Abstract: The present invention relates to a gravity based structure 5 with a topside 2 on at least one hollow concrete platform leg 1 with a platform leg wall and a circular cross section. The at least one platform leg, includes an upper leg portion (4) cut off from a lower leg portion 3. The lower leg portion 3 has an upper sloped cut surface 10 inclined at an angle in the range of 1°-10° off a horizontal axis. The upper leg portion 4 has an upper leg sloped cut surface inclined at the same angle as the lower leg sloped cut surface 10 of the lower leg portion 3 whereby the angles are complementary, the sloped cut surfaces forming an inner and an outer obtuse cone with a common vertical longitudinal axis. Furthermore, the invention relates to method of forming a conical cut through a concrete platform leg of a GBS.

Abstract: An improved multi-bolt and nut torque wrench for installing and removing bolts or nuts from flanged joints or the like which includes a plurality of torque stations having a plurality of high torque wrenches for engaging the heads of the bolts or nuts during a high torque phase of removal or installation; a plurality of low-torque motors operatively engaged with the wrenches for rotating the bolts or nuts during the low torque phase of removal or installation; a source of hydraulic fluid for driving the low-torque motors during the low-torque phase, and driving the high-torque wrenches during the high torque phase; and a mechanism for switching between the two phases depending on the torque needed.

Abstract: An ROV hot-stab device (100) comprising a hot stab body (102) having a flow bore (102A) that is adapted to receive a fluid, a housing (104) that is operatively coupled to the hot stab body (102), and at least one fluid inlet/outlet (104A/104B) defined in the housing (104). The device (100) also includes an isolation valve (103) that is at least partially positioned within the housing (104) wherein the isolation valve (103) is adapted to, when actuated, establish fluid communication between the bore (102A) of the hot stab body (102) and the at least one fluid inlet/outlet (104A/104B) and at least one sensor (114) positioned at least partially within the housing (104) wherein the sensor (114) is adapted to sense a parameter of the fluid.

Abstract: Systems and methods for deployment and retrieval of ocean bottom seismic receivers. In some embodiments, the system includes a carrier containing receivers. The carrier can include a frame having a mounted structure (e.g., a movable carousel, movable conveyor, fixed parallel rails, or a barrel) for seating and releasing the receivers (e.g., axially stacked). The structure can facilitate delivering receivers to a discharge port on the frame. The system can include a discharge mechanism for removing receivers from the carrier. In some embodiments, the method includes loading a carrier with receivers, transporting the carrier from a surface vessel to a position adjacent the seabed, and using an ROV to remove receivers from the carrier and place the receivers on the seabed. In some embodiments, an ROV adjacent the seabed engages a deployment line that guides receivers from the vessel down to the ROV for “on-time” delivery and placement on the seabed.

Abstract: A subsea power distribution device and system. The subsea power distribution device comprises a watertight housing accommodating at least one transformer, the transformer having a primary winding and a plurality of secondary windings; input terminals, electrically connected to the primary winding and arranged to be connected to a remote power supply; output terminals, electrically connected to the secondary windings and arranged to be connected to subsea power consuming devices. The switches are arranged to break the connections between each secondary winding and a corresponding output terminal, and the switches are arranged within the watertight housing.

Abstract: A subsea power distribution module includes an outer vessel defining an interior chamber and a plurality of power modules disposed within the interior chamber. The outer vessel is configured to maintain a pressure within the interior chamber substantially the same as an ambient pressure outside the outer vessel. Each power module includes a pressure vessel defining an interior chamber and a power converter disposed within the interior chamber of the pressure vessel. Each pressure vessel is configured to maintain a substantially constant pressure within the interior chamber of the pressure vessel.

Abstract: The invention relates to remotely operated multi-component search robots for underwater search and rescue operations, and particularly suited for searches under ice.

Abstract: A subsea payload such as an AUV (autonomous underwater vehicle) or an AUV garage is lifted from an underwater location by flying a latch unit through the water to the payload. The latch unit carries a lift line toward the payload. The latch unit is then attached to the payload and the payload is lifted using tension applied through the lift line via the latch unit. The latch unit can also be used on a lift line to lower a payload and then to release the payload at an underwater location. The lift line is supported by a heave-compensating winch on a surface vessel that effects z-axis movement of the latch unit. The winch maintains tension on the lift line to prevent the lift line falling on the payload. Movement of the latch unit on x- and y-axes is effected by on-board thrusters.

