Tug and Barge Flop, Wind and Current


#1

Regarding flopping on a barge and breaking away from the barge with a AHTS or a conventional tug(on the wire). Looking for constructive input/advice from experienced tug operators on their approach to this in very strong currents as well as strong winds.


#2

Use the wind and current to your advantage , that helps a lot.


#3

I like to flop driving dead into the wind and/or current. It’s not often you have both in very strong states. Let the wind push the boat around the turn and you’ll likely not need to go above clutch on your twist. Stay very close to the corner of the barge with the stern (10’ is a long way) and you won’t drag the barge around in a circle as bad. You’ll drag the barge around 15 degrees but it helps because the same principle as below.

Cutting loose I’ll put the barge barely on the upwind side: meaning point the barge almost into the wind but not quite, say 10 degrees off; keep the boat in the lee of the barge. The barge drifts faster in the wind than the tug, so you’ll be able to recover your person on the barge at all stop or maybe clutch twist towards. Make the wind help stick the barge to the boat. Then push the barge around through the wind using the gear weight and tire friction alone before starting to stream tow.

Plan your start of maneuver speed based on length of time needed to complete the maneuver, barge response to wind/current, and personnel transfer time. Current slows a loaded barge faster than wind. Wind affects an empty or high profile barge way more than current. The smoothest and most controlled flops end with very little or no headway on the barge once your first line is up. Try to get good at flopping at clutch, and it’ll help those times your timing was off and you need to use 30%: it’s not necessary to flop at max power if your planning and timing is good, but the number off people who use max is way more than those who use less. That’s an ingrained trait that’s held on from less-maneuverable days. My rule off thumb I teach guys is if you’re clutch ahead on one and your barge is catching you, then your barge is going too fast. A very heavy wind or current can change that dynamic.


#4

Thanks for the valuable input.
I have seen a few guys chase the barge in circles by not having their stern in tight or not a enough wire out for fear of getting it in the wheel. I hear different levels of worry how probable it is to suck the wire in the wheel during this evolution but would rather not find out the hard way.
Our drafts are either 16’ or 12’ foot depending on which vessel, props pretty well forward of the stern. One has kort nozzles, one doesn’t. I tend to be a little farther away from the barge before initiating the flop than others which I feel gives a little more wiggle room to maneuver/adjust approach if needed but does leave more wire in the water and perhaps more time for the barge to develop a mind of its own.

On cutting loose I generally do head up into the wind or if in a strong wind sit lee to the barge, but quite a bit Will try the 10 degree angle next time, makes more sense, more control/less pushing the barge around.
Point taken on the 15 degree barge swing on the flop as well.

Barge work isn’t our bread and butter but we do get tasked with it a few times a year. Nice to get input from someone more seasoned at it than I am. Thanks again.


#5

flopping alongside is one of those rare shiphandling maneuvers which went done by a man who understands the dynamics is a real treat to watch and when you are the master pulling it off, very gratifying then it goes so well. it is also a joy to have a crew who can get up on the barge in no time and catch the lines to make up alongside.

my experience was always that loaded barges were easy provided they weren’t filled with containers 6 high and that you had room to slow them down to a crawl before beginning to flop alongside however light barges could be a nightmare with any kind of a wind.

something not mentioned tho here is how much room one has to flop alongside…all fine if in open water outside jetties but it can be a mother if you need to come in on a short wire and make up inside where there is no room and you don’t have an assist to hold a barge while you are getting your lines up. I have never towed anywhere other than the West Coast and with the weather we have out here in the winter think the men who wire tow year round in this misery are the true masters of the profession. I haven’t even mentioned the old timers who used to tow regularly with only single screw boats and direct reversible mains. They were the master of the masters and my dear departed dad was one of those men who ran the last of the Miki tugs out here.