Page 17 of 115 FirstFirst ... 79101112131415161718192021222324252767 ... LastLast
Results 401 to 425 of 2867
  1. #401
    Thailand Expat Saint Willy's Avatar
    Join Date
    Aug 2019
    Last Online
    30-04-2022 @ 02:44 AM
    Posts
    11,204
    Quote Originally Posted by cyrille View Post
    Let's agree to disagree on that one.

    Anyway...off topic.


    very much sorry, sorry Mendip!

  2. #402
    Thailand Expat
    Klondyke's Avatar
    Join Date
    Aug 2014
    Last Online
    26-09-2021 @ 10:28 PM
    Posts
    10,105
    Quote Originally Posted by Mendip View Post
    a small ex-trawler... and there was no escaping it.
    However, let's admit: In a life threatening situation and if it could save your life you could surely succumb that sacrifice, couldn't you?

  3. #403
    Thailand Expat
    Mendip's Avatar
    Join Date
    Apr 2019
    Last Online
    Today @ 05:07 PM
    Location
    Korat
    Posts
    10,713
    ^ Klondyke... I look back at my younger self and my conduct on that boat and think, 'what a complete twat!'

    If I had that same opportunity again I'd lock the cabin door, throw the key out the port hole and give her a good seeing to for three weeks. It would take a crowbar to get me out of there these days!

    Believe me, I'd have behaved very differently if I'd have known that 30 years later my sex life would be reduced to sessions on Pornhub after waiting for the gardener to go out.

    I still remember that stewardess... I've rarely gone for blondes in the past but she had that Scandinavian platinum blonde, almost white hair and you couldn't help but get aroused. Barking mad as well... with hindsight absolutely perfect. The only blonde I've ever really fallen for was one of my first 'proper' girlfriends, a dirty blonde from Wedmore in Somerset... and I'm not talking about the shade of her hair!

    Anyway, this thread seems to be going way off topic. I blame Dillinger... one inappropriate comment implying the boat is full of 50 spank-happy sex starved offshore workers furiously wanking away for 12 hours a day while off shift, and it's opened the floodgates... so to speak.

    I'll try and bring it back round to work later when I get time.

  4. #404
    Banned

    Join Date
    Jul 2012
    Last Online
    09-05-2021 @ 03:25 AM
    Posts
    33,644
    I'm in the same boat as you at the mo Mendy, here grab my wooden oar and sing us a shanty .

  5. #405
    I'm in Jail

    Join Date
    Jan 2013
    Last Online
    14-03-2024 @ 09:39 AM
    Location
    Bungling in the jungle
    Posts
    10,387
    Dilly always could bring a thread about. Screams starboard and the tillars spin.
    More on point we, miss fish and I wish you fair winds and following seas.
    On another note my stepdaughter came up to visit from Tennessee. Lives near the Hermitage. Some history there. More to the point I brought out the big telescope and we looked at the moon. It's ours, yours and all. Enjoy the stars on your off time and remind yourself you are one for your daughter's sake. If not for you she wouldn't be where she is today.
    On another plane remember when star charts were priceless. Oh, lets not go there. May get lost. Thank the heavens for GPS. All the best and good luck.

    The fish.

  6. #406
    Banned

    Join Date
    Jul 2012
    Last Online
    09-05-2021 @ 03:25 AM
    Posts
    33,644
    ^ I thought you were in jail til the next Millenium?

    That must have been some serious arse licking let me outta jail photothread

  7. #407
    Thailand Expat
    Mendip's Avatar
    Join Date
    Apr 2019
    Last Online
    Today @ 05:07 PM
    Location
    Korat
    Posts
    10,713
    We finished the project up at Norne a couple of days ago and are now working further south near Åsgard. Another seabed mapping project for another new development... means more work for the future with any luck.

    Another nice evening tonight... it's not so lonely here as there's platforms, drilling rigs and boats all over the place.


  8. #408
    Thailand Expat
    katie23's Avatar
    Join Date
    Jan 2014
    Last Online
    @
    Location
    PI
    Posts
    6,558
    ^Lol. That Luigi guy does get around!

    @david48 - thanks for the music & the laugh. I remember that, and doing the running man! Cheers!

  9. #409
    Thailand Expat
    Klondyke's Avatar
    Join Date
    Aug 2014
    Last Online
    26-09-2021 @ 10:28 PM
    Posts
    10,105
    Quote Originally Posted by Mendip View Post
    I'll try and bring it back round to work later when I get time.
    Fair enough....

