History of Maritime Technology

Approximately 71% of the surface of the earth is covered by it. Water plays a major role in many aspects of human life. Since the first known records, humans have documented the need for transportation across bodies of water. This need prompted a drive for the development of safe, reliable, and efficient methods of accomplishing such travel. The concept involved more than simply getting from one place to another, it encompassed the distribution of goods, military power, and a means for exploration and discovery of new lands. Hence, the design of seafaring vessels is one of the earliest known areas of engineering ("Designing a Faster Boat Hull - ENGINEERING.com," 2011). The technologies that first made this possible have evolved in amazing ways. Of the many that enabled the success of maritime travel, the most influential include advancements in hull design, propulsion, and navigation technology.
From the earliest attempts at crossing large bodies of water, the first major obstacle has been the design and construction of a vessel which is capable of doing so. Shipbuilding is the combination of structural components that together make a fully capable vessel. The major component of enabling a boat to float on water is the hull. The hull of a ship or boat is often considered analogous to the foundation of a building. It is a well-known fact that the strength of any structure is only as good as its foundation and the same is true of the hull of a boat. As stated in Design of Ship Hull Structures, “The most important duty of the hull structure design is to supply a strong enough hull structure against the internal and external loads” (Okumoto, 2009, p. v). There are many different types of hull designs, each of which is engineered specifically for the type of work the vessel is intended to do. Major aspects of the design include shape and dimensions, hydrodynamic features, and materials used.
Vessels come in many shapes and sizes, and each is built for an explicit purpose whether it is fishing, sailing, transportation, cargo, recreation, or warfare. Each purpose requires certain aspects of behavior such as speed, stability, payload, or durability. As such, there are many different shapes in hull design, each one specially engineered to best satisfy the requirements of the type of vessel being built. For instance, common sailboat hulls usually take on a long and narrow shape that extends deep into the water. This design helps the boat slide easily through the water with the least amount of drag, while keeping it stable and upright in strong winds (Nautical Know How, Inc., 2006). The shape and dimensions of a ship’s hull are the foremost factors that determine its behavior when exposed to various conditions at sea. Buoyancy, stability, and drag are all considerations when employing different hull designs. Sophisticated software has become available in modern times, allowing engineers to design and even test the behavior of a hull before ever producing it. Common hull designs include, but are not limited to, flat bottom, “V” bottom, tri-hull, tunnel, catamaran, or even pontoon ("Designing a Faster Boat Hull - ENGINEERING.com," 2011). Aside from the basic shape and dimensions of the hull, additional features are sometimes added to compliment and improve their hydrodynamic efficiency.
Particularly in more recent years, numerous improvements have been made in hull designs which have allowed boats to more efficiently move through the water. These efficiencies come from improvements in the hydrodynamics. Hydrodynamics is the ability of an object to more easily and efficiently move through a liquid (Merriam-Webster's, 1993). Just as aerodynamics is the study of the forces of air on an object passing through it such as a car or airplane, hydrodynamics is the study of the forces of water on an object passing through it, in this case a boat. Improvements in hull hydrodynamics translate into greater speed with less effort, and therefore better fuel efficiency and longer range. Large vessels have the most to gain from finding new efficiencies as they use the most energy to sustain movement. Many of the largest ships on earth are used for cargo transport of goods of some kind. In this industry the old adage “time is money” is never truer. Therefore, speed is of the utmost importance. The bulbous bow and hydrofoils are two of the most interesting additions to a ship’s hull.
One of the most commonly utilized engineering breakthroughs on large ships today is the bulbous bow. A bulbous bow is essentially a bulb-shaped structure that is added to the submerged portion of the bow of a ship. An engineer by the name of David Taylor first designed the bulbous bow back in the early 1900’s when he was Chief Constructor for the United States Navy. A bulbous bow cleverly works by modifying the flow and improving the hydrodynamics at the front of a ship where it slices through the water. The first ship to be fitted with the device was the battleship Delaware in 1909, and it slowly gained popularity as hull designers realized the benefits. Today, almost all large ships utilize the technology and the fuel savings is said to be in the neighborhood of fifteen percent due to this improvement alone (Boyd, 2011).
