Controllable Pitch Propellers

SCP
Controllable Pitch Propellers
Application-oriented
propulsion systems

The SCHOTTEL Controllable Pitch Propeller –
the reliable propulsion system
for all ships with up to 30,000 kW
SCHOTTEL Controllable Pitch Propeller Systems (SCP) are
available in various designs, including:
• X-type, i.e. hydraulic cylinder mounted in the propeller hub
• Z-type, i.e. hydraulic cylinder mounted in the propeller shaft
Oil is distributed either via an Oil Distribution (OD) box mounted in
front of the gearbox (G-type), or via the W-type OD box, which is
mounted in the shafting.
Therefore different combinations of hydraulic cylinder arrangement
and position of oil supply can be implemented. The most common
is the X-type hub combined with oil supply in front of the gearbox,
the so-called “XG” configuration. Other solutions are the “ZG”
version, with the hydraulic cylinder in the shaft and the OD box in
front of the gearbox, and the “XW” version, with the cylinder in the
hub and the oil supply in the shaft.
The “X” type incorporates a hydraulic cylinder with the piston
directly connected to the yoke. Hence the design is simple, with a
minimum of moving parts, and achieves the highest reliability.
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To obtain optimum strength the hub is cast in one piece. The propeller
blades are mounted on large-sized blade carriers to minimize the
stresses in the system.
The yoke moving inside the hub is supported by sliding pieces. Crank
pins on the yoke operate the propeller blade carriers, which have
grooves guiding the pins. The propeller blades are bolted to the
carriers. The hub is sealed by a well-proven system consisting of a
pre-loaded sealing ring between the hub and the blade foot.
The hydraulic oil flows through an inner and outer oil pipe, both
mounted concentrically inside the hollow-bored shaft. The movable
double oil pipe also functions as a feedback system indicating the
current pitch of the propeller system.
The Z-type hub with the hydraulic cylinder within the propeller shaft results
in a considerably shorter propeller hub. The shaft-integrated hydraulic
cylinder moves the yoke by means of a rod leading through the hollow-bored
shaftline.
For all systems, propeller blades and hubs are available made of Cu-Ni-Al or even
stainless steel.
Controllable pitch propellers designed by SCHOTTEL offer the following advantages:
• blocking valves for pitch setting installed in the cylinder space of the hub, easily accessible
when docked without dismantling of the hub
• blocking valves allow operation in the ahead condition with 100% engine power without restriction
• blades can be dismounted in a nozzle without pulling the shaft
• the blade moving pin is part of the cast yoke, which achieves a larger control stroke near the end
positions of the blades, allowing finer pitch control. This also results in lower stresses in the pin.
• optimum matching of material between hub and blade carriers
• larger hub is cast in one piece, giving a rigid structure

Company Profile
SCHOTTEL-Schiffsmaschinen GmbH,
formerly Wismarer Propeller und Maschinenbau
GmbH (WPM), can look back on
a long history of industrial activity in
Wismar, Germany. Previous names were
“Alubau Wismar” and “Diesel Motorenwerk
Rostock” (DMR). WPM became
independent in 1991, and was taken over
by SCHOTTEL in 1998. The company
delivered its first controllable pitch propeller
in 1963. Previously, the propellers
were primarily manufactured for the
strong East German shipbuilding industry.
Today, as part of the SCHOTTEL Group,
SCHOTTEL-Schiffsmaschinen GmbH is
well-positioned for aggressive development
of the international market.
Today more than 100 employees use
modern facilities to produce the following:
• SCP controllable pitch propeller
systems
• shafts for fixed pitch propellers
• rudder shafts and machining of rudder
blades
First controllable pitch propeller from
Wismar built in 1963 for a fishing trawler
1,210 kW, diameter 3.3 m
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The SCP power range starts at 1000 kW
and goes up to 30,000 kW, with corresponding
hub diameters from 0.46 m to 2 m.
The propellers are available with 3, 4 or
5 blades, the standard version being the
four-bladed design. SCHOTTEL supplies
the complete package including the CP
propeller, shaftline, hydraulic system and
remote control system.
In another product line, SCHOTTEL
designs and machines shafts of up to
19.5 m in length and 80 t in weight.
One 12 m, one 15 m and two 20 m
lathe machines are available for manufacturing
these large shafts. With its
machine capacity the company is
excellently equipped for repairs and
machining work.

