Rollin' on the River

The Mississippi River is central to the US economy. The 2,350-mile waterway runs through ten states and is used to transport grain, corn, soybeans, iron, rubber, coal and other bulk commodities. 

Barges are especially good for bulk transport. They do not have their own propulsion system but lashed together, they form a ‘tow’ that is pushed by small, incredibly powerful towboats using up to and over 11 thousand horsepower. On longer, wider rivers with locks, a 15-barge tow is quite common, equivalent to about 225 railroad cars or 1,050 tractor- railer trucks.

Yet the same engine power that enables these impressive feats of transport creates a lot of noise and vibration that can trouble an essential element of the tow: the crew. 

“There can be a crew of ten people on board a towboat for a month at a time, and accommodation on the boat can be two to four stories high. It becomes a lot more difficult for crew to get much-needed rest when the boat is constantly noisy and shaking,” explains Ruud van Wijngaarden, Manager of the technical department at Trelleborg’s antivibration solutions facility in the Netherlands, who has more than 25 years of expertise in shock and vibration solutions. 

The issue is only worsening as companies seek more powerful vessels to push bigger, heavier loads. This means that the rubber mounts and steel springs most Mississippi towboats use cannot isolate a crew’s sleeping quarters sufficiently to protect them from the noise and vibration of operating machinery.

Such an intense environment is very unhealthy. A 2019 study of towboat crews on the River Danube travelling between Cernavoda and Drobeta in Romania, found that a lack of sleep caused by on-board noise and vibration led to the crew developing problems such as sleep disorders and high blood pressure. 

“It also becomes an issue for boat owners when trying to attract new people who will be willing to stay on-board for long periods of time, as well as to keep experienced crew,” continues van Wijngaarden. 

The alternative to crews staying on towboats is rotating them at the end of their shifts. Mandated in parts of Europe by health and safety legislation, it means a vessel has to come into port at least once a day to transport people to and from the boat. This is not practical or economically viable on the huge Mississippi River.

One solution is fitting Trelleborg’s Towair, which has been used in Europe for decades. Instead of steel springs or rubber mounts it utilizes air bellow vibration isolators.

Towair places the accommodation on air springs, along with movement limitation components, during barging to achieve optimum vibration isolation from a towboat’s deck to the accommodation. It eliminates all vibrations from 4 hertz upward.  

“A cushion of air separates the accommodation from the hull. A robust pneumatic system regulates the compressed air in the air springs and maintains the deckhouse at a constant, stable height, allowing for several centimeters of travel in either direction regardless of the load placed on the air springs,” explains van Wijngaarden. 

This seemingly simple, robust technology is largely unchanged since development for the Dutch market in the 1980s. Trelleborg introduced it to the US some years ago, but the industry there has been slow to change from older systems due to aging vessels and cost concerns. 

Could Towair stake a claim in the massive Mississippi market? Ruud van Wijngaarden thinks so.

“Although the US is not quite as advanced as Europe in this aspect of noise legislation, we see that it’s coming. Boat owners will need to change to attract new people who’ll want to stay on board,” says van Wijngaarden. 

“We also see a big replacement market for scrapped or resold vessels. The industry reckons around 650 articulated tugboats will be replaced in the next five to ten years. That will be the time for boat owners to consider investing in technology that improves crew consistency and the uptime of their vessels by avoiding off-boarding, hotel rooms and transporting people to and from the boat,” continues van Wijngaarden. Early adopters of Towair in the Mississippi River include the New Orleans-based Canal Barge Company. CBC uses the system to great effect on its flagship tow boat, the Merritt “Heavy” Lane Jr.  

As the industry changes, van Wijngaarden is targeting further customers in the US.

“Towair is a proven, sustainable and industry-leading solution. It’s ideally suited to the US and Mississippi towboat barge traffic. We look forward to Trelleborg making the most of this big opportunity,” says van Wijngaarden.”

This is an article has been reproduced from Trelleborg's T-Time magazine. To download the latest edition, go to: www.trelleborg.com/t-time