In the golden age of the Greek and Roman Empires, warships with oars were mainly designed, which played a decisive role in maintaining long-distance trade and imperial ties. Sailing ships were created around 3500 BC, mainly for merchant ships, and due to the limitations of labor costs, the crew on board kept a minimum amount. Merchant ships only use oars to help when they are in and out of port or when the wind and waves are calm. Battleships also sailed as closely as possible, but when battle was imminent, the mainsail was lowered and placed on some nearby beach. The oars provide less energy than the downwind, but for a short time the oars give the battleship enough speed and superior maneuverability. The oarsman's metabolism provides a way to store a lot of energy and then release it quickly, and the benefits achieved are difficult to achieve by sail.
Although paddles were less efficient for long-range navigation, ancient paddle-bound warships achieved an admirable level of technical improvement. The standard battleships of the Greek era were like the three-oared battleship (trireme) commonly referred to in English. The word is derived from the Latin triremis, which in turn comes from the Greek trieres, to the effect that it is "equipped with three groups." The actual meaning of the name was once a matter of debate among classical scholars. This controversy has been satisfactorily resolved today, largely due to the work done by J.S. Morrison. He designed a plausible image of these famous ships on the basis of information such as bibliographic references, shipyard records, drawing evidence and the dimensions of the platform at the storage platform.
The three-oared battleship evolved mainly from the simple designs of Greece and Carthage. Such early boats were open-aircraft boats with rows of oarsmen on each side of the hull. According to the chapters of the ancient Greek bottle paintings and Homeric epics, such small ships appear to have been built for the rapid and efficient use of the abilities of the crew, but another element was the need to make such ships very efficient. This innovation was born around 800 BC when the angle of collision of warships appeared and caused a revolution in ancient shipbuilding. Early naval warfare was a naval battle between man and man, most of which took the form of attacking enemy forces. Now the purpose of the people is to destroy the parts of the other ship; Casualties to the crew were secondary.
The advent of battleship angles of impact greatly increased the need for speed and maneuverability. Thus, the ancient Greek and Roman warships of the simple structure of Homer's pre-era era soon developed into ships with a narrow, long, low hull, with room for up to 25 oarsmen on each side of such a section. This type of ship is called the front and rear deck 50 paddle hand battleship (Penteconter), or 50 oared ship. After roughly reliable extrapolation, the dimensions of its hull show several design principles that have been retained in the later development of more complex warships.
The resistance of the ship when sailing in the water is determined by 4 main factors. One of the factors is frictional resistance, which is caused by the fact that water (like all other liquids) is viscous. Another factor is the profile resistance, or degree of streamlinedness. When water molecules cannot flow continuously and smoothly close to the hull, then they detach from the hull and increase the volume of displacement. If the water molecules are sufficiently separated, a vortex will form. The energy required to cause the vortex is dissipated from the energy that can propel the vessel, so the vortex resistance is the third obstacle.
All three factors are closely related. The fourth resistance comes from the waves, which can be seen as a more independent factor. It increases with the speed of the ship, like any other factor, but the rate of difference it brings to the speed is so great that it finally becomes the main obstacle. Waves are mainly determined by the ratio between the length of the ship and the wavelength caused by the ship's voyage. To know why this is the case, it is necessary to observe the way in which the waves formed by the movement of the ship interact with the hull when the speed of the ship increases.
When the bow comes into contact with a new current, it causes some of the currents to produce an acceleration that increases with speed. Gravity hinders this movement and causes the water to finally descend to and below the horizontal plane. Thus waves are formed. At the same time the boat moves forward. The combined effect of the two movements forms one or more waves, and when the speed of the ship is unchanged, the waves are stable for the hull. When individual water molecules have time to rise and fall several times before the ship crosses them, many peaks are generated at low speeds.
The increase in bow pressure that forms this wave is exceeded by the amount of stern pressure attenuation that lowers the horizontal plane from the start. Two sets of shock waves conduct energy from the boat into the water, which in turn increases the resistance to the hull by expanding the wet area of the hull. If the hull speed is such that the standing wave generated by the bow is coordinated with the wake after the stern shock, then the water level difference caused by the above pressure is enhanced. If the bow waves and the stern wake are completely uncoordinated, the water level difference is largely offset. The increase in hull velocity increases the wavelength of the interfering system, so that the ship that accelerates from zero passes through a continuous velocity region, where the resistance first increases at a faster rate and then decreases, in other words, the resistance curve rises in a zigzag shape.
Finally affected the length of the ship. The stern of the ship descends and the bow rises, so the ship must try its best to climb the waves it has caused. When the standing wavelength of the bow reaches the length of the hull, the effect becomes severe. When this happens, much more power is needed than what is provided to reach this point to further increase the speed of the ship. It can be seen that the longer the hull, the longer the speed crisis is postponed. The narrow hull can also be reduced to a minimum by means of the following measures, that is, a large part of the total pressure necessary to support the ship is removed from the two points of the bow and stern, and it is distributed along the two sides of the ship, and this part of the pressure on both sides of the ship affects the total increase in resistance through the friction of the lower surface.
