Farmington High School - Laurel Yearbook (Farmington, ME)

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THE LAUREL 25 From this island, the bridge continues to Oakland through a 1,400 foot cantilever span, built of steel girders and through several railroad and deck-type spans. Con- struction on a cantilever span is begun at each end. The arms of steel are literally pushed outward into thin air until they finally meet in midstream and are joined together. Excluding the piers from which the arms were begun, there are no piers of any kind to support the weight of the arms, either during the construction or after the span is completed. This brings up the problem of stretching thousands of tons of steel out into space so that the sag due to gravity will not cause the bridge to be lower in the middle than at the ends. This problem was overcome by tilting the outward ends of the arms, so that, at one time, these ends were about four feet higher than the level at the starting piers. In other words, the sag has been so calcu- lated that the enormous weight of steel bends 'itself downward, and thus, when the two sections are eventually joined, there will be no detectable difference in plane. This bridge, to be completed in August of this year, primarily will connect San Francisco, where six square miles at the northern tip of the peninsula support a population of 635,000 people, with the East Bay district, comprising Oakland, Ala- meda, and Berkeley, with a total population of 393,000. Each day 50,000 commuters cross from these communities to San Francisco. Previous to the building of this bridge, forty-five million people and five million automobiles were transported an- nually by means of ferries from San Fran- cisco to Alameda Country. Thus it will be seen that this bridge will be a great saving to the residents as well as for tourists. It is only after years of experiment and study that these bridges, of proportions never before thought possible by man, are rapidly nearing completion. As time ad- vances, new engineering feats will blaze forth only to be dimmed by still more stu- pendous realizations of the powers of man. Jay Pratt '36. OUR HERITAGE - THE NAVY HE world has had navies since the somewhat dim past, dating back to at least one thousand years before Christ. King Minos of Crete was the first sea lord. He issued a code of maritime laws which was in use as late as the fifteenth century. Since those times the navies of the world have developed tremendously, but some of the old institutions and traditions are still adhered to. The first naval vessel in this country- equipped to defend itself against attack, to harass enemy shipping, and to protect its constituents-was built at Plymouth Col- ony as a protection against pirates. She was christened the Blessing of the Bay and was the first truly American naval ship. During the American Revolution the United States had a. small but efficient navy, and the most conspicuous figure in it was John Paul Jones. Everyone has read ac- counts of his exploits in the Ranger and the converted French ship Bonhomme Richard. He was a master seamang and in the days of sail, seamanship was half the battle. In many encounters, especially the one between the Bonhomme Richard and the Serapis , Jones was handicapped be- fore the Hght by small-sized or unmanage- able ships, and only his superior ability to and his indomitable courage enabled him to come out ahead. john Paul Jones is sometimes called the Father of the American Navy , and he justly deserves that title. sail From 1794, when 'Congress first officially appropriated for a navy, to 1860, there were many advancements in ship construction and propulsion, such as the invention of the steamboat and the screw propeller. just a short time before the latter date, ships were made more invulnerable by armor plat- ing. In Europe this device was used spar- ingly, and the first complete ironclad in the world was the Monitor , built for the United States Navy by John Ericsson. You are all familiar with the appearance of the

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24 THE LAUREL these, the bay stretches to the right and left for about fifteen miles in each direction. The width varies from five to fifteen miles. On the tip of the southern peninsula is situated San Francisco. It is from this point that each of the bridges has a begin- ning: the San Francisco-Oakland Bay bridge extending in an easterly direction across the bay to the city of Oakland, and the Golden Gate bridge northerly across the Gate to the tip of the northern peninsula. The Gate bridge forms the key link in the proposed All-Pacific 'Coast-Highways Sys- tem. When the bridge is completed in May, 1937, coastwise traffic will no longer have to be ferried across the Gate. Instead, it may cross the new bridge and continue di- rectly along the coast, thus saving much time and expense. The bridge itself will be the world's long- est and most magnificent single span sus- pension type, and the first ever to be stretched across a major harbor entrance. This single span, looping gracefully from the high towers, is approximately four-fifths of a mile long. Probably the most interesting parts of this bridge are the two cables from which the deck, or roadway, of the bridge is sus- pended. Composed of thousands of strands of steel wire about the size of a lead pencil and supported by two towers of reinforced concrete each 745 feet high ftaller by 191 feet than the Washington Monumentj these cables, thirty-six and one-half inches in di- ameter, are constructed in place since there is no mechanical contrivance that could pos- sibly raise them to their high saddles. Enormous spools containing sixty miles of this wire are placed on each end of the bridge. Bights, or loops, are carried' in- dividually over the towers, allowance being made for the proper amount of sag. At the ends, these wires splay outward to the va- rious portions of the anchorage. The wheels carrying these bights have been per- fected to the extent that it is possible to string about three and a half million feet of wire in eight hours. While these cables are being spun and the decks assembled, much progress is being made on the San Francisco-Oakland Bay Bridge. This bridge crosses from San Francisco to Yerba Buena Island, bridging a two-mile expanse of water with twin suspension spans. The piers and towers on which these spans rest were constructed in water over a hundred feet deep plus an additional hundred feet of mud which had to be cleared away so that the piers might rest on the rock bottom of the bay. The construction of these piers differed from the regular mode in that they were built from the surface down instead of build- ing from the bottom up. Huge cellular, or honey-combed, caissons were constructed and floated to the pier sites. The honey- combing consisted of wells of steel tubing about fifteen feet in diameter. Metal domes were fitted and welded to the tops of these and then additional air compressed into them to make the whole structure buoyant. Concrete, poured around the wells, caused these caissons to sink. As they sank, the wells were lengthened by welding sections of tubing to the tops of them. This process was continued until the bottom of the cais- sons touched the mud. The domes were then removed and the mud brought to the surface by means of buckets. More con- crete was added as the caissons sank deeper into the mud until they finally rested on the bedrock. Yerba Buena Island, the eastern anchor- age for the second twin span, is situated midway between San Franciscoand Oak- land. This island rises 340 feet above the surface of the bay. Since the lower deck of the bridge is only 185 feet above the water, the height of the island presented an obstacle. After some consideration a tunnel was drilled completely through it, a distance of three thousand feet. This tun- nel has the largest bore of any ever built. This extraordinary width and height is necessary to accommodate the double decks of the bridge.

