Patent ID: 8113133

Claim:
A tank skirt fixed to a hull, configured to support a tank, and including a curved portion in plan view, the tank skirt comprising: a hull supporting member fixed to the hull; a tank supporting member fixed to the tank and made of a metal dissimilar to a metal of the hull supporting member; and a dissimilar joint structure configured to join the hull supporting member and the tank supporting member, wherein: the dissimilar joint structure is formed by an inserting groove formed at one of the hull supporting member and the tank supporting member and an inserting portion which is able to be inserted into the inserting groove and is formed at the other of the hull supporting member and the tank supporting member, and the inserting groove is constituted by a groove forming portion which is provided at said one of the hull supporting member and the tank supporting member and has a U-shaped cross section, and the inserting groove and the inserting portion extend in a circumferential direction of the tank supporting member; and the groove forming portion is joined to the inserting portion by friction stir welding with the inserting portion inserted into the inserting groove.