Abstract: An anti-biofouling method which suppresses biofouling in water includes a preparation step of using a copper alloy-made anti-biofouling object member immersed in the water as a cathode electrode, and immersing and arranging an anode electrode member serving as a counter electrode of the anti-biofouling object member in the water, and a current supplying step of supplying DC current between the anti-biofouling object member and the anode electrode member.

Abstract: A method is provided for estimating a temperature distribution history in the case of line-heating flat-plate steel by high frequency induction.

Abstract: A liquefied gas tank includes an inner tank (2) that stores liquefied gas and is disposed so as to be capable of self-standing on a floor surface (F), and an outer tank (3) that is covered over the inner tank (2) and is supported by an upper face portion (2a) of the inner tank (2). The outer tank (3) is configured to be capable of sliding on the upper face portion (2a) of the inner tank (2) in response to expansion and contraction in the horizontal direction of the inner tank (2), and to be capable of moving in response to expansion and contraction in the vertical direction of the inner tank (2). A ceiling portion (3a) of the outer tank (3) that is placed on the upper face portion (2a) of the inner tank (2) is not fixed to the upper face portion (2a) of the inner tank (2), and the inner tank (2) and the outer tank (3) are configured to be capable of sliding in the horizontal direction relative to each other.

Abstract: In a spar-type floating structure comprising a tall, thin floating body 2 and a ballast portion 3 provided to the floating body 2 so that the weight of the ballast portion 3 allows the floating body 2 to float in upright position, the floating body 2 includes a horizontally-extending first extended portion 21 arranged at the bottom, a horizontally-extending second extended portion 22 arranged in the middle, and a column portion connecting the first and second extended portions 21, 22 and extending up to the waterline, the first extended portion 21 forms the ballast portion 3, and the second extended portion 22 constitutes a buoyancy portion giving buoyancy to the floating body 2.

Abstract: A working system includes a floating type floating structure, and a working ship configured to perform at least installation or maintenance of the floating structure. The floating structure has a column section whose peripheral surface is located at a waterline when the floating structure is floating, a ballast section arranged below the column section and a flange section arranged at an intermediate portion of the column section. The working ship has a gripping section capable of engaging with the flange section, and a raising/lowering device configured to raise and lower the floating structure.

Abstract: A tank support structure includes an inclined surface (21) formed on a side surface section of a housing section (2), a plurality of support base sections (22) arranged on the inclined surface (21), and a plurality of support blocks (4) arranged in a bottom surface section (31) of a tank (3) including a portion opposed to the inclined surface (21) and arranged on the support base sections (22). Support block bottom surfaces (41) arranged on the support base sections (22) of the support blocks (4) and support surfaces (22a) of the support base sections (22) that support the support blocks (4) have surfaces parallel to a plane (S) including a segment (CC?) connecting two contact points (a first contact point (C) and a second contact point (C?)) with the tank (3) in each of the support blocks (4) and a straight line (Lf) passing a fixed point (F) of the tank (3) and parallel to the segment (CC?).

Abstract: A tank support structure includes an inclined surface (21) formed on a side surface section of a housing section (2), a plurality of support base sections (22) arranged on the inclined surface (21), and a plurality of support blocks (4) arranged in a bottom surface section (31) of a tank (3) including a portion opposed to the inclined surface (21) and arranged on the support base sections (22). Support block bottom surfaces (41) arranged on the support base sections (22) of the support blocks (4) and support surfaces (22a) of the support base sections (22) that support the support blocks (4) have surfaces parallel to a plane (S) including a segment (CC?) connecting two contact points (a first contact point (C) and a second contact point (C?)) with the tank (3) in each of the support blocks (4) and a straight line (Lf) passing a fixed point (F) of the tank (3) and parallel to the segment (CC?).