Another fairly recent improvement in efficiency is the hydrofoil. A hydrofoil is a wing-like attachment fixed to the bottom of the hull which behaves much in the same way an airplane wing does in air, it provides lift to the boat at high speeds; enough lift to actually push the entire hull out of the water. The benefit of this is a reduction of surface area that is in contact with the water, reducing drag and improving the hydrodynamics of the vessel. Hydrofoil boats look similar to any ordinary boat while sitting still or while traveling at low speeds. The difference can be seen when the vessel reaches higher speeds at which point the hydrofoil is able to lift the hull and support the vessel above the water (Wall, Drela, & Finberg, 1995). Various types of high-speed boats such as passenger ferries, sporting, and some military applications employ this technology today. As much as a hull’s shape has influence on the behavior of a ship, it is only one of many factors considered in its construction.
The materials used in ship building have evolved a great deal since humans built their first boats. As a naturally abundant and available material, the obvious choice in early times was wood, and remained so for thousands of years. When sealed properly, it offers many desirable properties for the building of a boat’s hull. However, as the size of boats increased and the demands placed upon them grew as well, the need for alternative materials arose. The two most common materials used in the construction of a boat’s hull today, depending on the size and purpose of the vessel, are reinforced fiberglass and steel. Specialty boats designed for high-performance applications such as racing sometimes utilize high tech composite materials such as carbon fiber. Carbon fiber is an extremely light, stiff, and strong material; however it is prohibitively expensive and unnecessary for most common applications. Fiberglass is most commonly used for smaller boats intended for recreation or other light duty work. This is due to its light weight, low cost, and relative strength. For larger ships intended for heavier duty applications, steel or other metal is almost always required to supply the ship with rigidity and durability. Another major advantage to these two materials is their ability, when maintained properly, to far outlast a hull made from wood ("Boat Hulls! What they are made of," 2011). Having satisfied the need to float and allow efficient movement through water, the next important factor is the ability to sustain forward motion.
Propulsion technology is another aspect of maritime engineering which has made huge advancements throughout history. In the earliest days of water travel, before the advent of steam power, there were two basic forms of propulsion that were available. These included sails powered by wind, and paddles operated by humans. These two methods were employed as means of propulsion on the smallest of boats to the largest of ships for a large portion of history. In fact, it wasn’t until about 3000 B.C. that the use of a sail to capture wind was discovered and put to use (Roder, 2008). Even for a sizable period of time after, paddles were still used in conjunction with sails as the technology had not quite been perfected. In about the year 1770, the first steam engine able to be used as a source of power was engineered by James Watt of Scotland. It took years more for the first steam engine to be successfully used in a boat. The first steam powered boats used large paddle wheels like those often seen at mills. These large paddle wheels were used for many decades, combined with sails, as the best technology available for powering ships. It wasn’t until 1827 when the first propeller was patented by an Austrian man named Joseph Ressel. This new device was made of iron and therefore much more durable and practical than the old wooden paddle wheels. Although many variations and minor updates have been made to the propeller since this time, it is still the most popular device used by all types of vessels today. However, while the propeller would remain in use, the steam engines of the 19th century could no longer keep up with the demand for power and efficiency required in modern times (Roder, 2008).
At the turn of the 20th century steam turbines were introduced and quickly became the preferred drive mechanism in ships as they were able to produce more power while being smaller than the former steam engines. How the steam was produced however, was in need of a dramatic change. The coal fired boilers that supplied steam to the turbines were very inefficient and labor intensive to operate. The first replacement design for the coal fired boiler was the oil fired boiler. However, while this solved some of the problems that plagued the original boilers, the oil fired boilers were still relatively inefficient and consumed large amounts of oil (Roder, 2008).
