Tug-Barges V. Great Lakes Vessels?

[Russ]

This topic has come up regularly and more compllete discussions can be found in the archives of this site. One advantage of the tug-barges is smaller crew size. The Coast Guard requires a three watch system on a boat that results in a crew size of 21 - 25 members. By comparison, a tug-barge combo only requires a two watch system and a crew size as small as 11. Next, a manned vessel requires a five year inspection for certification. A tug must also be inspected but the inspection is less expensive and the time in dry dock is generally shorter. Also, the inspection requirements for an unmanned barge are less stringent than for an manned vessel. Also, when the tug is in for inspection, an alternative tug can be used to keep the barge in service. In addition, the trade route can affect the favorability of a tug-barge combo. For example, a 1000 footer will only carry 45 - 50 cargos in a shipping season but the tug-barge combo Dorothy Ann/Pathfinder usually carries more than 100 cargos. In summary, the potential advanates of a tug-barge combo are (1) cheaper crew costs, (2) lower USCG inspection and certification costs, (3) flexibility in use (i.e., changing ut tugs, etc.), and (4) beneficial in the short haul trade routes.

[Guest]

One thing I can add is that the tug-barge concept is to have a few different units with all the same equipment in a fleet running in similar trade patterns and then you can realize operation efficiancy through swapping tugs & barges where required due to down time on one unit or another for repair or loading/unloading.

Another would be the ability to come out of the notch & break ice without assistance from a commercial towing firm.

-B in B

[hausen]

The vast majority of the cost savings is in labor. Coast Guard crewing regulations dictate that a tugboat pushing an unmanned barge needs fewer people working on board than a powered vessel. Converting a large bulk carrying laker to a tug-barge or building something like the Joyce L. / Great Lakes Trader is essentially taking advantage of a legal/semantic loophole in the law.

Most tug-barges on the lakes, especially the medium-sized and large ones, operate just like a powered vessel of similar size. The only major differences between the two (I'm sure someone will correct me if I'm wrong on any of this) are that the tug-barge has a hull separation at the stern (which usually makes her less fuel-efficient than a comparable powered vessel), the barge has less in the way of safety systems and is less rigorously inspected by the USCG than the corresponding parts of a manned vessel, and that a tug-barge carries a smaller crew.

[akopin]

What are the main benefits, if any, of taking a vessel (for ex. the Joseph H. Thompson) and cutting it up into a barge and in her case using the rest to make a tug? Since barges can still be self-unloaders with 250' booms - why ruin a good thing? Are there a lot of savings in terms of labor as I'm assuming you would need fewer crew on a barge than a vessel per USCG regs? Although, I would think that fuel makes up a lot more of the cost to operate than labor? I'm guessing maintenance would be slightly less, but not a huge savings? The engine configuration wouldn't change much would it? It takes a certain amount of power to push a certain amount of freight - and in the U.S. fleet there are vessels with one really large main engine or multiple smaller engines powering similar vessels, which tells me EPA regulations wouldn't drive this one way or the other. Are there other regulations, USCG or other, that make it more beneficial to be a tug/barge than a vessel? Is there a limit about how big you can make a barge? Or not really because the locks determine that. Is it a safety issue? Easier to maneuver or faster? More flexible/functional? Or am I way off here about their being a benefit at all - it's just something companies do to prolong the use of a vessel when it stops being functional/cost-effective as a vessel?

I was reading something from a few years back about the St. Mary's Challenger having been considered to be turned into a tug/barge and I just wanted to know what the benefit really could be. I mean, it would seem that a similar investment to repower would save a tremendous amount of fuel just due to the inefficiency of steam powerplants - so you'd probably get some of your investment back from those savings either way - assuming you'd have to buy or build a tug - so - what gives?