Have you heard of freighter wash? I hadn’t until recently. It happens when ships charge through narrow, shallow channels. As they do, water is displaced and moves away from the shore to support the massive boats. After the vessels have passed, the water rushes back with such force that it could easily cause people standing on the shoreline to loose their footing. It can be treacherous! Shorelines erode more quickly. My husband and I were able to experience this phenomenon first hand on Neebish Island. Join us as we investigate this marvel, the dangers of freighter wash.
Before we journeyed to Neebish, I joined their Facebook groups so I could learn about the area. In fact, Lori Miller had just posted a warning about ‘freighter wash.’ I was intrigued. I have witnessed a few inches of water moving away from the shoreline at Lime Island, but that was nothing compared to what we saw at Neebish!
Lori Miller
Lori Miller, a board member for the Neebish Island Historical Society, had taken us on a personal tour of the island earlier that day. It was incredible! She’d given us this map marked with her personal touch. (See the link below: “The Secrets of Neebish Island: Part Two – Islanders” for the story featuring Lori and Connie.)
On the map you can see how narrow the “rock cut” and the northern “Dock Beach” channels are for freighters.
After fastening our life jackets, DaViking got Thor into the water at the boat launch. Then we headed north to the Corp of Engineers “Dock Beach.”
(Notice the height of the water).
After hearing about the dangers of low water along the shoreline, he decided to raise the motor even higher. I am so glad he had that foresight!
Bernoulli’s Principle
In 1738 Daniel Bernoulli, a Dutchman, had coined this term, “Bernoulli’s Principle.” (Freighter Wash) This explains how moving water carries a lower pressure, so surrounding water is drawn toward the freighter to displace its weight. When this occurs it appears that the ship is sucking in surrounding water from the shoreline. It is also known as “the canal effect” since the degree of occurrence is stronger in shallower, narrower passages.
Shipping Lanes Around Neebish
We were positioned at the northern passage.
Neebish Island is flanked by cramped cannels. In fact since 1903 northbound ships began only traveling along the east side of the island and southbound vessels stay on the west side.
The eastern passage used to host two way traffic. However, it was so narrow that in 1899 the Houghton collided with a barge causing nearly a week in delays. Engineers devised a plan so this would never happen again. They dredged the western rapids creating a “rock cut” for smoother shipping traffic. (See the map above)
A Dangerous Freighter Wash
Within a short time of our arrival to the dock, a freighter with a concave bow entered our sightline. “Oh, goodie!” I have been known to mimic my elementary students. I may have even clapped my hands. (Thank goodness no one else was on the platform. Chuck is used to my antics.) The Jamno, aligned itself with the green buoy and flowed effortlessly through the narrow shipping lane. It was majestic to be this close to such a large vessel!
Suddenly, we heard the rattle of shoreline rocks as water threaded through the stones away from the land.
“Oh my gosh! Look!” we both called to each other. Then, we were only able to share wide-eyed looks of stunned silence. Shaking our heads, words were difficult to find. I glanced back at the ship’s progress. Then, I leaned over to see Thor still resting on the rough stones.
I checked Thor again and saw that it was still on the rocks. I wondered how long the water would remain displaced. “I’m glad I raised the engine.” Chuck managed to find words where I was still holding my breath.
When Jumno’s stern was several ship lengths away, a rising wave whooshed toward the shore. The cascade raised Thor with the lines stretched taunt.
Bernoulli’s Equation
P1+21ρv12+ρgh1=P2+21ρv22+ρgh2
The power of Bernoulli’s Principle was a sight to see! At home I did some research. There’s a formula to calculate the fluid density using velocity, height, acceleration and pressure. Modern scientists say it is missing an important factor of lift (force). Basically, the increase of speed, decreases pressure of the water surrounding the vessel which creates a greater effect. So I wonder if the ship was moving too quickly through the narrow passage.
I don’t really know about such things to pass judgement. I was simply captivated by this engineering event. So I drown myself in new information only grasping onto a few facts, trying to build some sense of understanding. The older I become, the more I realize I how little I understand about this world. I really do love learning, but I am unsure of my conclusion.
Another Freighter Wash
As another ship came around the corner of the passage, I decided to stand on the shore and get a better view of the changes in the water level. This boat had a full bow, unlike the first ship’s concave bow. I wondered if it would make a difference in the water displacement.
Clad in my life vest and quick-drying ‘adventure pants,’ I made sure I had secured my swim socks deep in the sand with the rocks circling my ankles. I had positioned myself on the bank, high enough to where I thought I’d get a little wet, but not loose my footing. Chuck stood nearby watching me more than the phenomenon. (He’s a special guy!)
The water swiftly moved off shore. Time seemed to pause. The water stayed in the channel for an exceptionally long time. Maybe it just felt that way as my feet were just getting cold.
The rushing surge of water was powerful on my lower legs. It whooshed just under my knees, then immediately started to recede. “You OK?” came a question from the dock. “Yuppers.” I smiled as I clicked pictures. Boy, I am one fortunate person, to have Chuck as my partner in these capers!
Neebish Island
Neebish Island is a unique community and holds many secrets. The Freighter Wash/ Bernoulli’s Principle was an unusual experience! I couldn’t wait to get home and research this paradox to try to grasp the forces of nature. Keep learning and having fun!
I encourage you to visit Neebish Island, a truly magical place. There’s a wonderful resort (cabins) with camping spaces available, too. Check out the other articles about Neebish below.
Related Links
Restless Viking merchandise is available!
‘The Secrets of Neebish Island: Part One – Pine River Canoe Camp article
The Secrets of Neebish Island: Part Two – Islanders article
Resources
Neebish Island Resort: 11550 16 1/2 Mile Rd, Barbeau, MI 49710 Phone: (906) 632-2067
https://www.sciencedirect.com/topics/engineering/bernoulli-principle
https://www.khanacademy.org/science/physics/fluids/fluid-dynamics/a/what-is-bernoullis-equation
4 thoughts on “The Secrets of Neebish Island: Part Three – The Dangers of Freighter Wash”
My Grandparents (Peers)had a resort on Neebish in the sixties, spent alot of summers there it’s beautiful.
It was wonderful to visit your island!
It would have had more of an impact if there had been a video instead of just pictures.
Great post. Very interesting about the freighter wash phenomenon.