Summary:

HP is the measurement of energy capacity for doing work.

How much thrust can one horse pull?  It depends on the horse and its strength.

https://en.wikipedia.org/wiki/Horsepower

In the 1920s, 100 years ago, we could purchase a Duesenberg Model J, one of the most potent cars of that era, with between 25 and 265 HP.

Today, it is common to find a vehicle with 400 HP and a superperformance car with 600 to 800 HP.

Article:

Horsepower (HP) is a standard unit of power adopted in the 1800s by Scottish Engineer James Watt.  This historical context adds a layer of appreciation for the evolution of this concept. One HP is the power required to lift 33,000 pounds one foot in one minute.

Equivalency measures are in watts and British Thermal Units per hour.  The electrical equivalent of one HP is 746 watts and 2,545 British Thermal Units (BTUs) per hour.

The subject gets complex when we consider internal combustion engines (IEs), electric motors, Turbine motors, the number of cylinders, sophisticated transmission shifting components, rear-end gear differentials, and rigging engines with sophisticated components like superchargers and turbochargers. This versatility of horsepower in different engine types is intriguing and encourages further exploration.  Additionally, technology has enabled engines to reach enormous horsepower levels.

Peak horsepower and revolutions per minute (RPM) also modify horsepower and torque.  Higher RPMs and additional engine modifications can significantly increase HP and torque.

Can we envision a vehicle with 600 horsepower or more? How would it be to line up a team of 600 horses with proper equipment, have them work hard, and measure their output? HP, a mathematical calculation, equates to lifting 550 pounds of weight a foot high in one second.

There is a difference between horsepower and torque. Torque is the rotating force produced by an engine’s crankshaft.  The greater the torque, the greater the ability to perform work.  The measurement is in pound-feet and newton-meters. 

There are two types of torque: static torque, which is similar to a torque wrench tightening a bolt, and dynamic torque, which is associated with the thrust.  A mathematical formula is related to the differential of horsepower and torque.

Let’s compare the HP of various engine types:

A healthy human can produce 1.2 HP, but only sustain .1 HP over several hours.  Trained athletes can make 2.5 or more and sustain .35 over several hours.

By comparison, I aim to illustrate how other engines compare to automobiles, industrial machinery, and large commercial transport vehicles.

A lawnmower may have between 5 and 7 horsepower

A John Deere tractor has a power range of between 22 HP and 910 HP.

Depending on the model, a Caterpillar tractor has from 360 HP to 1900 HP.

Honda Civic is available with 150 HP and 315 HP, powered by a 2-liter VTEC 4-cylinder engine.

Dodge Challenger’s 6.2-liter Hellcat V-8 produced 707 HP at 6000 rpm.

An 18-wheel, long-distance diesel truck could have between 400 and 2,400 HP, be built with high torque levels, and be made more efficient by a 10 to 20-speed transmission.

The Freight Locomotive has between 2,000 HP and 4,500 HP and can have one or more engines running simultaneously.

Jet Engine- up to 75,000 HP for each engine, a standard four, and up to ten engines, or 300,000 HP.

Cargo Ship- 14-cylinder, extra-large engine on the Wartsila.  TheWartsilaa 96C engine has 109,000 HP.  Each cargo ship has 1 or 2 main engines, with several auxiliary engines powering onboard systems.

Now, I’m going to use my one HP and get a large cup of coffee.  WhoWho’sith me?