Abstract: A system and method for coupling electrical power subsea. The system comprises a subsea electrical distribution system having at least one modular subsea circuit breaker assembly. The modular subsea circuit breaker assembly may be coupled to sources of power and/or subsea loads via one or more subsea power cable harness assemblies. The modular subsea circuit breaker assembly has at least electrical connector. Each subsea power cable harness assembly has a corresponding electrical connector. At least one of these electrical connectors is extendable to engage an electrical connector opposite it.

Abstract: An underwater cable deployment system for deploying an ocean bottom cable on the seabed including a cage having a lower frame and an upper frame, which lower frame is adapted to receive the ocean bottom cable and the upper frame is connected to an umbilical cable mounted on a vessel, the upper frame being removably attached to the lower frame, guiding and tensioning means for deploying the ocean bottom cable on the seabed, the lower frame further including a recording unit which is connected to the ocean bottom cable and is adapted to record data detected by at least one sensor unit of the ocean bottom cable and an electrical power unit adapted to provide power to the recording unit and to the ocean bottom cable.

Abstract: A connection system for subsea connection of a subsea umbilical to a subsea appliance, the system comprising a termination box fixed to the umbilical; a first coupling part mounted to the termination box; a second coupling part; a connection unit, to which the termination box is slidably mounted; and a landing unit, which has a fixed position in relation to the second coupling part. Guide members are provided on the connection unit and the landing unit for guiding the connection unit into a correct position in relation to the landing unit when the connection unit is lowered downwards into contact with the landing unit. The termination box is displaceable axially forwards in relation to the connection unit by means of an actuating unit so as to bring the first coupling part into contact with the second coupling part.

Abstract: A towed array sonar system 10 with a towed array 14, a deployment device 32 for respectively deploying and retrieving the towed array 14 into and from a body of water, a signal processing device 28 for processing the signals of the towed array 14 and at least one control console 30 for controlling the towed array sonar system 10. In order to create a mobile sonar system that can be deployed independently of a ship, the towed array 14, the deployment device 32, the signal processing device 28 and the control console 30 are installed in a container 12 that can be transported independently of a ship. The invention furthermore pertains to a method for carrying out a sonar mission using such a towed array sonar system 10.

Abstract: A deployment apparatus is described. The deployment apparatus is for deploying an underwater power generator having a power generating main body from a deployment vessel disposed on the surface of a body of water onto a pylon disposed on the bed of the body of water and the deployment apparatus includes: a frame including one or more connectors disposed on a base region of the frame, the connectors for releasable connection to catches disposed on an upper region of the power generating main body, the connectors being remotely operable between a connected position in which the connectors are engaged with the catches and a disconnected position in which the connectors are disengaged from the catches; and one or more cameras disposed on the frame for providing visual guidance to the vessel of the position of the underwater power generator relative to the pylon. A method for deployment of the underwater power generator is also described.

Abstract: Disclosed are an underwater moving apparatus and a moving method thereof. The underwater moving apparatus of an exemplary embodiment of the present invention includes a body; a propelling device installed on a rear side of the body; a thruster unit including an up and down directional thruster and a left and right directional thruster installed at the body; and a plurality of leg units positioned at both side portions of the body and including a multi-joint module.

Abstract: A spool has a cylinder, a first flange coupled to a first end of the cylinder and a second flange coupled to a second end of the cylinder. A compressible material surrounds the cylinder and an optical fiber is wrapped around the compressible material. When tension is applied to the optical fiber the compressible material can be deformed to reduce the tension on the optical fiber. When submerged underwater the water pressure will not compress the compressible material.

Abstract: An optical fiber management system for a remotely operated vehicle (ROV) includes a spool containing a length of optical cable, a motor coupled to the spool, a motor controller, a speed sensor and a feed mechanism. The motor controller can detect the speed of the ROV through water and control the rotational speed of the motor so that the optical cable is removed from the spool at a speed that is equal to or greater than the speed of the ROV. A feed mechanism is used to apply a tension to the optical cable so that it is removed from the spool and emitted from the ROV without becoming tangled.

