Steering gears and rudders: is it time to retrofit your vessel?2 June 2021 • 14:00-14:45 BST

Marine Propulsion Webinar Week

Part of

1-4 June 2021

Panellist documents

Page 2: David Wing, HoulderPage 8: Dr Noriyuki Sasaki, University of StrathclydePage 18: Lennart Dobele & Per Landegren, Humphree

© Houlder Ltd 2021 1

STEERING GEARS AND RUDDERS: IS IT TIME TO RETROFIT YOUR VESSEL?

DAVID WING, HOULDER

BASIC PRINCIPLES

Doc. © Houlder Ltd 2021 2

1845 1990s 2020s

WHAT’S CHANGED

Doc. © Houlder Ltd 2021 3

Image: Becker Marine Systems

- Performance prediction methods- Propeller design process- Commercial drivers- Regulatory requirements

REGULATORY REQUIREMENTS

Doc. © Houlder Ltd 2021 4

ATTA

INED

EEX

I

CAPACITY

REGULATORY REQUIREMENTS

Doc. © Houlder Ltd 2021 5

COMPLIANT

NON-COMPLIANT

Attained EEXI

Technical measures

Compliant EEXI

PRACTICAL CONSIDERATIONS

Doc. © Houlder Ltd 2021 6

Gate Rudder. Image: Yamanaka Shipbuilding / Wartsila

- Savings potential

- Arrangement

- Steering gear

- Bearing loads

- Hull structure

- Propeller performance

what is wrong with our rudder design ?

Gate RudderFlap Rudder

Noriyuki Sasaki Strathclyde University

Steering gears and rudders: is it time to retrofit your vesselDate: Wednesday 2 June - Time: 14:00-14:45 BST

A sail behind the fan will not work !

Tacking Tacking + Fan(propeller)

https://www.safe-skipper.com/tacking-a-sailing-boat/

Lift force

No tacking?

Principal of Wind assisted propulsion

Tacking operation of yacht

the conventional rudder works in the deflected flow of a propeller slipstream which deteriorates the sail performance

Yawing condition (Rolling condition is the same)

Working as a sail in oblique wind

Tacking Effect

Gate Rudder is under water sails

3 + 2 gate rudder ships (2018-2021)

400 TEU Container Ship ‘Shigenobu’ 509 type General Cargo ‘Koshin Maru’ 499 type General Cargo ‘Shinmon Maru’ General cargo (2022 retrofit)

Under Construction

670 TEU container (2022)

Ship type Container General Cargo General Cargo

Built year 2017 2020 2020

Sister ship Sakura (2016) unknown Shinko maru(2016)

Hull Form Existing New Existing

Engine Existing Existing Similar

FOC save 22% (voyage data) 33% (owner’s claim) 16% (voyage data)

more than 15% Fuel Saving at

the same speedthe same draft

Joint Sea Trial of Ships with Gate Rudder and Conventional Rudder

N. Sasaki Strathclyde UniversityS. Kuribayashi Kuribayashi Steam Ship Co. Ltd.N. Bulten Wartsila M. Yazawa Kamome Propeller Co. Ltd.

ShigenobuSakura

Sakura Shigenobu

Loa (m)

B (m)

d (m)

Main Engine

Rudder Flap Rudder Gate Rudder

Delivery August 2016 December 2017

111.4

17.8

5.24

3309kW x 220rpm

Full Scale Ship Performance online conference 20212021/2/10

March1845Tug of war (HMS Rattler and HMS Alecto)

Fuel Savings ( Joint speed trial)Wind Velocity 5-7 m/ secSignificant Wave Height 0.8 m

18% saving

1st double run2nd double run

3rd double run

Ship Speed (kts)

Pow

er (

kW)

Full Scale Ship Performance online conference 20212021/2/10

Shigenobu

Sakura

Ship motion Rudder Angle

Safer than conventional rudder on the same track

Cost & Return

Safety Navigation

Single rudder operation

Engine Torque variation

Flap Rudder

Gate Rudder

Average Speed 13.5 ktsMean output 2500 kW (75%)Operational Days 260 daysFOCR (g/kw hr) 200 g/kw hrFOC (ton/day) 12.0 ton/dayFOC /year 3120 ton/yearFOC save/year 780 ton/year (abt. €0.4M）

Flap rudder

Gate rudder

CR G.R retrofit

Rudder blades 1 2

Steering gear 1 2 1

Rudder shaft/trunk 1 2

Auto pilot 1 1

Propeller 1 0.8 0

Propeller shaft 1 1-α 0

Others - -

Retrofit factor K

total €0.8M €0.8M + K

2 years +α

Pivot turn/Crabbing by B/T & Gate Rudder

Speedy turn

Gate Rudder can support other EEXI technologies2023 2025

phase2

phase2

phase3

phase3

tanker, bulker etc.