The invention and optimization of the internal combustion engine was the next step in the evolution of marine propulsion. These engines were made practical for use in boats in 1910 and were immediately installed in ships as a main power source. Diesel fueled engines were quickly chosen as the preferred technology by the industry for the best balance of power, reliability, and efficiency. The new diesel engines required only a fraction of the space taken up by boilers, and were much more efficient. The internal combustion engine still accounts for a major portion of marine power systems of all sizes today. Larger vessels have begun using the ship’s engines to run electric generators which in turn power electric motors connected to the ship’s propellers rather than driving the propellers directly. This allows the electric generators to power other facilities onboard the vessel in addition providing the power for propulsion (Roder, 2008).
One final source of power used on only the largest of ships in history is nuclear power. Nuclear powered vessels today are almost exclusively used in military applications as it proved too costly to be feasible for most commercial vessels. Nuclear powered vessels employ the steam turbine by heating water with the nuclear reactor and producing steam to drive the turbines. These turbines can drive the ship’s propellers directly or they can be used to drive electric generators in a configuration similar to the one previously discussed. The chosen configuration depends on factors such as the design and use of the vessel (Roder, 2008).
Since the beginning of traveling the seas, there has been the crucial need of accurate and reliable means of navigation. Breakthroughs in this area have proven to be invaluable in the advancement of maritime technology. Navigation has remained an important need throughout history because it is necessary to not only to verify the direction of travel, but also to create records of routes. This was especially important to explorers whose objective was to discover and record locations of new territories with the intention of returning later. The history of navigation would eventually supply the world with the knowledge of the geography of the planet we now know.
As far back as 2000 B.C., the first basic navigation techniques were practiced by the sailors of Phoenicia. These consisted of tracking of the patterns of the sun and stars and following basic charts that were created as new lands were explored. However, it was not until the thirteenth century when navigators began to make detailed maps of their progress. Detailed records became important for their ability to be referred to on later voyages. Over time, various tools were engineered that enabled mariners to determine position, direction, and speed, and aided with the creation of more detailed charts and maps. Some of the earliest tools known to be used by maritime navigators included compasses, maps, astrolabes, and calipers. However, because of the lack of reliable technology, exploration was still confined to relatively small areas of shoreline which were within the limits of the navigator’s capability. It was not until the fifteenth century that a more global sense of exploration could safely take place. By the 18th century, navigation equipment, although still primitive when compared to today’s standards, enabled explorers to successfully sail around the entire world (Bratcher, n.d.).
Not surprisingly, after the turn of the 20th century some of the most useful and accurate navigational tools ever engineered were brought into use. One of the more basic, but most important tools was the gyroscopic compass. This compass was the first that could be relied upon to point true north, unlike the magnetic compass which was constantly affected by interfering magnetic fields from the earth or the vessel itself. Later in the century more high-tech solutions to navigation such as radar were pioneered. Radar is a technology that uses radio waves to detect objects that are unable to be seen by the human eye, because of either distance or poor visibility conditions. These systems became available in 1935 (Bratcher, n.d.). GPS is the latest in high-tech navigational tools. This technology uses satellites to accurately pinpoint the position of a vessel anywhere on earth.
The latest technologies available are pushing the limits of both accuracy and convenience. Today’s electronics have allowed for the creation of fully interactive digital mapping of the surface as well as underwater geography. Developments in sonar now allow ships to detect underwater obstructions and other dangers that may lie in their path. With modern GPS and digital mapping software, fully automated navigation systems similar to autopilot have been developed that allow vessels to steer themselves to pre-designated headings. While these are powerful tools which are relied upon by sailors around the world daily, even the most experienced mariners and navigators agree that this technology, although amazingly accurate and useful, is not always as reliable as some of the manual methods used in the past. Even today, as a precaution, ships still carry basic navigational tools and navigators are trained in their use (Bratcher, n.d.)
Since early existence, human beings have recognized the need of transportation across bodies of water. International trade, military dominance, and the pure desire to explore and discover new territory were all factors that encouraged the advancement of maritime technology. While there were many components of this, three of the most dominant include hull design and construction, propulsion, and maritime navigation technologies. It is without a doubt that these improvements changed the way travel, trade, and exploration have been conducted on this earth. Maritime travel is a need that will continue to be an important part of humanity for centuries to come.

References
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