NCSR 9-14 - Inclusion of Guidance On The Muehr Manoeuvre in The IAMSAR Manual (Germany)

E
SUB-COMMITTEE ON NAVIGATION, NCSR 9/14

COMMUNICATIONS AND SEARCH AND 13 April 2022
RESCUE Original: ENGLISH
9th session Pre-session public release: ☒
Agenda item 14
AMENDMENTS TO THE IAMSAR MANUAL
Inclusion of guidance on the Muehr Manoeuvre in the IAMSAR Manual
Submitted by Germany
SUMMARY
Executive summary: IAMSAR Manual Volume III includes information on four
"standard recovery manoeuvres" to be used by ships. Germany
proposes the addition of a fifth, which has the advantage of being an
approach manoeuvre for Panamax ships and all large ships to the
position of persons that are to be recovered from water.
The manoeuvre is reproducible. The tendency of the vessel to lay by
automatically to the wind is the key element of this shelter-providing
manoeuvre. This document provides the new approach manoeuvre
for inclusion in the 2025 edition of the IAMSAR Manual Volume III
and the amendments as requested at JWG 26 and JWG 27.
Strategic direction, 7
if applicable:
Output: 7.20
Action to be taken: Paragraph 10
Related documents: NCSR 7/16, annex, paragraphs 3.1.23, 3.1.24 and 3.1.25; and
NCSR 8/10, annex, paragraphs 3.1.3.1 to 3.1.3.5
Background
1 IAMSAR Manual Volume III, 2019 edition, includes information on four standard
recovery manoeuvres – the Williamson Turn, the single or Anderson turn, the Scharnov turn,
and the Lorén turn. The first three manoeuvres are designed to assist a ship's crew in returning
to a search track for a man overboard position and to find the person in the water.
The Lorén turn is designed to calm the area of sea in which the recovery is to be done.
2 There is one manoeuvre missing which provides full control over the manoeuvrability
throughout the entire approach process, especially in heavy sea conditions and with large
vessels. The "Muehr Manoeuvre" efficiently prevents the loss of steering when slowing down
the vessel, with the wind and sea from abeam.
I:\NCSR\9\NCSR 9-14.docx
NCSR 9/14
Page 2
3 Germany proposes that this manoeuvre be added to those already included in

Volume III.
Discussion
4 The manoeuvre was practically developed and verified by trials on different Panamax
container vessels and additionally during simulator-based exercises with several shipmasters
giving clear evidence that it is reproducible.
5 A core element of this manoeuvre is the safe and smooth operation under adverse
weather and sea conditions. In addition to the practical testing on board, the manoeuvre was
exercised and evaluated by the Maritime Education and Training Centre, Warnemünde –
Ship Simulator, Germany, on 16 October 2017 and during annual sessions thereafter.
6 It works under the influence of gale force winds as well as in good weather conditions.
It is a consistent manoeuvre for a standardized approach by ships to a recovery position,
without having to use the rescue or fast rescue boat. In particular, this manoeuvre protects the
safety of own crew in severe weather conditions as, in most cases, nobody has to leave the
assisting vessel. The manoeuvre is reproducible and provides a slow and safe approach.
7 This approach manoeuvre, using the drift effect of wind and waves, is independent of
the manoeuvre characteristics of the vessel. It is recommended to masters to carry out some
exercises to become familiar as shown in steps 1 to 5 of the annex.
8 Throwing life rafts or other safe floating rescue equipment leeward from the assisting
vessel and keeping them amidships may support survivors or even a rescue team.
This manoeuvre does also provide a good base (casualty leeward and amidships,
vessel stopped) for deploying professional hoisting equipment which is available for recovery
of people from sea. When recovery actions are requested, it is an appropriate performance
manoeuvre to achieve compliance with SOLAS regulation III/17-1 and
MSC.1/Circ.1182/Rev.1.
9 The proposed text, a diagram for guidance and a graphical illustration can be found
in the annex.
Action requested of the Sub-Committee
10 The Sub-Committee is invited to discuss the use of the manoeuvre among navigation
experts and to consider adding the information set out in the annex into the IAMSAR Manual
Volume III, after the position of the Lorén Manoeuvre.
***
NCSR 9/14
Annex, page 1
ANNEX
• Muehr Manoeuvre
— provides full control over the manoeuvrability during approach, especially in

