16 DOCUMENTARY HISTORY OF THE FLORIDA CANAL

 necessity-since vessels are really built on the principle of a trussincreased
 length necessitates a certain proportionate increase in depth, and in determining
 the alinement of the waterway these factors as to future increase in size of vessels
 must be given careful consideration.
 28. sipe of radds.-To etl ethititre savitrg in point of 'lling dltanee and
 hence in point of time a study has been made of the operating speed of vessels.
 In this respect it is to be observed that of the 1,487 vessels in the Gulf trade 669
 were of American register and 918 were of foreign register. The vessels in the
 American group were generally slower and therefore would benefit more greatly
 by a short cut out of the Gulf, particularly as they made 7,386 of the total number
 of voyages, or over 70 percent. Of this American group, only 60 vessels, or 10
 percent of the total, moved at a speed of 12 knots or better, whereas in the foreign
 group 210 vessels, or over 22 percent, moved at the higher speed. Of the American
 et, 488 were in the speed bracket of "10 knots and under 12 knots", but 586
 vessels of the foreign fleet were so classed. Seventy-two percent of the whole
 number of vessels fall in this bracket, and on the basis of actual voyages 10.5
 knots appears to be the average.
 This factor of speed bears an important relation to the benefits to be derived
 from the trans-Florida canal.
 29. We have assumed a speed of nearly 7 knots (exactly 6% knots) in the canal
 proper, which, for a vessel having a 10.5-knot speed in the Gulf or the Atlantic
 represents a reduction of 3.6 knots, or a los of 333 percent in opelting;spd
 through the canal. On the basis of 19 hours necessary to transit the waterway
 this loss amounts to but 66.5 nautical miles; for a 12-knot vessel the loss amounts
 to 5 knots, or 42 percent; and for a 14-knot vessel the speed through the canal
 reduced to one-half the normal speed the loss of distance amounts to 136% nautical
 miles in 19 hours. It appears that for the ordinary commodity freight vessels of
 10 to 11 knots are the most efficient-that is to say, they operate at the most
 economical rate per ton-mile and can accord freight rates more favorable than
 those to be had by vessels operating at higher or lower speeds. Since this class
 of vessels represents the greatest percentage in both number and dead-weight
 tonnage, they are entitled to the major consideration in matters of design of
 waterway and in computation of savings or benefits.
 30. Our report contains most elaborate and complete data on the shipping of
 the Gulf. Various exhibits set forth facts never heretofore available, particularly
 in respect of the vessels engaged in the Gulf-Atlantic coastwise trade of the United
 States; and, in addition, the report sets forth data never heretofore assembled
 in a concisely convenient form in respect of the foreign trade of the Gulf and that
 trade region which we have designated as "Area A." This foreign trade region
 is by far the most important in respect of the foreign trade of the Gulf ports.
 31. Speed in relation to distance between port determines the time, but
 savig by reduction of time consumed in travel can only be determined with a
 knowledge of operating costs of vessels. Elsewhere in this report there is a
 detailed analysis of the distance and the sailing time for vessels of various speeds
 operating between the various ports in the Gulf and various ports throughout
 the world. In the calculation of time, full consideration has been given to the
 effect of ocean currents on vessel movements. The Gulf Stream, for example,
 markedly increases the speed of vessels eastbound out of the Gulf, but tends to
 retard the speed of vessels west-bound. In fact, to eliminate or reduce this re-
 tarding effect vessels west-bound avoid the Gulf Stream whenever practicable.
 2. On the basic of calculations made at our request by the Coast and Geodetic
 Survey we have assumed a fairly direct line for a canal across the State which,
 if rigidly adhered to, will afford a distance of about 130 nautical miles between
 the head of the harbor in Jacksonville and deep water (30 feet) out in the Gulf.
 Our calculations are based on an average arbitrary speed of 10 knots in the sea
 approach and in the St. Johns River, and 6% knots in the canal proper, together
 with an allowance of 1 hour for lockages assuming a lock canal. On the basis of
 these assumptions we have calculated the distance and the sailing time between
 the various ports in the Gulf and all the ports in the world located on shipping
 lanes which would undoubtedly be shifted to the canal were the same constructed
 on an efficient plan. With the assistance of the Research Bureau of the United
 States Shipping Board, we have been enabled to determine the average operating
 costs of all vessels of various dead-weight tonnages, and with these factors of
 distance and speed producing a time factor and the operating costs per hour we
 have been enabled to compute very precisely the savings that-would accrue from
the use of the waterway such as we have assumed. Details of these computations
will be set forth elsewhere, but without elaborating further thereon at this time
it may be stated that the data assembled indicate: