A stone dumping vessel having symmetrical stone compartments includes a hull, a stone conveying unit, and an oblique fallpipe unit. The hull has a control cabin. A cannula compensating device of the oblique fallpipe unit is disposed on a side of the hull and connected with a fallpipe. Two sides of the control cabin are symmetrically provided with the stone compartments and dynamic positioning (DP) system cabins, respectively. The stone compartments are operated independently for automatically unloading stones to the stone conveying unit disposed at a lower center thereof. The stones are conveyed by independent conveyor systems disposed at the left and right of the control cabin to the fallpipe. The dynamic positioning (DP) system cabins and the cannula compensating device are adapted to position the hull and the fallpipe respectively so that the stone dumping vessel having symmetrical stone compartments can achieve high accuracy of stone dumping.

The invention relates to a seabed foundation (1) for an offshore facility, comprising a primary pressure chamber (7) connected to a primary pump (8) and one or more secondary pressure chambers (9) connected to one or more secondary pumps (10). According to an embodiment of the invention, said primary pump is a suction pump and said secondary pump is a pressure pump. The invention further relates to a method (12) of installing said foundation on the seabed (19), which comprises the steps of activating (14) said primary pump to create negative pressure in the primary pressure chamber (7), so that the foundation sinks into the seabed, and activating (15) said one or more secondary pumps (10) to create positive pressures in the secondary pressure chambers (9), so as to control the alignment of the foundation with respect to a substantially horizontal axis (16) during the sinking into the seabed.

A corrosion-resistant cover system, having a corrosion-resistant cover structured and configured to be arrangeable around an object having one or more metallic surfaces that are susceptible to corrosion. The corrosion-resistant cover is operable to provide increased corrosion resistance to the object by preventing contact between the one or more metallic surfaces and ambient conditions exterior to the corrosion-resistant cover.

This application discloses a new type of suction leg, an offshore caisson, a sit-on-bottom supporting platform. The suction leg includes a sealing long pile, this sealing long pile including a tubular pipe and a top head connected tightly to the tubular pipe to form cylindrical integral structure with sealing top and opening bottom. The top head has at least one opening to be able to open or close. The sealing long pile can be penetrated into the seabed by a gravity penetration method or/and a suction pile penetration method, or pulled out from the seabed by a buoyancy uplift method or/and a suction pile uplift method.

A steel plate and concrete composite tank unit, tank groups and offshore platforms with new type of tank units are disclosed. The tank unit comprises an outer concrete tank that comprises an outer tank shell, two heads and ring shell connections at both ends, an inner steel tank that comprises an inner tank shell, epitaxial structures at both ends of the inner steel tank. Inner tank shell is connected to the outer tank shell by epitaxial structures, and an isolation layer that is formed from the gap between the outer concrete tank and the inner steel tank where it is filled with isolation medium.

A stone dumping vessel having symmetrical stone compartments includes a hull, a stone conveying unit, and an oblique fallpipe unit. The hull has a control cabin. A cannula compensating device of the oblique fallpipe unit is disposed on a side of the hull and connected with a fallpipe. Two sides of the control cabin are symmetrically provided with the stone compartments and dynamic positioning (DP) system cabins, respectively. The stone compartments are operated independently for automatically unloading stones to the stone conveying unit disposed at a lower center thereof. The stones are conveyed by independent conveyor systems disposed at the left and right of the control cabin to the fallpipe. The dynamic positioning (DP) system cabins and the cannula compensating device are adapted to position the hull and the fallpipe respectively so that the stone dumping vessel having symmetrical stone compartments can achieve high accuracy of stone dumping.

An underwater base handles an autonomous underwater vehicle. The underwater a support structure to be hooked to a cable, a storing part configured to store the AUVs, an inlet part located above the storing part and configured to control access of the plural AUVs to the storing part, and a control part configured to control a movement of the inlet part relative to the support structure. The control part is further configured to wirelessly guide the AUVs while approaching the inlet part.

The present invention relates to a method for lowering a subsea structure to be installed on the seabed into the water through the splash zone, said subsea structure comprising subsea equipment arranged on a substantially flat support base for preventing the subsea equipment to sink into the seabed. The method according to the invention comprises: lifting the subsea structure into the air in a horizontal position in which the flat support base extends substantially parallel to the horizontal plane; tilting the subsea structure while suspended in the air from the horizontal position into a tilted position in which the flat support base is angled with respect to the horizontal plane; lowering the subsea structure into the water through the splash zone in the tilted position; and tilting the subsea structure while suspended in the water below the splash zone back into the horizontal position.

A foundation structure of an offshore plant, such as a wind turbine, comprising at least one foundation element that can be anchored to the seabed without a gravity foundation and without a floating foundation and a support structure fastened thereto for fixing the offshore plant. The foundation element is a pile that can be inserted into the seabed by means of drilling and/or by means of vibratory driving, can be fixed in the seabed by means of an organic and/or inorganic material, and is oriented at an angle from a vertical on the seabed. A method of installing the foundation structure on a seabed includes first anchoring the coupling element by means of piles inserted into the seabed and then connecting the support structure to the coupling element.

A new inner passageway through a pre-cast concrete structure damaged by corrosion may be formed by stackable inserts formed of polymer concrete. The inserts may be stacked in the old passageway through the pre-cast concrete structure such that an inner surface of the stacked inserts forms a new passageway through the pre-cast concrete structure. A grout may be poured between an outer surface of the stacked inserts and an inner surface of the pre-cast concrete structure forming the old passageway. The surfaces of the stackable inserts may have superior resistance to corrosive acids such that the need for future repair is greatly reduced. Suitable pre-cast concrete structures for rehabilitation include pre-cast concrete structures utilized in wastewater systems, including manholes and other similar structures. In this manner, the damaged pre-cast concrete structures do not need to be removed during the rehabilitation.