Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[david48]

I asked on Shipspotter why Fairmount Alpine was only doing 5 to 6 knots all the way from Singapore ,well there is a post on Shipspotter , It is listed under Tracking Fairmount Alpine ,  . Have a look it is towing a Barge called Iron Lady big does not do it justice the tug looks very small beside it . .https://www.youtube.com/watch?v=yqz2e0_YMOE
David

[Brian60]

In the case of this barge, I would say the speed is low because it would take some slowing down the inertial mass of it at any speed! Think how much room a supertanker needs to come to a halt, its the same principle.

When a working craft like this is not towing the speeds would not be much higher, slowly slowy catchee monkey as they say. Going slow may mean you arrive in port a day or two later, but you save thousands in diesel oil or whatever happens to be your propellant of choice.

The barge isn't that big a deal for something like the Alpine, take a look on facebook for towing oil rigs, now that is some mass to actually move!

[david48]

thanks for looking at my post , I did not explain myself very good , when I asked the question on Shipspotter I was trying to find out why she was going so slow Idid not know if she was towing or not .
It was the size of the barge , I have not seen one that big. As you say towing that would be no problem compared to a rig .
David

[Brian60]

Sorry got called to take neighbour to the airport David before I could post this......


https://www.youtube.com/watch?v=Wn_OZfj1B1Q

Quite an amazing feat of strength. You have just the one anchor handler towing this rig. There are four other tugs involved though. As you will see one on each corner for manouvering purposes, interesting to see two of them going astern for the full journey. I expect that is so they have maximum power available in the 'pull' mode should it be needed. I stand to be corrected on that though.


By the way David, did I follow your build of the Fairmount Alpine on another forum?

[david48]

Hi Brian
No ,It would be someone else build ,not up to speed on posting Pic yet ,but what I am doing is trying to write a build book with pictures .Its a discipline thing I keep forgetting  to update it .
I have just finished tracking Fairmount Alpine ,I found a web cam at the Hook of Holland Then another camera further into the Port. Two of Smits tugs picked up the tow at the port entrance.
There might be a report on Fairmounts web site ,it was a bit of epic tow.
David .

[Netleyned]

These sorts of tows are bread and butter to the towage firms
Amazing to us mere mortals though.

Ned

[Xtian29]

Hello


About the speed of 5-6 knots during oceanic towage, it's a normal average.  4 to 8 knots is the regular speed depending on weather and money (speed = fuel burning).


Sometime with the wind from back it's 8 knots and against wind and current it's 4 knot, that's life on oceanic towage : boring     


That barge is not that big compare to FPSO and other offshore structure and saying that is not the point

In the case of this barge, I would say the speed is low because it would take some slowing down the inertial mass of it at any speed! Think how much room a supertanker needs to come to a halt, its the same principle.

Thanks Brian for this link with video of a jack-up on the Bosphore, nice looking from helo but nothing to compare to oceanic towage, here the convoy is in a crowded channel, the main tug work with short line with the help of two tugs and then two other ones acting as ruder to stay in line.

Best regards

Xtian

[Mad Scientist]

A couple of thoughts about the Bosporus video...

I've seen this sort of move in Halifax Harbour many times. Once away from land, the ocean-going tug will tow the rig without any help.

The rig was partially disassembled for the move - all three legs plus the drilling tower. This was probably part of its design.

As for a tug being 'buttoned on' for the duration of the tow, there was a WWII USN officer who joked that he was one of the few to cross the Pacific going astern. The tow was a floating drydock, and his tug was on the stern to help control it.

Tom

[Xtian29]

The rig was partially disassembled for the move - all three legs plus the drilling tower. This was probably part of its design.

Not for the move, just to pass the 64m clearance bosporus bridge

there was a WWII USN officer who joked that he was one of the few to cross the Pacific going astern. The tow was a floating drydock, and his tug was on the stern to help control it.

Yes the rudder acting tug for high sea towage is not going stern first and her engine is going astern for some part of the trip as in this case the towing line is always from the bow -  This kind of job is like a challenge for the engineers as the propeller shaft and support are not built for that case.

Maybe the USN made some experimentation with a complete towage stern first, it could be possible with long hull and twin prop tugs but very unconfortable and quite dangerous ...

Xtian