Responding to “The Articulated Tug Barge (ATB) Quandary”

By Robert P. Hill

I read with great dismay, the article that appeared in your magazine’s February 2013 issue, entitled “THE ARTICULATED TUG BARGE (ATB) QUANDRY”. I’ll open with the definition of quandary:

noun, plural quandaries : a state of perplexity or uncertainty, especially as to what to do; dilemma.

There is no dilemma involving AT/B’s present in the coastwise or ocean transportation marketplace. AT/B’s are indeed increasingly supplanting ships in the Jones Act coastal trade. It is a trend that is slowly beginning to spread to coastwise transport in other regions of the world as well. But the reality is, that it is also a force in deep water/ocean transport as well. So I want to examine the assertions made by the article’s author and essentially show the inaccuracies present in them, and provide the actual facts that trump the opinions expressed by the author. My goal is to deal with the technical inaccuracies of the article. I will leave it to others to deal with the manning contentions – though I will cover them with regard to places where they are not correctly stated as they apply to AT/B’s themselves.
The very first paragraph of the article is grossly inaccurate. There is no “safety gap” between AT/B’s and ships. Every time AT/B’s insert themselves deeper into the maritime trades, shipowners will lament the “lack of regulation” the AT/B is alleged to have. Well, I design them for a living. It is all I do. I’ve done it for over 30 years. Anyone who believes that AT/B’s somehow get a pass regarding regulations, has no idea what they are talking about. We are presently engaged in designing AT/B’s for a whole range of product transportation, including LNG. So, please allow me to directly quote a section from a Specification we are preparing for an AT/B liquefied gas carrier, indicating the regulations and standards that are being applied to the design of this AT/B. Note that we apply a similar range of project-specific Regulatory scope in ALL the AT/B’s we design.

2.0.3 Applicable Regulatory Standards for Vessel Design
The AT/B will be designed to the following domestic and international regulations and standards for safety, portions of which are found to be specifically applicable to gas carriers, or to Articulated Tug/Barge Units, Barges carrying hazardous cargoes or Towing Vessels. Further Rules & Standards may be found to be applicable and will be applied as required:

  • IMO (IGC) Code for Carrying Liquefied Gases in Bulk
  • 46 CFR 38 Liquefied Flammable Gases
  • 46 CFR 54 Pressure Vessels
  • 46 CFR 151 Barges Carrying Bulk Liquid Hazardous Material Cargoes
  • 46 CFR 153 Ships Carrying Bulk Liquid, Liquefied Gas, or Compressed
  • 46 CFR 154 Safety Standards for Self-Propelled Vessels Carrying Bulk Liquefied Gases
  • 46 CFR 162 Engineering Equipment
  • 46 CFR 172 Special Rules Pertaining to Bulk Cargoes
  • ABS Guide for Building and Classing Liquefied Gas Carriers With Independent Tanks
  • ABS Rules for Building and Classing Steel Barges
  • ABS Rules for Building and Classing Steel Vessels Under 90M in Length
  • USCG Navigation and Vessel Inspection Circular 10-82, 10-92, 2-81
  • USCG Marine Safety Center Bulletin #01-98
  • OCIMF Standard for Loading Arms
  • API2000 Venting Atmospheric and Low Pressure Storage Tanks
  • 33 CFR 159 Marine Sanitation Devices
  • USCG NVIC 2-81 – Tug/Barge Units – Dual-Mode AT/B
  • USCG NAVIC 12-82 - Time Weighted Noise Exposure … Compliance w/IMO Noise Criteria.
  • ABS “Guidance Notes on the Application of Ergonomics to Marine Systems”
  • IMO Int’l Convention on Load Lines 1966 with declaration Resolution A 231 (VII) and A 320 (IX)
  • IMO International Convention on Tonnage Measurements 1969
  • IMO International Telecommunication and Radio Regulator of 1973/1976 and 1982 including GMDSS - Rules 1999 For Radio Communication
  • IEEE-45 Recommended Practice for Electrical Installations on Shipboard
  • IES Recommended Practice for Marine Lighting,
  • IEC, Electrical Installations In Ships
  • ILO, convention no. 92 and no.133 for crew accommodation.
  • US Environmental Protection Agency (40 CFR 140)
  • Federal Water Pollution Control Act (33 USCG 1251 et seq.)
  • ASTM Publication F1166 – Standard Practices for Human Engineering Design for Marine Systems, Equipment and Facilities - latest edition, as well as other ASTM Standards specifically called out in these Specifications
  • ANSI Standards, as specifically called out in the vessel Specifications
  • SAE Standards, as specifically called out in the vessel Specifications
  • Oil Spill Prevention Act of 1990
  • UL Standards, including, but not limited to UL 1581, Reference Standard for Electrical Wires,
  • Cables and Flexible Cords
  • IMO International Convention for the Prevention of Pollution from Ships, MARPOL
  • 1974/1978 Annexes I, IV, V resolution MEPC 14 (20) 07.09.84, resolution A 393 (x) and Annex VI
  • with all current amendments and/or modifications
  • ISPS requirements
  • SOLAS Certification (Tug – there are no living quarters on the barge)
  • SNAME guidelines for conduct of tests and trials
  • Other Flag State requirements. (Assumed to be Jones Act, USCG/American Flag)

