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7 Mg = SE SE Ne ER Py pe AN ee ea ET Ee Oe ee ee a Ee or ee ~ Recent Developments in the Lighthouse Service the coastal and inland waters of United States, so that they may be available for the safe navigation of vessels, is one of the the oldest activi- ties of the federal government, in fact antedating the formation of the union in several important instances. Pro- tection to the lives and cargoes en- trusted to vessels was demanded al- most as soon as the colonies had a merchant marine worthy of the name. Quite early in the history of the lighthouse service, lightships were in- troduced, the screw pile lighthouse was tried out, caisson foundations were de- veloped, and skeleton steel construc- tion made its appearance. With each lighthouse forming a pro- tected area equal to the range of its light and its fog signal, there came a time when a journey along the entire coast could be made without being for long out of sight of at least one light. When this stage had been reached it might be said that the “guiding” func- tion of lighthouses had become of equal importance with the “warning” function. The development of buoys, and the more recent increases in their sizes, with a consequent greater ability to re- main on station under adverse condi- tions, has made possible an expansion of the guiding function. The buoyage system has developed into a means of marking safe lines from the open sea through the intricacies of harbor chan- nels to the dock sides. Large sea type buoys now also serve as links in the chain of offshore lightships. Much progress has been made in the redesigning of buoys of all types. Hulls have been strengthened and made more seaworthy; moorings and moor- ing attachments now permit establish- ment of buoys in deep water, and minimize the possibility of buoys being dragged from station or breaking adrift. Another outstanding feature of re- cent lighthouse work is the substan- tial yearly increase in the number of automatic or unattended lights, aids of this type making possible a consid- erable increase in service at compara: tively small expense. The unattend- ed light depends for its effectiveness upon the perfection of automatic ap- paratus capable of burning for long periods of time without attention, of producing suitable light characteris- tics, and of replacing burned out bulbs where electricity is used. Multiple burners, flashers and other items need- ed in the operation of unattended lights have now been developed to a high degree of reliability. [Lite coas and otherwise marking combustion The use of electricity, while not new in the lighthouse service, has increased considerably in the last few years. In many cases this has been connected with the installation of radiobeacons, these signals requiring a _ current source easily augmented to serve other purposes as well. Electricity has made it possible to increase the candlepower of many lights without other changes. Fog signal equipment, other than radiobeacons, has also shown new ten- dencies. While the earlier installations of power signals depended usually upon the use of steam, this power source is gradually being replaced by air and electricity. In both of the new types, internal combustion engines are utilized, a decided improvement in efficiency over steam, as they are quickly started should fog appear sud- denly. ~ Lightship development has consisted of three parts closely interwoven. These are, improvements in hulls, new pro- pelling machinery, and new signaling devices. Certain changes have been made in the latest hulls to secure de- Sirable qualities of seaworthiness, and because of the requirements of the new types of machinery. The interior ar- rangements have tended to supply greater comforts for officers and crew. Improvements in signaling devices are comparable to those made at shore sta- tions, and are at the same time closely connected with recent choices in mo- tive power. Masthead lights of nearly all first class lightships are now electric in- candescent. On the older vessels cur- rent is produced by steam or internal auxiliaries, which also serve in certain instances for the pro- Ger Straits of light station, Mackinac Poe Reef MARINE REVIEW—July, 1931 duction of current for the radiobeacon. Steam fog signals, the normal equip- ment aboard the earlier steam propelled lightships are giving way to com- pressed air or electrically operated sig- nals where diesel power is available. The propelling equipment of light- ships, important not only to their effi- ciency and ability to remain on station, but directly related to the types of sig- nalling apparatus on_ board, - has changed considerably in recent years. From the earliest lightships, with no motive power other than sails, through the various types of steam propelled vessels, the lighthouse service has now turned to diesel engines. The choice rested very largely upon the adaptabil- ity of diesel electric equipment to auxi- liary purposes as well as for vessel propulsion. Diesel electric generating sets on the newer lightships are used interchangeably for propulsion and for operating signaling equipment _ in- stalled on the vessels. Modern engineering practices have made possible the economical erection of lighthouses at difficult points, and brought about a tendency to relocate those aids not situated at the most strategic points. A noteworthy example of such a change is the construction this year of a new lighthouse at Detour, Mich., on Lake Huron. The original station was erected on shore, more than a mile from the edge of the deep water channel, while the new station stands in deep water where vessels may lay their course to pass close to it. The most important single develop- ment in lighthouse work within recent years has been the adoption of radio as a signaling medium. The radiobea- con has made it possible for the great landfall stations to maintain their effi- ciency even in the densest fog. Radio- beacon signals are capable of intercep- tion up to distances of 200 miles, and are thus valuable also for long range clear weather bearings. The radiobeacon has passed rapidly through a number of stages since its adoption ten years ago. Operating periods have been increased until near- ly all stations operate for a portion of every hour in clear weather as well as continually during fog. Stations have been grouped and synchronized so that their signals are heard in rotation, a great aid in avoiding interference. The range of radiobeacons has been re- stricted to short radiuses where a bea- con is of only local value, this also lessening interference. Still in the experimental stages is the linking of radiobeacon signals with sound fog signals as a means of deter- mining distance. The use of electric lights on buoys has been tried out ex- perimentally. A positive acting fog sig- nal, not dependent upon wave action, for installation upon buoys, and to be controlled from a remote point, is also a possibility of the future. The more assured advances are, however, in the line of greater efficiency and service at decreasing costs. 23