  10. #410
    I'm in Jail

    Join Date
    Jan 2013
    Last Online
    14-03-2024 @ 09:39 AM
    Location
    Bungling in the jungle
    Posts
    10,387

  11. #411
    Thailand Expat
    Mendip's Avatar
    Join Date
    Apr 2019
    Last Online
    Today @ 05:07 PM
    Location
    Korat
    Posts
    10,713
    Quote Originally Posted by Dillinger View Post
    I'm in the same boat as you at the mo Mendy, here grab my wooden oar and sing us a shanty .
    I'm not grabbing anything mate.

    This thread started to show my commute to work, but I guess a commute is to work and back home again... and who knows when that could be.

    So, apologies in advance but this could be a long thread... I'm just gonna keep on going, maybe for months. I'm not at all sure I'll be able to get back home to Korat this year.

    How to fill it? I think the topic of masturbating has been exhausted (at least I hope so) so how about a bit about work? I think Ootai at least may be interested while he has his morning coffee in Isaan... (lucky bugger)

    Anyway...

    For seabed mapping projects we collect three main types of data... multibeam echosounder, side scan sonar and sub-bottom profiler. The relevant sensor equipment is usually fixed to the ROV but may be towed behind the vessel or mounted to the vessel hull.

    First up... multibeam echosounder. I guess most people are familiar with an echosounder a ship uses to find the water depth. A sound pulse is sent down to the seabed, it bounces back and the two way travel time of the pulse is measured. You know the speed of sound through water, so it's easy to work out water depth. A multibeam echosounder works the same way, but a constant stream of hundreds of sound pulses in narrow beams are sent in an arc to the seabed from the ROV, and the time taken for each sound pulse to return is measured. A typical frequency may be around 450 kHz.

    A map of the seabed can be produced from the multibeam echosounder data.

    Here's the typical seabed from northern Norway. The huge furrows are iceberg ploughmarks, formed maybe 10,000 to 12,000 years ago at the end of the last glaciation when the ice shelf broke up. The ice became mobile and icebergs drifted about, dragging their bottoms through the seabed (sea level was maybe 150m lower in this part of the world back then since so much water was locked up as ice). These ploughmarks maybe many tens of metres wide and 10m or so deep, and each one marks the path of an ancient drifting iceberg. These will have obvious consequences to the lay comfort of a pipeline and influence route design.



    Shipwrecks can be detected by the multibeam echosounder, although side scan sonar is the equipment of choice for searching for debris, shipwrecks, or more recently aeroplanes on the seabed. For aeroplanes you're looking for the engines... they are generally the only recognisable component to remain intact on the seabed after a plane hits the sea and breaks up.

    Here's a 65m long shipwreck we found a while ago almost across a proposed pipeline route we were surveying. The route had to make a slight detour. Wrecks don't look great in echosounder data.

    It's always a strange feeling to find a shipwreck as it may well mark the place where people have died. This one was probably a fishing boat and if it went down before radio, then as far as people on land were concerned it would have just disappeared. There may be some family on the west coast of Norway who talk about Great Grandad Sven-Ole who disappeared in the big storm of 1895... or something like that.

    Makes you think...


  12. #412
    Making people dance. :-)
    Edmond's Avatar
    Join Date
    Apr 2020
    Last Online
    @
    Location
    Cebu
    Posts
    13,753
    Very cool.

    Quote Originally Posted by Mendip View Post
    These ploughmarks maybe many tens of metres wide and 10m or so deep, and each one marks the path of an ancient drifting iceberg. These will have obvious consequences to the lay comfort of a pipeline and influence route design.
    What happens in such an instance? For example a 10m x 10m plough mark. It's presumably pretty damn long, so going over it would most likely be necessary, I'm guessing, do the pipes sometimes need support columns to bridge such a gap?

  13. #413
    Thailand Expat
    Shutree's Avatar
    Join Date
    Feb 2017
    Last Online
    Today @ 05:15 PM
    Location
    One heartbeat away from eternity
    Posts
    4,643
    ^^ Interesting stuff.

    When you find a wreck, is there a process or a requirement to report it somewhere?

  14. #414
    Thailand Expat lom's Avatar
    Join Date
    Jan 2006
    Last Online
    @
    Location
    on my way
    Posts
    11,453
    Quote Originally Posted by Mendip View Post
    The relevant sensor equipment is usually fixed to the ROV but may be towed behind the vessel or mounted to the vessel hull.
    I've just been reading about Ramform Tethys which you were not far away from some weeks ago, that is a very special vessel.