Abstract: A liquefied gas tank includes an inner tank (2) that stores liquefied gas and is disposed so as to be capable of self-standing on a floor surface (F), and an outer tank (3) that is covered over the inner tank (2) and is supported by an upper face portion (2a) of the inner tank (2). The outer tank (3) is configured to be capable of sliding on the upper face portion (2a) of the inner tank (2) in response to expansion and contraction in the horizontal direction of the inner tank (2), and to be capable of moving in response to expansion and contraction in the vertical direction of the inner tank (2). A ceiling portion (3a) of the outer tank (3) that is placed on the upper face portion (2a) of the inner tank (2) is not fixed to the upper face portion (2a) of the inner tank (2), and the inner tank (2) and the outer tank (3) are configured to be capable of sliding in the horizontal direction relative to each other.

Abstract: A boil-off gas processing apparatus for reliquefying a boil-off gas (22) generated within a liquefied gas tank (2) storing a liquefied gas (21) and returning the reliquefied gas to the interior of the liquefied gas tank (2) includes a boil-off gas discharge line (3) configured to discharge the boil-off gas (22) from the liquefied gas tank (2) to outside, and a boil-off gas reliquefaction line (4) configured to immerse at least part of the boil-off gas discharge line (3) in the liquefied gas (21) within the liquefied gas tank (2). The boil-off gas reliquefaction line (4) includes a pressure holding device (42) configured to maintains a pressure necessary for reliquefaction of the boil-off gas (22) and has a length (L) sufficient to be able to absorb an amount of heat necessary for reliquefaction of the boil-off gas (22).

Abstract: Lubricant oil (45) serving as second lubricant oil is supplied into an outer intermediate shaft (11c) by a lubricant oil supply unit (50) and accumulated therein, and thereby the lubricant oil (45) is supplied to a contra-rotating front seal unit (37). Thus, by bringing the front side of the contra-rotating front seal unit (37) (seal ring (37b)) into a wet state by the lubricant oil (45), it is possible to reduce heat generation and it is possible to extend the life of the contra-rotating front seal unit (37).

Abstract: In a spar-type floating structure comprising a tall, thin floating body 2 and a ballast portion 3 provided to the floating body 2 so that the weight of the ballast portion 3 allows the floating body 2 to float in upright position, the floating body 2 includes a horizontally-extending first extended portion 21 arranged at the bottom, a horizontally-extending second extended portion 22 arranged in the middle, and a column portion connecting the first and second extended portions 21, 22 and extending up to the waterline, the first extended portion 21 forms the ballast portion 3, and the second extended portion 22 constitutes a buoyancy portion giving buoyancy to the floating body 2.

Abstract: The thrust load of an outer shaft is received by a contra-rotating thrust bearing provided in a boss of a front propeller and transmitted to an inner shaft. The combined thrust load of the outer shaft and the inner shaft is received by an inner thrust bearing provided on the bow side of the power transmission unit and transmitted to a ship body. The rotational force of an outer output shaft is transmitted to the outer shaft via a flexible joint (gear coupling). Thus, the thrust load of the outer shaft is transmitted to the ship body only via the inner shaft without being directly transmitted to the ship body, and the axial displacement and angular displacement are allowed by the gear coupling, so that it is possible to eliminate the influence of the change of hull deformation on the shaft center of the outer shaft.

Abstract: A working system includes a floating type floating structure, and a working ship configured to perform at least installation or maintenance of the floating structure. The floating structure has a column section whose peripheral surface is located at a waterline when the floating structure is floating, a ballast section arranged below the column section and a flange section arranged at an intermediate portion of the column section. The working ship has a gripping section capable of engaging with the flange section, and a raising/lowering device configured to raise and lower the floating structure.

Abstract: The object is to facilitate the installation of a contra-rotating propeller on a mother ship. Disclosed is a contra-rotating propeller unit in which a predetermined part on the rear side of an inner shaft (12) is supported by a contra-rotating rear bearing (36) provided in a boss (13a) of a front propeller (13), and which includes an inner fixing tool (50) detachably attached to a tip of an outer shaft (11) to temporarily support a predetermined part on the front side of the inner shaft (12), and a contra-rotating thrust bearing (40) provided in the boss (13a) of the front propeller (13) to receive the thrust load from the outer shaft (11) to transmit the thrust load to the inner shaft (12).