Dynamic Positioning, Collision vs Allision

[cttief]

What do ya'll think?
If a vessel hits another vessel, that is holding station with a dynamic position system, is that considered a collision or an allision?

[dougpine]

Collision when you run into a vessel underway. Allision when you smack a fixed object. A DP vessel holding station is still underway.

[PR-9]

Collision. Because a vessel on DP is underway and making way through the water.

[cmjeff]

Collision. Because a vessel on DP is underway and making way through the water.

Thank you! The industry insists DP vessel's are not "making way" but this is idiotic as no DP vessel is floating with the current... they are powering into it.

[seadog6608]

Operating a vessel in DP mode is still underway and making way. I suppose a case could be made to consider her RAM due to the nature of her work. I don't know. Do vessels in DP mode show RAM lights? DP was still in its infancy when I left the oilpatch in '03.

[water]

Do vessels in DP mode show RAM lights?

The drillship we are working with does.

[richard8000milesaway]

i don't understand the logic of this "poll"; there is no "polling" or opinions here just a fact: a dp vessel on auto-position dp is a vessel UWMW.
polls are for subjective answers not objective facts ("is the chief engineer a dick?")
this is akin to a "poll" asking if water REALLY is denser then air.

(grumble. sorry for the rag. better get some coffee and wake up.)

[captbbrucato]

RAM lights apply; the vessel is underway. If she is not aground, made fast to shore, or anchored....she is underway. Speed over the bottom or speed through the water have little to do with the problem, the "nature of her work" determines her right to display RAM.
"Underway and not making way" is a distinction that applies to vessels in restricted visibility requiring a specific signal. If she displays RAM lights she would sound fog signals for a vessel RAM. She wouldn't degrade her status to "underway, not making way" over R.A.M. in fog.

[dougpine]

Lights or no lights, under Rule 2 BOTH vessels are obliged to avoid collision.

(a) Nothing in these Rules shall exonerate any vessel, or the owner, master, or crew thereof, from the consequences of any neglect to comply with these Rules or of the neglect of any precaution which may be required by the ordinary practice of seamen, or by the special circumstances of the case.

(b) In construing and complying with these Rules due regard shall be had to all dangers of navigation and collision and to any special circumstances, including the limitations of the vessels involved, which may make a departure from these Rules necessary to avoid immediate danger.

[PR-9]

Operating a vessel in DP mode is still underway and making way. I suppose a case could be made to consider her RAM due to the nature of her work. I don't know. Do vessels in DP mode show RAM lights? DP was still in its infancy when I left the oilpatch in '03.

A DP operation on it's own dose not restricts the ability to maneuver. It's the work that you are doing wile on DP (Drilling, subsea const, diving, ext...) that gives you the right to show the RAM lights. So if an OSV it's s/by waiting on orders on DP that vessel should not show RAM lights!!

[Capt. Phoenix]

If you are actively drilling couldn't you be considered anchored? A vessel with anchor down that is motoring into a head sea/wind to relieve stain on the anchor is still anchored...

[dougpine]

A vessel at anchor still has a responsibility to avoid collision.

[cttief]

I found this online. Of course it is from 1856 so it may be outdated.
<a href="http://legal-dictionary.thefreedicti...n">Allision</a>

ALLISION, maritime law. The running of one vessel against another. It is distinguished from collision in this, that the latter means the running of two vessels against each other; this latter term is frequently used for allision

[cttief]

does anyone know the legal definition of making way?
I don't think the COLREGs specify if it is through the water or over ground.

[PR-9]

does anyone know the legal definition of making way?
I don't think the COLREGs specify if it is through the water or over ground.

Through the water!

[cmjeff]

If you are actively drilling couldn't you be considered anchored? A vessel with anchor down that is motoring into a head sea/wind to relieve stain on the anchor is still anchored...

........no

[captbbrucato]

Through the water!

Maybe this will help.
Handbook of the Nautical Rules of the Road by Llana & Wisneskey
"Underway" should be distinguished from the phrases "making way through the water" (used in Rules 26, 27, and 35) and "making no way through the water" (used in Rule 35). A vessel that is "underway" need not be moving through the water but may simply be not anchored, aground, or made fast to the shore. If a vessel is making no way through the water, it is stopped and drifting, unless it is not underway. If it is moving relative to the water, it is making way. For example, if a ship is headed up a river, making five knots through the water, and there is a five-knot current against it, then it is making way through the water even though it is making no progress relative to the shore. Another ship drifting down the river is not making way, even though it is moving much faster over the bottom.

It is fairly common for river towboats (pushing ahead) to hold their position by putting the head of their tow against the bank and and applying some forward thrust to prevent movement. In this situation the tow is free to maneuver and not considered to be aground. Therefore, it is considered to be underway.