Engineering Wonders of the World
Volume I

138 ENGINEERING WONDERS OF THE WORLD. and its width at the bottom nowhere less than 300 feet. All the locks are to be in duplicate —that is to say, there will be two chambers side by side, so that, should one ever be out of repair, navigation may be continued with- out interruption through the other. Each chamber will have a usable length of 1,000 feet of 1,045 yards measured along the axis of the Canal, will mean the excavation of 5,140,000 cubic yards of earth, and the placing of 2,096,000 cubic yards of concrete masonry. The entrance to the Canal from deep water in the Caribbean Sea will be a channel, 500 feet wide, between huge converging masonry A CLOSE VIEW OF A STEAM-SHOVEL. (Photo, Atlantic Equipment Company.) The dipper lifts 5 tons of material in one stroke. Material is discharged by opening the flap bottom of the dipper. and a width of 110 feet. At each end of every flight there will be long approach walls, at which a ship may be stopped or checked a safe distance from the locks ; and at the head and foot of each summit lock two pairs of gates will be provided, so that a ship that has become unmanageable may always find two closed gates between it and possible danger. To show the immense work involved in the construction of the locks, it may be noted that the Gatun flight, extending over a distance breakwaters resting on substructures of material brought from quarries recently opened at Porto Bello, a seaport 18 miles east of Colon, and extending nearly two miles across the mouth of Limon Bay. Through the last, now a shallow estuary of mud and silt, but destined to be a well-protected harbour, dredges will scoop a channel 500 feet wide, with jetties or dikes on either side, between which vessels will pass to the shore line. Thence, through for the most part low-lying alluvial ground, a channel