Largest Steel Girders for the Innerbelt Bridge Roll into Town
What Are They?
Delta girders are named for the triangular shape they form once they are assembled. “Delta” is the fourth letter of the Greek alphabet and resembles a triangle.
Each Delta girder assembly is made up of six (6) steel parts; two Knuckles, two Delta Legs, one top girder and one “V.” Each Delta assembly is connected to the next with another straight girder (not shown in the image below).
The piece delivered today is the Knuckle –it connects the Delta Legs with the top girders.
In general, the Knuckle girders are 67 feet long, 8 feet high at the narrowest end and 18 feet high at the widest end.
There will be 80 of these Knuckle girders used on the main bridge section.
Each Knuckle weighs approximately 100,000 pounds – that’s about 8 million pounds of steel in the Knuckles alone.
Getting Them Here:
The truck that delivers them will be carrying a load that is 18 feet wide; it requires a special permit, escorted by Highway Patrol since it takes up two (2) lanes of traffic.
The streets along the delivery path have to be closed briefly while the truck is passing through, but they are opened as soon as the truck has passed.
Shipments of steel will continue to be made through next spring.
Where They’re Made:
The huge girders are being fabricated by High Steel Structures, Inc. in Pennsylvania.
As with all steel used on the new Innerbelt Bridge – and all ODOT projects – it’s made in America!
Steel Bridge Parts: