Horsepower: One horsepower isn't equivalent to a horse.

[Milkyway]

James Watt invented a novelty scientific equation to impress his future clients of the power of his steam engine.

300yrs later...
A drey horse's output was measured on a dyno, via a rope & drum setup replacing the cars engine... the Dyno recorded 5hp.
(The measurements were taken with the horse led at a normal walking pace).

Edited by Milkyway on Tuesday 13th January 18:31

[RizzoTheRat]

I think it was originally based on smaller pit ponies rather than big shire horses, but it was also supposed to be an average over a long period. A horse can manage a lot more power in a short burst but over several hours work it's average output will be way smaller.

[Lotobear]

...its a bit like one apple is not 1 Newton

[Milkyway]

RizzoTheRat said:

I think it was originally based on smaller pit ponies rather than big shire horses, but it was also supposed to be an average over a long period. A horse can manage a lot more power in a short burst but over several hours work it's average output will be way smaller.

I think that a horse can pump out about fifteen horses for a short period.
(Watts equation involved raising water over a set distance & period).

NB: The original 2CV (deax chevaux) @ 9hp... makes sense now.
Later ones...should have been called 6CV's.
(30hp = 150hp... in new money).

Edited by Milkyway on Tuesday 13th January 17:04

[Teppic]

RizzoTheRat said:

I think it was originally based on smaller pit ponies rather than big shire horses, but it was also supposed to be an average over a long period. A horse can manage a lot more power in a short burst but over several hours work it's average output will be way smaller.

Ponypower didn't have quite the same ring to it.

[Milkyway]

Teppic said:

Ponypower didn't have quite the same ring to it.

Acceptable for Mustangs.

[spitfire-ian]

When you look at it this way it makes more sense.

It's the force needed to lift 550 lbs, 1 ft in 1 second.

[Monkeylegend]

Horses, like people, come in all shapes and sizes.

[fooman]

Well if horsepower doesn't mean the power of a horse perhaps we should start using a unit of power measurement we can relate to, like a Schwarzenegger.

[Milkyway]

fooman said:

Well if horsepower doesn't mean the power of a horse perhaps we should start using a unit of power measurement we can relate to, like a Schwarzenegger.

1hp = a shetland.
In reality, about 0.5hp... but this keeps it simple.
(Sorted).

Edited by Milkyway on Tuesday 13th January 17:57

[Rusty Old-Banger]

fooman said:

Well if horsepower doesn't mean the power of a horse perhaps we should start using a unit of power measurement we can relate to, like a Schwarzenegger.

10,000,000 Schwarzeneggers = 1 Norris.

[Milkyway]

Rusty Old-Banger said:

10,000,000 Schwarzeneggers = 1 Norris.

Chuck or Lando...just for clarity.

[Warhavernet]

If you want a sore brain figure out the strange relationship
between the Foot-Pound [ft-pd] and the Pound-Foot [pd-ft].

[Evanivitch]

spitfire-ian said:

When you look at it this way it makes more sense.

It's the force needed to lift 550 lbs, 1 ft in 1 second.

People also forget this was the sustained effort of a horse working ploughing a field. It wasn't a quick, fast effort on a Dyno.

The ability of static engines to provide continuous power was their biggest attraction. If you wanted short bursts of power there were plenty of gravity solutions.

[Milkyway]

I have just read another way of looking at it.

1hp: A horse turning a 24ft mill wheel 2.5 times in a minute
(That seems a bit more logical).

In comparison: HumanPower
Average: 1.2hp
Athlete: 2.5hp

Edited by Milkyway on Wednesday 14th January 19:20

[Simpo Two]

Milkyway said:

I have just read another way of looking at it.

1hp: A horse turning a 24ft mill wheel 2.5 times in a minute
(That seems a bit more logical).

But that doesn't include load/friction...