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The Evolution of Tugboats

Posted February 08, 2014 12:00 AM by CR4 Guest Author

Tugboats have a rugged, old world charm that attracts a brand of enthusiasm few other boats can. They are one of the sea's most hardworking, yet humble, marine vessels, and their history holds tales of perseverance, family tradition and community. When the first tug launched from a Scottish harbor in 1871, its power betrayed its size and unassuming purpose. Within a century, tugs had become a commercial replacement for horses and mules, and were directly responsible for the ballooning American canal system.

While they appear to have their feet planted firmly in past centuries, they are untouched by the concerns of today. The sector's experience of the recession was a tumultuous one dominated by a fickle freight industry.

On a more positive note, as tugboats emerge from a shaky five year revenue crisis, their technological future is becoming brighter than ever. Like the rest of the travel industry, anti-pollution concerns, high tech innovations, and budget worries are expected to alter the way designers approach their projects, transforming tugboats into prouder vessels with plenty to brag about.

Eco-friendly Propulsion

In 2008, the fact that tugboats ran on diesel caused plenty of hand-wringing as the sector faced the 2007 regulations governing all remanufactured marine engines. Tough standards meant that, by 2015, all tugboats for sale would have to reduce their emissions by 90%. Hybrids were the obvious answer, and many expected that technology would change before expected price increases in diesel fuel. The actual change was more sluggish than expected, but the sector is currently making significant inroads. The world's earliest hybrid tugboat was launched in 2010, and in 2013, the first liquefied natural gas tugboats were launched bearing Rolls Royce engines. The tug's past as a pollution-belching vessel will soon be too distant to remember. Smoky harbors will eventually be a thing of the past, but tugboats enthusiasts will be rewarded with more than simply a clear conscience.

Pocket-Friendly Engines

As liquefied natural gas (LNG) becomes increasingly available, tug owners will find themselves with easier budgets to contend with. The non-toxic, non-corrosive gas has a greater energy density than diesel, which makes it more cost-efficient over long distances. By 2020, it is likely that an even more energy efficient innovation will give tug operators more bang for their buck: The E3 tug project hopes to offer a fresh hybrid propulsion system that functions more cleanly, quietly, and cost-effectively. Cheaper production will not only offer cheaper running costs but lower investment outlay, too, as production becomes faster and less expensive.

High Tech Features

Today's tugs need far more horsepower than they did in the past and with that, maneuverable docking will need to improve. They will operate with fewer crewmembers, and will slowly work towards better automation. Compact ship docking tugs can currently pull over 60 tons despite their compact size, but as the market becomes increasingly competitive, they will singlehandedly manage the work that used to require four tugs. As marine personnel availability dwindles, tug design will focus increasingly on this aspect, but comfort is another influential factor. Low sheen finishes now offer reduced water reflection, while on-board solar power offers hot water.

Tomorrow's tugboats will follow in the footsteps of the motoring sector by introducing more comfortable, user-friendly features that will revolutionize the industry. Yesterday's trends have shaped the tug market relatively little, but the current changes will bring about a far more dramatic evolution. This is partially due to the fact that the industry is burgeoning, with rapidly growing sales, revenues, and production rates. As tugboats increase in demand, those who design them will have greater expectations to sate.

Editor's Note: Carolyn T. has been involved in the boating industry for over 10 years. She is a blogger in her free time who primarily focuses on tugboats.

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Re: The Evolution of Tugboats

02/09/2014 12:56 AM

I think that the evolution of the actual propulsion systems is far more important and more interesting than the engines that drive them. The 360 degree drive systems have been the biggest game changer in the efficiency of the boats than anything else. An extensive article would probably be well received by those not familiar with what has been happening in the tow boat world.

Always good to hear about boats though.\


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Re: The Evolution of Tugboats

02/11/2014 7:17 PM

there were diesel electric tugboats on the great lakes 40 years ago. Probably elsewhere too, but I don't have that knowledge. These are now called hybrids. Diesel motor runs a generator which runs a big electric motor (and charges some batteries), which turns the propeller. I seem to remember they were DC motors but I could easily be wrong on this. The diesel ran at a constant speed for best efficiency.

I remember walking over the electric motors. they were huge. the diesel was a 12? cylinder straight running at about 500 RPMs. I watched an overhaul. for me this was great entertainment.

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Re: The Evolution of Tugboats

07/07/2014 9:06 PM

I call BS here.

"LNG has a greater energy density than diesel" No way! Give us a break!!!!!!!!!

The energy density of LNG is comparable to propane and ethanol but is only 60 percent that of diesel and 70 percent that of gasoline.[4]

Fuel Comparison Chart - Alternative Fuels Data Center says:

One gallon of LNG has 64% of the energy of one gallon of gasoline.

One gallon of diesel has 113% of the energy of one gallon of gasoline.

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