The Fourrudes ratio proposes the decisive limit for the maximum speed of a ship with a fixed power supply, which is the ratio of hull length to velocity square root (since resistance tends to increase with velocity square root). The ratio is named after the British naval architect William Froude, who elucidated these issues in the mid-19th century.
Of course, one cannot expect the ancients to make the above analysis. However, they came up with a practical understanding of the main obstacles to the ship's high speed by experimenting with the modification method. The hull of the 50 oarsmen warship is 38 meters long, and the maximum width of the hull is about 4 meters. Its length-to-width ratio is about 10:1, which is a representative ratio of warships designed to reach maximum speed, and it remains until the end of ancient oared warships. It was agreed that, for such ships, the above length was very close to the maximum feasible limit for building ships from wood. In fact, in the case of the narrower, longer three-oared warships, the limits of timber construction seem to have been exceeded. Even if a complex system of mortise, tenon and bolts is connected to the hull plates by dispersing the stress in large quantities onto the hull, it is not safe for a three-deck oared warship to descend into the water unless a thick anchor cable is installed from the bow to the stern and subjected it to the significant pull of the windlass. It is not known where the anchor cable is indeed placed, but when the anchor cable is forced, it seems necessary to make its compressive effect on the ship not to be extremely weakened. Wood is difficult to adapt to stressed joints on its own.
The width of this type of hull is the nearest minimum width required for an oarsman to sit side by side and place the hinge of their oars on the side edge (the top panel of the hull). The shaft of the paddle should not be too close to the handle, otherwise the paddle will be very laborious. The modern practice is to extend one-third (or slightly less than one-third) of the pulp to the inside of the shaft. Since the oars of the three-oared battleship were the same length as those still in common use today, the same permissible limits seemed appropriate for antiquity. Finally, considering that the shoulders of adjacent oarsmen need to leave a certain gap between the ends of the oars, then one can find that the hull of the 50 oarsmen battleship saves its propulsion device in a small cabin. The draft of the hull is also very small, about half a meter. As a result, the displacement is very small and the resulting friction is also very small.
Since the hulls of battleships were made of light and soft wood sparingly, their draft was shallow. The hull is only about 3.5 centimeters thick, and some parts are even thinner. The hulls of merchant ships written in the documents were usually heavier, but ancient poets described such merchant hulls by pointing out that the wood separating sailors from death was only three fingers thick. The minimum hull appears to be to have the crew accounting for about a third of the system's total weight. We estimate that the displacement of a three-decker oared battleship, including a paddler, is less than 40 metric tons.
The meticulous construction of the hull has a further effect on its speed. The hull profile of the supertanker is now a familiar perception that it has a spherical bow that protrudes forward underwater, minimizing the formation of bow waves by avoiding sudden changes in momentum in the water. Ancient angles of impact were different in structure, but at least some of them had the same effect. The stern of the two-oared battleship, like all modern racing speedboats, rises gradually and cleanly from the water, thus minimizing the formation of vortexes and wake waves. Two-oared battleships may actually have set sail cleanly compared to modern ships, which tend to be equipped with fins to support the rudder. Ancient ships took the helm with oars hanging from the sides of the stern. This may hinder vortex formation while minimizing the wet surface.
Such ships show the same thoughtful design considerations on the water part: the low hull minimizes wind resistance, with the exception of the tail, where the gradually rising curve of the hull extends into a ridge or fan. This feature not only helps prevent low hulls from sinking by back waves, but also reduces the jolts that such vessels tend to cause under typical light ballast conditions by increasing hull moment of inertia. If a strong wind hits the ship, the stern ridge can also help to turn the boat into the wind, so as to reduce the accident of the ship sinking due to the waves hitting the side of the ship.
Therefore, even before the era of three-oared warships, two-oared warships began to embody a lot of shipbuilding expertise. The effect was achieved in terms of speed: the fastest front and rear deck 50-oar battleships had a maximum speed estimated at 9.5 knots (17.6 km/h), which was only about one knot slower than the best modern racing speedboats.
In addition to the performance aspect, the two-row paddle battleship also has an emotional aspect, as if it itself liked the design of most of the huge ships in history. Some ships today still flaunt their hulls by coating them with asphalt to make them waterproof, installing ventilation holes, or applying contrasting markings to the bow of a ship that is visible just above and behind the angle of impact. The angle of impact is often wrapped in copper and decorated with multiple sword-shaped patterns, or given the shape of a huge boar's mouth. For example, some two-tier oared battleships are black and dazzling near the angle of impact, and their tail ridges are raised high like the tail of a beast. Sometimes along the ship's upper side are also equipped with a wave screen made of hairy tanned animal skins. The oars add to the animal shape: the salted whitened handle flashes up and down at the same time, which is often compared by ancient poets to the movement of a bird's wing. Even simulating the rainbow of animals; Aristotle pointed out that when the oar hits the water, the flash is positive, and the splashing waves become a rainbow.
