System Reliability Design, Fort Street Project

We are assisting DTE in the design of a new 16-inch steel main in downtown Detroit. Due to the project’s high visibility and potential risks, DTE requested detailed design and analysis. To accomplish this, a 3D model of the road right-of-way will be created for the most accurate design. The model will be based on Mobile LiDAR data and Subsurface Utility Engineering (SUE), which consists of:

• SUE Level D – Design One call and use of plans
• SUE Level C – Field survey of manhole inverts
• SUE Level B – Ground penetrating radar
• SUE Level A – Visual verification of utility crossings (Hydrovac)

Prior to extensive redevelopment in downtown Detroit, DTE Energy is proposing to replace approximately 4,500 feet of 22-inch mechanically joined steel pipe with 16-inch steel pipe. The proposed improvements would allow DTE to upgrade the existing system from 50 PSIG to 150 PSIG (< 20% SMYS), which would make it possible to provide higher volumes of gas in a smaller footprint. This will also improve DTE’s ability to supply gas to the new 60 PSIG system being installed in the areas surrounding Detroit.

The project consists of the following west-east route:

• Horizontal directional drilling (HDD) of US-10 to replace existing 22″ hanging from Fort St deck and tie-in to existing 16″ east of US-10 (replace ~800′ 22″ CI).
• Elevate existing 16″ along Fort from tie-in to Washington, and along Washington to Larned (Elevate ~2,100′ 16″ STL).
• Replace existing 22″ along Larned from Washington to Randolph and tie into existing 24″ going around Millender Center (Replace ~2,000′ 22″ CI).
• Elevate existing 24″ around the Millender Center starting at Larned, going north on Randolph, east along Congress, and south along Brush to Larned (Elevate ~1,000 24″ STL).
• Replace existing 22″ along Larned from Brush to US-375 (Replace ~1,200′ 22″ CI).
• HDD of US-375 to replace existing 22″ hanging from Larned St deck and tie-in to existing 22″ east of US-375 (Replace ~800′ 22″ CI).