[QUOTE=jdcavo;20987][I][/I]
ATBs are considered the same as “dual-mode” ITBs…[/QUOTE]
In my reading of NVIC 2-81 there is an absence of a bright line distinction between Pushing Mode and Dual Mode ITB’s that would support the general statement that “ATBs are considered the same as dual mode ITBs.” I understand that the NMC may consider them the same, but I don’t see the support for it in the language of NVIC 2-81, specifically as follows:
“A [B]Pushing Mode[/B] ITB tug may
be -connected to the barge with either a rigid or an [B]articulated connection[/B] system.”
“A [B]Dual Model[/B] ITB is similar to a tug and barge where the. tug is secured in the
barge notch or on fenders by means such as [B]wire rope, chains, lines or other tackle[/B]
now commonly used in offshore towing in that it is in all respects equipped to tow
by hawser.”
By those definitions alone ATBs would seem a lot more likely to fall under the “Pushing Mode” category. I understand that part two of those definitions goes on to describe the differences between towline pull stability and installed equipment etc. which may (or probably does not, as we heard from jnovak) make a stronger case for ATB’s to fall into the “Dual Mode” category - but the language used is not definitive, it is vague and descriptive.
For example, there are “and” “or” and “for example” descriptions which point the reader in a direction but do not preclude multiple interpretations.
I think it is worth the time for the USCG to publish a NVIC which clearly addresses ATBs. Crowley’s new 750 class is going to be larger than a lot of tankers - I think it would make sense to be able to upgrade an unlimited license from sea time on of them the same way you would on a similar size tanker - which would be the case if they were considered parallel to Pushing Mode ITBs right?
Anyway thanks for all your informed and helpful replies over the years Mr. Cavo, they are always appreciated.