Hi everybody
Can anybody tell me what is the reason why some oil tankers have got deck pipes which are not symmetrically placed with respect to the longitudinal axis?
Some tankers have got deck pipes on one side, but not on the other. Like this one…
Thank you
Purely a function of that particular design. The reasoning falls in line as to why all cars are not the same; different design, different equipment, or different purpose.
No need to make bends around those things (vents?) at the centerline?
Are you talking about the cargo manifolds? Your picture has a tanker with port and starboard manifolds… This is where you connect to load/discharge cargo…
Thank you for the answers.
I am going to explain you the background.
I need to carry out a design of a wind assisted system (basically wing sails) on board an oil tanker. I am just trying to choose where to place these devices. I thought that if I chose a tanker with pipes not exactly in the middle line plane, I would have the chance to place my devices in the symmetrical plane in order not to have stability problems. So I was thinking that maybe if there is a reason why those pipes are not in middle maybe there is a reason why I should not place my devices in the symmetrical plane.
What do you think about it?
[QUOTE=fran.cesc17;180296]Thank you for the answers.
I am going to explain you the background.
I need to carry out a design of a wind assisted system (basically wing sails) on board an oil tanker. I am just trying to choose where to place these devices. I thought that if I chose a tanker with pipes not exactly in the middle line plane, I would have the chance to place my devices in the symmetrical plane in order not to have stability problems. So I was thinking that maybe if there is a reason why those pipes are not in middle maybe there is a reason why I should not place my devices in the symmetrical plane.
What do you think about it?[/QUOTE]
We’ll, I’m no designer, but I know what I’ve seen and it is common for many tankers to use the centerline for the main fire fighting foam monitor placement as is also seen on the tanker photo you present, to allow efficient coverage of the deck area and minimize piping runs serving same. Hopefully your design is able to accommodate the need for such deck fire fighting coverage without impediment.
[QUOTE=fran.cesc17;180248]Can anybody tell me what is the reason why some oil tankers have got deck pipes which are not symmetrically placed with respect to the longitudinal axis?
Some tankers have got deck pipes on one side, but not on the other. Like this one…[/QUOTE]
In that picture, the lines on each side are for different purposes. The ones on the port side running aft from midships are cargo lines going to the pumproom where they tie into the bottom lines servicing each tank. The ones on the starboard are not cargo lines. The largest of them looks to be an inert gas/vent line, and one of the smaller ones appears to be the supply line for crude oil washing.
As the saying goes, there is more than one way to skin a cat. In this case, design a ship as long as the end goal, and desired functions are achieved.
[QUOTE=jdcavo;180303]In that picture, the lines on each side are for different purposes. The ones on the port side running aft from midships are cargo lines going to the pumproom where they tie into the bottom lines servicing each tank. The ones on the starboard are not cargo lines. The largest of them looks to be an inert gas/vent line, and one of the smaller ones appears to be the supply line for crude oil washing.[/QUOTE]
What jdcavo says is exactly correct abt the sample photo ship.
There is no reason the pipelines have to be on CL. Arrange your design accordingly …
Your piping could be below deck, or in a housing as well as not to be exposed to the elements. C/l or close to c/l piping is the cheapest, therefore most common.
[QUOTE=fran.cesc17;180296]Thank you for the answers.
I am going to explain you the background.
I need to carry out a design of a wind assisted system (basically wing sails) on board an oil tanker. I am just trying to choose where to place these devices. I thought that if I chose a tanker with pipes not exactly in the middle line plane, I would have the chance to place my devices in the symmetrical plane in order not to have stability problems. So I was thinking that maybe if there is a reason why those pipes are not in middle maybe there is a reason why I should not place my devices in the symmetrical plane.
What do you think about it?[/QUOTE]
Just make sure you keep in mind the class rules on structure and visibility.
http://ww2.eagle.org/en/rules-and-resources/rules-and-guides.html
ABS Steel Vessel Rules 2016, Part 3, Chapter 6 (Navigation), Section 1 (Visibility)
“1.1.1(b) No blind sector caused by cargo, cargo gear or other obstructions outside of the wheelhouse forward of the beam which obstructs the view of the sea surface as seen from the conning position is to exceed 10°. The total arc of blind sectors is not to exceed 20°. The clear sectors between blind sectors are to be at least 5°. However, in the view described in 3-6-1/1.1.1(a), each individual blind sector is not to exceed 5°.”
