AIS towing questionSep 22, 2011
To the editor: The AIS information for a tug I recently encountered at night in Block Island Sound said the tug was “towing.” Unable to detect any lights aft of the tug that might indicate a barge in tow, I called and was told he was pushing, not towing. It was then I realized the green light observed forward of the tug was not his, but the barge. (Should have realized that earlier and not thought “that’s a heck of a big tug.”)
Question: Is towing not only pulling something, but also “on the hip” and/or pushing?
I assume the captain entered the AIS information. It’s possible upon entering the sound from the sea he might have been towing, i.e., barge behind, but had repositioned for better control in a more restricted area and not changed the AIS data.
—Dave Benfer crews on Charles Garabedian’s Outbound 44, Watercolors, recently participating in the Marion-Bermuda race. Benfer currently owns a Kadey-Krogen trawler.
Former U.S. Navy officer and Professional Mariner navigation e-mail newsletter author Jim Austin responds: As I understand from your message, a tug which (I assume you picked up visually) was transmitting an AIS message that included her status as “towing” with no further breakdown as to what type of “tow.”
You wondered “... is towing not only pulling something, but also ‘on the hip’ and/or pushing?” I guess the immediate answer is that “towing” is often used (perhaps loosely) in such a manner that it doesn’t specify as to what type, whether astern, on the hip or pushed ahead.
Having said that, it’s interesting that Rule 24 is entitled “Towing and Pushing” ... and further, Rule 24 (c) “... a power-driven vessel when pushing ahead or towing alongside ...” seems to suggest that a vessel on the hip is considered as being “towed.”
You didn’t mention any lights on the tug itself, but having seen the starboard sidelight of the tow (being pushed ahead) and from the probable angle, I would expect the tug to have been showing two vertical white mastheads as well as her green sidelight.
As for the AIS message, so far have been unable to find out if the vessel transmitting (the tug) has the ability to refine “towing” more specifically as to what type of tow.