rule 27 - vessels nuc

Rule 27 - Vessels not under command or restricted in their ability to manoeuvre

(a) A vessel not under command shall exhibit: (i) two all-round red lights in a vertical line where they can best be seen; (ii) two balls or similar shapes in a vertical line where they can best be

seen; (iii) when making way through the water, in addition to the lights prescribed in

this paragraph, sidelights and a sternlight. (b) A vessel restricted in her ability to manoeuvre, except a vessel engaged in

mine clearance operations, shall exhibit: (i) three all-round lights in a vertical line where they can best be seen.

The highest and lowest of these lights shall be red and the middle light shall be white;

(ii) three shapes in a vertical line where they can best be seen. The highest and lowest of these shapes shall be balls and the middle one a diamond;

(iii) when making way through the water, a masthead light or lights, sidelights and a sternlight, in addition to the lights prescribed in subparagraph (i);

(iv) when at anchor, in addition to the lights or shapes prescribed in subparagraphs (i) and (ii), the light, lights or shape prescribed in Rule 30. 1


(c)  A power-driven vessel engaged in a towing operation such as severely restricts the towing vessel and her tow in their ability to deviate from their course shall, in addition to the lights or shapes prescribed in Rule 24(a), exhibit the lights or shapes prescribed in subparagraphs (b) (i) and (ii) of this Rule.

(d) A vessel engaged in dredging or underwater operations, when restricted in her ability to manoeuvre, shall exhibit the lights and shapes prescribed in subparagraphs (b) (i), (ii) and (iii) of this Rule and shall in addition, when an obstruction exists, exhibit: (i) two all-round red lights or two balls in a vertical line to indicate the side

on which the obstruction exists; (ii) two all-round green lights or two diamonds in a vertical line to indicate

the side on which another vessel may pass; (iii) when at anchor, the lights or shapes prescribed in this paragraph

instead of the lights or shape prescribed in Rule 30.

2


(e) Whenever the size of a vessel engaged in diving operations makes it impracticable to exhibit all lights and shapes prescribed in paragraph (d) of this Rule, the following shall be exhibited: (i) three all-round lights in a vertical line where they can best be seen. The

highest and lowest of these lights shall be red and the middle light shall be white;

(ii) a rigid replica of the International Code flag "A" not less than 1 metre in height. Measures shall be taken to ensure its all-round visibility.

(f) A vessel engaged in mine-clearance operations shall in addition to the lights prescribed for a power-driven vessel in Rule 23 or to the lights or shape prescribed for a vessel at anchor in Rule 30 as appropriate, exhibit three all-round green lights or three balls. One of these lights or shapes shall be exhibited near the foremast head and one at each end of the fore yard. These lights or shapes indicate that it is dangerous for another vessel to approach within 1000 metres of the mine clearance vessel.

3


(g) Vessels of less than 12 metres in length, except those engaged in diving operations, shall not be required to exhibit the lights and shapes prescribed in this Rule.

(h) The signals prescribed in this Rule are not signals of vessels in distress and requiring assistance. Such signals are contained in Annex IV to these Regulations.

4


Rule 27 considers following classes:

–  Vessels not under command –  Vessels restricted in their ability to manoeuvre –  Vessels engaged in difficult towing operations –  Vessels restricted in their ability to manoeuvre,

engaged in dredging or under-water operations, if there is an obstruction

–  Small vessels engaged in diving operations –  Vessels engaged in minesweeping

General

5


Rule 3 (f) gives the definition of a vessel not under command: “A vessel which through some exceptional circumstance is unable to manoeuvre as required by the Rules and is therefore unable to keep out of the way of another vessel”

Vessel not under command (NUC) Rule 27 (a)

6

A vessel not under command shall exhibit:

–  When making way through the water •  Two all-round red lights in a vertical line •  Sidelights •  A sternlight

–  When NOT making way through the water •  Two all round red lights only in a vertical line

–  BY DAY •  Two black balls in a vertical line



7

•  Rule 27 (a) (i) and (iii) •  Vessel not under command •  Making way through the water •  Port side view



All-round lights

8

•  File 27 (a) (i) and (iii) •  Vessel not under command •  Making way through the water •  Stern view



All-round lights

9

•  Rule 27 (a) (ii) •  Vessel not under command •  By day



10



Important remarks −  A vessel can be entirely not under command (NUC) e.g. engine

breakdown. After a while she will than make no way through the water. −  A vessel can also be partially NUC e.g. in adverse weather conditions

−  A vessel that suddenly becomes NUC must replace her masthead lights by two red lights

−  A vessel NUC is a danger to other vessels. It is thus important to see weather or not she is making way through the water

−  The two red lights are all-round lights. NUC-vessels must be seen as such all over the horizon

−  There is no difference between a power-driven vessel NUC and a sailing vessel NUC

−  Vessels less than 12 m do not need to exhibit the red lights or black ball (except those engaged in diving operations) 11



Both these vessels are NUC due to adverse weather conditions. It is nearly impossible to apply a course alteration

12



This sailing vessel is also NUC because she has insufficient wind to manoeuvre adequately

13

Rule 3 (g) gives the definition of a vessel restricted in her ability to manoeuvre: “A vessel which from the nature of her work is restricted in her ability to manoeuvre as required by these Rules and is therefore unable to keep out of the way of another vessel.”

