The difference between Thrust and Horsepower Explained
Many past and present Newport Vessels customers have asked us to convert the pounds of thrust specification for Newport Vessels trolling motors into horsepower specification that is common for gas motors and cars.
First, pounds of thrust is a static force measurement while horsepower is 550 ft-pounds of work per second, a measurement per unit time. So you cannot make a direct comparison between thrust and horsepower unless you also know the speed of the vessel when it is absorbing that thrust. So although there is no direct translation, you can estimate the horsepower rating of a given electric motor by multiplying the amp draw times the voltage to find the wattage of the motor. Then wattage divided by 746 will give you an estimate horsepower of the motor. So every 746 watts is roughly equivalent to 1 horsepower.
Using this formula the popular Newport Vessels NV-Series 55lb Thrust Trolling Motor is rated as 624 watts at the highest forward speed and so 624/746 = 0.84 and would be roughly equivalent to a 0.84 horsepower motor.
We hope this makes this confusing topic a little clearer!
5 comments
I thank you for a good intelligent answer. Usually I get someone waffling on just to sound superior,instead of helping to educate and enabling people to make informed decisions. Thanks alot you have given me the information to buy a motor that suits my needs and my brain is still intact cheers
nice motors never will buy one until you come up with an extended tiller like Bixpy so you don’t have to twist your back to operate and steer. Amazingly unintelligent design.
This is easy. I have a West Wight Potter 15 with a motor mount off to one side of the transom. I use a 55 lb trolling motor in-harbor with no problem though I like to put a 2.5hp OB on to go out in the big water. Just look up any photo of a Potter 15 online.
I have a small, (14 foot ) sailboat I would like to be able to safely use in the ocean, but have no idea how powerful a motor I will need to do so. Also, not sure, short of a sidemounted trolling motor, how it could be mounted without interfering with the rudder of the sailboat. Please adise. And thanks in advance for your help.
To the newportvessels.com owner, Your posts are always informative and up-to-date.