What is ship bollard pull?

Bollard pull is the most commonly used measure of ship-assist tugs performance which have propellers optimized for maximum thrust at close to zero speed. Ships requiring high bollard pull can be fitted with a nozzle, which increases thrust by up to 20-40% compared to open propellers.

How many tons can a tugboat pull?

As a guideline, for example, a 10,000 IHP boat can provide around 100–140 tons of static bollard pull. In reality there are other factors at play, such as the propeller(s) type, whether it is single or double screw, and the towboat draft.

What is the strongest tugboat in the world?

Island Victory
The worlds strongest tug is Island Victory (Vard Brevik 831) of Island Offshore, with a bollard pull of 477 tonnes-force (526 short tons-force; 4,680 kN). Island Victory is not a typical tug, rather it is a special class of ship used in the petroleum industry called an Anchor Handling Tug Supply vessel.

How is a tugboat so powerful?

Most tugboats are still powered by diesel engines. Many newer and larger tugs have two diesel engines, some with a combined total of over 6,000 horsepower! There are also hybrid tugs that combine diesel and electric power, and LNG-powered tugs.

When do you start the bollard pull test?

The bollard pull test starts with warming up the main engines. The test covers a range of different engine powers; however, the test should start with the maximum bollard pull while the test location’s water is still undisturbed. The subsequent bollard pull measurements should start after at least 10 minutes to allow the water to settle.

What should the water depth be for a bollard pull test?

The minimum required water depth should be obtained below the tug keel and within a radius of 100 m from the tug to avoid water circulation. During the bollard pull test, recording the tug’s displacement, draft, and trim is necessary to note in the bollard pull certificate.

Can a surveyor issue a bollard pull certificate?

Bollard pull test certificates issued by Surveyor are acceptable, or by another recognized body provided that acceptable procedures for the tests are produced.

What is the maximum tension of a bollard pull?

The most common bollard pull definitions are as follow: The Maximum Bollard Pull, also called “Static Bollard Pull,” is the maximum recorded tension achieved shortly after the test’s commencement over a period of approximately one minute.

What is ship bollard pull? Bollard pull is the most commonly used measure of ship-assist tugs performance which have propellers optimized for maximum thrust at close to zero speed. Ships requiring high bollard pull can be fitted with a nozzle, which increases thrust by up to 20-40% compared to open propellers. How many tons can…