If the enemy were kind enough to free the slaves or just keep em chained. That is actually a good point. We think nowadays in terms of freedom because most of the world appears to be free. Slavery does as far as I’ve heard exist in some parts of the world even today. Perhaps some rowers earned their freedom through rowing in some cases. One of the things to consider is that all aspects of life occur when people are chained like that. So in some cases chained rowing would been in some cases as disease would have been rampant. I don’t think in some cases rowing bench areas were very pleasant. Ya gotta remember that bak then the connection between hygeine & disease wasn’t well-known. The olympias builders may not have gotten very many details right as there aren’t many exact details of rowing life. It’s all mostly conjecture. I’d probly volunteer a 2hr row. After that tho i’d probly not volunteer again for a few days. I think modern rowers would probly be screened for tb. By the way, a belated merry christmas y’all.
Pretty old thread to revive. Sorry. Given today’s notions of sea travel, but limited to available materials of the time of the Greek trireme:
The question of gearing was mentioned, as to how to coordinate 170 men to effectively power one or two screws. Unless I completely don’t know what I’m talking about, the easiest way is to construct a two-stroke mechanical engine using block-and-tackle and a counter weight.
This method, well known to the ancients, lifts a weight until its stored energy is needed, in this case to turn the propeller shaft. Thus, half the men on a single propeller have already done the work, while the second half labors to store the next “stroke.”
With some coordination, you could do without the block-and-tackle, and directly lift your counter weight, via leather belts or ropes. The most efficient power is by the legs, so you set up a pulley system for your happy crew. Ideally, you don’t increase ship’s weight, and use cargo on a platform, instead of using dedicated counter-weight.
I suggest the two-stroke because this keeps the ship’s center of gravity stable, because you don’t want to heave large weights above your water-line without a counter. Also, since this is stored gravitational potential energy, it is quite easy to regulate prop speed. With two screws x two strokes per, you now have a four-stroke trireme that can turn on a dime, even go into reverse.
Or is that just nuts?
Best guess: bicycle driven hydrofoil. Shouldn’t be a problem to scale it to however many peddlers.
When it comes to using oars on a hydrofoil, sculling would cause less torque difficulty than sweeping (a problem encountered by hydrofoil kayaks), but there would still be one hell of a problem with the long stroke recovery period of rowers. I doubt that modifying a Mirage drive to work with two-legged drives against floorboards rather than alternating single leg drives would solve the problem because there would be much stuff underwater to get the boat up on its hydrofoils.
Although it probably would be fighting the hypothetical, sails would be the way to go, and if masts were prohibited, then kites would be the way to go, with the peddlers only hammering away when becalmed or in close maneuvering.
I think using hydraulics to transmit force to propeller is the way to go. Instead of pedals push a lever back and forth. That uses the whole body. It’s just a bunch of hand pumps for wells attached to the floor or wall. Also using a helical vertical axis wind turbine would catch the wind equally well in any direction and can transmit that force to the propeller.
Thoughts?
There would also be the restriction of size or RPM of the propeller. Today I believe it is around 100 RPM. Past that the efficiency of the prop drops of by a squared factor. That is why the biggest ship engines run at 103 RPM at a full speed bell. I am talking about ships of 103,000 Hp. The Navy goes a different route. They give up efficiency for size. Destroyers can do between 300 and 400 RPM. But while going that fast they churn up a lot of water and burn a lot of fuel.
People mention chains as part of the drive system. How far back could we make a bicycle chain? Could the ancients have made one?
I realize that this is an old thread but ISTM like there are at least two separate questions.
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Is a screw more efficient propulsion than rowing?
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Is the act of rowing more effective than pedaling?
Assuming the answer to the first question is yes, then one could still power that screw by teams using a rowing motion coordinated together as opposed to pedaling.
Then of course what would have been technologically feasible.
The second question is most unsettled.
The act of rowing is a fairly whole body movement. Mostly legs then back core and least arms. Cycling is almost all legs. Point rowing.
The recovery on rowing though does not contribute to power production, while power contribution is made by each leg throughout a pedaling rotation. Big point cycling.
Any evidence to settle the question? Yes!
Rowing costs more energy per unit power produced than cycling does. So even if the propulsive power gained per unit power produced was the same cycling would win.