CR4® - The Engineer's Place for News and Discussion®

 Previous in Forum: Risk Based Inspection for Pressure Vessel Next in Forum: Turbogenerator Vibration
Active Contributor

Join Date: Aug 2012
Posts: 22

# How to calculate the Bollard Pull/Power of a Propeller?

09/03/2012 3:04 AM

If I now know the Bollard Pull of a Fixed Pitch Propeller, how should I calculate the Power of it? or the other way round?

Interested in this topic? By joining CR4 you can "subscribe" to
Anonymous Poster #1
#1

### Re: How to calculate the Bollard Pull/Power of a Propeller?

09/03/2012 3:13 AM
Off Topic (Score 5)
Guru

Join Date: Oct 2007
Location: India
Posts: 1259
#2

### Re: How to calculate the Bollard Pull/Power of a Propeller?

09/03/2012 3:24 AM
Active Contributor

Join Date: Aug 2012
Posts: 22
#3

### Re: How to calculate the Bollard Pull/Power of a Propeller?

09/03/2012 5:43 AM

Hi, the question is how to calculate or assume the horse power of a propeller when you know the bollard pull. For example, if I know the Bollard pull is 700kN, how could I know the approximate horse power?

Guru

Join Date: Oct 2007
Location: India
Posts: 1259
#4

### Re: How to calculate the Bollard Pull/Power of a Propeller?

09/03/2012 6:48 AM

There are rules of thumb only, (no established accepted formula)for converting propeller power (shaft horsepower) to bollard pull, such as one ton pull per 100 horsepower for a conventional propeller or 1.2 to 1.5 tons pull per 100 horsepower for a propeller fitted with a nozzle. (The owner may save the cost of a bollard pull test and simply apply one of the factors to convert propeller power to bollard pull without ever knowing what the real figure is. It is unlikely that the owner would ever select a conservative conversion factor.)
Between bollard pull & HP, horsepower is probably a more reliable measure. No convention established (to my knowledge) by any classification society.

Guru

Join Date: Oct 2008
Posts: 40533
#5

### Re: How to calculate the Bollard Pull/Power of a Propeller?

09/03/2012 2:43 PM

Maybe you should study this:How to Search the Internet

It might save you some time.

What is formula for calculating the Bollard pull of a ship

Off Topic (Score 4)