But the main aspects of the ship's functions that drove the designers of the two-oared battleship, between Homer's time and about 500 BC, had some basic steps of trying to fit more power into the basic hull of the 50-oared battleship. The details are not fully understood, the whole situation is too complex to be simply explained, but in essence it is to expand the hull upwards by adding superimposed decks or adding more paddler seats. A double-decker ship produces a two-decker oared battleship, or "double-decker device" ship, which produces a three-decker oared warship when a third batch of oarsmen is added.
These steps have not been taken without jeopardizing the stability of the hull because the minimum necessary measures have been carefully taken. Even in a two-row oared battleship, if the second group of oarsmen is simply placed above the head of the first group of oarsmen, the ship may dangerously experience a top load situation. The final design was simply to extend the ship's rim slightly upwards to a length of less than half a meter. At the rim, as before, a line of oarsmen was arranged, except that they were now the middle tier of a group of three. Under them were the oarsmen arranged in the bottom cabin of the ship, and the men were too close to the surface of the water, about half a meter, and they were in danger of lowering the edge of the hull to the surface. So their oars protrude from the portholes on the line, leather padding protects the porthole edges, and paddle handles prevent seawater intrusion.
There was an outboard bracket on the top oar plane of the ship, an innovation that could have changed the two-oared battleship to a three-oared battleship. The outboard bracket allowed shipbuilders to move the hinge of the top paddle 60 cm outward from the rim. This allows the top row paddler to sit side by side with the middle row paddler, rather than above their head, adjusting the height of the superstructure by about 50 cm.
The density of oarsmen in the hull is further completed by taking an echelon arrangement, that is, the top row personnel sit about half a meter in front of the middle row personnel, and the middle row personnel sit at about the same distance as the bottom cabin personnel. Each row of people was still crowded, and they only had about a meter of space between them. This means that if a person swings a paddle even slightly out of tune, it will cause his back to touch the knuckles of the person behind him, or his knuckles will touch the back of the person in front.
The bottom cabin crew had another clearance problem. As comedy writer Aristophanes talks about in his play Frog, when they reach forward and start paddling, their noses are close to the hips of those sitting above and in front of them. Sometimes the paddle is so hard that the paddler farts at the right moment.
The most rigorous and necessary condition is to arrange the positions of three people in a trapezoidal shape. As can be seen from the three-layer paddle battleship shown in the side view, the oars of each three people must keep their oar handles extremely closely parallel when rowing, and if the paddles are not entangled, it is best to keep a distance of 30 cm. If entanglement occurs, the effect of dominoes may implicate most of the remaining paddles in that case. Therefore, it not only seriously affects the speed of the ship, but also affects the course of the ship.
In order to properly manage this system, continuous training and exercises are necessary. At the same time, due attention is also paid to the factors of encouragement. Ancient oarsmen were mainly recruited from the free class of citizens. They therefore had a stake in the survival of their ancient city-states. Generally speaking, slaves were used only in emergencies, and often after they had gained their freedom. It is not difficult to see that as long as there is a disgruntled person on board, the voyage will be destroyed. Whipping was never used; One of the lead singers shouted a synchronized paddle. Paddlers receive higher rewards as a further encouragement. This played a very important role in their operations, for they were generally recruited from the poor classes of the cities, and the cost of the refined protective clothing worn by the heavy infantry was not sufficient for them.
One can imagine that there must be some social tension between the sweat-soaked oarsmen on a three-deck oared battleship and the heavily armed sailors who remain solemnly on the deck to fight on the ship. Only in some of the more democratic ancient city-states, such as Athens, great trust was placed in the angle of impact powered by oarsmen, and the divisional forces of the division were reduced to a minimum. The Athenians carried only 14 sailors with only 14 sailors in the three-oared warships used in the Peloponnesian War. However, in the case of a dense crew, 170 oarsmen could be squeezed into the hull, and this hull did not change much in length and width to the length and width of the 50 paddlemer battleship.
The result of this hard work lies in the astonishing level of speed and maneuverability. A reasonable estimate of the maximum speed of a three-decker oared warship is as high as 11.5 knots (21.3 km/h). Indeed, these estimates may have been too conservative, as they envisioned the hull draining water in the battleship's march, and some naval architects said that the three-oared battleship resembled a modern speedboat, both light and decisive, enough to adapt to poorly designed situations. In this case, the maximum speed can be increased by up to 50%. These speeds lasted only 5 or 10 minutes before the crew fatigued, but when they peaked, they were comparable to those reached by a weight-bearing horse of a cavalry team in the Middle Ages.
A three-oared battleship can reach its top speed for about 30 seconds from a stop, but since it can reach half speed in about 8 seconds and a quarter speed in less than two seconds, it does not take long to provide sufficient power to the battleship for a decisive blow. Obviously, the three-oared battleship is very suitable for galloping. Moreover, they are highly maneuverable. For example, by paddling backwards on one side and forward on the other, the crew will be able to rotate the boat slightly longer than the boat itself. It is inevitable to be impressive to look at a fleet with many of these warships maneuvering across the water or galloping back at full speed after an exercise to determine which one enters the port first.