[QUOTE=Nav_Arch;180349]Just make sure you keep in mind the class rules on structure and visibility.
http://ww2.eagle.org/en/rules-and-resources/rules-and-guides.html
ABS Steel Vessel Rules 2016, Part 3, Chapter 6 (Navigation), Section 1 (Visibility)
“1.1.1(b) No blind sector caused by cargo, cargo gear or other obstructions outside of the wheelhouse forward of the beam which obstructs the view of the sea surface as seen from the conning position is to exceed 10°. The total arc of blind sectors is not to exceed 20°. The clear sectors between blind sectors are to be at least 5°. However, in the view described in 3-6-1/1.1.1(a), each individual blind sector is not to exceed 5°.”[/QUOTE]
Thank you. This is actually one of the biggest problems I have to deal with. I have already read it (and I do not really understand why it says “No blind sector caused by […] is to exceed 10°” and then it says “each individual blind sector is not to exceed 5°”. Is it 5 or 10?)
However I think that I may need to contact SOLAS to see if this requirements can be changed for this case.
[QUOTE=+A465B;180332]There is no reason the pipelines have to be on CL. Arrange your design accordingly …[/QUOTE]
Not in case of a retrofit…
[QUOTE=z-drive;180333]Your piping could be below deck, or in a housing as well as not to be exposed to the elements. C/l or close to c/l piping is the cheapest, therefore most common.[/QUOTE]
Thank you!
I cannot see the attached images…
there are also steam lines to heat the oil, inert gas/vent etc. for some of these they could cross over to stb. or port and tie into a line going aft to save piping.
[QUOTE=Nav_Arch;180349]Just make sure you keep in mind the class rules on structure and visibility.
http://ww2.eagle.org/en/rules-and-resources/rules-and-guides.html
ABS Steel Vessel Rules 2016, Part 3, Chapter 6 (Navigation), Section 1 (Visibility)
“1.1.1(b) No blind sector caused by cargo, cargo gear or other obstructions outside of the wheelhouse forward of the beam which obstructs the view of the sea surface as seen from the conning position is to exceed 10°. The total arc of blind sectors is not to exceed 20°. The clear sectors between blind sectors are to be at least 5°. However, in the view described in 3-6-1/1.1.1(a), each individual blind sector is not to exceed 5°.”[/QUOTE]
Thank You.
I had already seen it and I thought that was a main concern (even though I do not really understand why it says “No blind sector caused […] is to exceed 10”, but then it says “each individual blind sector is not to exceed 5°”. Is the limit 5 or 10 degrees?)
I suppose I need to contact a classification society to find “equivalent arrangements”
Thank you
[QUOTE=fran.cesc17;180546]Thank You.
I had already seen it and I thought that was a main concern (even though I do not really understand why it says “No blind sector caused […] is to exceed 10”, but then it says “each individual blind sector is not to exceed 5°”. Is the limit 5 or 10 degrees?)
I suppose I need to contact a classification society to find “equivalent arrangements”
Thank you[/QUOTE]
The way I read the rules is that:
1.1.1(a) specifies you have to see the water +/- 10° off center line, with the intent that the bridge is high enough off the deck
1.1.1(b) specifies the allowable obstructions of 10° (20° total) within the 225° field of vision, or 5° if within the +/- 10° of center line
1.1.1© specifies the field of vision (can’t have any walls on the port and stbd side of the bridge blocking the view)
[QUOTE=jdcavo;180303]In that picture, the lines on each side are for different purposes. [/QUOTE]
Very much so. Port side are load and discharge to/from manifold. The starboard side are IG piping, COW, vents, firefighting, electrical, hydraulic, Butterworth and a few other miscellaneous pathways for housekeeping and monitoring systems.
They tend to stick to the centerline because that keeps the comparatively delicate piping away from the amazingly destructive power of boarding seas.