Abstract: A spool has a cylinder, a first flange coupled to a first end of the cylinder and a second flange coupled to a second end of the cylinder. A compressible material surrounds the cylinder and an optical fiber is wrapped around the compressible material. When tension is applied to the optical fiber the compressible material can be deformed to reduce the tension on the optical fiber. When submerged underwater the water pressure will not compress the compressible material.

Abstract: Subsea oilfield equipment (2), such as an oil and/or gas production template, is installed at the water bottom (16) by means of a submerged installation vessel (1) from which hoisting lines (3A, 3B) are deployed to support the equipment during the installation procedure, which lines (3A,3B) are reeled from at least one hoisting line reeling winch (3A,3B) mounted at the submerged installation vessel (1) to lower the equipment (2) at a desired speed and in a substantially horizontal position onto the water bottom (16).

Abstract: In various embodiments, an apparatus for use in the recovery of unmanned underwater vehicles includes a recovery vehicle configured to be coupled to a winch via a tether. The recovery vehicle includes one or more sensors for locating the unmanned underwater vehicle, a first mechanical linking device for coupling the recovery vehicle to the unmanned underwater vehicle, and a plurality of steering mechanisms for actively guiding the unmanned underwater vehicle in such a way as to allow the first mechanical linking device to capture the unmanned underwater vehicle by locking onto a second mechanical linking device of the unmanned underwater vehicle.

Abstract: A method and a device are described for survey of an ocean floor, and also cables and the like on the ocean floor in ocean areas with strong currents, as a submersible survey platform (10) is lowered from a surface vessel with the help of a winch system (12) on the vessel to a desired distance in relation to the ocean floor. The desired fixed distance from the ocean floor is controlled in real time in relation to the topography of the ocean floor at the same time as the vessel moves forward to drive the platform (10) along a desired trajectory with the help of one or more sensors that register the distance to and possibly direction towards the ocean floor and which are connected to the winch (12) via a control system (14). At the same time, sideways movements of the platform (10) caused by currents are compensated for with the help of one or more sensors that are connected to a number of thrusters (16) on the platform (10) via said control system (12).

Abstract: A system for communicating with a remotely operated underwater vehicle (ROV) includes a winged ROV coupled to a surface buoy by a tether. A controller on a support ship is coupled to the tether and the control signals are then transmitted through the tether to the ROV. Feedback and sensor signals are transmitted from the ROV through the wireless transceivers to the controller. The wings of the ROV produce negative lift which is greater than the buoyant force of the ROV and the vertical tension forces on the tether.

Abstract: Methods and apparatus for monitoring a remotely operated vehicle umbilical condition in real time allowing for improving of power delivery as well as early detection of threats to integrity of the umbilical. The umbilical may include an optical fiber. Processing equipment may enable distributed temperature sensing along the optical fiber.

Abstract: Pollutants such as hydrocarbons which have settled on the bed of a body of water are removed to the surface using a submersible vehicle positioned above the bed of a diver supported on a platform above the pollutant. A wand at one end of a pipe evacuated by a centrifugal pump is manipulated to draw the pollutant to the surface for treatment or disposal.

Abstract: An electrical power system for stationary or movable subsea loads (7) providesone common feeder for multiple electric motors which can be individually controlled. Operational flexibility and operational safety for operation in varying water depths is provided by encapsulating electrical functional element (6) of a subsea power system with a subsea electrical distribution system (5) individually or in-groups. Electrical functional element (6) and their semi-conductor elements are arranged within at least one fluidized internal pressure casing (13). An external pressure casing (12) is provided for the subsea electrical distribution system (5) and/or other components of the subsea system. A high frequency power transmission to the subsea pressurized distribution system (5) with pressurized semi-conductor components reduces weight and size of subsea transformers (4b) and cables (9) employed in subsea systems (10).

Abstract: A remotely operated underwater vehicle includes a case to which is attached a camera for transmitting video to a remotely located base station. A tether having four pairs of twisted wire operably connects the underwater vehicle, and the camera to the base station. Video is transmitted from the camera to the base station on a pair of twisted wire.

Abstract: A propulsion system is provided for an underwater vehicle such as a Remote Operated Vehicle (ROV). Two propellers are independently driven by motors, while the orientation of the propellers is simultaneously controlled by a third motor. A means is provided for reprogramming the control electronics that can be disabled when the vehicle is underwater. The control electronics also provides that all signals including video are transmitted to a base station without requiring coaxial cable.

