THE PRIESTMAN DREDGE.

Dunstan Times, Issue 983, 18 February 1881, Page 3

THE PRIESTMAN DREDGE.

The following particulars of this dredger we received by the last Home mail from the paientees, and publish for general information

‘•These dralgers .ire composed of large self-tiding aiul dischaging scoops or buckets, with the necessary engine power for working the same. The shell, side frames, and s rafts of r he bucket are ma le of wrought iron, with cast iron drums for peculating the two chains required in opening and closing. Fur very stiff material a grab working in a similar manner is required, made with long and powerful sttcl tines, litted into strong wrought iron fiaures. The buckets and grabs con be made semicircular when necessary for sinking cylinders, &c. The engines work upon massive cost iron foninlaioris, with wrought iron pillars securely fitted in the centre. The jrlra are wrought iron, the three largest sue dredgers ' eing titled with cast iron rollers, tra.elling on roller paths in the centre of the foundations Wrought iron hut water feed tanks are supplied, upon wlricir tile boilers stall I. The boilers are of the vertical type, with steam and water tidings eornple e. Two cylinders are supplied to each engine, fixed to strong cast iron side frames, which work -the lifii g barrels uirtot, designed for working the self-acting bucket and grab at a great speed, together with all necessary working parts, including lifting, lowering, and turning gear, hot water feed pumps with suction an r delivery pipes complete The chains are ma le to work the bucket or grab at a depth of 20 feet below water, nut they can he made to work at a much greater depth it requir ed. “The selfacting bucket is suitable for mud, soft sand, &c.; for stiff mini, a grab with spaces between tho times is most suitable. For hard s.mdy material, a grab with inter-locking tines, set close together, is luces-ary.” Capabilities.—Approximate quantities of material the dredgers will remove per day of 10 working hours—average height of lift being 20 feet from water level—worked iiy one min only, with buckets or grans capable of holding :

lOewt. Mml, 250 tons. Clay, 150 tons. 3D „ » 500 „ „ 000 „ oo „ >. 650 „ „ 400 „ 40 „ „ S00 „ 500 ,,