MARITIME – PROPULION & PERFORMANCE CALCULATOR
Bollard Pull Estimate
A precise tool.
What is the Bollard Pull Estimate & How does it work?
Bollard pull represents the maximum static thrust a vessel can exert while tied to a fixed point, commonly used to assess tug and towboat capability.
It is derived from the engineβs delivered power (P) multiplied by the overall propulsive efficiency (Ξ·) and divided by the effective waterβjet velocity (V) generated by the propeller at zero ship speed.
The relationship is expressed by the classic thrust equation, allowing designers to estimate required power for a target pull or, conversely, the pull achievable from a given power plant.
T = frac{P cdot eta}{V}
T = Bollard pull (kN)
P = Engine power (kW)
eta = Overall propulsive efficiency (decimal)
V = Propeller advance speed (m/s)
P = Engine power (kW)
eta = Overall propulsive efficiency (decimal)
V = Propeller advance speed (m/s)
Parameters
Result
β
Frequently Asked Questions
What is bollard pull in maritime terms?
Bollard pull is the maximum static thrust a vessel can exert while tied to a fixed point, used to assess tugboat capability.
How do you calculate bollard pull?
Bollard pull is calculated using the formula: Bollard Pull = (Engine Power Γ Propulsive Efficiency) / Effective Water-Jet Velocity.
Why is propulsive efficiency important in bollard pull calculations?
Propulsive efficiency accounts for energy losses in the propulsion system, affecting how much of the engine’s power is converted into thrust.
What does effective water-jet velocity represent?
Effective water-jet velocity is the speed at which the propeller generates thrust when the vessel is stationary.
Can bollard pull be used to estimate required engine power?
Yes, by rearranging the formula, you can estimate the required engine power for a desired bollard pull.
How does bollard pull affect tugboat operations?
Bollard pull is crucial for determining a tugboat’s ability to move other vessels or barges in port or during towing operations.
What factors can increase bollard pull?
Increasing engine power, improving propulsive efficiency, or optimizing the effective water-jet velocity can all boost bollard pull.
Results are for informational purposes only and do not constitute professional advice.