SHOCK AND OAR : Part III

 

One of the failings of much writing about galley warfare, and especially trieres combat, in the past has been to focus on the act of ramming only from the point of view of the target.


I have scribbled about rams and the effects on the target. What I would also like to get across is the fact that a ramming attack is a double-edged event. To put into perspective, to the other lunatics like me and maybe some half -interested others, how the full picture of what was going on in this type of combat was more complex, more uncertain. more frightening and more skillfull than is generally appreciated.

Dare you take to sea for battle in a trieres ?

Trieres combat, and galley combat in general, required the cooperative efforts of 200 or more  men to put to use the near-perfected product of thousands of hours of skilled work by experienced craftsmen. The whole project could be wrecked by poor management, a moment's error of judgement or the vagaries of nature. In the Second World War many thousands of tank crew took imperfect vehicles into combat and found the harsh realities of cooperation under restricted conditions while under threat of death an almost intolerable physical and psychological challenge.  A few moments could bring a shift between the vehicle and its crew being victorious and elated at destroying and damaging other vehicles and into a state of abject fear and trepidation as the enemy turned the tables on them. A lot of technology and training could be put in danger by a ditch beside the road, a poor electrical connection or if the team in the other tin can had a smidgin more luck or skill.

In the back of each crewman's mind....

Newton's Third Law was first defined and written down by him but many people had prior awareness of it. The crew of a trieres in particular. If a ram is accelerated into a target then the attacking ship will also feel some repercussions. Newton's First Law was felt by the oarsmen in their legs and arms as they accelerated the ship towards the target. Newton's Second law was appreciated by the kybernetes in his calculation of how much speed he could coax from his crew and how fast they could accelerate and how much momentum he would need to damage his target.

The Third Law means that the momentum of the attacker will come back to bite him if he slams his trieres into a target without regard to this relationship. It is one thing to shoot a stone ball into the wall of a town with as much force as one can generate from a katapeltes and quite another to treat a mass of wood populated by 200 men in the same way.

A trieres hitting an imoveable target will almost instantly decelerate to a stop.  The trieres is subjected to an opposite force which stops it dead. The crew also experience this opposite force, which also stops them dead- maybe literally. This is the same deceleration which affects the unfortunates in a car crash. This is what trieres combat with rams is about. A series of car crashes.: but car crashes which are executed deliberately and in a controlled manner.

The trieres in a car crash has two problems to overcome.

The first is that the structure of the ship should survive the impact. If it does not then the crew is lost anyway and even if the target is eliminated then they have gained no advantage for their side.

The second is that the crew should survive the impact. The crew must be able to continue the fight after damaging a target ship otherwise their effort gains no advantage for their side.

THE SHIP

A trieres had two systems which contributed to its survival in a collision.

The ram itself was mounted at the front of the vessel as an extension of the keel and supported by the stem post. The centre of mass of the ship is projected forward very closely to the driving centre of the ram which means their is little turning moment to stress the structure. The ram mounting is solid and braced to resist being deviated from a forward course as it impacts the target. The ram itself is of massive bronze and formed like a modern girder. It is harder and stonger than any wood it impacts. The whole structure of the ship is mounted onto the keel and this forms the axis of attack as it bears the whole mass of the ship into the target. Because the ship is built to withstand the force of the sea resisting its progress then it is well suited to surviving an impact along that same axis. It is not coincidence that the ram as a weapon developed out of the cutwater as a hydrodynamic structure. Trieres must have been built to withstand the expected stresses of combat impacts.

 In addition, the ship's crew were not passive passengers but riders who could act to help achieve an effective impact. The rowers could obey commands to accelerate or decelerate and the kybernetes could steer the ship into the target at an angle of attack of his choosing. A good kybernetes could judge, given an appreciation of the relative courses of his own ship and the target, the correct angle of impact to achieve a hole in the enemy's vessel.

THE CREW
The crew were well aware of the implications of the meeting, no matter how controlled, Flying oar looms and tight spaces under the deck left little scope for avoiding at least a sore head from an unexpected collision.

Brace,brace,brace : one possible method after Wegener-Sleeswyk

 The deck officers must have communicated the moment of expected impact to the keleustes and on to the oarsmen. The oars must be out of the water at the moment of impact and the men braced on the beams and benches around them to take the strain.  The stresses he would experience are about 1.5G which amounts to a man of 75kg being slammed in the front by 113kg or so. It gets worse. If the target is more massive than the rammer then deceleration is more sudden and the impact rises to a maximum of 2G. This means each rower must brace himself as if being slammed by 150kg or approximately 3 medium sized lambs or two unarmoured dwarves.

Multiplied by 2 !

 EXECUTING THE ATTACK : DON'TS

If the ram was slammed into the enemy ship at a wildly oblique angle then the lateral forces experienced by the ram mounting could shatter the structure and tear it off. This we know happened on a large scale in early ramming battles. Experience was gained and applied in future tactics.