The above list of regulations that our units meet, is not a “wish list.” It is the reality of what we do. To be certain, there are some regulations that do not apply to Unmanned Barges. Why? Because they are as noted; “unmanned.” As a designer however, I have yet to have a client who did not ask me point blank if something that is not required by regulation, is truly needed for safety – and not a one who refused to install something I felt was necessary for the safety of the crew.
It is news to me, and to my clients that charterers allow extra days when chartering an AT/B due to weather being a concern. An AT/B can operate in the very same weather as a ship can, and truth be known, ships sometimes slow more than AT/B’s in bad weather due to propeller and rudder emersion.
I do not know of a single AT/B utilizing a high capacity connection system that came out of the notch because a pin broke – the connections are designed along with their surrounding structure, for as much as 3X the expected loads. Name me all of the AT/B accidents using a major connection system since they came into widespread use in the 90’s where there was a casualty? An oil spill?
The author’s description of the motions of an AT/B is also incorrect. The contention regarding emergency hawsers parting due to no catenary is also incorrect. The AT/B’s I design have at least 1000’ of emergency hawser aboard. It is pure scare-tactics to contend that if an AT/B barge got away we’d have a repeat of the North Cape disaster. Rubbish. The North Cape was a single hull barge – all AT/B petroleum and chemical barges are double hull and the North Cape got away from a towing tug, in horrible weather they should not have been out in – not an AT/B. Whatever would befall an AT/B barge aground would also happen to a ship aground. And look at the largest spills since the 90’s. How many were from AT/B’s – how many from tankers? MANY more tanker accidents with significant spills. It is more likely that a ship will lose steering (see recent experience) or propulsion (see recent problems with fuel switchover in ships) than a tug losing a properly sized towing hawser while holding station offshore. So by the author’s reasoning, we should see tankers as the real “quandary”. He cites ship accidents as the reason why one has to further regulate or by implication, bad – the demonstrably safer AT/B.
AT/B motions? “Poor Souls” and pendulum movement? Has the author ever even ridden an AT/B? I have. There are YouTube videos that can be watched. The motion is not horrible even in extreme seas – and we design these boats for a significant height sea spectrum exceeding 7M.
It also not universally true that AT/B’s have a crew of only 7. Several of the ones we have designed have 10 to 14 aboard. All of our AT/B tugs are capable of berthing a minimum of 10. There is also a major problem with this statement written by the author: “Industry consensus says these ‘ships’ (when connected) are constructed to take advantage of a loophole in the law. Since these boats do not travel more than 200 miles from the U.S. coast and are not engaged in international voyages, they are not subject to the International “Standards of Training, Certification and Watchkeeping” (STCW) nor will they be subject to the upcoming “Maritime Labor Convention 2006” (MLC 2006) guidelines coming into effect 20 August 2013.”
Talk to an AT/B operator instead of relying on hearsay. AT/B’s ROUTINELY operate in trans-oceanic service. I know because my boats do it. The limitations of space for this article do not allow me to enumerate the many cases of such, but they operate under the same international rules as ships do.
Space limitations again prohibit me from answering each inaccuracy in the article, but interested parties are welcome to contact me at [email protected] to hear the REAL AT/B story. I would not send a person to sea on an unsafe vessel design. The safety of these crews is everything to a naval architect. We have to think of them constantly. To suggest by inference that those of us who design or operate these vessels care nothing for the concepts of safety or environmental protection is to do an injustice to a lot of good people. The TRUE AT/B record speaks well for itself.


Robert P. Hill, N.A.
President, Ocean Tug & Barge
Engineering Corporation
[email protected]


(As published in the March 2013 edition of Marine News -


Marine News Magazine, page 60,  Mar 2013

Read Responding to “The Articulated Tug Barge (ATB) Quandary” in Pdf, Flash or Html5 edition of March 2013 Marine News

Other stories from March 2013 issue


Marine News

Marine News is the premier magazine of the North American Inland, coastal and Offshore workboat markets.