Mechanical Specifications of the LWT Pit Hog™ 
Model BCV-4 Remotely Controlled Dredge
Owned by Orange County Water District  

LWT dredge breaks up hardened material in recharge basin
(Photo: Courtesy World Dredging & Marine Construction)

Controls & Readouts
Power disconnect switch on electrical enclosure on-board - power on/off; Functions remotely controlled from short or on-board;
Dredge Power unit(s) 1 and 2 - on/off;
Hydraulic cooling pump - on/off
Slurry pump - on/off and speed
Rototiller (Auger) - forward/off/reverse and speed;
Travel - forward/reverse and speed:
Boom hoist - up/off/down;
30° dredging head (Auger) tilt - extend/off/retract.
Other measuring or sensing devices: Flow meter readout (slurry pump output), bottom sensor (dredging head float), speed sensors and readouts (Rototiller, traverse winch and slurry pump), hydraulic system(s) pressure readouts and fluid flow rate indicators and HPU hour meter.

Note: Manual/auto switch and dredge/shore switch must be positioned on-board dredge to select mode and location of operation. Auto mode(s) include an operator interface on-shore or a laptop computer on-board the dredge.

Power
230/460 VAC, 3 phase, 60 Hz electrical power Rototiller motor drives and traverse winch - 100 hp slurry pump drive, boom hoist and head - tilt cylinder - 60 hp

Slurry Pump/Gorman-Rupp
Model T3A60-B, Self-Priming Centrifugal Pump
Typical head capacity - 1,750 rpm
250 gpm @70 ft. tdh (water)
Materials of construction: Pump casing - cast iron; mechanical seal - Silicon carbide rotary and stationary faces
Suction & Discharge diameter - 3.0"
Semi-open impeller diameter - 8.75"
Sphere size (maximum) - 2-1/2"

Dredging Head
Hood assembly - welded 6061 Marine grade aluminum alloy; Ski (AR360 steel) at each end; OAL = 9'-6-1/8" Rototiller - 9" dia. - 1/2" thick wall x 8' lg. with 40 Ditch Witch teeth (20 RH & 20 LH). Drive - 45 hp hydraulic motor coupled to 17-4 PH SS shaft with sprocket and chain power transfer to Rototiller. Speed variable from 0.0 to 200 rpm.

Lateral Move System & Propulsion
Automated system with shore-based winches strategically located around basin. Treble sheave hydraulic winch with 3/8" dia. 7x19 galvanized wire rope (traverse cable) with proximity switches and stops at ends.  Winch drive - hydraulic motor with planetary gear reducer drive - traverse speed variable from 0.0 to 130 fpm.

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