Welcome to the SDMB, kinulpture. In the event that you stick around, here’s a friendly word in your ear: we tend to converse mostly in plaintext around here, even people who are posting from smartphones and other things like that.
That said, I think the website you linked to looks pretty interesting. How long have you had an interest in this subject?
Ancient rowers didn’t have sliding seats, but they did wear butt pads so they could slide on the benches.
I suspect there are also efficiency problems that come with having more than one oarsman per oar.
The fulcrum of the oar of a racing scull is a couple of feet outboard on what is essentially a piece of scaffolding called a rigger. You get the idea from this illustration. The distance from the oarsman to the fulcrum, and the distance from the fulcrum to the distal end of the oar are carefully calculated so that the connection between the moment of force generated through the lever and the stroke length of the oarsman along the axis of the boat all combine to produce the most efficient use of the oarsman’s energy.
If you have multiple bodies on one oar, then if the inboard man’s range of movement is optimised, that condemns the outboard man to a much shorter stroke length, which no amount of physical strength can realistically compensate for. It’s kind of like trying to chop down a tree with an axe that’s only 12 inches long.
But you have to have multiple oarsmen per oar because once a vessel gets to a size worth using in a fight, structural considerations mean that there’s no real way to get enough oars out into the water if every man had one, even using biremes and triremes, without also having a whole heap of wasted space. So two men per oar are better than one, but not as good as two would be if they had an oar each.
Efficiency? They had that problem whipped.
Sure they used sail as much as possible, but a trireme cruises just nicely with only a half or one third of the men rowing, so with shifts it is possible to row all day. A trireme probably has a similar probleme to a three deck ship-of-the-line: with waves, you can’t really open the lowest line of hatches, they leak more than enough when closed.
The trouble with treadmills is that you can lift or squat more than your body weight. A treadmill, sorry, hamster wheel, is that it relies on gravity to turn the wheel, so the total force is gravity times body weight modified by what angle you are at on the wheel - most efficient at the 9-o’clock position. Legs and even arms are quite capable of exerting more force than that. However, a ship where the hold is basically a long series of hamster cages around a driveshaft would probably be most efficient, although you would need a gearbox or belt to transfer the high-up driveshaft down to the propeller. The key technology I suspect is a water-tight shaft through the hull.
Of course, you can probably fit a lot more bodies 6-across or more on rowing benches than single-file on a long hamster wheel. And an exhausted rower can probably keep up (or let hs buddies do the work) while an exchasted “hamster” will become a dead weight spin cycle lump. But a hamster-ship would be longer, narrower and more aquadynamic(?) than a rowboat and significantly less vulnerable in closed quarters without a lot of aors to be fouled.
Also, the prop would have to be of reliable construction, likely metal. I suspect paddle-wheels were the original ships, built that way because that construction required less quailty materials than a high-powered prop. Quality metallurgy is an important technology - it took a while for late medieval technology to figure out how to reliably build cannon that did not blow up when fired. Casting an efficiently shaped prop big enough to drive a large ship - probably beyond most Roman technology. Also, if your prop did break - at least on a trireme, they probably could swap an oar from a supply on deck in a matter of less than a minute.
In the end, I suspect the minimal advantage would not outweigh the dangers of technical failures like a broken prop or broken drivetrain.
In the rowing context, you’re basically forced to participate (slave or not): you have to follow the ambient rhythm and you have to dip you oar deep enough and feather high enough, otherwise the whole system falls apart in an orgy of tangled oars.
But if everybody has a set of pedals that are directly linked to all other sets of pedals, so that they all turn at the same speed, what’s forcing you to participate? You could just rest your feet on the pedals and coast along…
We had a discussion hereabout why there are no examples from antiquity of the basic bicycle mechanism for human powered devices. I am still not sure why it is conspicuously absent from the historic record.
Why use pedals?
I instead imagine some central shaft, a long log; it has arms with ropes on the end and handles, and the men sit facing the shaft on opposite sides and pull on the rope/handle like a series of rowing machines.
The main shaft rocks back and forth; at the stern end, it is attached by a connecting crank to a shaft that converts back-and-forth to circular motion, like the old steam locomotives. This drives the propeller.
In the end, you have something like a huge multi-man shp diven much like the the old foot action sewing machines, or the cartoon railroad hand-pump cars; but with pull rather than push; or you have a guy on the top bench pulling, and a guy below him pushing on an opposite crank with his legs.
You don’t get more Rube-Goldberg than that.
I’ve brainstormed this concept for about 30 yrs. & we had an almost duplicate conversation on our facebook peace fleet page. This is how I found your conversation here just by googling. & it’s quite a coincidence too.
