Dynamic Positioning Pricing, Recommendations, Experiences, How to?

Discussion in 'Boat Design' started by nikezz, Oct 26, 2010.

  1. nikezz
    Joined: Aug 2010
    Posts: 35
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    Location: Asia

    nikezz Junior Member

    Hi all,
    I am new to dynamic positioning and I was wondering if there were any experts on this forum on dynamic positioning. I was wondering

    1) What are the price quotes for your vessel and your requirements from your experience? Examples please.

    2) Are there any companies that you have had good/bad experiences with for DP and who would you recommend?

    3) How do I ensure that the DP system I buy is what the supplier's specifications state? Any loopholes the supplier would try to use for their advantage?
     
  2. JRMacGregor
    Joined: Oct 2005
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    Location: Scotland, UK

    JRMacGregor Junior Member

    Hi

    I assume you are dealing with a reasonable size commercial vessel, which has to meet international/class DP standards (perhaps for offshore) - and not a yacht.

    I assume you are referring to the DP system itself, and not to the following items which are critical for the overall DP operation, but can be obtained separately;
    - power management system (PMS)
    - vessel management system (VMS)
    - generator controls
    - propeller and thruster drives and thruster controls
    - main switchboards
    - DP sensors (DPGPS, gyro, hydroacoustic, MRU etc)

    There are a few major DP system suppliers. They include;
    - Kongsberg
    - Converteam
    - ABB
    - Nautronix
    - IHC (for dredging)

    The first named has the biggest reputation. They also can sell you a power management system and VMS. It is very helpful to reduce interface technical and commerical problems if you can combine these in one order. But they do not sell the electrical motors etc.

    The next two named are able to sell you a DP system together with VMS, PMS and also big elements of the electrical system (switchboards, motors, alternators). This further reduces the risk.

    The last two named focus on the DP computer itself (and perhaps some of the sensors).

    The more you can package all these things together, the easier life will be for everybody. Probably you have to pay more for it - but a specialist company is then making sure all the parts "talk to each other" There is no point to have a good DPGS and DP computer if the PMS and thruster controls will not respond properly to the commands from the DP computer.

    The DP system alone will cost $1.5m or so. Depends on DP2, or DP3 class, and how many senors, control consoles etc.

    How do you ensure the package is what you paid for ?

    These companies all have an international reputation - so they DO deliver what you ordered. The problem is more likely to be an error or omission in the order.

    Other things that can give you comfort;
    - make sure it comes with a class certificate and a class approved FMEA for the DP system
    - perhaps have a FAT at their factory before the system is shipped to your yard
    - your OVERALL DP installation will probably have to pass class and have an overall FMEA - this can find a lot of issues (maybe the yard has to bear the cost of fixing them, but at the end they will produce a system that works)

    Some of the suppliers are very strong - almost monopoly - so you have to take what you get. You can be exposed to very expensive costly extra days from commissioning technicians. So waiting time in your yard or on sea trials can be very expensive for you.
     
  3. nikezz
    Joined: Aug 2010
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    Location: Asia

    nikezz Junior Member

    Thanks JR. I was wondering if you had a quote from them before. I would like to know the range of prices for the DP system i.e. $500, 000 for the bow thruster and all the necessary bits and pieces. I was just wondering if there was a breakdown in their prices. Thank you.
     
  4. land locked
    Joined: Mar 2011
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    Location: wynnewood,oklahoma

    land locked New Member

    Looking around at dynamic positioning companies for the up grade of a Semi Submersible very much like the transoceanic 702 which has a Kongsberg ( I think) system. I found that a company (thrust master of Texas) offering a package system using Diesel hydraulic power packs and windows based electronic control system. then from China a totally solid state control system configured like Kongsberg's system control stations.
    I think every company is using a mathmatical computation based on converging inputs which may or may not very and input what is called white noise. all this sound like Quantized raw data before it becomes digital. who am I to say.
    Now comes my question. what makes a Semi sub or drill ship qualify to drill or operate in water deeper then say 5,000 feet? if they stay on station and do not wander all over the ocean what is the international regulation body or committee that says you can or can not drill in water below this or that depth of water?
    The of course what does anybody have to say about the hydraulic powered thruster package (power and thruster end) the company claims 100,000 hours no brake downs recorded.
    land locked
     
  5. JRMacGregor
    Joined: Oct 2005
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    Location: Scotland, UK

    JRMacGregor Junior Member

    Landlocked

    If you have a DP rig the thing that determines ability to drill in deep water is not primarily the DP system. Stationkeeping gets easier in deep water because the riser can tolerate a surface vessel offset expressed as a PERCENT of the water depth. That offset is greater in deep water than in shallow.

    An anchored rig would have difficulty carrying the anchors for deepwater work. Because long chains are heavy.

    What really makes the difference is the riser handling equipment. To keep the riser tensioned in deep water you need big riser tensioners - perhaps 2000 tonnes of force.

    And you need powerful mud pumps to keep the mud returning to surface in the long riser.

    Your DP system would need to be classed DP2 or DP3 to prove it can survive a failure of a component or compartment.
     

  6. powerabout
    Joined: Nov 2007
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    Location: Melbourne/Singapore/Italy

    powerabout Senior Member

    Nautronix DP was bought by L3 quite a few years ago.
    L3 does the same as KB and Converteam.
    L3 probably have the largest market share on semi subs as that was what the original program was designed for and is still based on.
    One of the reasons the semi subs like L3 is it is very simple and you can teach someone to repair it in a about 4 days.
    They use off the shelf components.
    With a KB you will be flying in a technician ( that probably cant fix it either on the first try especialy if its a Kpos)

    The sensors are a big deal and KB will package all the stuff together (including the UPS's and stone age Sperry gyros )with the bottom range of products. You are free to choose with L3 and Converteam.

    The only fast footwork I have seen in a quote was KB calling a 2 axis MRU a VRU that the industry undertands as a 3 axis which you will need on a semi as it uses acoustics and cost 3 times as much.
    So make sure you only use the terms 2 axis and 3 axis when referring to a vru/mru to prevent that mis understanding.

    Be very careful with other less well known brands as almost all of the rest have feed back control like the above 3 BUT do not have vessel modeling built in. You may as well buy a Mercury outboard with the joystick and fishing hook button as that is what they are.
    You also need global 24 hr support, the others dont have that.
    Cheers
    PS Since 2008 all dp class vessels need to have independant FMEA before it gets class ( not before time I must say)
    The ship yard can cut many corners that will stuff up your DP FMEA, you need to on your toes when the vessel is built.
    I have never been on a pre 2008 dp class vessel that could pass a fmea without a lot of work assuming the owner didnt have it done when new.
     
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