The year 427 BC was held with the impact of the most famous long-range three-oared warship of that period. The inhabitants of the city of Mitylene on the island of Lesbos rebelled against their Athenian masters, who later retaken the city. Cleon, the leader of the athenian agitators, proposed the execution of all the inhabitants of the subordinate city, and his speech was successful at the popular meeting. So a three-ply oared warship set out to send the order to the garrison in Athens. With the political fervor of the Athenians so high, the three-decker oared battleship set sail in the early afternoon of the same day, about shortly after the decision was adopted at the meeting. But, as Thucyddes writes, because the nature of the ship's mission was terrible, it did not sail at a rapid pace. Due to the rotation of operation with one or two oarsmen and the arrangement of slow rowing, the ship's speed will not exceed about 4 or 5 knots per hour. Early the next morning a popular meeting was convened. The cool head took the advantage and withdrew the order to slaughter. The Mitirin envoys in Athens, who were expecting this change, arranged for a fast ship and a team of elite crews to provide them with high-energy food during the voyage and promised to give them a large sum of money if they could get the orders before the first battleship arrived.
The second ship apparently set sail for Liesburg about 24 hours after the departure of the previous one, a voyage of about 345 kilometers. They reached the high seas before dusk, and the crew paddled continuously throughout the night. They even eat and paddle, eating wheat cakes that have been moistened with wine. The night was very clear when sailing, and there were no headwinds. In order to increase the speed to the maximum extent, the commanders either equipped another row of enough oarsmen to rotate the original three rows of oarsmen, or two rows of three row oarsmen were kept on continuous duty at night, and the third row of oarsmen was rotated to sleep. Either way they could use it, so that at noon they arrived at Mitilenes just as the first battleship arrived. Thus, it appears that they spent less than 24 hours on the entire voyage, with a speed close to 9 knots (16.6 km/h). The first battleship had already submitted the order, but the garrison had not yet had time to put it into effect. A new type of ferry can complete this voyage in 14 hours.
Around 400 BC, a second important step forward was taken in the design of warships. At that time, four-row oarsmen's ships known as four-row oared warships developed, and in 399 BC, an engineering group composed of Dionysius of Syracuse built the first five-row oared warships (i.e., five-row oarsmen's ships). The number of these arrangements initially appeared to be a simple continuation of the trend determined by the original single-oared battleships and two-oared warships, but this was not the case. There are many cases in which ancient warships with more than three oars were never built. In fact, this conclusion can be considered correct, because the inevitable angle of the paddle in the fourth row of paddles will make the operation there more difficult. Even on a three-deck oared battleship, the top row oarsmen were noticeably more difficult to maneuver than the other two rows, and this row of oarsmen sometimes had to earn extra wages.
It seems that what happened at that time was that one row or more was equipped with a double. If the hull of a three-oared battleship is minimal, the method of equipping the top row with two people is adopted about the first step, so that the ship becomes a four-row. Only there can you find enough extra space to configure the other two rows of paddlers without having to make major changes to the design. It seems that the Carthaginians had taken another approach, and their warships were largely modeled on the wide hull chosen by the Phoenicians; Apparently from the beginning they had built a battleship with each floor wide enough to accommodate four oarsmen shoulder to shoulder. However, the main route of battleship development initially stayed on that narrow hull.
The transition from a four-oared battleship to a five-oared battleship would require a redesign of the hull unless it was assumed that the shipbuilder would be happy to place the additional oarsmen on a shaft close to the oars, where the increase in power was small. It was thought that the most likely design change would be that the shipbuilder deepened the outboard bracket, making it a double-layered thing, and configuring the upper and middle rows as double. The bottom row is still about single, in order to try to maintain the speed of this narrow part of the immersion in the water, although the draft depth of the four-row oared battleship and the five-row paddle battleship certainly increases with the weight of the additional oarsman. Since the original top row of three-decker oars had 31 oarsmen on each side and the other two rows had 27 oarsmen on each side, the newly designed four-row oared battleships probably had a total of 232 oarsmen and a total of 286 oarsmen in the five-row oared battleships.
It was not until a century after the introduction of four-row and five-row-oared warships that the earliest legendary data for this series of changes began. However, these illustrations show that, depending on the actual need for oars, most or all of the oars of the larger Greek warships of the third and second centuries BC were mounted on a large outboard bracket (a box or a paddle frame) rather than on the hull. The ancient Romans tended to imitate the Carthaginians' preference for a wider hull with a single oar hatch inside. They were not particularly good crew members, and only wanted to grab enemy ships at the first opportunity and then drive their troops onto deck, so that naval warfare could be transformed into combat that could apply the infantry tactics they were good at. Therefore, the speed of the ship is not as important to them as the ship's ability to carry troops.
In the first decades of the emergence of four- and five-oared warships, such designs were slowly popularized through the Fleet of the Mediterranean. In 330 BC, the Athenian fleet consisted of only 18 four-row oared warships, compared to 492 three-row oared warships. Over the next six years, however, the small number of four-row oared warships more than doubled and construction began. An evaluation of the reasons for the slow initial adoption of heavy warships would facilitate a more detailed comparison of some of the physical characteristics of three-oared, four-oared, and five-oared warships.
