PROFESSIONAL MEMOIRS Corps of Engineers, United States Army, and Engineer Department at Large Published Quarterly at the Engineer School, Washington Barracks, D. C., by the CONTENTS. 1. Locks and Movable Dams of the Ohio River- By Mr. J. W. Arras, Assistant Engineer. 2. A System for Filing and Indexing Professional Literature.. Page. 7. Railway Transportation Required for a Pioneer Battalion, U. S. A. 613-617 By Capt. W. H. Rose, Corps of Engineers. 8. Harbor Improvement on the Pacific Coast of the United States_ By Maj. William Wright Harts, Corps of Engineers; Assoc. Inst. C. E., M. Am. Soc. C. E. Reprinted by special permission from the Council of the Institu- tion of Civil Engineers, London, England. 9. Andrew Atkinson Humphreys. (See frontispiece). 10. A Civilian's Suggestions for a Technical Reserve for the Army-- Additional discussion by Dr. C. P. Steinmetz, Consulting Engi- Subscriptions, $3.00 per year, in advance; single copies, 75 cents. ing rates on application. Address all communications to PROFESSIONAL LOCKS AND MOVABLE DAMS OF THE OHIO RIVER BY Mr. J. W. ARRAS MAINTENANCE AND OPERATION The system of improvement inaugurated on the Ohio River contemplates fifty-four locks and dams between Pittsburg, Pa., and Cairo, Ill. Of these there have been constructed and placed in commission, or are practically ready for operation, numbers 1, 2, 3, 4, 5, 6, 8, 11, 13, 18, 37, and the dam at head of falls at Louisville, Ky. Except the last named, the dams are composed of Chanoine wickets in their navigable passes with pool-regulating weirs, generally of bear-trap gates or Chanoine wickets. The lengths of wick eis vary between 9 feet 9 inches for the lowest weirs and 18 feet for the highest passes, and the vertical heights of bear-trap gates above upper sill from 9.2 to 15 feet. The usual width of navigable passes is 600 to 700 feet, and of bear-trap gates 91 to 94 feet with extreme limits of 52 and 120 feet. This arrangement of dam will probably be closely adhered to above Louisville, while below the falls some. modifications may be found advisable because of material difference in stream conditions. The approximate lock dimensions are 110 feet width and 600 feet length between lock gates. The locks are equipped with the rolling type of gate, built of steel, and with a few exceptions are filled through sixteen cast-iron butterfly valves, 41⁄2 feet in diameter, in river wall above dam, and emptied through the same number of similar valves in that wall below dam. Concrete masonry throughout, with timber pile support and stonefilled protection cribwork on gravel foundations, wooden wickets and iron or steel working parts constitute the principal forms of construction. Generally the power for lock operation, involving principally the valve and gate maneuvers, is compressed air, generated by steam, gas engine or water turbine plants or a combination of two of these. For operating dams steam is used on maneuvering boat, for repairs. steam on derrick and pump boats and hand power or compressed air for operating weirs. Each lock is provided with a duplicate power plant to prevent delay to navigation in event of a machinery breakdown. The operation of lock valves is accomplished through the medium of a neutral oil delivered into the valve-jack system by means of pumps or by direct pressure from the compressor system. The foregoing brief description of Ohio River movable dams is deemed sufficient by way of introduction to the subject under consideration, in view of the frequency of comparatively recent publications dealing comprehensively with movable dam construction. What shall follow is therefore intended to apply as far as praeticable to their maintenance and operation. It is probable that in the past too decided a distinction has been made between original construction and maintenance and operation. oftimes tending, doubtless, to the disadvantage of both. While apparently differing widely in the nature of their operations, yet in reality their relationship is so close that at any time the latter may involve almost any feature of the former and eventually must of necessity absorb practically all of it. Happily, the advisability of bringing and keeping these two departments of work in closer touch as a means to their mutual advantage is being more fully realized. As this policy is developed unsatisfactory elements in the works are eliminated and cost of both construction and operation reduced. Failure to recognize the value of this essential doubtless caused many of the nation's railroads to suffer greatly in their original building, whereas in their reconstruction, in large part at least. which in some cases was also almost immediate, the dominant consideration has been economy of operation and maintenance. In factory, mill, and mine construction to-day only that is regarded as superior which tends to minimize the cost of operating and maintenance proportionate to the output. And so all along the line of the great commercial industries economy in cost of production is the watchword. And these questions of economy are usually determined not so much by a fine discrimination among highly developed mechanisms as by a careful selection and application of designs and agencies which experience has shown to have best withstood the test of endurance to perform their functions faithfully at the minimum cost of repair, renewal, and operation. Nor will such policy necessarily militate against progress along industrial lines. New principles are indeed rare and new inventions are, as a rule, but new applications of the old principles. Out of the innumerable new things comparatively few stand the test of time, and the great majority are rejected without trial because of too evident defects. Most large establishments are but a combination of well-known details, whose indiscriminate or arbitrary selection, however, would hardly have inured to success except possibly at excessive cost. In any event their determination on the basis of previous reputation is a safer policy, which in view of defi Fig. 1. Dam No. 2 in raised position; length of wickets, 17 feet 10 inches nite knowledge as to past failings and the specific modifications desired is more certain of actual progress at a minimum of expenditure. However, the foregoing observations are not intended as antagonistic to the adoption of any really meritorious new device or scheme. This age has achieved many mechanical and structural successes well worthy the effort and cost, and will no doubt add others of equal worth. On the other hand, they are merely offered. as a caution against an over-indulgence in new experimentations. made up in large measure of old, tried-out and condemned devices or contrivances, unmindful of the fact that these have been elimi |