Jay, Dave and Puget, When you tow through Wrangell Narrows, how do you time the tides? I'd guess you'd want the current on your nose for steerage (?), although you've got 18 miles to cover at slow speed so you'll see much of a tide cycle. Take us through your logic of the timing of the tide you want to go through there. We can learn from your experiences.
Hi Ken - Well, I remember what it is for WESTERLY! Going with the current is the preferred mode.
Be at Pt Alexander northbound at Petersburg HW - 1:30. At 7 kts water speed, this gets you to Papke's Landing or even Mountain Point where the ebb starts, and you will dock on the early ebb at Petersburg. If wanting to arrive at Petersburg at HW slack, you will want to enter a little earlier, and will end up bucking the last stretch from Scow Bay into Petersburg. Also, you can enter the narrows a lot earlier if desired, and kill some time in Scow Bay before continuing to Petersburg.
Of course, these times may not work as well for faster boats. Also, note that atmospherics and variations in tidal exchanges can effect current velocity, and where the current changes.
Southbound from Petersburg: Depart at Petersburg HW - :30. Even with WESTERLY's cruise at 7.2 knots, the ebb will push you past Pt Baker on a large tide.
Transiting the narrows with a loaded oil barge is not too much different than the times above. There is a relationship between the weight of the tug, the power of the tug, and the weight of the barge to maintain a speed where you can keep the barge in the channel (assuming a short towline). Generally about 70% power allowed sufficient reserves with a fully loaded barge.
The critical timing was to be off the old Union Oil dock in Petersburg north harbor at HW slack, and it was always desirable to transit during a rising tide.
As noted by others, there are much larger and more powerful tugs towing larger barges through the narrows these days, capable of increased speeds and control.
