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Bollard pull is a conventional measure of the pulling (or towing) power of a watercraft.It is defined as the force (usually in tonnes-force or kilonewtons (kN)) exerted by a vessel under full power, on a shore-mounted bollard through a tow-line, commonly measured in a practical test (but sometimes simulated) under test conditions that include calm water, no tide, level trim, and sufficient ...
Bollard pull: 110,000 lb (50,000 kg) Water cannons: fore and aft, 3,500 US gal/min (790 m 3 /h) C-Tractor is a class of fourteen tractor tugs built by North American ...
The capstan equation [1] or belt friction equation, also known as Euler–Eytelwein formula [2] (after Leonhard Euler and Johann Albert Eytelwein), [3] relates the hold-force to the load-force if a flexible line is wound around a cylinder (a bollard, a winch or a capstan). [4] [1]
Bollard pull can increase up to 30% with ducts. With decelerating ducts, the circulation opposite of the Kort nozzle, resulting in a negative thrust of the duct. This type is used for high speed vessels with increased exposure to cavitation and vessels that want to reduce noise levels, such as warships.
The term tractive effort is often qualified as starting tractive effort, continuous tractive effort and maximum tractive effort.These terms apply to different operating conditions, but are related by common mechanical factors: input torque to the driving wheels, the wheel diameter, coefficient of friction (μ) between the driving wheels and supporting surface, and the weight applied to the ...
The reference load used in the design and testing of the towing winch is twice the static bollard pull. Even if AHTS-vessels are customized for anchor-handling and towing, they can also undertake, for example, ROV ( remotely operated underwater vehicle ) services, safety/rescue services, and supply duties between mainland and offshore ...
The vessel's twin shaft lines with controllable pitch propellers can be driven with a maximum power of 18,800 kW (25,200 hp) and, when used in boost mode together with the 1,200 kW (1,600 hp) drop-down azimuthing bow thruster, generate a bollard pull of 307 tonnes (338 short tons). [7]
The same type of "weigh bar" can be used to measure horizontal loads and "drawbar pull" of wheeled/tracked or vehicles or "bollard pull" of boats or the "thrust" of jet engines when a proper "test rig" is designed and constructed to provide "frictionless" fore-aft movement of the load relative to the weigh bars.