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26 THE LAUREL Monitor , the so-called cheese-box on a raft. There was a motive for this type of construction, and Mr. Ericsson found it while on a trip to Sweden. On viewing some lumber-rafts on the lakes, he discov- ered that during rough waters an ordinary boat tossed on her beam ends, and a raft with its elevated cabin remained very steady. It can easily be seen that the steadier the ship is, the greater accuracy can be obtained by the gunners. He built the Monitor with the aforementioned in mind, and surmounted the raft-like structure with a revolving turret. This craft pre- sented an extremely formidable appearance, but was most uncomfortable for the men who worked her. Everyone has read of how two great ironclads, the Monitor and the 'A Virginia , fought a battle to a tie, both ships retiring after a half-day's battle. By two ships and one brief action, naval warfare had seen its greatest change in history. The ironclad had come to stay. During the administration of Benjamin Harrison about 1890, the construction of the first ships which constitute our navy today was brought about. Among these was the ill-fated battleship Maine which was blown up in Havana Harbor. During this period our navy rose from twelfth to fifth position in the ranks of world navies. Today our navy runs a very close second to that of Great Britain, the so-called mis- tress of the seas. A modern navy consists of several types of ships. First, there are the capital ships or ships of the line. These are the largest and most powerful ships afioat, averaging around 29,000 tons apiece in weight and considered to be almost invulnerable. Next, come the aircraft carriers, which are the mother-ships to the eyes of the fleet, the airplanes. After them are listed the cruisers, both light and heavy types. These vessels are smaller and more mobile than the capital ships, but they do not carry such heavy ordinance. Then come the destroy- ers, which are the most numerous of all the types of fighting craft. These, being small and very quick, are used mainly for scout- ing and to convoy fleets of transport ships in time of war. Last, but important for their actual fighting value, come the sub- marines. These fill out the list of actual fighting craft, but there must be countless other ships to take care of the combating vessels, such as colliers, tankers, ammuni- tion ships, hospital units, and many others. In 1931, the United States had 398 fight- ing ships afioat, and about this same number of non-combatants. This enormous fleet, to be of any use at all, must function with coordination and speed. Radio has made this possible. In days of yore, a ship was a miniature kingdom, with the captain as ruler over life and death. After only one day from port, he was out of touch with his superiors for months at a time. Today a ship's commander is but a cog in a great machine. Radio has made this possible, and today's whole navy is as much a single unit as was Admiral Dewey's fieet of six ships at the battle of Manila Bay. The personnel of a modern naval ship is a highly trained group. The bluejackets are young, vigorous men, many of whom are highly trained in technical and mechanical fields. The officers are trained at the United States Naval Academy at Annapolis. This is a school on a par with the highest, and, although it is perhaps not so much in the public notice as West Point its worth is recognized in official circles. There a student receives a broad education in technical and literary lines. The requirements are very hard, and the social training which one re- ceives certainly fits one for the position of an officer and a gentleman. While at the Academy, a man has the rank of mid- shipman. On his graduation he is com- missioned an ensign and serves two years in the navy as an officer of the line. All in all, the crew is a highly trained unit, and each ship is in keen competition with its neighbors in the fieet to keep up the scores in gunnery practice and to keep down the costs of operation.