Abstract: A propulsion system is provided for an underwater vehicle such as a Remote Operated Vehicle (ROV). Two propellers are independently driven by motors, while the orientation of the propellers is simultaneously controlled by a third motor. A means is provided for reprogramming the control electronics that can be disabled when the vehicle is underwater. The control electronics also provides that all signals including video are transmitted to a base station without requiring coaxial cable.

Abstract: A remote operated, underwater non-destructive ordnance recovery system, includes a powered remote controller, a floating remote controlled transceiver wired to a remote disposal unit having a hydraulic grapple, an ordnance recovery basket, and the method in which these devices are used to extract unexploded underwater ordnance. The remote disposal unit includes an electrically driven internal hydraulic pump with bio-degradable hydraulic fluid in a closed loop system. A base includes variable footplates to stabilize the hydraulic grapple by remotely adjustable telescoping legs. A control head that receives signals from control cables and transfers them into hydraulic value actuation, an extendable fully rotating boom, two ballast tubes, a rotating grapple, and lighted underwater cameras on the control box and ballast tubes are also included in remote disposal unit.

Abstract: A floating lowering and lifting device (1) includes a floating structure (2) and a lifting unit (3) lowerable from the floating structure (2) towards the sea bed, the lifting unit (3) having a chamber (5) with at least one gas-inlet opening (9) in its wall (27) and an equalization opening (23, 25) in its wall (27), a gas supply (13) being connected to the gas inlet opening (9) The device includes a control element (15) connected to the gas supply (13) for controlling a gas supply rate to the chamber (5), wherein the chamber (5) includes a releasable coupling member (7) for releasably attaching to a load (8).

Abstract: Disclosed is a system that performs inspection and repair of an underwater structure, specifically core internals in a pressure vessel. An underwater vehicle is provided with a drive wheel, a contact force generating unit (e.g., thruster) that presses the drive wheel to a vertical wall of the underwater structure, an ascending force control unit (e.g., ballast) that controls the buoyancy of the vehicle, a guide roller that engages with and is pressed against an undersurface of the underwater structure by the ascending force controlled by the ascending force control unit. The underwater vehicle is appropriately positioned with respect to the vertical direction by the guide roller. The drive wheel is driven for rotation so that the underwater vehicle runs horizontally along the vertical wall to reach the inspection or repair site, where the inspection or repair is carried out by work tool mounted to the underwater vehicle.

Abstract: An apparatus and method is provided for transporting, installing, retrieving, and replacing a sensor array of individual sensor pods at a geographically remote location, such as on the sea floor. The apparatus consists of a remotely operated vehicle (ROV), a carousel attached to the ROV, a pod ejector mechanism attached to the carousel, and a manipulator with a manipulator end effector attached to the ROV. The carousel contains a plurality of sensor pod holders, where each sensor pod holder is capable of holding a sensor pod. The pod ejector mechanism is capable of discharging a fresh sensor pod, while the manipulator end effector is capable of lifting a depleted sensor pod and placing the depleted sensor pod in an empty sensor pod holder in the carousel.

Abstract: A device for inspecting submersed plant parts is particularly suited for ultrasonic inspection of screws in the core baffle of a nuclear reactor pressure vessel. The device includes a remote-controlled underwater vehicle that is provided at its end face with a carrier that can be pivoted about a pivot axis oriented parallel to the longitudinal central axis of the underwater vehicle, and is provided with a holding device for an inspection head that is arranged on the carrier spaced apart from the pivot axis.

Abstract: An apparatus for cutting wooden piles underwater and a method of use are disclosed. The apparatus has a frame and brace configured for engaging a pile. A pressure medium activated cutting device is connected to the frame and oriented at an angle such that a pile can be cut at a point below the bottom surface. The frame and brace are placed on opposite sides of the pile and connected to each other with a chain or cable. The apparatus has lines attached thereto and the other ends of the lines are attached to a boat or other flotation device. Using the disclosed apparatus to remove pilings causes significantly less turbidity than devices or methods currently available. Additionally, using the disclosed device also eliminates the need to decontaminate silt removed from the water using the currently available methods or devices.

