mitch10284

03-05-2013, 11:17 AM

Hello. I'm working on constructing an anchoring system for Barges on the MississippI River in St Louis and need to determine the force the river will impose on an anchored barge. I'm using the Drag Force Equation

F = 1/2 x velocity^2 x density x Area x Cd

Assumptions

Drag Coefficients

Cd = 1.98 for the bow

Cd = .005 for bottom and sides

Density = 62.4 lb/ft^3 for water

Barge is 35'x195' and sits 11' in the water

I've been told by a few Barge Captains the river can reach 26 ft/s during a strong flood. I'm designing for worst case so I've used this number.

The problem I'm having is that the drag force numbers I'm getting seem to be way high.

Bow - 16,576,329 lb

Sides - 466,433 lb

Bottom - 742,053 lb

Hoping someone can confirm these numbers are incorrect and can help me out.

Thank You

F = 1/2 x velocity^2 x density x Area x Cd

Assumptions

Drag Coefficients

Cd = 1.98 for the bow

Cd = .005 for bottom and sides

Density = 62.4 lb/ft^3 for water

Barge is 35'x195' and sits 11' in the water

I've been told by a few Barge Captains the river can reach 26 ft/s during a strong flood. I'm designing for worst case so I've used this number.

The problem I'm having is that the drag force numbers I'm getting seem to be way high.

Bow - 16,576,329 lb

Sides - 466,433 lb

Bottom - 742,053 lb

Hoping someone can confirm these numbers are incorrect and can help me out.

Thank You