Pugsley Wharf Current Analysis


 

Pugsley FEMElements from the Port of Saint John Baroclinic Hydrodynamic Model model were examined along the faces of the Pugsley Terminal and the Pugsley Wharf, as shown in the chart and aerial photo below. The current magnitude was calculated along the face of the two wharfs and preliminary results are presented below.

The model was constructed covering the entire Saint John Harbour using FVCOM and resolves the tides, currents, salinity and temperature. More information can be obtained here: http://www.omg.unb.ca/people/haigh/port_sj.html
The simulation was run using data from April 22nd, 2008, which was in the middle of a strong spring freshet from the Saint John river and during the spring tides.

Aerial



Pugsley Terminal

A profile of current velocities along the wall of the Pugsley Terminal was examined over a tidal cycle. The A and B labels in the photo below match those in the current profile images.

Pugsley Terminal

In the following figure, the top graph shows the current magnitude throughout the water column along the face of the Pugsley Terminal for April 22nd, 2008. The second figure shows the corresponding phase of the tide, while thethird and forth figures show tangential and normal velocities respectively along the wall.

Currents

Maximum current speed during a tidal cycle at the seabed along the wall was determined to be 1.35 m/s.

The maximum seabed currents at three different points along the terminal wall was calculated as follows. The numbers match the locations shown in the following figure.

Location Seabed Current Magnitude Units
1 1.22 m/s
2 1.15 m/s
3 0.38 m/s

numbers


Pugsley Wharf

A profile of current velocities along the wall of the Pugsley Wharf was examined over a tidal cycle. The B and C labels in the photo below match those in the current profile images.

Wharf

In the following figure, the top graph shows the current magnitude throughout the water column along the face of the Pugsley Wharf for April 22nd, 2008. The second figure shows the corresponding phase of the tide, while the third and forth figures show tangential and normal velocities respectively along the wall.

Wharf_Anni

Maximum current speed during a tidal cycle at the seabed along the wall was determined to be

1.34 m/s.

The maximum seabed currents at three different points along the terminal wall was calculated as follows. The numbers match the locations shown in the following figure.

 

Location Seabed Current Magnitude Units
1 0.76 m/s
2 0.67 m/s
3 1.34 m/s

numbers


Conclusion

The maximum seabed currents along both the Pugsley Terminal and Wharf exist close to the intersection of the two walls (point B). The maximum velocities occur at the end of the ebb tide and are a result of the strong flows coming from under the Harbour Bridge. The above figures show that the current magnitudes in the water column are stronger than those at the seabed due to friction in the bottom boundary layer.


Ian Church, 2011

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