Rams and Rowers
Back in the antediluvian days when Noah and I were boys, ships were graceful, streamlined creations whose sloping prows cut through the water as they danced across the waves. The yacht-like stern overhung the propeller and rudder in a way that was visually pleasing and contributed to the ship's safety at sea. The cabins were set back from the sides of the ship, allowing ample space for the deck, and the whole thing was an aesthetic feast.
Today it might seem that little has changed. Decks are no longer around, having been swamped by vast tiers of cabins (if passenger) or buried beneath an avalanche of poorly-fastened containers (if cargo). Sterns are now simply a wall across the end of the ship, which relies for its sea-worthiness on sheer size - and from time to time pays the penalty for disregarding basic principles of seamanship by being overwhelmed by a following sea.
You watch a ship sail into port and so long as you close your eyes to these defects you can still admire the grace of the sloping stem as it cuts through the water. Then, several days later, empty of its cargo and much higher in the water in consequence, the ship sails out of harbour and you discover that lurking beneath that graceful stem was a monstrous great bulge that juts aggressively out in front of the ship.
It would take an expert in the dynamic flow of liquids or some such discipline to explain the physics of it, but apparently this bulge, which normally sits just below the waterline, reduces the resistance that the ship encounters as it moves through the water - and as reduced resistance means reduced fuel consumption and therefore cheaper costs, the result is that everything, from passenger cruise liners to oil-carrying supertankers to expensive racing yachts, is now disfigured with just such a bulge.
Some years ago I read a book - whose name and author I have long forgotten - which described how a certain gentleman organised the construction of a wooden boat in which he and a team of modern argonauts could recreate Jason's famous voyage in search of the Golden Fleece. Despite the fact that he only had a crew of about twenty and his boat was therefore hardly a warship, he felt that historical accuracy required that the boat be fitted with a ram.
It turned out to be a most fortunate decision, for the ram proved extremely useful. Not, of course, for ramming other ships - even propelled by twenty rowers at full tilt, his little ram would not make much of an impression against a modern metal ship (a fibreglass yacht might have fared worse!)
Most of the time they island-hopped, drawing their boat ashore on some deserted beach as evening approached. Once or twice, however, they found themselves far from land as night fell and were obliged to spend the night in the cramped and uncomfortable boat. When morning came the weary crew took it in turns to stand on the ram, a most comfortable position from which to perform their ablutions.
His most surprising finding, however, was that the ram actually made passage through the water easier, somehow cutting into the oncoming waves and lessening their force as they thumped against the bow.
Despite the illustrations one commonly sees of ancient warships, rams were not sharply pointed. The last thing you wanted was to drive your ram into the side of an enemy ship and have it stick there like a nail in a plank. You wanted to either punch your way through, causing as much damage as possible as you went, or you wanted to bounce off so that you could back up and have another go.
|
| A bronze ram dedicated at Olympia and probably made in Sicily. The points projected forward and aided in damaging whatever the ram struck. |
There is, in the museum at Olympia, a bronze object described as the head of a battering ram. The terse label in the museum gives no reason for this identification and personally I doubt it. I think it is the head off a ship's ram: the blunt shape looks ideal for crunching through the thin planking of a ship's side, breaking and splintering the wood and making as big a hole as possible to allow the sea to flood in as soon as you backed away.
Of course, the likelihood of inflicting substantial damage depended on two things: the angle at which you struck the enemy and the speed at which you were travelling. Obviously the ideal angle was 90°, because otherwise there was the possibility that you would simply be deflected to slide ignominiously along the side of your adversary.
Speed depended solely on the strength and skill of your rowers - and unlike most fiction, Greek rowers were free men who volunteered for the job and were proud of their skills. The Romans too used free men - who had to provide their own oars - until nearly the end of the empire. It was only in barbarian times that galley slaves became popular.
The standard warship of the Greek navy was the trireme, an elegant and streamlined vessel about 130' long and 18' wide, powered by 170 rowers arranged in three banks down each side of the ship. The amount of organisation required to jam such a crew - plus the 40 fighters and other crew - into such a ship was impressive, while the discipline that ensured that 170 oars hit the water at the same moment was awesome.
The results were equally impresive. Not only could a properly trained crew turn their ship almost in its own length while travelling at speed, then slam into reverse with just as much power as going forward, but they could then row at 7 or 8 knots (8.25-9.3 mph) for sixteen hours or longer!
The full impressiveness of these accomplishments wasn't properly understood until The Trireme Trust was formed by Cambridge historian John Morrison and naval architect John Coates to recreate a Greek trireme. Crewed by enthusiastic volunteers - rather like the ancient originals - the replica ship was able to achieve 9 knots in a short sprint and could turn 180° in less than 60 seconds and only two and a half ship-lengths.
No doubt those figures could be improved with training, but the acting captain only had limited time and had to beware of provoking his crew into rebellion. The most startling finding, however, was that vast amounts of energy were wasted by rowing - 30% of the energy expended by the men was lost in friction between the oars and the sides of the ship, but mostly in the wasted energy of moving the oar back through the air at the end of every stroke.
Presumably the ancient oarsmen faced a similar energy loss, which makes their feat of rowing for sixteen hours - or longer - at a steady 7 knots so amazing. Even with the full cooperation of the modern crew, the best they could manage over an extended period was 5 knots.
In 2004 exercise physiologist Harry Rossiter was able to measure the metabolic rates of some of the oarsmen on board the replica. "After about 4 knots the values we came up with for the metabolic demands were very high," he reported. "It was clear that a sustained 7 knots was outside the aerobic capacity of the modern oarsmen."
Several suggestions have been made on how this could be improved: the replica was only 120' long and lengthening it, even by only 10', would certainly help it to go faster. In addition the additional space between rowers, would give them a slightly longer stroke - and angling the rowing benches would make the stroke even longer. However none of these improvements would account for the difference between what the modern, tall, well-fed oarsmen could accomplish and what the ancient ones could do.
It is impossible that the oarsmen were a specially selected few from a large pool of possible rowers. At the height of its power Athens alone fielded a navy of 200 triremes, which meant 34,000 oarsmen - a substantial fraction of the city's population! Skeletal evidence from excavated burials indicates that the average male height was 5' 5.5", whereas the average height of today's crew was closer to 6'.
One possible solution may lie in diet: as another article on this site reveals, ancient gladiators were almost completely vegetarian and modern studies have shown repeatedly that vegetarians tend to have greater endurance than meat-eaters. The rowers came from the lower classes of society - men who could afford a wooden oar but not bronze weapons or armour - and meat was a rare luxury for that part of society.
So far as I know, however, there are no plans to invite the Vegetarian Society to provide a test crew for the Olympias. Perhaps someone should suggest it to Rossiter.
slide ignominiously Mind you, even a less than optimal attack could still inflict considerable damage on your enemy - not on the fabric of the ship but on its propulsive power and therefore on its ability to continue the struggle. In fact it was one of the recognised tactics to approach your enemy head-on and then run down his side, breaking his oars and crushing his oarsmen. Your own oarsmen, forewarned, shipped their oars at the last moment. Return
rebellion That this was always a possibility was demonstrated by the disastrous Battle of Lade in 494 BC which ended the Ionian Revolt. The Ionians, led by Dionysius of Phocaea, had been drilled relentlessly for a week - necessary considering that the Greeks had 353 triremes against the Persian 600 - and when it came to the actual confrontation the crews simply sat on their oars and went on strike. Return
© Kendall K. Down 2009
