There have been no methods of 'modified open cut' construction that permit the use of rigid pipelines requiring sag bends for the crossing of rivers, streams, and watercourses.
Optional methods of construction to overcome the limitations in the 'modified open cut' methods of river crossing have included: aerial crossings of the river, directional drilling and horizontal augering beneath the river bed. These three forms of construction are usually very costly. The directional drilling and horizontal augering methods are also limited by certain subsurface ground conditions.
In an effort to overcome the construction limitations and to compete economically with directional drilling and augering, a welding chamber has been invented that will allow a successful welded joint to be made in the middle of the river. The limitations of the carrier pipe and the installation of sag and overbends are no longer a concern. The application of this chamber will allow successful, economical and environmentally sound methods of performing 'modified open cut' crossings.



The AQUASHIELD Welding Chamber is designed to provide an environmentally safe, dry working area for a welder to lineup, weld and apply protective coating to various sized steel pipes. It is a two piece circular steel structure designed to withstand external static ground and water pressures. It is used in a vertical position with an open top and with a sealed, enclosed floor. The diameter of the chamber varies with the size of the steel carrier pipe to be welded and the amount of working room required to facilitate the welding and coating.
The use of a bagging or damming system for the purpose of isolating the two stages of the crossing (as described above) will be undertaken. Upon completion of the excavation of the trench, the first portion or half of the pipeline is installed, complete with the AQUASHIELD mounted at the end of the pipe. This will be located at the furthermost point into the river.


The AQUASHIELD is constructed to a height that will allow the top of the chamber to protrude above the surface of the water, thus providing a comfortable amount of freeboard when in place. When the first portion of the crossing, along with the AQUASHIELD, is satisfactorily lowered to position, the first portion of the crossing is backfilled to the original condition of the river bottom. The cofferdam is dismantled, allowing the watercourse to reenter, and is reinstalled on the opposite side of the crossing, again isolating a work area for the installation of the second portion of the crossing. The cofferdam is looped around the end of the first portion of the crossing to encompass the AQUASHIELD. At this time, the trench excavation for the second portion of the crossing commences, beginning at the AQUASHIELD and working toward the opposite river bank.

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A series of weights will be placed on the AQUASHIELD to compensate for the buoyancy once the chamber is free of water. The AQUASHIELD can now be dewatered. The AQUASHIELD is now safe for the welder to enter to complete the necessary works for the connection of the pipes, i.e., lineup, welding and coating. Upon satisfactory completion of the pipe connection, the second half of the crossing is now ready for backfill. At this point the upper section of the AQUASHIELD may be removed by releasing the fasteners that connect the upper section to the base. The buoyancy compensating weights will be lifted free and the upper section of the AQUASHIELD will be pulled off and salvaged for another project. The base will simply be left in place and backfilled along with the installed pipeline. Once backfilling has been completed, the coffer dam will be dismantled and removed, leaving behind a completed crossing.

Environmental concerns are met, costs are reduced, and a successful crossing is visually co-ordinated throughout.

Modified Open-Cut Crossings bullet The AQUASHIELD Method bullet Investment Opportunities
The Patent bullet The Principals bullet Contacting Us bullet H O M E