Offshore supply vessels

[anonymous-user]

I understand how and why boats float but these things just look very unstable given they operate in the North Sea!

[PushedDover]

They don’t defy like a car carrier does !!



It’s not about what you can see, it’s what’s below the sea that counts

[Simpo Two]

pablo said:

I understand how and why boats float but these things just look very unstable given they operate in the North Sea!

Can boats of that size be gyro-stabilised?

[normalbloke]

PushedDover said:

They don’t defy like a car carrier does !!



It’s not about what you can see, it’s what’s below the sea that counts

Yes, you’re right.

[PushedDover]

Simpo Two said:

Can boats of that size be gyro-stabilised?

Yes - ‘stab tanks’ are standard and can be either ‘active’ or ‘static’
You can use further tech too but not usually the case for PSV / OSV type

[JoeRRS]

Try working on a DSV on the back deck in the north sea in winter.... very stable though.

[anonymous-user]

https://www.tdw.com/wp-content/uploads/2016/08/Tro...

A bit obsessed now. A fascinating drawing though

[Taffer]

pablo said:

https://www.tdw.com/wp-content/uploads/2016/08/Tro...

A bit obsessed now. A fascinating drawing though

So you'll have seen in the cross section drawings that pretty much all the machinery, fuel, ballast, dry bulk, and other cargo tanks are near or below the waterline.

The superstructure, despite being quite tall, is mostly empty space and relatively light, and doesn't have as big an effect on stability as it may seem.

[Shinysideup]

I normally work onboard Ultra Deep Water Drillships or Jackups or Semi-Submersible rigs, which are all as stable as the USS Nimitz.
A while back i joined a smaller DSV at Gibraltar and sailed on it via the Bay of Biscay up to Norway.
The captain was running it with minimal ballast, plus factor in bad weather and it was the pukiest journey i've ever had.

Edit: The most apparently 'physics defying' vessel i've been on was a Jackup rig on tow. Imagine 3x 400ft legs attached to basically a barge hull.

Edited by Shinysideup on Monday 7th November 18:07

[anonymous-user]

Taffer said:

pablo said:

https://www.tdw.com/wp-content/uploads/2016/08/Tro...

A bit obsessed now. A fascinating drawing though

So you'll have seen in the cross section drawings that pretty much all the machinery, fuel, ballast, dry bulk, and other cargo tanks are near or below the waterline.

The superstructure, despite being quite tall, is mostly empty space and relatively light, and doesn't have as big an effect on stability as it may seem.

Yes the weight balance is quite interesting,I sort of knew all that really, they just look odd when they’re in the water

[PushedDover]

Meh.

Your Offshore vessel looks less ‘tippy’ ….

[anonymous-user]

I see the tide is out….

[Katzenjammer]

If find how these big boats and fancy offshore rigs and vessels float far more mind bending than air and space craft flight dynamics

[Koyaanisqatsi]

Some interesting info on semi-subs

https://www.e-education.psu.edu/png301/node/909

[andy97]

It seems fairly likely that the Royal Navy’s new Multi-Role Ocean Surveillance Ships (MROSS) will be based on this sort of offshore supply vessel design.
I think the first one is due in service in early 2023 and is likely to be crewed by the Royal Fleet Auxilliary. Given the timescales, I assume that the first one of the two, will be bought from the open market and fitted out accordingly.

https://www.navylookout.com/protecting-seabed-infr...

Edited by andy97 on Monday 14th November 12:02

[PushedDover]

Many multi-role vessels out there. I guess DSV variant or ROV capable makes it more suitable (and the dictator of the design) to get down there to thwart the peskie Ruskies.