The Daily Alaska empire., 1936-10-12

chions to hold a load of rock Foul compartments run the entire length of the barge, of which two are air compartments and two water com partments. Dumping of the barges is controlled by valves. At the load ing station each barge is filled by a flexible conveyor and then lowed by the tug to the point where the load is to be dumped When this point is reached the towing cable is reeled in by the towing winch un- til the tug has been attached to the barge by manila line and the steel towing line removed. Next, the 14-in. valves are opened by hand, the manila line is cast off, and the tug steams away from the barge, returning and taking it in tow after dumping is finished.
 On each valve stem there are two valves, one on the deck be- low water and the other on the deck above water When the valves are opened. the water enters into the water compartment through the submerged valve, and the air is liberated through the valve on the upper deck. Though there is a set of valves at each end of the barge i, for each water compartment, only one set is used for dumping. An interval of about two minutes is re- luired to put enough water into he water compartment to change the center of gravity and thus force the barge to list. When this occurs, the water in the compartment rush. es to the side and the load begins to slide toward the lower side. Listing continues and is accelerated by the movement of the load until the mo- mentum turns the barge completely over, dumping it's 6O0-ton load of rock The complete dumping cycle | requires only 3la minutes.
 When the barge has turned over
 shc valve that permitted the air tc escape from the water compartment becomes automatically the water valve through which water from he water compartment is diScharg- ed After the barge has been dump ed, the water compartment rides above the water line on the outside of the barge, thereby letting the water in the water compartment drain out. These valves are again closed before the barge is reloaded Thus, when the barge is brought to the loading station, the waste ma terial is loaded upon the deck that was previously the bottom of the | barge For continuous operation three barges are provided, one fol loading, the second for towing, and the third for repair. The barges are of sturdy construction and require little repair work. R4
 Both tug and barges were de- signed and their construction was supervised by H. c. Hanson nava'
 architect, Seattle, Wash, and al
 units were built by the Winslov
 Marine Railway & Shipbuildine Company, of Winslow, Wash. They were delivered at Juneau during tho summer of 1885 after a wharf anc loading station had been complet- ed At Juneau there is variation o1 about 25 feet in the tides. It wa.
 therefore necessary to provide ar adjustable conveyor belt to reduce wear on the decks of the barges tl a minimum.
 Dumping into Gastineau Chan. nel both along the shore and 1T the deep waters, is by permission
 from the War Department of tn,
 United States Government. Tha part of the channel covering tn, permit to dump in the deep water! held by Alaska Juneau Gold Min. ing Company has been charted ane marked off into blocks or sections ! The crew of the tugboat makes { daily report showing in which sec. tion each barge load has beer dumped. This enables the engin
 eering department to determine thu exact amount of waste dumped il each section. The approximat' amount of waste that each section will hold being known, dumping car be so regulated that the water vii
 not be made too shallow for navi
 gation. Soundings are made at ire, quent intervals to check the records
 When the aforedescribed system of handling waste was adopted, i
 was not expected that it would greatly decrease the cost obtained
 with previous methods; rather i
 was hoped that costs would be kep from rising and that they migh be stabilized at the prevailing fig ure for several years. Indications are that this will be attained. Tn, method has now been in use fol more than ten months. During tha . time there has been some extremei, r cold and stormy weather. The onl, delay experienced from weather con
 ditions was when the water was s, . rough as to make it impossible fo
 a man to go from the tug to tn
 barge to open the valve. From pres ent indications the barges will las