![]() ![]() ![]() As the working of the grab causes considerable oscillation of the barge, it is well to place the gold-saving tables, sluices, &c., on a separate barge. The vertical lift from deck board, for stability, should not be over 20 ft., or, deducting the length of the grab, say, 14 ft. The weight of such a grab, with engine and boiler, would be about 17 tons platform dimensions, 5 ft. working pressure, and surplus boiler powder to drive a centrifugal pump, trommel, and winches would cost about £600. A one-ton capacity Kingston dredge, with 7-in. Both firms recommend, for this purpose, the double-chain grab. Rose, Downs, & Thompson, Limited (see illustration), and Messrs. ![]() Well-known makers of this form of dredge are Messrs. The grab, or “ clamshell ” type of dredge, consists of a self-filling and discharging scoop or bucket, with the necessary engine power for working this from a crane. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |