- Apr 16, 2011
- 6 min read

ATB vs. ITB, v2.0

The original ATB vs. ITB post, from November 2008, was due for a major updating, including lots of photos, so here it is.

Warning: before you read any further , please be advised that these are my definitions and opinions. Others, including but not limited to the U.S. Coast Guard, naval architects and some of my fellow mariners, may disagree. C’est la vie. In any case, I get asked this question often and what follows is my standard answer: “Within the rather broad category known as towing vessels there exists a sub-category known as ATB’s, which stands for Articulated Tug & Barge. There is another sub-category known as an ITB, or Integrated Tug & Barge. They are not, and never were, the same. Nor are either of them, with some limited exceptions, a real tug in anything but name.” This answer, I believe, is based on sound logic and reasoning, not regulatory doublespeak or wishful thinking.

Moving right along, this is an ITB…..

…..which, as you can plainly see…..

…..is no tug…..

…..not even a little bit, except for having propellers.

Even at their peak of popularity there were very few ITB’s in existence, so many of you might never have seen one. They bear no relation whatsoever to a real towing vessel. They were designed from the keel up as nothing more than regulation-beaters, capitalizing on the uninspected vessel-status of towing vessels to get away with lower manning, construction and operational-safety standards. They’re simply small to mid-sized tankers with detachable propulsion/control units that are rigidly connected and do not move independently. An ITB “tug” disconnected from its “barge” is a sight to behold: unstable in anything but the calm waters of a well-protected harbor, and having the ability to do absolutely nothing remotely tug-like besides moving about under its own power. Click here for more photos and some history.

An ATB, on the other hand, is a different story. There are two basic types of them, purpose-built (new) and converted, and they presently use one of six connection systems: Articouple, Bludworth-Cook, Hydraconn, Intercon, JAK and Westec. The generally-accepted slang term for them is pin boats, the reason for which should be obvious. When “pinned in” to their barges an ATB pivots on the transverse axis provided by said pins, allowing the “tug” to pitch independently from the barge, but they roll as one.

The purpose-built type are generally not very seaworthy when disconnected and outside of the notch in open or exposed waters, although some people might try to bullshit to the contrary, and even in protected waters they’re very limited in what they can do. For the most part, unless there’s another compatible barge around for them to move, they’re pretty much useless as a tug. The idea of getting out of the notch at sea, in anything but calm to near-calm wave/swell conditions, and taking the barge in tow the old-school way is sheer lunacy. Unless they’re pre-rigged to an emergency hawser and can just back out of the notch and roll around on the barge it isn’t going to happen. Furthermore, you wouldn’t want to be up in that high wheelhouse getting whipped around by the seas without the strong stabilizing influence of the barge. The probability of seriously injuring or even killing someone while attempting this maneuver would be unacceptably high. Suffice it to say that you just don’t ever get out of the notch on purpose unless you’re in port. Unintended/unexpected pin retractions at sea in bad weather have occurred on the West Coast and I understand that they were pretty ugly.

To illustrate the modern, purpose-built type, here’s Reinauer Transportation Co.’s ATB Meredith C. Reinauer…..

…..and the Vane Brothers ATB Brandywine…..

…..and Moran Towing Co.’s ATB Linda Moran.

None have a lower house, or a doghouse, and they were never meant to operate as a conventional tug. To the extent that they were ever intended to to tow anything astern it’s strictly emergency-only, and no one really wants to find out firsthand what that would be like in bad weather.

A new twist in the on-going evolution of ATB’s is the Robert Hill-designed facet tug, of which the ATB Ruth M. Reinauer…..

…..is an example.

Most of the largest ATB’s in the petroleum trade in the Northeast seem to use Intercon systems…..

…..and here’s what the “ladders” on the barge (what the pins from the tug engage with) look like…..

…..up close.

The conversions, older (or just plain old) conventional boats with new pin systems and upper pilothouses installed, can also be limited in their operational capabilities out of the notch, but to what degree depends on the specific conversion job. Depending on which pin system is chosen, whether or not the hull underwent drastic shape modifications to accommodate it, and whether the new fendering offers adequate hull protection determines whether that particular boat can perform basic barge-docking assist work and/or do conventional alongside towing and pushing. Some can, and some can’t, and some can do a little, sometimes. It also depends a lot on who’s driving the boat: a skilled, experienced operator with a strong conventional-towing background can make all the difference in the world.

