Modular cast iron covers replace antiques in Detroit street

Asphalt manhole covers

Where Fort Street runs through Detroit's heavily industrialized southwest side, a section of it immediately adjoins a huge Marathon Oil Co. refinery. The major roadway carries a great deal of heavy truck traffic, including semitrucks hauling steel—and yet some infrastructure under the street still had traditional-style cast iron covers that were close to 80 years old. Owned by the Detroit Water and Sewerage Department (DWSD), the existing covers could fairly be described as antique and were intended to protect some below-ground water-regulating valves within the city's combined sewer overflow control system.

Other than the advanced age of the covers and their state of disrepair, DWSD was also faced with significant failure of the surrounding pavement. As a summer 2012 resurfacing of Fort Street was being planned by the Michigan Department of Transportation (MDOT), reuse (and raising) of the old covers was being considered by DWSD. Instead, Ermatic modular covers by EJ were presented as a new and innovative solution that would provide easier accessibility.

Working with Cadillac Asphalt, subcontractor Fort Wayne Contracting (a specialist at resetting street castings) would provide installation of the Ermatic units. The city considered and chose the modular covers to provide occupational safety improvements and greater ease of access, in a heavy-duty design sufficiently capable of withstanding the demanding traffic conditions.

Fort Wayne Contracting conducted an inspection of a modular cover unit preassembled at the Metro Detroit branch of EJ located in nearby Oak Park. DWSD scheduled the installation by Fort Wayne Contracting to coincide with ongoing MDOT work.

"We had the pleasure of installing two [modular cover] units . . . during July 2012 over some Detroit Water & Sewer monitoring wells," said Chris Honore, owner of Fort Wayne Contracting. "It was a two-day installation that went off without a hitch thanks to the construction and durability of the units. Due to the high volume of truck traffic in and out of the refinery, the heavy duty Ermatic was the perfect application."

Other project participants included procurement by Lakeshore Engineering (a planning, design and construction-management firm); with eventual oversight of the installation provided by civil engineering consultant Mannick & Smith Group.

Material makeup of the modular cover model used on the Fort Street project consisted of ductile iron covers, providing an AASHTO M306 H-25 load rating.

The complete cover line includes load ratings from pedestrian use to applications such as airfields and seaports. For particularly high wheel loads, an extra-heavy-duty airport version is available.

The covers are a highly engineered modular system that can be customized to fit any underground vault dimension or cover configuration, for a wide variety of applications.

Some other product attributes:

  • Other load ratings available upon request;
  • Standard sizes between 2 x 2 ft and 10 x 17 ft;
  • Custom sizes available;
  • Water resistant;
  • Security locking;
  • Lift assist available; and
  • Continuous trench covers for any length. Beamed multiple covers for large openings.

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