Work Boat World

The tug and barge alternative

Baird Maritime

Ships and Shipping editorial – March 2008

Lunching recently with one of the world's leading shipowners, talk turned to the cost of small modern bulk carriers.

As both a ship owner and shipbuilder, my friend was amazed to have found that an 8,000DWT self-propelled bulker was nearly double the price of a similar sized dumb barge with an accompanying tug with which to move it.

In fact, as we looked out the restaurant window at the steady stream of passing semi-trailer trucks ("lorries" for the English), we were inspired to discuss possible alternatives.

At current prices, it would be possible to purchase a tug and two, possibly three, 8,000DWT ore barges for about the same amount as a self-propelled 8,000DWT bulker.

While, obviously, at sizes larger or smaller than 8,000DWT the price differential between a tug/barge combination and a self-contained bulk carrier may be different, it is the concept that counts in this exercise.

Particularly over shorter routes, inland and short-sea operations and similar, the tug/barge arrangement provides enormous flexibility. The semi-trailer truck analogy is an apt one.

Your prime mover, the tug, is kept operating practically flat out. It suffers from almost no down time. The captain simply pushes the full barge into its unloading berth and immediately picks up an empty one to return to the other terminal.

Depending on route length and unloading times, one tug should certainly be able to handle more than one barge. In the truck business, averaged over both long and short haul, I believe the ratio is about two trailers to a prime mover.

The Articouple and Taisai Engineering people have been pushing the concept of closely coupled tug and barge combinations for years. They have had, to my knowledge, only limited success.

Obviously, theirs is not the only solution, even if it is a very good one. The more traditional towed barge arrangement is still very effective. Perhaps a bit harder to manage and more fuel expensive but undoubtedly at a much lower capital cost than closely coupled arrangements.

The world's ship yards are currently swamped with order for bulkers both big and smaller. There are smaller yards, though, that can build barges and tugs at considerably less notice. Similarly, tug engines are relatively quicker to obtain.

At current low prices dumb barges can be regarded as almost a "throw-away" option. However, the fact remains that if reasonably well maintained barges, without the complications of engines and propulsion systems, can be very durable. They are relatively easily and inexpensively adapted to other trades if conditions change.

Much the same applies to tugs. They are built strong and are generally long-lived. They can also be quickly modified to suit other trades.

I have no idea whether the concept applies to much larger barges. I imagine, though, that it would even if it requires much larger or even multiple tugs to facilitate it.

This may only be a short term arbitrage solution but I think not. Certainly the concept is worth examining and perhaps not only by those operators working shorter routes or with comparatively smaller vessels. Conventional wisdom is not always correct.