heavy sea conditions and with large vessels, based on a controlled heaving to
swing turning action.
— provides a standardized approach to a recovery position without using the rescue

or fast rescue boat. It provides safety and protection of own crew in severe
weather conditions. The manoeuvre is reproducible and provides a slow and safe
approach speed.
— this manoeuvre does also provide a good base (casualty leeward and amidships,
vessel stopped) for deploying hoisting equipment which may be available for
recovery of people from sea. It is an appropriate approach manoeuvre supporting
requirements resulting from SOLAS regulation III/17-1 and MSC.1/Circ.1182, as
amended.
Muehr Manoeuvre procedure
1 Vessel is steering into a course head on to wind and sea, keeping the casualty
position slightly on the portside. *
2 The vessel is now slowly reducing speed, maintaining manoeuvrability at all times.
3 At this position, the speed is already down to ʺminimum still steeringʺ. Once the:
- casualty is abeam of the port side shoulder, the rudder is set hard to port;
- followed by a short and strong engine manoeuvre ahead. An available bow

thruster can now be set ʺfull to port sideʺ, supporting the turning motion.
- Directly thereafter, an astern manoeuvre must follow, until the vesselʹs headway
is stopped.
4 Keeping the bow thruster pushing to the port side will support the tendency to turn
and lay by to the wind. If the casualty position is now too far leeward, kicking the engine ahead
with hard a starboard rudder and using the tendency of the stern to move sideways to port
when going astern again, will support together with the still pushing bow thruster the
leeward drifting.
5 Once the vessel starts to shelter the casualty position against the wind;
- its drifting speed will be reduced.
- Depending on the size, surface area, draft and wind speed, the vessel will now
provide a loofward protection zone against incoming waves and a leeward
upstream of water, which pushes the casualty away from the shipʹs side, keeping
it permanently at a safe distance of 1-3 m.
*
Vessels with no bow thruster and right-handed fixed propeller will most likely prefer the casualty to be
positioned on the starboard side.
NCSR 9/14
Annex, page 2
- If the casualty is coming closer to the hull, engine manoeuvres should be carried
out with caution in order not to push away or harm the person concerned by the
propeller or overhanging stern. The casualty position should be always kept
amidships.
Caution:
The drift behaviour described above is to be

expected by ships having an even distribution of
Wi nd
the area exposed to wind by superstructure and
cargo or in ships with aft superstructures. A vessel
with the centre of windage forward of the centre
of gravity (forward superstructure) which is
stopped beam to the wind encounters a force
caused by the wind, which causes the vessel to
fall off and to bear away from the wind. As a result 4)
the centre of the windage and of the
hydrodynamic pressure starts to move and
creates an unfavourable drifting heading of the
vessel.
Smaller vessels may have the disadvantage of

not providing sufficient shelter against wind and
sea to protect the recovery (or rescue) position on
the leeside of the vessel. 3)
Vessels with a very shallow draft (e.g. in ballast
condition) may provoke risks by:
— not being able to create a sufficient
upstream of water on the leeside of the
vessel to calm the sea and to provide an
adequate shelter.
— generating an underset (undertow),

caused by current due to fast drifting,
which may endanger casualties to be
dragged below the hull. 2)
Note: The Muehr Manoeuvre has been practically
evaluated with different container ships of a length
between 150 m and 300 m. It is recommended for
masters to carry out exercises to become familiar
with their own ship, evaluating different cargo and
sea conditions.
1)
Diagram: Muehr manoeuvre, procedure with right-handed

fixed propeller and assistance by bow thruster
___________

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E

SUB-COMMITTEE ON NAVIGATION, NCSR 9/14

AMENDMENTS TO THE IAMSAR MANUAL

Inclusion of guidance on the Muehr Manoeuvre in the IAMSAR Manual

3 Germany proposes that this manoeuvre be added to those already included in

Action requested of the Sub-Committee

— provides full control over the manoeuvrability during approach, especially in

— provides a standardized approach to a recovery position without using the rescue

Muehr Manoeuvre procedure

- followed by a short and strong engine manoeuvre ahead. An available bow

- its drifting speed will be reduced.

The drift behaviour described above is to be

Smaller vessels may have the disadvantage of

— generating an underset (undertow),

Diagram: Muehr manoeuvre, procedure with right-handed

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