400 REPORT OF BOARD OF CONSULTING ENGINEERS, PANAMA CANAL.

would add 30 per cent to the tonnage, making the capacity of the Poe lock upward of 50,000,000 tons in twelve months.
 In order to apply this to the Panama Canal an estimate must be made of the relative capacity of a flight of two or more locks and a single lock.
 A single lock would pass the greatest traffic when ships moved in opposite directions alternately. Ships awaiting lockage would have to lie at a greater distance from the lock than when all are moving in the same direction, and this will be taken at 400 feet. The waiting ship would not usually begin Moving toward the lock until the outgoing ship had completely passed it. This requires a movement of the outgoing, ship of 1,650 feet. On this basis the passage through a single lock like the Poe lock would require:Mi.Se
 From stop at approach pier to stop in lock ..................................... 9 40
 Closing gates........................................................--------2 00
 Filling or emptying lock................................................------9 22
 Opening gates........................................................---------2 00
 Moving out: Mn.
 Acquiring speed of 1. 7 miles, 300 feet.................................----4
 Increasing speed to 4.4 miles, 1,350 feet...............................----5
 -9 00
 Interval between two ships ............................................ 32 02
 With a flight of two locks, the waiting ship would lie, say, 100 feet from the lock, and the interval would be as follows:
 Mn. Se.
 From stop at approach pier to stop in lock...................................-----7 40
 Closing gates........................................................--------2 00
 Filling or emptying-lock (9 minutes 22 secondsX0.707) -------------------------- 6 36
 Opening middle gates..................................................--------2 00
 Moving into next lock: Mn. Se.
 Acquiring speed of 1.7 miles, 300 feet............................----4 00
 Moving at this rate, 300 feet...................................-----2 00
 Reducing to stop, 200 feet.....................................-----2 40
 5 40
 Closing middle gates...................................................-------2 00
 Emptying or filling lock................................................------9 22
 Opening outer gates....................................................-------2 00
 Interval between ships............................................------40 IS
 The capacity of the St. Marys Falls Canal would be reduced by introducing another lock of the same dimensions, in the ratio 40 m. 18 s. : 32 m. 32 s., or 20-2 per cent, or from 50,000,000 tons in twelve months to 39,750,000 tons. With duplicate locks the capacity would be: Tons.
 For two flights of one lift (see above).....................................-----100, 000, 000
 For two flights of two lifts (as above)......................................-------79,500,M0
 While the larger locks of the Panama Canal will not be operated quite as quickly, the average tonnage per lockage will be so much greater that a traffic of 80,000,000 tons can be handled at the locks without difficulty.
 As before stated, the estimates of time for lockage and of traffic capacity for the Panama Canal are made for locks of a usable length of 1,000 feet. With locks of a usable length of 900 feet the estimated capacity would be somewhat greater because a ship would have to move a shorter distance in the locks.