Late in 1861, in a dim office somewhere in Philadelphia, an anonymous clerk dipped his pen in ink and, quite unknowingly, wrote the first chapter in the history of oil tankers. The brig Elizabeth Watts, he wrote, had recently sailed for England carrying 224 tons of a substance called petroleum.
Not much is known about the Elizabeth Watts. She carried the world's first really substantial cargo of oil and arrived safely in England 45 days later. Beyond that the records are blank—except to note that the ship's master had considerable difficulty in recruiting a crew. Sailors, not unreasonably, balked at signing on with a ship that was quite likely to explode and burn to the waterline halfway down the Delaware River. The master of the brig had to take drastic measures. He canvassed the inns, plied the sailors with grog and gently guided their staggering steps up the gangway. By the time they woke the ship was scudding into the Atlantic under full sail.
From the vantage point of 1966 such tactics undoubtedly seem extreme. Yet they suggest the kind of problems that were to confront shipowners as, in the last half of the 19th century, they began, with considerable uneasiness, to cope with this new, unpredictable and often deadly cargo. The brig's voyage, after all, was undertaken only 27 months after Colonel Edward Laurentine Drake drilled America's first producing oil well; petroleum was still a relatively new substance whose properties and characteristics were but dimly understood. Furthermore, with technology at a relatively simple stage, the j methods of shipping liquids were decidedly limited. The early history of the tanker, in fact, was primarily a struggle to find safe, quick and economical ways of loading, storing and unloading a valuable but volatile liquid on the inflammable and unstable brigs, schooners and clippers that sped the commerce of the world across the oceans in the 1860's.
In those days there was only one way to transport liquids: in kegs. Since the kegs were quite undependable because they leaked, and since they not only wasted precious space but had to be loaded and unloaded slowly by hand and since it was apparent that petroleum was to be a cargo of considerable volume (one year after the first trip Philadelphia shipped nearly 239,000 barrels), shipowners were soon experimenting with new, often ingenious, sometimes bizarre methods of handling and controlling the cargo. Some fitted square upright iron tanks into the hold. Some tried tin boxes encased in wood. Some, realizing at once that if the hull itself could serve as the container, ships could carry more and weigh less, tried to oilproof the wood hulls with clever, but usually ineffective, combinations of planking, felt and cement.
But leakage was only one of the problems. In warm weather oil expanded; in cold it contracted. Carry too much, it spilled; carry too little, it sloshed about with enough force to capsize the ship. There were gases to worry about too, with their deadly vapors settling silently into double bottoms to lurk in wait for the unwary lantern, the heedless candle or the forbidden pipeful of Virginia tobacco.
The solution to most of the problems, of course, was the iron ship, with its nonabsorbent, leakproof hulls, its compartmentation and its relative resistance to fire. But technology hadn't quite caught up to theory in the 1860's and although an iron sailing ship expressly designed for oil—the Atlantic—was built as early as 1863, and although the Nobel brothers in Sweden launched a steam-propelled tanker in 1878, the level of iron work was such that there was still considerable leakage and loss. With the introduction of steam the problem got worse. Shipowners had to face the hair-raising hazards implicit in keeping huge coal fires burning constantly just a few feet from poorly-constructed, usually leaky tanks of petroleum.
As the century waned, however, technology improved. In 1884 farsighted British shipbuilders, finally realizing that one key to better ships was simply closer riveting, launched the 300-ton Glückauf, an iron tanker propelled by steam in which the oil was carried—safely—against the hull. The modern tanker had arrived.
For the next 34 years changes in tankers were generally no more than improvements in the basic idea. Then, in 1920, Sir Joseph Isherwood introduced a new system of combined transverse and longitudinal framing which strengthened the ship, reduced its weight and substantially expanded its capacity. About the same time significant improvements were made in the arrangement of the compartments, in the number and kind of pumps and in sizes of mains. And not long after, in astonishing succession, came breakthrough after breakthrough in physics, chemistry and engineering, each adding impetus to the feverish technological development of those hectic years when the world was recovering from one war and preparing for another.
Most tanker shipments consist of crude oil.but when crude is refined into products that are marketed across the water from where the refinery itself is located, they too must be shipped. Such familiar products as gasoline and fuel oil need no special care except the usual safety precautions while being loaded, carried and discharged. The newer and less well-known products in the petroleum spectrum, however, require exceptional handling, and some now even call for specially-designed tankers in which to transport them.
One example of the latter is bitumen, a semisolid at normal temperatures. This particular end product of crude oil must be heated to temperatures ranging from 250 to 350 degrees Fahrenheit while being loaded. Steam heating coils in the cargo departments of bitumen ships maintain the cargo in a pumpable state in transit. Petroleum gases, on the other hand, are liquefied by cooling—to 31°F for butane down to -259°F for methane—so they can be shipped at atmospheric pressure, and giant containers built on the principle of a Thermos bottle hold these liquefied gases at their required low temperatures aboard ship.
Concurrently with these developments there have been many innovations introduced ashore and along coastlines to keep pace with the larger and specialized modern tanker. Larger-diameter pipelines are being laid, bigger-than-ever storage tanks built and deeper harbors dredged. Longer jetties are being constructed, too, some so long that pier workers and seamen from tankers use cars to get to shore. A new approach to loading is the "sea island," an offshore installation connected by pipelines to the shore being built in water deep enough to admit the gigantic tankers still in the planning stage. Maintenance and repair facilities are growing with and sometimes ahead of the biggest tankers. Petroleum Press Service reported in February that a dry dock capable of handling tankers of 250,000 deadweight tons is being planned in Japan to be in service by October 1967.
Communications are posing their own challenges in the new tanker era. As more and faster oil ships take to the sea lanes the petroleum industry has had to develop highly complex and carefully balanced routing systems and, to make them work, vastly complicated systems of radio, radiotelephone, Teletype and telegraph services.
To some forward planners the progress tankers have made up to now represents only a beginning. Ahead, they say, are such innovations as submarine tankers, nuclear-powered tankers, hovercraft tankers—tankers that travel over the water on cushions of air—and such startling possibilities as floating tanks magnetically coupled to a sort of floating locomotive, and floating inflatable plastic containers linked together like freight cars.
Some of these ideas are already the subject of study; all will be seriously considered and many will undoubtedly be in use by the end of the century. If the history of tanker development has demonstrated anything it is that there are few limits to what can be done and what will be accomplished.