Description
This complex project involved an underwater crossing on the Potomac River to install a new communication system from Maryland to Virginia for an undisclosed client. For this project, Danella Engineering and Construction Company was responsible for design engineering, permit acquisition and construction management.
Project Details
During the project, Danella’s team of expert engineers successfully:
- Followed a complicated set of engineering requirements.
- Danella Engineering was allowed less than a one foot-per-mile error to meet the needs of the client.
- Danella had to convince multiple agencies to allow the client to attempt the directional bore crossing, which was carried out by another construction company using Danella’s engineering specifications.
- Developed base map information to determine the path of the communication system, both under water and on land.
- This project involved 84 miles under water, on land and on railroads. It included GPS of features and overlaying those reference points and duct systems onto the base maps to develop construction drawings for bid purposes.
- Danella’s CADD (Computer Aided Design and Drafting) department provided the necessary hardware and software design services to create drawings, paper to digital conversions, complete base mapping, customization and production.
- Met an extensive list of environmental permits.
- Previous attempts by other companies to cross the river for telecommunications or electrical construction had caused environmental hazards, particularly related to the riverbed. Choosing to do a directional bore was designed to eliminate these hazards.
- Danella created contingency plans if the project caused what is known as “crack outs,” where mud is introduced into the river through a crack in the riverbed. These plans met the environmental standards of the Army Corps of Engineers.
- Adhered to multiple county, state, federal and private rights of ways and standards.
- Danella acquired all necessary permits from departments of transportation, federal agencies, county and local municipalities, and supported the private right-of-way acquisition effort with the client’s team.
- Led the construction bid process with the client and performed construction management duties.
- Danella supplied the client with detailed weekly reports, as well as engineering support to verify any changes requested by construction contractor during construction.
Unique Challenges
The chief challenge for this project was the development of a one directional, deep water bore nearly 16 feet below the river bed that could only be completed from one side of the river, from Maryland headed to Virginia. A bore of this manner had never been attempted for a span of over 8,100 feet; this actual bore was 9,325 feet.
According to Thomas J. Brady, Vice President of Danella Engineering and Construction, Danella devoted nearly 20 employees to this project from 2008 to 2009. David Kraft, Project Manager, noted that the Potomac River is “constantly moving and changing, and doesn’t have a sound river bed. You are better off drilling in rock, but we didn’t have any rock until we got to the Virginia side.”