Abstract: The method for lowering an object to an underwater installation site, wherein a submersible remotely operated vehicle (ROV) having at least one thruster for providing lateral thrust is interconnectable to an object, entails providing a vessel, having a winch and suspension cable; interconnecting and lowering the object and ROV towards the underwater installation site using a suspension cable, providing at least one anchor near the installation site; interconnecting each anchor and ROV with a positioning wire, while the ROV and object are suspended in the holding position; tensioning and adjusting the length of each positioning wire such that the interconnected ROV and object are positioned with respect to the installation site; and further lowering interconnected object and ROV, which are positioned by at least one positioning wire onto the installation site while keeping the interconnected object and ROV suspended from a suspension cable.

Abstract: Apparatus and methods for remotely installing vortex-induced vibration (VIV) reduction and drag reduction devices on elongated structures in flowing fluid environments. The apparatus is a tool for transporting and installing the devices. The devices installed can include clamshell-shaped strakes, shrouds, fairings, sleeves and flotation modules.

Abstract: A device (20) for replacing equipment, i.e. modules on an installation (10) on the seabed. The device comprises a box-shaped buoyancy element which has storage spaces (25) for equipment together with winch devices (22) assigned to each storage space. During use the device is lowered from a vessel (1) to the seabed by a crane (3), but is stopped a distance from the installation, whereupon the locally provided winches (22) are used to pull up and position the equipment.

Abstract: The method of providing in excess of 60 kilowatts of electrical power to the electrical motor of a subterranean electric drilling machine through a substantially neutrally buoyant composite umbilical containing electrical conductors to reduce the frictional drag on the neutrally buoyant umbilical. Drilling and casing subterranean monobore wells are contemplated to distances of 20 miles from a wellsite. For drilling applications, the umbilical possesses a drilling fluid conduit. The umbilical also possesses high speed data communications such as a fiber optic cable or a coaxial cable that is used in the feedback control of the downhole electric drilling motor. Such umbilicals are also useful to provide power to remotely operated vehicles for subsea well servicing applications.

Abstract: To install a modular seabed processing system (1) on a seabed, a monopile foundation (3) is first lowered down and driven into the seabed. A docking unit (4) is lowered towards the installed foundation (3) so that a mating clamp system (6) mounted on the docking unit is aligned with a spigot (5) on the foundation. The clamp system then clamps the spigot to fix the docking unit onto the foundation. Flowlines (2) and an electrical power connector plug (18) are connected to the docking unit. A first retrievable substantially autonomous module (8) is lowered and connected to the docking unit (4) by a multi-bored connector (10, 11) and the plug (18) on the docking unit is engaged by a corresponding socket (17) on the module. Isolation valves (14, 16) in the docking unit and module are opened so that the module (8) is able to act on fluid received from the flowlines (2) via the multi-bored connector (10, 11).

Abstract: A cable array robotic system and apparatus for applications such as cargo handling at sea and pallet handling in manufacturing, based on a multi-cable robotic control system is disclosed. The cables are deployed from three or more folding, telescoping masts at the corners of a work area. The cables attach to an end-effector (e.g. a spreader mechanism) that grips an object (e.g. a container) and affects desired movements as directed by an operator through a computer controlled graphical user interface using pointing directives such as “put that there”. Various sensors and cameras enable a high degree of control over the end-effector (e.g. spreader or pallet) as it is moved from place to place. Sufficient control is possible so that the present cargo handling system may unload, without pendulation, the deck and hold of a ship onto a sea-going lighter during sea state three conditions in a container handling application at sea.

Abstract: A system that is usable with subsea wells that extend beneath a sea floor includes a station that is located on the sea floor and an underwater vehicle. The underwater vehicle is housed in the station and is adapted to service at least one of the subsea wells.

Abstract: Apparatus and methods for remotely installing vortex-induced vibration (VIV) reduction and drag reduction devices on elongated structures in flowing fluid environments. The apparatus is a tool for transporting and installing the devices. The devices installed can include clamshell-shaped strakes, shrouds, fairings, sleeves and flotation modules.

Abstract: To install a modular seabed processing system (1) on a seabed, a monopile foundation (3) is first lowered down and driven in to the seabed. A docking unit (4) is lowered towards the installed foundation (3) so that a mating clamp system (6) mounted on the docking unit is aligned with a spigot (5) on the foundation. The clamp system then clamps the spigot to fix the docking unit onto the foundation. Flowlines (2) and an electrical power connector plug (18) are connected to the docking unit. A first retrievable substantially autonomous module (8) is lowered and connected to the docking unit (4) by a multi-bored connector (10, 11) and the plug (18) on the docking unit is engaged by a corresponding socket (17) on the module. Isolation valves (14, 16) in the docking unit and module are opened so that the module (8) is able to act on fluid received from the flowlines (2) via the multi-bored connector (10, 11).

