Rock Port, Missouri Emergency Case Study

Acrow Bridge Reopens Flood-Damaged Route in Rock Port, Missouri

Project enabled expedited restoration of railway freight service within the region

During the extensive Midwest flooding beginning in March 2019, the Nishnabotna River, a tributary of the Missouri River, topped its banks and levees. As the water rushed downstream, it caused severe scouring and the immediate closure of the bridge on U.S. Highway 136 in Rock Port, Missouri.

While not heavily traveled, it was particularly critical the route be restored as quickly as possible as it provided the only access for BNSF Railway crews to service flood-damaged equipment and resume full freight service within the region.

In order to quickly restore safe passage, it was decided to “overbridge” or slide a longer Acrow bridge inside the damaged structure. While the existing bridge is 150´ long, Acrow’s structure is 190´ long with a width of  18´ and HS-20 loading.

he project came with a particularly tight delivery and erection requirement, however, Acrow was able to meet the deadline — the structure was opened to traffic eight days after receipt of the order. Acrow’s bridge
is expected to be in use for three months while BNSF Railway completes repairs in the immediate area.


Rock Port, Missouri Emergency Case Study Bridge length:
  • 190´
Bridge width:
  • Single-lane 18´ roadway
Live load:
  • 1 Lane of HS20-44
  • TL-3 Guardrail load
Deck surface:
  • Aggregate anti-skid epoxy
Bridge specifications
  • (A) Panel chords, diagonals & verticals, panel reinforcing chords and rakers to AASHTO M223 Gd 65
  • (B) Decking, raker brace, transom, diagonal brace, chord brace, swaybrace, transom brace, diagonal chord brace to AASHTO Gd 50
  • (C) Panel pins to ASTM A 193 Gd B7
  • (D) Bolts to AASHTO M164M – A325
  • All major components galvanized to AASHTO M111 – ASTM A 123
  • All bolts are hot dipped galvanized
  • All pins are electro galvanized
Bridge erection:
  • Full cantilever launch