& thanks for the welcome. If you go to : www,humanpoweredboats.com , Click on photos, other displacement hpv’s scroll down to about 6th pic from bottom. You wannna look for veleau 12. For more info on veleau 12 just google it just make sure you add boat. I’ve been trying to contact the owner for an update. Veleau 12 is 10 person pedal power on central shaft. Probably the most people pedaling 1 boat in existence. It’s tough wading through all the pedal boat ads. I knew of veleau 12 through the ihpva research long ago.
One of the first attempts of steam powered vessels was also hand cranked. Please google: patrick millers vessel. This was multiple paddle wheels between trimaran hulls. I don’t think this setup would be as efficient but is a good study. It would seem however this would have less complications which has some merit. I never have liked long complicated Chain sprocket gear systems. Too many moving parts.
Explain how in weightlifting, World Records for the Clean and Jerk (580 lbs) are less than half that of the Squat (1268 lbs).
Wouldn’t you just want your pedals to be just two very long boards that ran from front to back? The pedals would be attached to several cranks along the way, but power would be transmitted from only the crank at the rear (assuming stern drive). The pedalers would have to be in sync anyway for any simple mechanism. The long flat boards aren’t ideal pedal since they don’t rotate, but people standing on them should be able to get a good running motion going.
IRT the best use of muscle-power, there’s probably a reason the first human-powered aircraft used a bicycle instead of a rowing machine.
Here’s a diagram of a treadmill ferryboat. Substitute a twin-screw propulsionn for the paddlewheels, and a transmission station.
Or: all those guys pump water channeled into a high-pressure jet, shooting into a turbine that drives the plant.
A warship could have a large compliment of marines, who march across the seas.
I don’t think that boat can take off. Too much friction in the bearings.
Several of the early “submarines” were hand cranked power.
Earliiest known land pedaled vehicle was something the size of a pedicab/rickshaw. This was in 1500’s if memory serges correctly. & was treadle powered which I agree with. This thing weighed 1000±lbs I doubt it went very far. For any history of human power: www.ihpva.org . Some1 mentioned here in an earlier thread using other body parts doesn’t add much & wears you out faster. Dr alan abbott&co worked this out long ago. I’ve studied their research since abt 1980. Treadle power has been proven too because the extra motion in cyclic takes away energy adds work. & adds drivetrain complications. Yes a long rod(s) to crankshaft would be the way. A treadle rod would also act as a sorta flywheel too. If y’all study veleau 12 as long as I have you would see where more than 10 ppl would add conplications. I don’t think she’s been on open ocean just rivers, canals, probly some bays.
Open ocean will be a bit different than river sprinting. But veleau12 is still a good test study. Please google: pedal powered lunar rover. Several yrs worth of research there. Treadlepower mentioned a lot. Tessarakonteres is is largest known oar vessel in antiquity. 4000 rowers. Eventual patrick miller posible hand-cranked vessel woulda been 270ft. 100ft model was given to king of sweden. A snuffbox was given in return. 100ft model was catamaran style. I have seen vague reference to articulated oars in antiquity. I lost the link to it though. oh yeh please google: ictineo sub similar to yet far more advanced than hunley. 2 models were built. None got far I guess maybe interest had died out by the time crimea started. I actually found ictineo thru a scifi short story i’d read a bt the confederacyb uying her from spain. Her name wasn’t mentioned tho I had to dig a lil bit. I findmany supposedly learned people don’t know cornelius drebbel.
Ok found “piotr koschka” was foot pedal powered until automobile engine replaced this. I can’t seem to find any other foot-power subs utilized bak then.I have. Found there to be somewhat of an historical bias towards foot power on water. Rowing itself really wasn’t started as pure sport until 1880’s approx. Possibly outa boredom or something. Actual warship use of oars probly didn’t die out until maybe widespread use of ironclads. Oars r that good. Wooden vessels could also be turned quicker w/oars.
Presumably, a Christian slave on a Muslim galley (or vice versa) might foul oars in an attempt to be rescued. I’m reasonably sure that a Spanish galley might free Genoese slaves found on a Berber galley, for instance. When you combine it with the slave’s low life expectancy, you might find that some would occasionally try it, especially if a slave got wind that the battle was going poorly for their own ship and that the enemy was of their own religion.
If the slaves aren’t chained, the boat’s going nowhere near the battle. They take over the ship and head home way before that.
Right-- a desperate slave might foul the oars in hope that his ship would lose the battle without being sunk, and he might be rescued as the opposing forces board and capture the ship.
