Passenger Trains > San Joaquin 713 crossing the Middle River Bridge

Went out to the BNSF bridge over the Middle River in the Delta near Antioch, California and photographed Amtrak California 713 on its way to Oakland on Friday, Dec. 28.  I'd never been to this location before.

Jim Maurer

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Very nice.  That's an interesting counterweight system on that bascule.

EsPee1229 Wrote:
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> Very nice.  That's an interesting counterweight
> system on that bascule.

It’s called an “Abt” bascule bridge, after its inventor Hugo Abt. There were only 8 of the type ever built, and three of them are on the old ATSF line thru the San Joaquin Delta. The three (San Joaquin River, Old River, and Middle River) were built by the American Bridge Company between 1928-1930...

I believe the San Joaquin River Bridge (closest to Stockton) has been straight railed, and no longer moves, however the Old River (Orwood) is staffed by a tender 24 hours a day, and the Middle River can be opened with 24 hours notice to BNSF...

Are there any videos of the Abt Bascule in operation?.
I can't seem to figure how it all moves together.
TIA.

James R.(Jim) Baker
Whittier, CA

JimBaker Wrote:
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> Are there any videos of the Abt Bascule in
> operation?.
> I can't seem to figure how it all moves together.
> TIA.

It looks like the counterweights would pundulem downward, which will push connecting struts back (toward the right). The action would then pull the lift portion of the span backward, causing it to lift.

I've never seen it in action myself.

Gary 

JimBaker Wrote:
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> Are there any videos of the Abt Bascule in
> operation?.
> I can't seem to figure how it all moves together.
> TIA.

That would be very cool.

Thanks Gary,  I still need to see it in operation though!

James R.(Jim) Baker
Whittier, CA

Here is some animation of the bridge motion from the tube (you’ll have to copy/paste the link)...

https://youtu.be/MAVqx5Hcv4Y