Sub M

I have recently been asked to help get an old tug through Sub M inspection. It’s the first one to be inspected in this company and maybe the second for the local CG.

The local CG questioned stability when the vessel was floated out of dry dock with a 5 degree list. No ballast on board and so fuel was transferred to correct the list. The day tank is on stb and has always been balanced by ballast or potable water. They said the vessel must sit at exactly 0 degree list with fuel tanks pressed full and other tanks dry(quoting stability test requirments). Even though we can prove a safe operational history they are not comfortable with the way the reg’s are written and they are looking for a way to avoid passing us on the stability issue without some mathematical backup to cover there decision in the event of an accident. But what good does it really accomplish when all they can require(after list is corrected) is an operational test where they ride along and “ determine” wether they feel the boat is stable or not? A slack tank isnt going to affect the feel of the boat so it should have no effect on their determination after going for a spin in the harbor.

I understand the issues old, modified vessels( lighter engines, upper pilot house) can have with stability and so 3 years ago I asked the CG how they were going to address stability testing with Sub M and they said clearly that existing vessels would only have to prove their safe operational history and would not be required to complete the full stability test process.

144.300 Stability standards for an existing vessel.

(a) The owner or managing operator of an existing vessel operating under a stability document must be able to readily produce a copy of such document.

(b) The owner or managing operator of an existing vessel not operating under a stability document must be able to show at least one of the following:

(1) The vessel’s operation or a history of satisfactory service does not cause the stability of the vessel to be questioned by either the Coast Guard or a TPO engaged to perform an audit or survey.

(2) The vessel performs successfully on operational tests to determine whether the vessel has adequate stability and handling characteristics.

(3) The vessel has a satisfactory stability assessment by means of giving due consideration to each item that impacts a vessel’s stability characteristics which include, but are not limited to, the form, arrangement, construction, number of decks, route, and operating restrictions of

Subchapter M: What a farce?

Large Fishing vessels and small passenger vessels are both subject to stability calculations and stability documentation prepared by a naval architect. Small passenger vessels under Subchapter T and freight vessels under Subchapter I are further subjected to USCG supervised stability tests —- as they should be. There is no excuse not to require the same level of stability testing for tugs, including retesting after major modifications, like lighter engines, adding an upper house, or GRT tonnage reductions. The fact that a tug is old and “proven” has nothing to do with whether it meets objective stability requirements today.

I am stunned by some of the tugs I see that have “passed” Subchapter M. There is far too much focus on Subchapter M paperwork which everyone knows (with a wink and nod) is mostly unnecessary, meaningless, pencil whipped bullshit. There is a total lack of focus on stability, structural and watertight integrity, fire hazards and fire stops, safe walking surfaces, stairs, ladders, gangplanks, sewage systems that actually work, adequate fuel filtration and spill prevention, properly cleaned and coated potable water tanks. adequate safe and sanitary crew living spaces.

There are a lot of old tugs that are good well maintained boats that should pass inspection, but there are a lot of existing tugs that are poorly designed and maintained that should be put thru major refits or phased out.

When a tug gets a USCG Subchapter M COI, that should mean something. It should mean that the tug meets objective present day standards, similar to other developed countries —- within reason. Unfortunately, Subchapter M is a corrupt regulatory failure that accomplishes nothing.


I agree that all inspected vessels should meet modern stability requirements. But that’s not how the reg’s were written and most companies aren’t going to go above and beyond the regs to that degree. I am just glad there is now some focus on addressing issues on these old tugs.

While it is my intention to assist the company in meeting the standard at minimum expense, i do hope the Coast Guard does a thorough inspection and enforces the standards as written.

P.S. Not all industries require older equipment to meet modern standards. Commercial trucks have to meet the standards in place when they were built generally speaking. Trucks pior to a certain year do not require ABS, all new trucks do. Old trucks are not required to be updated.

Do you all not do incline tests or is that just a yacht thing?
Would you WANT to jawbone the USCG into signing off the old tug if it actually isn’t stable?

Airplanes for the most part fly on their original certification when built, but if an issue becomes apparent you will have to fix it to keep flying. Example DC-3 wing spar fitting need to get X-Rayed now to check for cracks every so often, but they didn’t back in the 1930s.

Yachts are irrelevant to this conversation.

I am interested in meeting the new standards. Higher standards than many tugs have been held to in the past. How to meet the standard as written is what i am talking about. Exceeding them is a nice idea but i am taking things one step at a time.

Feel free to contact the USCG with any issues you have regarding these regulations.

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Not saying tug = yacht, but an incline test is a pretty basic thing. Is that not common?

Inclination experiments are required in all sorts of situations, but they are enormously expensive and not something you do for fun. I’m sure a fresh stability book would satisfy the USCG in this instance, but then there’s this bit:

Also, not to sidetrack the discussion, but about this:

Surely, you don’t mean that as a generalization? In that case, there is discussion to be had and stories to be told…

No, not generalizing. It’s just the layout of this tug. A lot of small tanks. @10,000 in 5 tanks. Based on my experience its not noticable.

My interest here is to hear the experience of others going through this process. Each MSO handles things a little differently.

My tug had an incline test for an upper house add-on prior to inspection, so this won’t help much, but the COI on here is very restrictive about personnel allowed because the resulting stability letter from the incline test was restrictive. This was a TSMS- option; since the USCG is already involved in yours, I’m guessing yours is not TSMS but direct inspection. Since they saw it list and said something, then I’d budget in the incline test because I doubt they just forget it.
And, I agree that they missed the boat to make the industry safer manning-wise; the companies were already ramped up expecting tougher standards and it didn’t happen. Inspected boats can still be manned with a Captain and an OS. The AWO got what the companies wanted.

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So they aren’t go to buy off on option 1, the history of satisfactory service so you have two options to make the USCG happy with either the operational test or a stability assessment. In the end it the USCG that has to sign off on it so they need to tell you what they will accept.

Mr. OCMI, what what operational tests would be necessary under option 2 in order to satisfy you?
Mr. OCMI, what type of assessment is necessary under option 3? Would a letter from a PE attesting to the stability of the vessel as constructed, specifically addressing the six elements in 46 CFR 144.300(b)(3) the satisfy you?

If the OCMI is going to hold up a COI they need to give specifics as to why and how to clear that so that you know how to proceed.

You also have the right to appeal, 46 CFR 1.03-20 provides guidance on how to appeal decisions of an OCMI should that be the company’s choice.

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