Dry-docking at Yokosuka
By STARS AND STRIPES Published: March 1, 2009
U.S and Japanese sailors worked Friday at Yokosuka Naval Base, Japan, to dry-dock AGS 5103, a Suma-class oceanographic research ship with the Japan Maritime Self-Defense Force.
Dry-docking allows workers to maintain the underside of the ship by taking it out of water. The process can take up to eight hours.
Workers begin by opening flood gates in the caisson, a barrier wall between the dry dock and the water. After the dock is completely flooded, the caisson is removed and the ship can enter. Once the ship is in, the caisson is replaced and water is slowly pumped out.
When the water reaches a certain level, divers enter the water and ensure the hull of the ship aligns with the holding blocks underneath. With the bow and stern in place, services such as electrical, water and discharge are connected to the ship. The remaining water is removed from the dry dock and the ship given a final inspection.
The U.S. Naval Ship Repair Facility and Japan Regional Maintenance Center oversee all dry-docking operations at Yokosuka Naval Base.