Model Boat Mayhem - Forum

Please login or register.

Login with username, password and session length.
Pages: [1]   Go Down

Author Topic: How do Buoy Vessels do their work?  (Read 4818 times)

Martin [Admin]

  • Administrator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 18,926
  • Location: Peterborough, UK
    • Model Boat Mayhem
How do Buoy Vessels do their work?
« on: June 03, 2010, 01:46:31 PM »


To settle another Sunday lunch discussion, hHow do Buoy vessels do their work?

ie. I take it navigation buoys have heavy weights or anchors attached to their tail ends, so when the vessel comes along and
picks the buoy out of the water for repair / maintenance / repair etc;

1. Is the weight / anchor disconnected before lifting the buoy?
2. Is the crane powerful enough to lift the buoy + weight / anchor too?
3. If the weight / anchor is disconnected first, how is it retained?
4. Are all / important buoys replaced before removal?






Logged
"This is my firm opinion, but what do I know?!"    -   Mayhem FaceBook Group!

bwmarks

  • Guest
Re: How do Buoy Vessels do their work?
« Reply #1 on: June 03, 2010, 04:53:32 PM »

Martin, in my experience (USCG) the answers are:

No, the buoy is left attached to the chain and sinker, the sinker/chain essentially anchors the tender as the buoy is worked

Yes, but not all at once, detach buoy, lift chain

It isn't disconnected

If the sinker is on station and the chain is good, basically, the old buoy is pulled on deck, removed from the chain and the new buoy is attached.

Brian
Logged

Martin [Admin]

  • Administrator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 18,926
  • Location: Peterborough, UK
    • Model Boat Mayhem
Re: How do Buoy Vessels do their work?
« Reply #2 on: June 03, 2010, 10:38:02 PM »

Excellent thanks Brian!   :-)
Logged
"This is my firm opinion, but what do I know?!"    -   Mayhem FaceBook Group!

farrow

  • Guest
Re: How do Buoy Vessels do their work?
« Reply #3 on: June 03, 2010, 11:12:17 PM »

Hi Martin,
I had several years of doing this work in the RMAS (MoDn), after the 1996 contract a inspection on a light buoy meant retrieving everything, then breaking it down into its component parts and measuring it. The allowance was 11% wear of original size, worn parts where renewed and the whole lot remade and laid to a position tolerance of +/- 15ft.
The mooring was a steel clump of ethier 3 or 5 tons have known 7t, the risers where 38mm open link chain the riser being made to length reuired for depth, this leads to a 38mm box swivel which then is attached to the buoys bridle whichis made of 2 legs of 38mm OEL chain. The Trinity house have a similiar arrangement except they use 38mm chain cable.
The vessel positions herself alongside the buoy first to check position. The Sal class would drop a stern anchor lying to 3/500 ft of wire using the forward 380 degree thrust bow thruster to maintain position. Then the gemini is launched and its crew pass a chain snotter connected to a recovery wire, which is lead through the side rollers to the forward 7t capstan. On completion of this the crane is slewed out and the gemini crew connect the crane lifting strops into the buoy.
Then the capstan heaves in on the recovery wire, hopefully if the wire and chain are correctly plced the chain snotter clenchs under the bridle swivel, when the swivel breaks the surface, the buoy is lifted out of the water, when it is possible a working main wire is now connected into the riser chain below the swivel, when this is done and the main has the weight then the bouy is brought in board and disconnected. After this the after main heaves awy until the clump comes level with the side rollers and the clump is recovered using the crane.
The trinity house tenders do the work in a slightly different but more efficient manner as thier boats are designed for only buoy work where as the RMAS vessels are multi purpose.
Logged

Umi_Ryuzuki

  • Guest
Re: How do Buoy Vessels do their work?
« Reply #4 on: June 04, 2010, 10:18:47 AM »

There's a bit of insight here at 4:30 into the clips...

http://www.youtube.com/watch?v=jca47fug0O4

 :-)
Logged

Martin [Admin]

  • Administrator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 18,926
  • Location: Peterborough, UK
    • Model Boat Mayhem
Logged
"This is my firm opinion, but what do I know?!"    -   Mayhem FaceBook Group!

