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.
The most interesting part of this is the fact that the term “horsepower” needs to be replaced by “human power” simply because an average person might only be capable of having around 1.2 total horses worth of power. Well, actually, the answer is much harder than you might think, because an average horse can have up to 14.9 horsepower when it is running its fastest, but then again, this all differs depending on the horse itself. Since you have heard of horsepower as it pertains to high-performance cars, you may be thinking the fastest horses make the most amount of horsepower. The idea behind the concept of horsepower is based on assuming that the fastest horses are capable of doing the most work per minute.
Scottish inventor James Watt created the concept of horsepower as expressing the amount of work that a horse can perform over the course of a full day, on average. Scottish engineer James Watt invented the measure of horsepower in the 18th century as a way of comparing draft horses to steam engines. He was the one who gave the standard unit of horsepower its name, which we are still getting conflated about, comparing the mean power of 18th-century draft horses with the power of a steam engine.
The steam engine was a costly machine to buy, and had Scottish engineer James Watt claimed it produced as much power as an average horse for short periods, nobody would have wanted one, since they already had their work horses. Instead, Scottish engineer James Watt invented the term horsepower, and made it equal to how much work a horse was able to do over a whole day. Instead, Scottish engineer James Watt designated horsepower as equivalent to the amount of work a horse was able to exert over a long period of time.
The term “horsepower” came into being in the late 1700s, thanks to Scottish engineer James Watt, who wanted to compare the output of contemporary steam engines with old-fashioned draft horses. James Watt was the scientist who decided to first call the power output from horsepower – and did so as a way of equating the engines output with the horses.
A common legend holds that horsepower (hp) was created when one of Watts earliest customers, a brewery owner, specifically requested an engine to equal horsepower, and chose the strongest horse he had, and drove it to its limits. The simplicity of the horsepower unit was such an appreciative thing, that, in all of our electrical and mechanical devices, we began measuring horsepower from horses. James Watt decided to measure a steam engine against the average output of one horse for one day.
From his estimates, James Watt (1736-1819) calculated that a horsepower was equal to one horse doing 33,000 feet-pounds of work in a minute. He then arbitrarily multiplied 2 2 by 50% to nail one horsepower down to 33,000 feet-pounds per minute, or 550 feet-pounds per second, the measure that we still use to describe available horsepower in cars, boats, and even some lawnmowers. By taking into account the number of times an hour that horses turned the grinding wheel, and working out the amount of force that they were putting into it, Scottish inventor James Watt was able to devise his formula for horsepower.
James Watt defined about one horsepower as the amount of work required of a horse to extract 150 pounds out of a hole 220 feet deep. One horsepower is approximately the everyday working effort of a healthy draft horse, meaning James Watt, a famous Scottish engineer, was fairly precise in his estimates, with within reasonable margins of error.
The average working horse will reach just under 15 hp maximum in the dash, whereas an individual in the midst of his or her prime 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. To understand the roots of horsepower, we must set our clocks back to the 18th century, when the arrival of steam power was poised to bring about early retirements for many of the laborious horses.
Different horses with different powers would have had different amounts of horsepower, and the same principles would hold true for humans. These numbers can vary greatly, however, particularly considering lighter horses such as Arabians or Thoroughbreds, and it is equally variable for humans, since a man such as Usain Bolt might easily have had an overall power of 3.5 horses.