THE CUBA REVIEW^ 



Vi 



cavated. For this reason the scraper-bucket excavators are more satisfactory as well 

 as more economical for excavation, although their capacity is considerably less than that 

 of the large-size shovel used. Three of these excavators are now at work, together with 

 one 90-ton Bucyrus steam-shovel. The excavators operate 1.25-cubic yards Page buckets, 

 although a larger capacity of bucket is contemplated. The bucket swings through a 

 radius of 60 feet, and without difficulty removes all the ore for a width of about 100 feet 

 down to the rock bottom, the projecting rock and stumps being discarded. Each ma- 

 chine-crew consists of one operator, one fireman, and three pitmen. As the machine 

 works up hill or down hill continually, and the track follows the same grade, cars can 

 be dropped down by gravity to be loaded as needed, with a minimum aomunt of loco- 

 motive service. 



The nodulizing plant, located on the east side of the raw-ore yard, consists of twelve 

 rotar\- kilns, 10 feet in diameter, and 125 feet long, set at an inclination of % inch per 

 foot, and 20 feet apart. The kilns are of the type commonly used in the manufacture of 

 cement. The diameter, however, is unusually large in order to overcome trouble from 

 "ringing-up" in the hot zone, which often causes serious delays in the operation of kilns 

 of smaller diameter. Each kiln is carried by two steel tires rigidly fastened to the shell. 

 The cut-steel driving-gear attached to the shell close to the tire near the cold end is 

 152.78 inches in diameter, and 4 inches in pitch. Each kiln is driven by a 35 horse-power 

 variable-speed motor. A 7.5-ton over-head electric traveling-crane, carrying a man- 

 trolley with 3 cubic yards grab-bucket, is provided for removing the nodules from the 

 trough of the nodulizing plant and loading them into oO-ton electric transfer-cars on 

 the track passing alongside of the trough. 



The construction at the water-front is somewhat unusual. Close to the front leg 

 of the bridge, and parallel to its runway, is a trestle extending over one side of a trough. 

 A transfer-car brings the nodules from the nodulizing-plant, and discharges from one 

 side into this trough, in position to be readily loaded into the vessel, or to be moved 

 back to storage under the main span of the bridge by the grab-buckets. The bottom of 

 the trough is one foot above high tide. Its outer wall is formed by planking spiked to 

 a row of piles. All of this construction, being above the water-line, is not subject to 

 damage by the teredo navalis. From the outside of the trough-wall the bottom drops 

 of? at an angle of 45 degrees to 28 feet deep at the fender-line, which is approximately 

 under the hinge of the boom of the bridge. 



Considerable dredging was necessary in order to provide a suitable harbor. A basin 

 1,500 feet long, 200 feet wide at each end, and 400 feet wide at the widest point, was 



General view of nodiiliziiiK plant at I-clton. Twelve kilns arc in operation. 



