Smooth Waters

Inspection of nine areas can help ensure proper operation of your hydraulic dredge.

By Cash Maitler

A properly maintained hydraulic dredge can be the deciding factor in how much material an operation produces. These general maintenance practices can help keep hydraulic dredges performing well, but actual maintenance practices may vary depending on the type of dredge(s) being utilized. Be sure to refer to your owner’s manual or consult the manufacturer for proper maintenance details.

Hull

Periodically inspect the hull and pontoons for possible leaks. To increase the life of the dredge, it is important to keep the hull and pontoons of the machine painted and minimize bare metal exposed to the water. Where thin areas are detected, it is typically possible to seal weld a scab plate over the area and extend the useful life of the hull or pontoon.

Dredge pump

The dredge pump is its heart and one of the most critical components to maintain. It is important to check the bearing oil levels or grease the bearings daily, depending on the pump. If your pump is equipped with packing, you should periodically adjust or replace the packing so that a small stream of water leaks from the stuffing box when running. If sand or other material is present inside the stuffing box area, it is important to clean the stuffing box to prevent accelerated wear. If your pump is equipped with mechanical seals, inspect the seals for wear and leaks. In the case of underwater pumps, it is especially important to make sure the bearing housing seals are in proper operating condition to prevent water intrusion and damage to the bearings.

The pump is one of the most critical components of a hydraulic dredge to maintain.

In addition to checking the bearings, it is also important to periodically inspect and adjust the pump for wear. Abrasive materials tend to wear out the “wet end” pump components over time, requiring periodic adjustment and replacement. It is important to check the impeller, case, and liners for wear and make adjustments or replacements in order to maintain efficiency. Over time, if wear occurs, recirculation or other factors can cause performance losses, increasing the cost of production.

Fresh water/jet pump

If your dredge is equipped with a fresh water or jet pump, you should frequently inspect it for proper working order. Most of the same maintenance procedures for the centrifugal dredge pump apply to the fresh water or jet pump. Check to inspect the bearing oil level or grease the bearings. If the pump is equipped with packing, adjust the packing so that a small stream or drip occurs when the pump is operating. Typically, the fresh water pump or jet pump do not need adjustment, but, periodically, it is necessary to inspect the impeller and wet-end components for signs of wear or cavitation.

Engines/motors

Check the bearing oil levels or grease the bearings in the dredge pump daily.

Check the engines and motors daily or on an operational shift basis. Inspect and tighten any loose belts. Make sure any and all fluids are clean and at operating levels. Change filters according to the manufacturer’s recommendations and refer to your owner’s manual for further instructions.

Winches

The winches and cabling need to be inspected and maintained daily. Be sure to inspect your cables for frays, kinks, or any other signs of wear. Check all winches for proper oil levels, leaks, and any signs indicating a need for repair. Check to make sure that the cable is able to properly spool on and off the winches and not create a bird’s nest.

Cutter/jetting system

Inspect the cutting teeth, arms, chains, and other devices for wear and misalignment.

Depending on the type of dredge being utilized, it is important to periodically inspect the cutting and/or jetting system to agitate the material being pumped. For cutting systems, inspect the cutting teeth, arms, chains, and other devices for wear and misalignment. Overlook the drive mechanisms for any signs of leaks indicating possible seal failures. For underwater drives, this is especially important to protect against possible water intrusion into the drive. For jetting systems, you should inspect the jet pump and all connecting piping and hoses for cracks and leaks. Check the bearing oil levels or grease the bearings on the jet pump daily, depending on the type.