It is clear from the design of the three-oared battleship that one of the main problems faced by the designers of the battleship was to avoid excessive weight on the upper part. These conditions, which determine whether the boat is smooth and whether it can return to stability on its own when tilted, are now often considered in terms of the boat's steady height. Concepts in this area date back to the pre-eighteenth century AD, although Archimedes already knew most of the concepts of fundamental physics and mathematics. Indeed, there are some indications that Archimedes' study of floating bodies was inspired by his work on the stability of ships. From the example of a typical battleship profile shown in Figure 3, the center of gravity may be at some point in the hull and will be somewhere on the centerline due to symmetry.
It is conceivable that the ship moves as if its weight were concentrated at this point and pulled down toward the center of the earth by gravity. If the boat is tilted to one side, the center of gravity of the smaller part of the hull immersed in the water will move in the same direction. The buoyancy of the water will act on the center of gravity of the part immersed in the water, acting as a vertical push. As long as part of the centroid immersed in the water moves sufficiently in the oblique direction, the buoyancy force of its upward action cancels out the downward acting gravity force by transmitting it to the lowered side of the hull, and the final effect of the two forces acting together will make the ship return to stability on its own. The steady center height of the ship is the distance between the upward force of its center of mass and buoyancy and the centerline of the ship. As the illustration shows, the greater the centering height, the smoother the structure of the ship.
With sufficient knowledge of the dimensions of the three-oared warships and the availability of crew and other storage items in their hulls, it is possible to estimate their steady height. The numbers obtained for factors such as the draft depth of the ship, the amount of wood used for the hull and the arrangement of the oarsmen in the hull are susceptible to changes in the imagination. Even a slight change in one or more of these factors can lead to a change of five or six kilometers per hour in the wind, which can cause the ship to capsize. However, as long as the parameters of the various types of ships are left unchanged, the ratio between the steady center values will be correct, even if the values of both are not absolutely correct. Since this method is correct, it is inevitable to assume that the hull and contents of the transition from a three-oared battleship to a four-oared or five-oared battleship are as little as possible. Since shipbuilding has historically been extremely conservative about making such changes, this assumption seems entirely possible.
The most inexcalculable in this analysis is the ballast load on the ship, because the ancient two-row paddle battleship had enough hull space to accommodate enough ballast to make considerable changes to the smooth characteristics of the hull. When we estimate ballast, we are willing to keep the hull lighter and better, in harmony with other obvious efforts made by hull assemblers in ancient times, that is, to create the hull to match the strength of the oarsmen to the greatest extent. We estimate that the ballast is 13,000 kg, which is enough to prevent wind pressure of less than 6O km/h from blowing the hull down at both ends of the hull beams.
As a result of this method of estimation, the steady height of the three-decker oared battleship is about O.4 meters, which is just enough, but by no means has a rich margin. Therefore, unless the water is very calm, the caution shown by the ancients to avoid war is quite reasonable. In the case of a five-row oared warship, adding four additional rows of paddlers to the top two rows of the ship would create a problem, that is, to make the stability of the ship against its speed. If a five-row oared battleship adopts the same size immersed in water as a three-oared battleship and still retains the same assumptions mentioned earlier, the steady height of the five-row oared battleship is only 0.1 meters. Such a ship is difficult to withstand the wave pressure and will overturn under the wind force of more than 30 kilometers per hour.
This apparently unsatisfactory condition suggests that shipbuilders were modifying their hull designs under heavy pressure. From some of the reasons we have already mentioned, the only good option that shipbuilders can consider is to increase the maximum width of their hull. But this practice necessarily requires some sacrifice of speed, which is the main reason for designing a vessel with a larger number of platoons in the first place. In the case of a five-row oared warship, if the hull is stabilized and widened to the same width as the three-oared battleship, its speed can only be 14% faster than that of the three-oared battleship, and its acceleration is worse. If 62 paddlers were added to the top row and 54 more in the middle row, the size of the crew would have increased by nearly 70 percent. If the stability of a five-row oared battleship were reduced to as previously envisaged, the speed would increase by as much as 29 percent.
Having learned these problems, one can understand more clearly why the construction of a sizable number of four-row and five-decker paddle warships began only after two-thirds of the century had passed. This tendency of the Athenians to cling to the historical tradition of their three-oared warships can also partly explain the reason for this delay. The warships that had triumphed in salamis would not give up easily. However, this analysis does not yet show that the fame of four-oared and five-oared warships began to increase significantly around 330 BC and the special competition of ancient naval weapons that followed.
The development of these supposedly six-oared warships began in Macedon and Syracuse as early as 340 or 35O BC, but was not heard until after the death of Alexander the Great in 323 BC and after his empire split into rival groups. By around 315 BC, Anigonus, one of Alexander the Great's heirs, had built seven-row oared warships. In 301 BC, his son Demetrius the Besieger was listed as a battleship in his fleet as high as thirteen platoons. Before Demetrius' death, he built a sixteen-platoon battleship. His opponents have built battleships that are the same or more than it, but surprisingly, some have fewer rows of oars. For example, Lysimachus built an eight-oared battleship that was thought to be able to compete with Demetrius's sixteen-row paddle warship. This kind of race obviously means that more is happening in the role of the number of paddle rows. The movement culminated in a twenty-row oared warship and two thirty-oared warships built in the Middle Ages, as well as a giant forty-oared warship launched about forty years later.