Abstract: A method for controlling subsea drilling operations including, in at least certain aspects, controlling the subsea drilling operations with a control system having three subsea pod containers of a control system, each with apparatus for controlling the subsea drilling operations, the system also having activation apparatus for activating a chosen one of the subsea pod containers and maintenance apparatus for maintaining the two subsea pod containers other than the chosen one in a standby mode providing triple redundancy of control of the subsea drilling operations.

Abstract: A method and an apparatus, for deploying an object or a load on the seabed, the object or the load being coupled to a hoist, such as a hoisting wire in order to enable the object or the load to be lowered to the seabed from a vessel, the apparatus including a body having parts for releasably securing the object or the load to the body and propulsion for moving the body when submerged, whereby the propulsion is positioned offset from the parts for releasably securing the object or the load, in order to be able to induce rotational control on the hoist, when the propulsion is in use.

Abstract: A cable-driven manipulator can precisely manipulate tools and loads using position, velocity and force control modes. The manipulator includes a plurality of cables (2 or more) that are independently controlled by modular, winch drive-mechanisms and coordinated to achieve intuitive manipulator movement in all six degrees-of-freedom. The manipulator consisting of modular sub-assemblies and components (i.e. winch, amplifier, servo interface, sensory feedback), can be rapidly reconfigured to adjust to new applications. Various combinations of manual and automatic control can also be implemented. The winches can be controlled manually by a multi-axis joystick, or can be automatically controlled by computer.

Abstract: An apparatus for manipulating an object located proximate an underwater floor is disclosed, in a preferred embodiment comprising a foundation implantable in the underwater floor; a lifting frame extending between the foundation; and a multiplicity of slings mounted adjacent to each other and attached to the lifting frame such that each of the slings is suspended in a cradle-like configuration from the lifting frame. Each of the slings further comprises a top surface facing away from the underwater floor and a padding material mounted proximate the top surface of each sling. The foundation may further comprise suction piles. A monitoring system comprising instrumentation may also be used to aid in guiding the load transfer of the object from the floor to the lifting frame.

Abstract: A method for retrieving a subsea pod from a lower marine riser package platform by connecting a buoyant pod retriever to the subsea pod and raising the subsea pod to the surface. In certain aspects, such a method is accomplished without an interruption of associated subsea drilling operations and/or without disconnecting the lower marine riser package from an associated subsea stack. Such a method, in certain aspects, includes: positioning a retrieval module above the pod container, the retrieval module having a pod holder releasably connected thereto; disconnecting the pod holder from the retrieval module; lowering the pod holder to the pod container and releasably connecting the pod holder to the pod container; releasing the pod container from the subsea lower marine riser platform; raising the pod holder to the retrieval module and releasably connecting the pod holder with the pod container to the retrieval module; and raising the retrieval module with the pod container to a location at the surface.

Abstract: A TMS, cage type or top hat type incorporates a deployment frame. The TMS may be operated by a winch from a surface vessel. The TMS delivers a main ROV and a smaller mini ROV. The main ROV is fully functional to accomplish the necessary task subsea. However, in the event there is an operational failure of the main ROV, the mini ROV can be deployed. The mini ROV may have fewer functionalities than the main ROV, but can at least offer video and lighting to allow monitoring of a particular location subsea. All the necessary positioning capabilities are available on the mini ROV.

Abstract: There is provided an improved apparatus for recovery of sea-bed material. Known apparatus suffer from problems such as low recovery rate and capital cost. The invention, therefore, provides a recovery apparatus comprising a vehicle upon which are mounted a duct permitting communication between the sea-bed and a location remote therefrom, structure to introduce sea-bed material into the duct and structure to advance sea-bed material through the duct.

Abstract: Flying lead hydraulic and electrical umbilical arrangements are disclosed for control of a subsea christmas tree for production and workover operations. Alternative arrangements for deep water ROV arrangements for a conventional christmas tree are illustrated in FIGS. 2A, 2B and in FIGS. 3A, 3B, and 3C. Alternative arrangements for a horizontal christmas tree are illustrated in FIGS. 5, 6, and 7.