Re: Thrust = Hp ?
Youre very welcome Dave though I'm sure I've just confused the situation.:redface:
I'll try again.
If your motor puts out 28ft-lb/s of thrust per second and 1HP is 550ft-lb/s then your motor is equivilant to .051HP.
That would also mean your 1.5hp would be putting out about 825ft-lb/s of thrust.
I'm still not certain this is correct... thrust is the force required to move a certain weight, a certain distance during a cetain amount of time. i.e 28lbs, 1ft in 1 second is 28ft-lb/s.
I like you man and it is late in the day, I am retired and I just came upon this remarkable stuff named Old Forester.....really smooth.
So forgive me if I get off track a tad.
HP applied is the dissipation of energy. Hp is energy consumption per unit time. Hp is torque (moment of lateral inertia) x rpm (hence time) + a constant (whoopee). Any time you are in a fluid environment (water, air, snow, mud), thrust is your execution of HP. If you were Cookie on 77 Sunset Strip in California (like back in the early days of TV), you weren't interested in thrust, just torque and rpm's......getting your "mil" blasting down the strip....and then combing your curly locks (with Royal Crown Pomade all over them) on your head and talking jive talk. Ha! Ha!
Jet engine, trolling motor, or outboard motor doesn't matter. Thrust varies as does the load. Example: When in high school, I deck handed on a tug boat that ran barges up and down the Intercoastal Waterway in South Texas to New Orleans, LA. and North up the Mississippi River to Vicksburg MS. where we met the Northern river boats and changed tows. They went North with ours, we went South with theirs.
The tug was 100 ft long and had a 400 Hp Atlas diesel engine. Name was the LONE STAR....of all things. The engine was so enormous that you could crawl down into the jugs to overhaul it. It ran at like 1000 rpm [clitty clack, clitty clack (exposed valve train push rods/valve stems rattling)] and turned a 8' prop with a pitch on the order of 1' (thereabouts) on a 2:1 reduction gear. That said, it could run half a dozen barges 135' x 60' x 8' draft (lots of tons I assure you) at 10 mph, and could do it days on end.
Back then (1958 time frame) we would fuel up on the canal and take on a thousand gallons of diesel at the unheard of price of 9 cents per gallon...course no road tax and we had the volume.
So, how does this relate to the issue of thrust vs hp. Well, I think it relates very closely and may give one some insight into the differences.
I hope you enjoy this caviot of my past. I enjoyed sharing it with you.
As usual, the obnoxious Mark,
Mark. Grin.
