Co. in October 1908, and was named the
"Leviathan." Her length is 487 ft., beam 69 ft., and depth 30 ft. 7
in. Her dredging machinery consists of four centrifugal pumps driven
by four sets of inverted triple expansion engines, and connected to
four suction tubes 90 ft. long and 42 in. in internal diameter. Her
propelling machinery, consisting of two sets of triple expansion
engines, is capable of driving her at a speed of 10 knots.

Another powerful and successful sand-pump dredger, "Kate" (Plate I.
fig. 7), was built in 1897 by Messrs Wm. Simons & Co. Ltd. for the
East London Harbour Board, South Africa. Its dimensions are: length
200 ft., breadth 39 ft., depth 14 ft. 6 in., hopper capacity 1000
tons. The pumping arrangements for filling the hopper with sand or
discharging overboard consist of two centrifugal pumps, each driven
from one of the propelling engines. The suction pipes are each 27 in.
in diameter, and are so arranged that they may be used for pumping
either forward or aft, as the state of the weather may require. Four
steam cranes are provided for manipulating the suction pipes. Owing to
the exceptional weather with which the vessel had to contend, special
precautions were taken in designing the attachments of the suction
pipes to the vessel. The attachment is above deck and consists of a
series of joints, which give a perfectly free and universal movement
to the upper ends of the pipes. The joints, on each side of the
vessel, are attached to a carriage, which is traversed laterally by
hydraulic gear. By this means the pipes are pushed out well clear of
the vessel's sides when pumping, and brought inboard when not in work.
Hydraulic cushioning cylinders are provided to give any required
resistance to the fore and aft movements of the pipes. When the vessel
arrived at East London on the 18th of July 1897, there was a depth of
14 ft. on the bar at high tide. On the 10th of October, scarcely three
months afterwards, there was a depth of 20 ft. on the bar at low
water. Working 22 days in rough weather during the month of November
1898, the "Kate" raised and deposited 2-1/2 m. at sea 60,000 tons of
dredgings. Her best day's work (12 hours) was on the 7th of November,
when she dredged and deposited 6440 tons.

A large quantity of sand-pump dredging has been carried out at
Boulogne and Calais by steam hopper pump dredgers, workable when the
h