These warships are not as famous as the three-oared battleships. And they're just as controversial. But claims of satisfaction with such a battleship design have been proposed in recent years, especially by Lionel Casson of New York University. His view was that the design of a six-row oared battleship could be completed by equipping two-oars, and that a six-row oared battleship could be so logically configured with its lowest row of oarsmen. At this point, a wide hull became indispensable, regardless of whether the various shipbuilders or cities had earlier adjusted their designs in this direction. Since the advent of six-row oared warships, some new oar configurations have been designed. By arranging more people (up to eight people) for each oar, you can achieve an equal number of paddle rows. (When this paddling configuration became popular again during the Renaissance, eight people in one paddle was considered the largest significant number.) ）
Since each paddle is equipped with more than two people, the paddler can no longer operate when sitting. There were benches on board, but when the oarsman was about to start paddling, he had to stand up, walk forward, and (if the oars were long) step on a stool to insert the oars into the water at the end of the outside of the boat. The paddlers ended with a paddle move when they stepped back and threw themselves on the bench. Extrapolating from late European experience, this configuration allowed the entire crew to include a small number of skilled oarsmen, and the personnel in the cabin were the most critical. The problem of paddler configuration occurred anyway, and the large physical exertion (due in part to the inevitable result of the 17.5-meter-long oars of the time) undoubtedly showed that the operational efficiency of the ship had declined more than the widening of the hull alone.
At one time, the configuration of too many oarsmen was envisaged, and the number of oars taken was more uncertain than before. At that time, a four-row oared battleship could be a three-decker oared battleship with a double oar top row, a two-deck oared battleship with two rows of double paddle, or even a single-deck oared battleship with four people per oar. Demetrius's sixteen-oared battleship could likewise have two rows of eight men per oar, or three rows were added to sixteen men in some combination, such as six people per oar in the top row and four men per oar in the bottom row. When this happens, there are other reasons besides stability to prefer the hull to a wider and shallower choice.
In addition to Demetrius's sixteen-row oared battleship, there are some indications that the meaning of the number of oars has changed for another reason. It turned out that such a battleship was challenged by the eight-decker paddle battleship built by Lysimachus.
Casson made a number of arguments for believing that the eight-row oared battleship and all other warships with sixteen or more rows were built as catamarans (connecting the two bodies with brackets). Lysimachus' battleship may have had two deck oarsmen. They operate in each hull, with four people per paddle. This configuration was sufficient to accommodate all the larger oared warships of all classes, including forty row oared warships, which had three rows of oars per hull, perhaps eight, seven, and five oarsmen in descending order, and a total of 20 oarsmen on each side of one hull. The hull of such a battleship is very wide, which makes it possible to build such a battleship longer than a three-layer oared battleship. The forty-row oared battleship has a hull up to 128 meters long and can have 4,000 oarsmen.
Most reports of the operation of such a giant warship agree that the battleship is stable, but slow. Judging from the results obtained from the previous five-row oared battleships, it is reasonable to think that when the number of oars is increased to more than five rows, its operating level continues to decline. A rough estimate suggests that their power-to-displacement ratio is as low as one-sixth of the corresponding value for three-decker oared warships. If the three-oared battleship and its bow angle had an advantage in the early days, why did Alexander the Great and his successors have to resort to low-speed and poorly maneuverable warships?
One part of the answer is that the bow angle is no longer popular, but replaced by anchors and decks. The ancient Romans, in particular, threw up to 120 sailors into the deck of their five-row oared warships. This figure means (and confirmed by surviving charts) that the hull of the ancient Romans was wide and had only double or single row oars. The giant catamaran carried a considerable number of troops. Lysimachus' eight-row paddle battleship had 1200 sailors on deck, while the forty-row paddle battleship once carried 2850 sailors and 400 deck sailors. Apparently, in a ship-to-ship encounter determined by sailors, one such super battleship would be able to crush a three-decker paddle battleship of no matter how many (each carrying 15 to 30 sailors). The facts of space show that it is impossible to encircle such a super battleship with enough three-oared battleships carrying the equivalent of a catamaran battleship.
On the other hand, this argument does not pay sufficient attention to the bow angle. Unless such a super battleship can be surrounded by a row of smaller warships, the blow of a three-oared battleship alone is enough to destroy it. If its attack power is limited by low speed, then why build such a battleship and its size is getting larger and larger? Apparently, the shift toward slower warships and deck battles suggests that somehow was found around 330 BC to counteract the bow angle.
Ancient catapults seem to provide most of the answer to this confusing matter. It has long been mentioned that heavy warships carry catapults, and it is known that this powerful and modified weapon relies on the elasticity of tough ropes rather than on the easy to bend traditional bow, which came to prominence around 332 BC. During the siege of the city of Tyre that year, Alexander mounted his heavy catapult on his warships to bombard the city walls. Later, Demetrius increased the number of battleships from seven to sixteen, with naval catapults.