  15. #415
    Thailand Expat Saint Willy's Avatar
    Join Date
    Aug 2019
    Last Online
    30-04-2022 @ 02:44 AM
    Posts
    11,204
    Super interesting stuff, Mendip. I know sweet FA about it.

  16. #416
    Thailand Expat OhOh's Avatar
    Join Date
    Jul 2010
    Last Online
    Today @ 11:59 AM
    Location
    Where troubles melt like lemon drops
    Posts
    25,218
    Quote Originally Posted by Mendip View Post
    seabed mapping projects
    The route of the survey is presumably decided initially as a straight line, with possible links to existing pipelines.

    If you find an area where due to multiple obstructions etc. do you run a parallel survey which may be more over a more suitable route or is that left to the land office to decide and a return survey ship is brought in later?

    What width of seabed can you survey in one pass?

    What depth to seabed can the ship attached radars "illuminate/record" the information?

    Who supplies the radar hardware and software, European, USA , Asian .... ?

    What specs are your computers, hardware and software, normal off the shelf PC or high spec monsters?

    One hopes the ROV videos are more exiting to watch.
    A tray full of GOLD is not worth a moment in time.

  17. #417
    Thailand Expat
    Mendip's Avatar
    Join Date
    Apr 2019
    Last Online
    Today @ 05:07 PM
    Location
    Korat
    Posts
    10,713
    ^ OhOh... after an initial route proposal a reconnaissance survey may be carried out, as were doing up at Wisting. We covered about a kilometre wide corridor of seabed within which the client will hopefully design their final route. We found one major obstruction and had to carry out further survey to widen the corridor in that area to hopefully find a suitable corridor of seabed around the obstruction.

    All of our survey sensors are mounted on an ROV. The higher altitude the ROV flies, the wider the swath we can cover. For example flying at 100m altitude we covered a seabed swath around 450m, so we did two adjacent survey lines like that and one low altitude, high detail survey along the centre. The wider the swath, the lower the resolution the data is... with also survey speed playing a role in data density. We tend to use low frequency settings for greater range, high frequency for smaller range. Low frequency is low resolution (high range), high frequency is high resolution (low range). A with anything there is a compromise between cost and quality. High resolution surveys are more expensive as we have to carry out more survey lines and use a slower survey speed.

    After the reconnaissance surveys there will probably be a detailed survey covering the route that has been decided upon... maybe a year later. That will be high resolution and maybe cover a 200m wide swath of seabed. Immediately before the eventual pipe lay a visual 'pre-lay' survey will be carried out to make sure there has been no new obstructions added, ie dropped debris or shipwrecks.

    Our depth limitation is how deep the ROV can go, since that is our survey platform, not the vessel. I've been on ROV surveys down to around 2.2km water depth... but I think 3km is generally no problem these days.

    European and American hardware/software.

    Off the shelf computers, but I'm sure they have upgraded memory and RAM.

    Like anything... it's interesting at first but after 5 weeks of 12 hour shifts my motivation is waning.

  18. #418
    Thailand Expat
    Mendip's Avatar
    Join Date
    Apr 2019
    Last Online
    Today @ 05:07 PM
    Location
    Korat
    Posts
    10,713
    Quote Originally Posted by Edmond View Post
    Very cool.



    What happens in such an instance? For example a 10m x 10m plough mark. It's presumably pretty damn long, so going over it would most likely be necessary, I'm guessing, do the pipes sometimes need support columns to bridge such a gap?
    A 10m deep ploughmark would probably be at least 80m or so wide, and their side walls are rarely steeper than 30 degrees. A cable will mold to the seabed but a rigid pipeline will require additional support, usually in the form of dumped gravel to fill the depression. The shoulders of the ploughmark may be pre-dredged also, to further smooth the relief.

  19. #419
    Thailand Expat
    Mendip's Avatar
    Join Date
    Apr 2019
    Last Online
    Today @ 05:07 PM
    Location
    Korat
    Posts
    10,713
    Quote Originally Posted by Shutree View Post
    ^^ Interesting stuff.

    When you find a wreck, is there a process or a requirement to report it somewhere?
    I think all wrecks will be added to a register. Usually at some point, maybe during a later survey campaign, some time will be spent to visually inspect a wreck in the hopes of identifying it, but that depends on how generous the client is. Everything costs money.

