, but due to certain unexpected events in the Talbott Quadrant, and especially in light of the Battle of Manticore, Albrecht Detweiler decided to accelerate the operation and carry out only the Manticoran Alliance part with goals to destroy new generation Apollo-capable ships in shipyards and stop their missile production.
However, only the second goal was reached, as most of the new ships had already left their building docks. (SI2)
There were actually six separate attacks on the Manticore System itself, one for each inhabited planet's orbital infrastructure, and each divided into two separate waves, although they were carefully synchronized to form a single, devastating blow. (HH12)
- See here for a full list of Oyster Bay casualties.
- HMSS Hephaestus, the Royal Manticoran Navy's primary space station and home port, was hit by eighteen graser torpedoes and completely destroyed.
- HMSS Vulcan was also completely destroyed.
- HMSS Weyland was also completely destroyed, but the loss of life was minimal due to a surprise emergency evacuation exercise in effect at the time of the attack. The loss of life aboard the space stations was estimated at 5.4 million. Additional loss of life from the attacks on the orbital shipyards amounted to 396,000, with more being killed aboard small craft and private vessels that found themselves caught in the crossfire.
- The majority of the dispersed orbital yards were destroyed
- Edward Saganami-C-class heavy cruisers:
- Roland-class destroyers completing their final fitting out, with almost their full complements embarked:
- Yard tugs
- The Blackbird Yard was completely destroyed with almost 100 percent of the workforce. Because it was located far away from Grayson, there were no collateral casualties like at Manticore. However, High Admiral Wesley Matthews was at Blackbird at the time of the attack and was killed. (HH12)
Multiple fragments of HMSS Vulcan hit the Tannerman Ocean on the planet Sphinx. The resulting impact surge killed more than 10,000 people in dozens of small coastal towns, including Tanners Port, and inflicted billions of dollars worth of damage. Several fragments also hit the city of Yawata Crossing, destroying it completely.
On Manticore only 200 people were killed. (HH12)
Oyster Bay had catastrophic consequences for Manticore's economic and military strength: most of the workforce trained to build ships of war was gone, as was most of the missile-building capacity. More than 13 million people were killed, and no one even knew where the attack came from. Queen Elizabeth III, however, made it clear that she would not allow her Empire to fall before its enemies.
First Space Lord Thomas Caparelli assumed full responsibility for the Royal Manticoran Navy's inability to prevent the attack, and offered his resignation to both First Lord of the Admiralty White Haven and the Queen herself. They both refused to consider it; partially in the belief there had been no way to predict the sudden technology shift, partially because of the possibility of the media perceiving it as a desperate attempt to find a scapegoat.