If the approach to ram was conducted at too-acute an angle then it may either not bite, experiencing a greater resistance from the hull than if it was attacked obliquely, or the speed of a target pursued may be so great that the net ramming speed is insufficent to damage the target.

The combined impact velocity of the attacker and target must be kept in a range sufficient to breach the target's hull but insufficient to damage the attacker. This is why the best way to attack another ship was from the stern quarter.

Gets it right the second time ! A perfect anastrophe.

The worst way to attack another ship was on the bow quarter. In this configuration each vessel will experience a force equal to the sum of their momenta. A trieres built to sail at 15 knots and be rowed at 10 will be severely tried, to say the least, by a head-on impact at equivalent to 20 knots.

It was only marginally less bad to attack a target from the beam if the target was moving. If the target is crossing then the lateral stress on the bow timbers was at its maximum and this was the weakest aspect of its structure. In addition, the forces affecting the crew of the attacker would be severe. They would be thrown forwards by the deceleration of the impact AND to the side opposite to that to which the target was moving. Heaven help any on deck who did not have a good hand-hold in that situation.

And what of the human sardines squished amongst sweat, farts, bilge and curses into this high-speed wooden can and expected to hurtle themselves at an unseen foe? What happens to them on impact ?

So much seems to hinge upon the kybernetes that we can only increase our admiration for these men. They were not of sufficient social status to warrant more than a few cursory lines from ancient authors but it was their skill and judgement derived from years of experience which was the key to a successful ramming attack.

The kybernetes must control the speed of his vessel. He must control the angle of attack and he must judge the timing to perfection with his ship moving in three planes on the sea.

The poet Lucian wrote about the pilot of a giant grain freighter, The Isis, he visited in Athens harbour in AD. This was about a sailing ship of great size but a sneaking admiration is to be detected in this terse and outwardly disrespectful description of an unassuming kybernetes who must have nevertheless exuded a sense of great  skill and confidence.

'Samippus: And all depends for its safety on one little old atomy of a man, who controls that great rudder with a mere broomstick of a tiller! He was pointed out to me; Heron was his name, I think; a woolly-pated fellow, half-bald. 
Timolaus:  He is a wonderful hand at it, so the crew say; a very Proteus in sea-cunning.'
(Lucian - The Ship. 35)



EXECUTING THE ATTACK : DOS

Once the ram became de rigeur for sea battles, mariners must have rapidly gained knowledge of how to use it to best effect by reports spread of various trials and errors. Herodotos tells us that the Phoceans learnt an early lesson in his account of the battle of Alalia in 535bc. They won, but many of their ships were almost as wrecked as their targets, the bows being ruined by the impact forces.
By the time we have good evidence for the structure of warships we can see all the longitudinal timbers meet behind the ram so that all impact forces are distributed along the whole ship and focussed through the bronze tip of the ship.

To hit an enemy effectively only required a small advantage in speed to give the required excess force to penetrate the tenon-and-peg hulls of triereis. Computer simulation has established that  different types of wood in the target or different angles of approach do not significantly change the basic rule which is that an advantage of 1/2 knot in speed will mean a penetrating hit.

On the other hand this means that vastly excessive speed will send the attacker barrelling in to the target and as the breach widens and the attacker slows he is more likely to get wedged-in and unable to withdraw. In this classic situation the crew of the ruined ship will launch a frantic boarding attempt, seeking for survival aboard the (more) bouyant victor.

The same excessive speed will tumble deck passengers into the briney and injure some rowers.

Shock and Oars !

This means that lightness of touch was a required attribute of a successful warship commander. The cooperation between the deck officers to feed information to the poop deck and the cooperation - almost empathy - required between the kybernetes, pentekontarchos and trierarch could only be developed by intensive practice. Just when sufficient speed had been achieved, just where the best angle of attack lay to ensure a hit and space to back-off, and the exact moment at which to stop rowing and brace for impact should all be judged and broadcast to ensure an attack was delivered.

The best position for an attack was to sit on the tail of the target as per an aerial dogfight.
In this position the target's speed is obvious, any change of course he makes is signalled by movements of his pedalia. By the same token, the target cannot read the attacker's changes in course and speed until after a disadvantageous delay.

 

The other significant advantage of the tailing position is that when the ram is set at the target it will hit a receeding target at an acute angle which minimises the stresses on the attacker. Transverse stress were the worst in terms of damaging a ship's bows and converging course would give increased shock of impact.

In trieres combat the secret was to ram the enemy in the right place, from the right position of attack, and with just enough force necessary to do the job.

In later times, as larger ships appeared, one could count  more on the mass of ones' own vessel to survive impact especially against smaller vessels. The trieres was a Formula One vehicle rather than a Stock Car and had to be treated as such.