Examples

− cable-ships − dredgers − survey vessels − salvage vessels − supply vessels


Vessel restricted in her ability to manoevre Rule 27 (b)

14


A vessel restricted in her ability to manoeuvre and underway shall exhibit

AT NIGHT

–  When making way through the water •  Three all-round lights (red-white-red) in a vertical line •  Masthead light(s) •  Sidelights •  A sternlight

–  When NOT making way through the water •  The red-white-red lights only in a vertical line

–  At anchor •  The red-white-red lights and one or two anchor lights


15

BY DAY

•  A black diamond between two black balls in a vertical line

– At anchor •  The black diamond between the two black balls

and the anchor ball

For the anchor lights and anchor ball, see Rule 30



16

•  Rule 27 (b) (i) and (iii) •  Vessel restricted in her ability to manoeuvre •  More or less than 50 m •  Making way through the water •  Bow view



All-round lights

17

•  Rule 27 (b) (i) an (iii) •  Vessel restricted in her ability to manoeuvre •  More or less than 50 m •  NOT making way through the water



18

•  Rule 27 (b) (ii) •  Vessel restricted in her ability to manoeuvre •  By day



19

•  Rule 27 (b) (iv) •  Vessel restricted in her ability to manoeuvre •  More or less than 50 m •  At anchor



20

•  Rule 27 (b) (iv) •  Vessel restricted in her ability to manoeuvre •  By day



21



Supply vessels

22

Important remarks

−  Vessels which see a vessel restricted in her ability to manoeuvre must take sufficient action to keep out of the way.

−  They must also take care not to hamper their operations.

−  Cable-ships and salvage vessels should be passed at a large distance with reduced speed, especially with divers underwater.

−  Vessels less than 12 m. do not need to exhibit the red-white-red lights or black ball-diamond-ball (except those engaged in diving operations)



23


–  AT NIGHT

•  The red-white-red lights in a vertical line •  Two or three masthead lights in a vertical line •  An additional masthead light for vessels of 50 m or more •  Sidelights •  A sternlight •  A towing light

–  BY DAY

•  A black diamond between two black balls in a vertical line •  When length of tow exceeds 200 metres, an extra black

diamond

Vessel towing and unable to deviate from her course Rule 27 (c)

24


•  Rule 27 (c) •  Power-driven vessel towing and unable to deviate from her course •  Towing vessel less than 50 m •  Tow exceeding 200 m •  Underway •  Bow view 25


•  Rule 27 (c) •  Power-driven vessel towing and unable to deviate from

her course •  Tow exceeding 200 m •  By day 26



27



28

Vessel engaged in dredging or underwater operations with obstruction

AT NIGHT –  Same lights as for vessels restricted in their ability to

manoeuvre, whether making way or not, and in addition: •  On the obstructed side: two all-round red lights •  On the clear side: two all-round green lights

BY DAY –  Same shapes as for vessels restricted in their ability to

manoeuvre and in addition: •  On the obstructed side: two black balls •  On the clear side: two black diamonds


Dredging and underwater operations with an obstruction Rule 27 (d)

29

AT ANCHOR

–  AT NIGHT •  The all-round red-white-red lights •  On the obstructed side: two all-round red lights •  On the clear side: two all-round green lights

–  BY DAY •  The black ball-diamond-ball shapes •  On the obstructed side: two black balls •  On the clear side: two black diamonds And NO anchor light(s) or anchor ball



30


•  Rule 27 (d) ((i), (ii) •  Vessel engaged in dredging or underwater operations •  More or less than 50 m •  Obstruction on left side •  Making way through the water •  Bow view


31

•  Rule 27 (d) (i) and (iii) •  Vessel engaged in dredging or underwater operations •  Obstruction on both sides •  At anchor



32

•  Rule 27 (d) (i), (ii) and (iii) •  Vessel engaged in dredging or underwater operations

obstruction on the right side •  Making way through the water or not or at anchor •  By day



33



Dredger, more or less than 50 m., making way through the water, obstruction on her starboard side 34



Dredger with obstruction on the right and free passage on the left. Not making way through the water (or at anchor)

35



Dredger with obstruction on both sides. All vessels must give a wide berth and if necessary, slow down

36

Important remarks

Paragraph (d) of Rule 27 only applies to vessels dredging or to vessels engaged in underwater operations if there is an obstruction on one side or on both sides.

If neither side is obstructed, these vessels shall be considered as ordinary vessels restricted in their ability to manoeuvre and show the corresponding lights or shapes.

When both sides are obstructed, the vessel should be passed at as great a distance as possible or wait until one side is clear.

On the obstructed side, long wires often extend horizontally by means of which the vessel moves laterally.



37


Small vessels engaged in diving operations Rule 27 (e)

If a vessel is passing too closely, the small vessel engaged in diving operations should make the letter A (� −) with the signal lamp (Aldis lamp) or with the whistle

38


Small vessels engaged in diving operations Rule 27 (e)

By day

Code flag “A” means: I have a diver down; keep well clear at slow speed

39


A minesweeper shall exhibit:

•  AT NIGHT –  Three all-round green lights in an isosceles triangle –  The ordinary navigation lights

•  BY DAY –  Three balls in an isosceles triangle

•  AT ANCHOR –  Three all-round green lights or three balls –  One or two anchor lights or the anchor ball

Minesweepers Rule 27 (f)

40

•  Rule 27 (f) •  Minesweeper •  Less than 50 m •  Underway •  Bow view



41

•  Rule 27 (f) •  Minesweeper •  More or less than 50 m •  Underway •  By day



42



43



44



Minesweeper at anchor Top green light not visible

45



By day

46

Important remarks

−  With minesweepers, whether they make way through the water or not is not taken into account.

−  Minesweepers usually operate in groups. They should be avoided positively and in ample time.

−  It is forbidden to approach a minesweeper closer than 1.000 metres



47

rule 27 - vessels nuc

Documents

allround lights

allround red lights

allround green lights

towing vessel

powerdriven vessel

vertical line

similar shapes

subparagraphs b i