Without the constraints of ground movement, this catapult can reach a large range. Archimedes built a naval catapult, each firing a javelin weighing 78.5 kilograms or a javelin 5.5 meters long. The latter is mostly just a trick of cutting down medium-sized trees and attaching the trunk to the tip of iron. Using one of the above two projectiles, the range of the catapult is exactly within 200 meters, but when using smaller projectiles, the range can be more than twice. Much of the attention paid to the effects of such naval catapults was focused on stone projectiles. There were good reasons to suspect that such projectiles could penetrate the hull and sink the ship. Even if a stone bullet can penetrate the superstructure of a ship, the layer of sand or stone that serves as ballast will effectively block the projectile.
However, this view ignores the susceptibility of sailors and paddlers to the firing of catapults. Arrows and stone bullets are just as good for such an attack, especially since a new type of arrow was created in Greece around 500 BC. Angle cone arrows have a strong penetrating power. Julius Caesar once wrote that a projectile is enough to penetrate a solid oak about a foot. Ancient warships must have had little resistance. Theonhrastus had reported that the upper deck of the three-oared battleship was made of wood from the Linden tree, which had moderate mechanical strength, but it was the lightest and most suitable wood available in the Mediterranean basin.
My colleague, James F. Of the School of Aeronautics and Astronautics Engineering at Purdue University. Doyle once tested a modern replica of an ancient horn-cone-shaped arrow, large enough to be fired from the smallest type of reinforced catapult, which could prove that the existence of this catapult came from an ancient ammunition pile. He found that the arrow could penetrate five centimeters of basswood, an American variant of the Linden tree, and that the arrow's ability was less than half the speed expected when it was fired. This thickness was too conservative even if needed, and the device produced much less power than Archimedes's naval catapults. Even if the battleship deck was made of oak wood and had the same thickness as the hull plates, larger warships could still be fitted with many catapults, highly penetrating launch plugs, and could carry at least half of the rated dispatch fleet.
The exact requirements for this kind of shooting do not seem too much, and in the Middle Ages, British handbow archers used to practice shooting at the "bullseye" with a range of more than 200 meters (using a wooden stake to control a piece of cloth to the ground). The exact size of the bullseye is unknown, but its full diameter is certainly smaller than the deck of a three-story oared battleship about five meters wide. Rolle Smith, president of the National Association of Stone Archers, reported that he would use modern shooting equipment and shoot immediately without preparation, concentrating the arrows within a three-meter radius of 365 meters. Since the large size of the ancient catapults were mounted on adjustable brackets, they could do it almost well as well. With the visibility of large arrows in flight, aiming is easier.
A catapult arrow that is fired through the upper deck of a three-deck oared battleship has the potential to hit one of the oarsmen in the dense arrangement (which is characteristic of the design). In fact, the arrangement of the paddler echelon suggests that a fairly long arrow may hit more than one oarsman at a time, and when the arrow is fired at a distance, the angle of incidence is almost at a right angle. In a paddle equipped with only one loader, even one casualty can make the entire row of paddles out of tune for a few seconds, making it even worse if the hit person is in the top row of the most vulnerable and drops the paddle between the other paddlers. Even if no one is injured, and a long arrow suddenly appears in the dense line of paddling, it is likely to interrupt the operation of some oarsmen before cutting the arrow, and the consequences will be the same as above. Since a three-oared battleship can sail to a distance of its own length in less than six seconds, a delay of a few seconds is sufficient.
Therefore, in order to minimize the danger from catapult launches, it appears that there has been an important incentive to change the design of the battleship. Replacing single-person paddles with multiple rows of long paddles will reduce the number of cases where one person is injured and other paddlers can't paddle together. The combined strength of six oarsmen or eight oarsmen is enough to grab the javelin-type arrow shaft that shoots in their middle. A smaller number of paddle rows makes the target of the projectile less dense. Therefore, from this advantageous position, the main tendency in battleship design after the time of Alexander the Great was correct.
Considerations for the stability of the ship also help to illustrate changes in the approach to impact. For there are many reasons to state that the best method of impact is to take a blow at the side of the hull of an enemy ship or at the rear of the ship's side. Therefore, a ship that is intercepted and parked in the water, its hull side facing the opposing warship with a collision angle attack is the most vulnerable. However, when the battleship used catapults, the tactical position was almost reversed. A parked battleship can fire all its guns at an angle perpendicular to the axis line. Because the parked battleship has critical stability, and its target is disturbed by the sway, which introduces an error in the elevation angle of the launch projectile. The elevation angle scattering, in turn, leads to an error in the hit distance. The battleship's enormous length minimizes its front and rear bumps, and the bumps turn into wind resistance errors when firing. But. Since oncoming battleships are 10 times their length, a target that is almost perfectly suited to the firing characteristics of defensive warships will emerge.
Attacking warships, on the other hand, fire their catapults along a line that is actually directly opposite. The ship wouldn't have much bump either, but it wouldn't be able to withstand the bumps either, as its target was only about three meters wide (other than the oars). For attacking battleships, rocking can cause serious problems, because when the catapult is lifted up to give it sufficient range, the head of the catapult is raised farther away from the center of rotation of the battleship than the tail end of its wing.
