CommScope ConQuest Conduit Construction - Manual (Page 35)

Underground Installation Methods 4.17
Submarine Installation
Submarine Plowing Method
There are two basic methods of submarine construction used, Sub-Aqueous Terrain Plowing and Floor Surface
Placement.
Sub-Aqueous Terrain Plowing
Construction with this method can be accomplished with one of several technologies designed for this special task.
Installation with this method can eliminate the issues of buoyancy if the conduit is buried deep enough. It also offers the
best protection from fishing activity, boat anchors, tidal and current effects, and other submarine hazards. Burial depths
need to be varied based on the soil conditions to provide adequate protection.
Self Propelled Bottom Crawling Vehicles are operated in the same manner as track driven plows. These are
land-based bulldozers with a sealed diesel engine outfitted with special snorkeling equipment for the air intake and
exhaust manifold. While most are operated manually, there is a growing number of remote controlled units being
employed.
Large Sled-type Conduit Plows are designed to be
towed by a powerful boat. This has been the standard
plowing method for many years. Plowing may be started
and completed on the shoreline. Shoreline finishes can be
completed using a tractor to finish the pull in water too
shallow for the boat from the shore.
Jet-assisted Plows are similar to the sled-type plows
and are also towed by a powerful boat. The difference is that jet-
assisted plows use forwarding aiming high-pressure water jets to fluidize the soil and rear aiming low-pressure water jets
to direct the fluidized soil to the rear. The forward water jets ‘open’ the trench for the conduit to be placed in before the
fluidized soil pushed back by the rear jets settles and starts the backfill process.