Netleyned

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 8,945
  • Location: Meridian Line, Mouth of the Humber
    • cleethorpes mba
Re: How do Buoy Vessels do their work?
« Reply #6 on: June 04, 2010, 01:20:28 PM »

Now we know how the word buoy is pronounced  ---- BOOEY %% %% %% %%


Ned
Logged
Smooth seas never made skilful sailors
Up Spirits  Stand fast the Holy Ghost.
http://www.cleethorpesmba.co.uk/

farrow

  • Guest
Re: How do Buoy Vessels do their work?
« Reply #7 on: June 05, 2010, 09:26:58 PM »

Hi Martin,
The video on the Yanks system, was interesting. We used to lift buoys and risers with the crane much the same with the Sal class 25t crane. But we were stopped by the H&s regulations, because with suction on the mooring clump you was not lifting a none weight.
In 1989 I went onto the THV Mermaid for a beer with the chief Mate, he showed around the vessel, as at the time I was driving the old S.M.V. Goldeneye. He was taking the mickey out of my old tub compared to his vessel, but when I showed him around my old tub he was left a bit in aw re of my girl as she could perform tricks he could only dream off with his, because his was purely a buoy maintenance boat. But the Mermaid recovered much the same as the American, as the riser chain came across the deck it was led through the gypsy wheels of a capstan, after which the riser was broke the buoy was stowed into a special bell mouth tube which could take buoy's with 20ft long tubes. The capstan heaved in the riser up down into the lower hold, the hold was fitted with two capstans to pull the chain around. Have added a pic of a standard nav buoy mooring. I do have a video which I took of a buoy inspection at Portsmouth with RMAS Moorhen, but afraid it is too big in memory to load here.
David
Logged

Jimmy James

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 988
  • Location: Kings Lynn Norfolk
Re: How do Buoy Vessels do their work?
« Reply #8 on: June 11, 2010, 06:28:52 PM »

I was on the Salmaster for a wile and on the Survey V/l Sea Profiler (Ex Shackleton) on Profiler we were handling up to 12 Trinity House pillar buoys a day we always lifted the buoys on board broke the cable just clear of the bridal then heaved the cable in on a gypsied capstan on the fore deck ...if the buoy was to be relaid the cable was flaked down on deck ready to re lay or if not the cable was washed and sent below to be broken into 15 fathom lengths ready for the next job ....
The Profiler was acting as Guard ship for the lay Barge doing the power cabels between UK and France ... the Barge never stopped moving  but hauled her self across the channel on her anchors working 24hrs a day and we had to lay the warning buoys ahead of her and pick up the redundant ones after she had passed them  ... there were always 6 or 8 buoys in the water at any one time we used to have great fun with some of the traffic  and used to fire off boxes of maroons (Explosive flares) to chase them away....
Freebooter  O0  :-))  %%
Logged
Retired  Ships Officer/ Master.
Experience: 50+ years at sea under Sail, Steam & Motor
Kings Lynn

farrow

  • Guest
Re: How do Buoy Vessels do their work?
« Reply #9 on: June 16, 2010, 10:10:19 PM »

Hi,
There is one other buoy work which the RMAS did which was different, an that was the Met buoys in deep water some up to 175miles West of Ireland, the moorings where nearly .25 of a mile deep. It used to take over 1.5 hours to just lower and the clump and loose the buoy. We used to use the forward capstans at first, backing one capstan onto the other, but the capstan motors and bearings used to burn out frequently as the max running time was about 15/20 minutes officially for the caps. Eventually they fitted a special capstan on a portable rig, but this was not popular as the barrel was too small.
To recover the moorings a sonic signal was sent down to bole the mooring above the thrash chain, so the clump and thrash chain was sacrificed each time, mind you we spent most of our time chasing moving buoys for recovery as the fisherman kept fouling and cutting the moorings(in shallow and deep water).
Logged

Jimmy James

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 988
  • Location: Kings Lynn Norfolk
Re: How do Buoy Vessels do their work?
« Reply #10 on: June 17, 2010, 09:31:01 PM »

Old Dodes
 Spent some time chasing met buoys as well ... they were a bit of a pain ... we had an incident NW of Sula Scar where 3 of the buoys stopped T/x  we went to check them out  and found that they had all been boarded the hatches opened and bits of the electronics were missing ,we had to recover all three and when the Techs started checking out the damage they found a small Russian made screw driver in the bilges of one of the compartments ---This was in the mid 70's and a lot of Russian Trawlers were working around the area (these buoys were about 3.5 ton's with a 25/30 foot instrument tower bolted to the top)
Freebooter  :-))
Logged
Retired  Ships Officer/ Master.
Experience: 50+ years at sea under Sail, Steam & Motor
Kings Lynn
Pages: [1]   Go Up