In response to being awarded a hydrographic survey job for a large drinking water reservoir, Substructure applied its specialized knowledge of geophysical surveying to the design, testing, and fabrication of a highly mobile platform that also would be environmentally compliant.

On top of the usual challenges of creating a reliable survey vessel (stability, sound interference, repeatability), Substructure considered environmental factors, such as removing gasoline and diesel entirely from engines and power supplies. Research of American Water Works Association (AWWA) standards provided information about what products could be used on and around drinking water facilities.

The hull of this new barge is based on Substructure’s custom-built aluminum work barges. Substructure’s main survey vessel, Orion, is driven by a specially designed jet-drive system, but for the specialized reservoir barge, Substructure selected a 10-horsepower electric motor for propulsion to eliminate the risk of leaks or spills from a gas or diesel engine. To run the wide variety of electronics required aboard a hydrographic survey vessel, as well as the electric motor, Substructure chose a propane-powered generator. The barge design allows for minimum fuel consumption with maximum survey duration.

Because nontoxic biodegradable crankcase oil was used in the double-isolated generator and because propane was used as the engine fuels, Substructure's vessel meets all of the AWWA standards for drinking water applications.

As with all Substructure survey projects, the highest quality of reliable and repeatable data was expected. Working from the stable aluminum barge, Substructure was able to design and build a side mount for the SONAR head. All hydrographic components on the barge were physically surveyed in for tight integration. Patch testing was conducted before surveying to ensure reliability of data sets.