Careers at TKDA

Engineering | Architecture | Planning

Twin Ports Interchange

TKDA Led Railroad Coordination Efforts on Major Reconstruction Project

When the Minnesota Department of Transportation (MnDOT) reconstructed the I-35, TH 53, and I-535 interchange, TKDA led the railroad coordination for the project. The primary need for the project was to replace structurally deficient and load-restricted bridges that limited the capabilities of the Port of Duluth-Superior and to correct the interchange geometric deficiencies. When the original interchange was constructed, nearly all BNSF tracks in the corridor were reconstructed, which resulted in geometric track layouts that did not fit current BNSF standards. However, the existing interchange layout did not allow BNSF to expand its capacity through the corridor.

TKDA developed several options for staging and track realignment for presentation to BNSF. Through regular project coordination meetings, discussions of the options resulted in a mutually beneficial layout for both BNSF and MnDOT. The MnDOT bridge pier locations are compatible with the proposed Twin Ports Interchange layout and optimize bridge span lengths. For BNSF, the new layout resulted in a 4-track corridor, two existing and two future tracks, which is an improvement over the existing track corridor.

Additionally, our hydraulics team combined Miller Creek and Coffee Creek into a creek that flows beneath the interchange and rail yard via a concrete box culvert. We included weirs inside the fish passage culvert with ramped approaches in the direction of flow. Weirs were also included on the upstream face of the remaining three high-flow culverts to direct low flows into the fish passage culvert.

CLIENT: Minnesota Department of Transportation
LOCATION: Duluth, Minnesota