  20. #420
    Thailand Expat
    Mendip's Avatar
    Join Date
    Apr 2019
    Last Online
    Today @ 05:07 PM
    Location
    Korat
    Posts
    10,713
    Quote Originally Posted by lom View Post
    I've just been reading about Ramform Tethys which you were not far away from some weeks ago, that is a very special vessel.
    Lom... your powers of detection are obviously not limited to Coco's thread!

    Yes, we had to break off survey a couple of times to make way for the Ramform Tethys. She's a seismic survey vessel, very advanced and can tow some 20 odd streamers at a time. The streamers may be 1km or so long (I think) so she has a very poor turning circle and they get extremely annoyed if a vessel causes them to go off their survey line. We can just stop the ROV and vessel, so have to give way. There is a strict order of priority in this industry.

    I was hoping to get a picture of the Ramform Tethys while we were up at Wisting but we were never allowed close enough.

    From the net... hopefully.


  21. #421
    Thailand Expat Saint Willy's Avatar
    Join Date
    Aug 2019
    Last Online
    30-04-2022 @ 02:44 AM
    Posts
    11,204
    Wow, that’s an interesting piece of kit

  22. #422
    Making people dance. :-)
    Edmond's Avatar
    Join Date
    Apr 2020
    Last Online
    @
    Location
    Cebu
    Posts
    13,753
    Quote Originally Posted by Mendip View Post
    A 10m deep ploughmark would probably be at least 80m or so wide, and their side walls are rarely steeper than 30 degrees. A cable will mold to the seabed but a rigid pipeline will require additional support, usually in the form of dumped gravel to fill the depression.
    Cool, cheers. I didn't expect that.


    Without wanting to go too OhOh. How do they get the gravel down to the spots that needs bridging?

    Is there a lead gravel-ship that leads the way when the pipe is being laid?

    And how do they get it down to the exact spot, I'm kinda imagining a helicopter dropping water on a forest fire, that just scatters and spreads it all over the place.



    It'd be pretty cool if there are gravel engineers that joy-stick it down like a Tetris computer game.

  23. #423
    knows
    hallelujah's Avatar
    Join Date
    Nov 2006
    Last Online
    Today @ 03:33 PM
    Posts
    13,445
    Yet another top thread and a guaranteed Golden Teakdoor Boot for Mendip come the annual end of season polls!

  24. #424
    Thailand Expat Saint Willy's Avatar
    Join Date
    Aug 2019
    Last Online
    30-04-2022 @ 02:44 AM
    Posts
    11,204
    Quote Originally Posted by Edmond View Post
    It'd be pretty cool if there are gravel engineers that joy-stick it down like a Tetris computer game.
    I would think so. Dropping a bucket on a line, to release close to site. Because otherwise this...



    Quote Originally Posted by Edmond View Post
    I'm kinda imagining a helicopter dropping water on a forest fire, that just scatters and spreads it all over the place.

  25. #425
    Thailand Expat
    Mendip's Avatar
    Join Date
    Apr 2019
    Last Online
    Today @ 05:07 PM
    Location
    Korat
    Posts
    10,713
    ^^^ The gravel is poured down a chute that extends down to the seabed. There's an ROV at the bottom of the chute for positioning and maneuverability. These rock dumpers are big beasts with JCBs and bulldozers on the back deck to keep the gravel flowing.

    The seabed will be prepared well in advance of a pipe lay, so no need for a lead ship. You can't risk delaying a lay barge spread. Many cables and pipelines will be covered in gravel after the lay for protection against trawling etc. Unless anything goes very wrong the gravel dumping is usually inch perfect these days as positioning is so good. We may get involved with pre and post rock dump surveys to ensure the necessary volume of gravel has been dumped in the right place.

    Rock dumping is big business, costs a small fortune and the Dutch have it sewn up...I guess it's just an extension from their dredging expertise. As with anything there's more to it then meets the eye. Rock berms are built up using several layers of different grades of gravel for maximum stability. Rock with low iron content id preferable since any ferrous content screws up the pipetrackers we use to determine depth of pipeline burial during surveys.

    The Rolling Stone is a 'famous' rock dumping vessel... well, famous in offshore pipeline circles anyway.

    Last edited by Mendip; 01-09-2020 at 11:41 AM.

Page 17 of 115 FirstFirst ... 79101112131415161718192021222324252767 ... LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •