HP Calculation

Power equals force times velocity. Your force is ten tons if you are speaking of English tons. If you are speaking of metric tons, which equals 1000 kg, then your force is the acceleration of gravity multiplied by ten tons. You give your velocity in meters per minute. That is a very slow speed and odd units. Regardless, you can convert to all metric: force in Newtons and speed in meters per second and you will end up with a calculation of power in Watts per the P = F *v equation first cited. Then you convert the Watts to horsepower using 746 Watts = 1 hp. If your hoist capability was ten metric tons, the calculation looks like this:

10 tons *1000 kg/ton * 9.8 meters/second squared * 10 meters/minute*1 minute/60 seconds = 16.33 kW

16.33 kW * 1hp/746 Watts = 22 hp

If you meant English tons, as in 2000 pounds, then the calculation is:

10 tons * 2000 pounds/ton * 10 meters/minute * 1 minute/60 seconds * 3.28 feet/meter = 10933.33 foot-pound/sec

1 hp = 550 ft-lbs/sec, so

10933.33 foot pounds/sec * 1 hp/550 ft-lb/sec = 20 hp

I would add some margin so your hoist isn't running at max capacity. Also, the motor will drive the hoist through some huge gear reduction. That transmission will have losses. There are likely lots of people who can speak to these issues from experience. The above calculations are basic physics.