Thus, when the battleship rocks, the head of the projectile is farther away from the side of the port than the tail end. If you complete the aim when the battleship is vertical (the only time it is easiest to aim when the ship is vertical) and fire when the ship has crossed the vertical line, the result is that the projectile will fly far away from the target. The boat travels most quickly in the middle of the swing, making it difficult to determine the exact vertical line. For a catapult of the size envisaged earlier, when firing an arrow from 200 meters towards an oncoming three-decker paddle battleship, an error of only 1.5 degrees away from the vertical line would cause the launch to fail completely.
Since we assume that the target ship is on the side of the attacking battleship, this error problem may not be very serious. However, the boat swings to a lesser extent also affects the elevation angle of the catapult, just as the boat will have a sudden slight tilt when rowing. Regardless of the large ratio between the length and width of the battleship, the bow will still be slightly raised as the oar is paddled, and then it will be lowered again. Even in calm seas such irregularities are extremely difficult for long-range low-target launches. In addition, if the target boat stays in the water, the damage to its oarsmen is less than the damage to the boat in transit.
Thus, on the whole, catapults seem to counteract at least some of the threats that arise from the angle of impact and make the tactics of attacking enemy ships welcome again. The catapult appears at the appropriate time to account for the changes observed in the rowing organization; Its level of effectiveness can damage the oarer, if not sink, and its launch from the port side platform can also deflate the impact method. The enhanced stability of catamarans makes them particularly suitable for platforms as catapults. What remains to be explained is why, after about 250 BC, such large warships gradually disappeared from the stage and were replaced by three-oared warships or smaller ships.
It seems to be partly due to tactical reasons. The slowness and insensitivity of large warships seems to have contributed to the development of harassment tactics for faster small warships. For example, an open boat called Lemboi at the Battle of Chios in 201 BC effectively harassed the heavy warships of the Rhodes. After starting the assault and causing the large ships to lose their formation, the Lemboi boats unwittingly blended into the middle of the large ships, damaging or disturbing the oars of the large ships and disrupting their steering. The disadvantage of the catapult's design is that they usually cannot be fired at an angle below the horizontal line, which means that there are local safe zones around large warships that allow those small boats to unknowingly blend into the big ships. Unfortunately, there appears to be no record of small boats rushing between the two hulls of the catamaran, partly because they are protected by outstretched outboard brackets, and when the oars of the boats slide over the sides of the large ship, they break suddenly. It's an exciting idea, but at least some catamarans have angle devices that protrude between the two hulls and block the ship's intrusion.
Part of the reason for the decline of heavy battleships can be traced back to the larger political events of the time. As the Roman Empire expanded its territory and ceased hostilities with Alexander the Great's successor, its navy was increasingly limited to what only small ships could do, such as suppressing piracy. The last great naval battle of antiquity was fought at Actium in 31 BC, in which Autony's heavy fleet was defeated by a light fast fleet led by Octavian's fleet commander Agrippa. The latter added tactical equipment that would be helpful to its boats, such as iron hooks and launchers fired by catapults, some of which were fired in the same way. The size and complexity of these new empires also suggest that their navies should be multifaceted in order to carry out tasks such as **** and patrolling. The increasing cost of heavy warships in terms of manpower and material resources also made them opposed in the imperial era. Even the Roman Empire had reduced its military spending to a minimum.
When the Roman Empire began to decline, the shipbuilding industry's greater focus on relying entirely on human physical strength was also lost. After about 325 AD, the three-decker oared battleship was no longer heard. The standard paddle-bound warships of the late Roman Empire and the Byzantine era were large fast sailing ships that relied heavily on Greek fire for offensive purposes. This early incendiary agent could be sprayed through a flamethrower or in a catapult launch jane. Large speedboats usually have two rows of paddles, each with one, two or three paddlers.
The next major warship innovation came in the early fourteenth century. At that time, the Italians adopted a Zenzile oaring system, which was characterized by dividing the oars into three oars in groups, as in a three-tier oar battleship, each oar was operated by one person. The novelty was that all three of them sat shoulder to shoulder on a shared bench, which was placed obliquely inside the boat so that the oarsmen would not interfere with each other as they paddled. The main reason for the new system is probably that it has a lower center of gravity and greater stability than a two-row oared battleship. The compass has spread to Europe in recent times, so it is possible to navigate stormy climates with greater confidence. Under conditions that its Greek ancestors could not have done, they could boldly escort warships.
The final change in the design of the battleship came around 1550 AD, when the wide hull battleship with multiple oars per oar had to be restored due to the need to load heavy cannons. Although the guns loaded on these ships were only used for direct fire, their weight made it necessary to make many of the same changes related to catapults dating back about 2,000 years. But the future belongs to a battleship that is capable of firing a heavy full range of guns without interference from oars and oarsmen on either side of the hull. After the Battle of Lepahto in 1571 AD, the role of single-deck galleons declined, and after one last anchorage in shallow seas such as the Baltic Sea, the ship disappeared completely. By the time such ships were eclipsed, they had survived the civilized world of the West for 2,500 years. In a civilized environment where machines are increasingly dominant, it is an unusual survivor who directly uses human physical strength.