Is a Retractable Better Than a Tunnel Thruster?

As oil and gas exploration moves into deeper waters, we see an increased demand for bow thrusters.  OSVs and crew boats are getting larger and are becoming more difficult to dock.  Deep-water drillers and producers don’t allow support vessels to dock at their platforms and demand that vessels hold station in open sea while offloading […]

Bow Boat for Barge Tows

The other skippers shake their heads in disbelief.  They have been windbound for two days, but Breathwit Marine Contractors still runs a 3 barge empty tow at 7 knots.  The West end of the Intercoastal Canal with all its narrow bends, river crossings and locks is hard enough to maneuver in nice weather.  But with […]

DP Conversions of Existing Vessels with Thrustmaster’s Modular DPS

Abstract As older offshore production areas become more congested and new exploration moves to deeper  waters, the demand for dynamically positioned vessels, barges and platforms increases rapidly.  Rather than scrapping older vessels and replacing them with DP-capable newbuilts, many existing vessels and rigs can be upgraded for DP at a fraction of the cost of […]

Tips For Noise-Critical Tunnel Thruster Installations

Tunnel thrusters have a bad reputation for being noisy.  Since some thrusters are used only for short periods of time during docking, a noisy thruster may occasionally be acceptable for certain applications. However, there are many applications where noise is critical, and a noisy thruster is not acceptable, even if it is used only for […]

Tips on Thruster Selection

A bow thruster used for docking and undocking should be capable of producing thrust in pounds of force (lbf) equal to twice the lateral cross sectional vessel area below the water in square feet or two to three times the lateral cross sectional area of the superstructure above the water, whichever is greater. Sizing of […]

Portable Dynamic Positioning: Opportunity for Short-Term Projects

Increased activity in offshore petroleum exploration and both pipe and cable lay has led to the need for vessels with true dynamic positioning (DP) capability. This need is the product of both exploration in deeper offshore waters and the infrastructure congestion of mature undersea fields. Conventional mooring systems utilizing anchors and anchor handling vessels are not practical in […]

Tips on Thruster Installation

Thrustmaster tunnel thrusters are easy to install.  The whole unit has already been installed in a section of tunnel and all you need to do is install this section of tunnel in the hull. With hydraulic tunnel thrusters, orientation is not critical.   You can direct the strut opening straight upward, down, fore, aft, or […]

Hydraulic Power Systems and Controls

Thrustmaster hydraulic tunnel thrusters can be powered by open loop or closed loop hydraulic systems.  The simplest and least expensive system is an open loop system using a fixed-displacement pump and a directional control (“bang-bang”) valve.  The valve is solenoid operated and controlled with an electrical signal from the joystick in the pilot house (See Figure 1 […]

Thrusters On Semi-Submersibles And The Coanda Effect

Thrustmaster of Texas, Inc. The Coanda effect is the phenomenon in which a jet flow attaches itself to a nearby surface and remains attached even when the surface curves away from the initial jet direction. The phenomenon derives its name from a Romanian born aeronautical engineer – Henri Coanda. In free surroundings, a jet of […]