It is a common misconception to think of one hp as equivalent to peak power output from a horse, capable of peaking at about 14.9 horsepower. In fact, most horses are capable of just 50% of Watts rate of 33,000 lb-ft, and a horsepower does not equal the strength of an individual horse. No, that claim (one horsepower is equivalent to one horses strength) is misleading, because a healthy horse may produce up to fifteen horsepower a stroke.
In reality, a horses maximum output may be as high as fifteen horsepower, while the maximum human output is slightly higher than a single horsepower. The average horse has a maximum output of 14.9 horsepower, while the average human has a maximum output of just 1.2 horsepower. While it is true that a horses maximum output is about 15 horsepower, when a horses output is averaged out over a working day, it ends up being about one horsepower.
While it might seem obvious that one unit of horsepower is the average horse output at any given moment, it is not really. You would think a horse would have an equivalent to a single unit of horsepower, but that is not really true. Well, actually, the answer is much harder than you might think, as an average horse could have up to 14.9 horses horsepower when it is running its fastest, but then again, this all differs depending on the horse itself. The average working horse maxes out at a little less than 15 hp in the dash, whereas an individual horse maxing out will reach about five hp.
The Iowa State Fair in 1925 determined the average horse could maintain a maximum production of about 14.9 horsepower for short bursts. Scottish inventor James Watt created the horse power figure as an expression for the amount of work that one horse can average for a full day. Scottish engineer James Watt invented the measure of horsepower in the 18th century as a way of comparing draft horses to steam engines. The intent behind creating horsepower was, at that time, to compare steam engines power to that of draft horses.
He was the man who gave a standard unit to Horsepower, a name that we are still getting confused over, comparing the mean power of the 18th-century draft horse with the output of the steam engine. James Watt was the scientist who decided to give The horsepower name first, and did it as a way of equating the engines power with the horses. In the late 18th century, when Scottish engineer James Watt invented the term “horsepower,” horses were the dominant power source in the world. Instead, Scottish engineer James Watt defined a horsepower as equal to the amount of energy that can sustain a horse over a long period of time.
Instead, he invented the term “horsepower” and made it equivalent to the amount of work that a horse is able to do over a complete day. By noting how many times an hour a horse turned the millwheel, and by working out the amount of force it put down, Scottish inventor James Watt was able to then devise his formula for horsepower. James Watt chose to compare a steam engine he had built with an average power output of one horse for one day.
The simplicity of the horse power unit was so appreciated, we began measuring horse outputs on it, in the presence of all electric and mechanical devices. A common legend holds that the horse power (hp) was created when Watts first customer, a brewery, specifically requested a motor to go along with a horse, and chose the strongest horse he had, and drove it all the way.
The idea behind the concept of Horsepower is based on assuming how much work a healthy horse could do in one minute. Horsepower (hp) is a unit for measuring strength, or how fast a job is done, typically referring to an engines or motors output. The measure of horsepower is a measure of how much sustained power the motor produces when it is running at varying capacities.
In the case of imperial horsepower (also known as mechanical horsepower), a unit of horsepower is equivalent to 745.7 watts of energy. One horsepower unit is equivalent to 33,000 feet-pounds per minute or 550 feet-pounds per second (745.7 watts).
Interestingly, one horse putting out 1 horsepower could hoist 330 pounds of coal 100 feet in a minute, 33 pounds of coal 1,000 feet in one minute, or 1,000 pounds 33 feet in a minute. One horsepower is equivalent to the work required to lift 550 pounds one foot in one second, and it can be calculated to be also 33,000 pounds-foot-per-minute. One horsepower is approximately the everyday working power output of a healthy draft horse, meaning the estimates by famous Scottish engineer James Watt were fairly accurate, with a reasonable margin for error.
Scottish engineer James Watt, though he was aware of this trick, accepted the challenge and built a machine that was in fact even stronger than the numbers achieved by a distiller, and the output from this machine became Horsepower (hp). The funny thing about this is the fact that the term horsepower is supposed to be replaced by Human Power, simply because an average person might only be capable of having around 1.2hp of output total. These numbers can vary greatly, however, particularly considering lighter horses such as the Arabian horse or Thoroughbred, and it is equally variable in humans, since a man such as Usain Bolt can easily have a total output of 3.5 horsepower.