Below is Reinauer Transportation’s ATB Craig Eric Reinauer, an old Halter-built Tidewater tug from the Gulf that, among many other things, got an Intercon conversion.

Note the fendered “knuckle” within which the Intercon pin is housed.

Another example is K-Sea’s ATB Volunteer…..

…..which was a JAK conversion.

In this case the “knuckle” is, like the Intercon example above, fendered to a degree…..

…..but its large size and sharp angles make it appear completely unsuitable for towing alongside: just one roll and you could have a big hole. This is not a characteristic of the JAK system (or any other) per se, however, as the JAK-tug Houma…..

…..is clearly capable of “hip towing” her bunker barge without a problem. It all comes down to the particular conversion and the hull alterations required to make it work with a given barge. For the record, most of the ATB conversions I’ve seen do not appear to have much, if any, legitimate conventional towing capabilities left after they come out of the shipyard. In addition, conversion-ATB’s can be somewhat to very limited in what barges they can connect to. Converting a diverse fleet of conventional tugs, as K-Sea and Reinauer have done, is complicated, and it’s almost impossible to get every pin boat to be interchangeable with every appropriately-sized barge in a cost-effective manner. If you can manage to get even a few to work with each other you’re doing pretty well.

Towing astern, although maybe a little more more feasible than with the purpose-built ATB’s, can still be a very dicey proposition. Most of the conversions have had their towing machines removed for stability reasons and only have an emergency synthetic-line hawser and a capstan in their place. As ATB’s become more numerous, captains and mates possessing the traditional skills required for conventional towing operations are becoming steadily older and scarcer. Crews that can do softline hawser work (including deckhands and engineers) are even rarer. There is little that can be done about this phenomenon: it is simply change driven by demographics and technological evolution. We are already seeing the formation of the first generation of “towing vessel officers” with absolutely no towing experience. Nor are they likely to gain any because all they’ve ever known have been ATB’s, so it naturally follows that they won’t be able to teach skills they don’t have to others. As time passes that knowledge will continue to dwindle away. So it goes…..the best that the industry can do in the meantime is to strictly segregate towing vessel mariners by their capabilities so that the risk of accidents caused by incompetency in conventional towing operations is minimized.

Anyway, here’s an example of one of those limited exceptions I mentioned earlier: the tug Ellen S. Bouchard (a conversion) pushing the B. No. 282 west-bound through the Kill Van Kull. The high upper pilothouse affords good visibility (tremendously important but often neglected on many tugs) and the absence of visible wire or spectra push gear marks her as an ATB. Upon close examination…..

…..you can see the main pilothouse, the doghouse, a double-drum towing machine, a Texas bar (towing arch), and push wires draped over the quarter. She’s a real tug and ready to tow a barge astern when necessary, not just for emergencies.

The Bouchard Transportation Co. has, interestingly, chosen to take a very different route regarding the rapidly growing trend towards adopting the ATB as the standard for coastal transportion of petroleum products. Nineteen boats in their twenty three-boat fleet are pinned. Of those, a total of fourteen were conversions. Unlike their competitors, however, they’ve largely kept the conventional tug attributes: the main (lower) pilothouse, aft controls in the doghouse, working towing machines, etc.

Even more interesting is the fact that of their five new-build ATB’s…..

…..like the Intercon-pinned ATB Morton S. Bouchard IV…..

…..all of them are conventional towing-capable too. Only the Danielle M. Bouchard is questionable because she lacks a lower pilothouse, although she does have a towing machine and Texas bar.

So if most of these ATB’s can’t really tow, astern or alongside, are they still legitimately tugs? I still say no. Licensing-wise the U.S. Coast Guard did the right thing and eventually acted to break the worsening advancement bottleneck by issuing ATB-restricted licenses to ATB-trained mariners who have no conventional towing experience, and found themselves with little or no opportunity of getting any. But more still needs to be done, particularly with the TOAR.

ATB vs. ITB, v2.0

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