Michael Carr - Tons Per Inch Immersion, or What Was I Thinking?


#1

Carr: Tons Per Inch Immersion, or What Was I Thinking?

“How’s it going skipper?” the Chief Engineer asked.

Good post.


#2

written by a total amateur…simply impossible to truly understand the nature of this lift. What was the vessel they were trying to move out from under this lift? Why not a tug to pull this mystery vessel away? Afterall the gummint was paying and they always are willing to pay.

All he seems to be able to do is to talk about everybody’s preoccupation with drinking coffee…

that and using FUCK, FUCKING and FUCKED everywhere possible…

GODDAMED how I hate SHITTY writing!


#3

I’d call it a story rather than an article.


#4

Lots of coffee and f-bombs. Sometimes art imitates life, and vice-versa.
With no bow thruster probably would have had more f-bombs and coffee.


#5

Excellent story! How about providing names, dates, and places? Was this operation digitally recorded?


#6

Why not kedge an anchor with a fair bit of scope and work the bow off with it in conjunction with the thruster?

Also, from the fact the C/E said he could press up all tanks in an hour that this was a relatively small vessel. I don’t think I’d be considering messing with the ballast without doing some calculations first. If for nothing else, to see how it might affect the stresses on the ship at all points of the lift. It might cut down on all that “stress” this Captain was feeling as well. I know I always feel better when I’ve thought out every angle or at least attempted it.


#7

As per the authors Facebook page - Those of you who sailed on the LSV 3 Small Tug cargo mission from Port Hueneme to Tacoma WA might enjoy this “sea story”. Sail Army! Note: Mount Rainier in the background.


#8

gCaptain call itself a blog so I’ll call it a post.


#9

The linked post is a narrative about solving the problem of getting the boat successfully unloaded and into the water.

There are time constrains, equipment limitations, tight clearances.

So the captain comes up with a plan, pick the tug off the deck and slide out of the way sideways and lower the tug into the water. The plan almost works but the wind and current are just a little to strong to successfully clear enough space for the tug.

So it seems like a maneuvering problem, with a little luck on wind and more skill on the controls the plan can be pulled off. The captain is locked into this solution. It’s what he does, he’s a boat handler.

But then this:

“How’s it going skipper?” the Chief Engineer asked.

The chief see the problem differently, the problem is not a skill in maneuvering problem, applying more skill is the wrong approach. It’s a power problem, more thrust is needed.

So solution is ballast down so props, thrusters have more bite in the water.

Capt and Chief framed the problem in different ways.


#10

Unless the props and thruster were ventilating the difference in amount of thrust produced in that situation would be all but impossible to measure much less impact the operation.

The only thing that ballasting down would change is the variation in thrust caused by waves in open water. They were not subject to the orbital variation in water velocity caused by waves near the surface in that glassy calm dock.

The chief was just smart enough to know that if the boat was lower the crane lift would be reduced and so would be the length of the tag lines which would be at a better angle … the tug was less likely to swing enough to scare the captain.


#11

My take was the boat was in equilibrium and when the tug was lifted the change in forces involved caused the boat to move, established a new equilibrium at a lower draft.

I don’t think the post was meant as a technical dissertation, I thought the main point was the chief framing the problem in a different way. In any case the main point remains unchanged.


#12

Not sure the author was addressing this, but it reminded me of something I learned standing in front of a lathe with a chisel in my hand, looking at a spinning chunk of expensive wood – if you aren’t willing to fail, you can’t succeed.


#13

The class of LSV the tugs were loaded on have a light draft of 6ft and loaded draft of 12 ft.


#14

My experience on the car ships, in ballast draft is ~ 7.2 m and loaded is ~ 8.7 m, but the difference in the way the ship handles is subtle. But when everything is pumped out and min fuel for entry into the drydock it’s a big change. On a windy day it’s like trying to steer a ping pong ball.


#15

taking a basically simple operation and dramatizing it for entertainment value but which to me showed him not to be such a proficient “boat handler”…

to me this entire blog or whatever you want to call it showed a man without either skill or knowledge of the dynamics of vessels in motion and to this professional, the only entertainment came from realizing all this.

the takeaway…call a professional next time


#16

Yeah, could be that there was no wind at all, and the chief didn’t pump any ballast but knew in an hour the tide was going to change and push the boat the other way. Sort of the opposite of this joke.

Anything is possible but I would put more weight on the account of a mariner that was actually there.


#17

The one I’ve heard is a supposedly true story about Alfred Hitchcock, concerning his movie Lifeboat.

Someone complained that it shouldn’t have background music, since they were in a lifeboat in the middle of the ocean. Hitchcock replied “You tell me where the camera comes from, and I’ll tell you where the music comes from.”

I wonder which one led to the other…