Container, LNG/Gas, General, etc.

EEDI

EEXIGate rudder Technology

Gaters (retrofit /coastal ships)

Wartsila (w/w exclusive licensee)

Kamome prop. (exclusive licensee Japan)

Gate Rudder -15% (without slow steaming)

technology Possible risk Gate Rudder

slow steaming # weak maneuverability at severe weather condition# relatively large sea margin

# protect speed loss due to helm# reduce the excessive sea margin

wind assist propulsion

# ship drifting and resistance due to yaw motoin

# dragging an anchor at severe weather condition

# generate the trust in the same manner of sails on the deck# increase bollard pull force by gate rudder

Thank you for your attention

GATERS (2021-2023)

WP1 (Design Model Test)

WP2 (F/S Monitor)

GATE Rudder System as a Retrofit for the Next Generation Propulsion and Steering of Ships

Gaters Coordinator: University of Strathclyde;Prof Mehmet Atlar (mehmet.atlar@strath.ac.uk) ;Tel: +44790089022

Erge : expected power savings 12%speed range 10kts – 12.5kts

75%MCR(kW)/Dp2/Vs2(kts)

Expected fuel saving

www.gatersproject.com

Humphree ECO Steering

Lennart DobeleR E G I O N A L S A L E S M A N A G E R –

U K , T h e N e t h e r l a n d s , P o r t u g a l , C r o a t i a , G r e e c e , M a l t a

Per LandegrenS a l e s & M a r k e t i n g D i r e c t o r

0%

1%

2%

3%

4%

5%

6%

7%

8%

9%

10%

0° 2° 4° 6° 8° 10° 12° 14°

Adde

d St

eerin

g Fu

el c

onsu

mpt

ion

≈60 % reduced steering lossAdded fuel consumption, when steering

High-Speed RoPax Ferry, 36 knots

Saved fuel

Rudder demand [°]Calm conditions – WJ only steering 5-6°

Side wind conditions – WJ only steering around 10°

Humphree ECO Steering

• Reduced life-cycle costs

• Better maneuverability/safety

• Positive environment impact

• Re-fit possibilities

• Fully automated fuel-savings

• Reduced waterjet wear & tear

Optimizing waterjet steering

Waterjet steering only:

• The “steering” by waterjets slows vessels down at cruising speeds during course keeping & turns

Humphree ECO Steering:

• Same steering forces, with ≈ 60% less steering-losses

• Higher speeds (with same power) for course keeping & turns

• Tighter turns possible

• Reduced waterjet wear & tear

with courtesy of Wärtsilä

with courtesy of Wärtsilä

Same steering forces at ≈60 % less steering-lossesFuel consumption, when steering (For maintaining speed)

High-Speed RoPax Ferry, 36 knots

Saved fuel

Rudder demands [°]

0%

1%

2%

3%

4%

5%

6%

7%

8%

9%

10%

0° 2° 4° 6° 8° 10° 12° 14°

Adde

d St

eerin

g Fu

el c

onsu

mpt

ion

Side wind conditions – WJ only steering around 10°

Calm conditions – WJ only steering 5-6°

Steering performance resultsBenefits during turns

• Higher speeds during turns (with same power)

• Tighter turns possible = Improved safety

Course keeping performance

• Straighter courses with Humphree ECO Steering

Suitable projects

• All waterjet-driven vessels

• All common hull forms: Monohull, Catamaran, Trimaran

• All ship sizes between 15m … 120 m… and larger

• All segments. Yacht, Commercial, etc.

When is Humphree ECO Steering saving fuel

• At ship speeds higher than 12 knots

Which vessels can benefit:

… When switching system on:

• 0.8 knots faster at calm sea conditions auto-pilot course keeping.

• Higher fuel efficiency / short ROI• Better maneuvering, better course keeping, etc.

MOLSLINJEN Press Release:”Humphree ECO Steering = …

… When switching system on:

• 3.5 knots faster at moderate turns• Ship operator reported 3-5 % fuel savings

depending on route and weather• Better maneuvering, better course

keeping, etc.

What happens…