SCP Types
Principle: *** *** ***
Example: SCP 154 4XG
SCHOTTEL
Controllable Pitch Propeller
Size of Hub, Diameter in cm
Number of Propeller Blades
Hub/Control Cylinder Arrangement
Hydraulic Oil Supply Arrangement
(G: At Gear, W: Inside Shafting)
Position of Control Cylinder
Hub Material Inside Shafting Inside Hub
Steel
Bronce
A
Z
C
X
Type SCP-XG
X-type hub with the servomotor fitted in the hub, the oil supply unit
arranged in front of the reduction gear.
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Type SCP-ZG
Z-type hub with the servomotor in the shaft line, the oil supply unit
arranged in front of the reduction gear.
Type SCP-XW
X-type hub with the servomotor fitted in the hub and the oil supply unit arranged in the shafting.

Propeller Design
Designing a CP propeller blade is a complex process,
requiring an extensive range of expert knowledge in the
specialized fields of fluid physics and mechanical engineering.
In addition to hydrodynamic blade design, the calculation
of hydrodynamic loads and their effects when the
blade pitch is changed and in various operating conditions
are of great importance.
In order to provide advanced blade shapes and satisfy
ever-heightened requirements, use is made of state-of-theart
calculation methods, refined continuously by means of
Computed pressure distribution
research projects carried out in cooperation with research
institutes.
The blade design is initially executed through the use of circulation theory verification and optimization
techniques. Here SCHOTTEL employs two tried-and-tested methods developed at the
HSVA in Hamburg and the SVA in Potsdam, which are currently
the most powerful programs in existence. Openwater
diagrams, pressure distribution, cavitation and pressure
fluctuation properties are calculated for all relevant
operating states in the vessel’s wake.
In addition to close cooperation with research institutes,
SCHOTTEL also draws on the invaluable years of experience
of leading experts in the field of propeller design.
The strength of the blade is verified through the use of
FEM (Finite Element Method), achieving the optimum combination
of mechanical expedience and hydrodynamic efficiency.
Cavitation test
Almost every propeller undergoes extensive model tests, where it must prove that it actually
possesses the required characteristics with regard to efficiency, cavitation and pressure fluctuations.
In these tests the SCHOTTEL design regularly competes head-to-head with technology
from other suppliers, and as the results show, SCHOTTEL produces some of the best propeller
designs on the market.
Hydraulic System
The pump and motor unit forms an essential part of the
hydraulic system. This assembly delivers the oil quantity
needed for adjustment of the propeller blades and produces
the pressure required for pitch control. Two electrically
driven pumps (1 active pump, 1 standby pump, each with
100% capacity) are mounted on the cover of the hydraulic
tank, with the pumps running in the oil. The compact control
block, incorporating all the indicators and the individual Hydraulic unit
instruments necessary for pitch control, is located on the
top of the tank. The piping between the pump and motor unit and the oil supply unit is part of
the shipyard’s scope of supply. Lubrication oil is fed through the stern tube into the hub. This
system is not connected to the hydraulic system of the controllable-pitch propeller unit.
Optionally a two-pipe system can be supplied, in which case the hydraulic oil is used to lubricate
the hub.
Remote Control
The remote control system is
designed to provide automatic
control of a SCHOTTEL controllable
pitch propeller. The
system is based on a microprocessor-controlled
system
architecture with 2-wire bus
communication between central
unit, ECR and bridge. An HMI
(human-machine interface) allows
clear, user-friendly control, set-up
and maintenance of the system.
The system is type-tested to GL,
LRS and ABS (other classes on
request) and meets class requirements
according to AUT24 and
UMS.
Standard features:
• Control from ECR, bridge and
wings
• Combinator and constant
speed mode
• Up to 3 acceleration programs
• Load control management
• Automatic SLOW DOWN
• Automatic SHUT DOWN
• Self monitoring
• Non-follow-up control from
ECR and bridge
• Pitch measurement system
• Main engine interface
The system is powered with 24 V
DC. A separate supply should be
provided for the back-up system.
Options:
• Engine telegraph systems and
electric shaft system in the
wheelhouse area
• Clutch control system
• Interface for DP systems
• Interface for manoeuvring
printer
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SCP in action
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1 COT WOLGASTERN
SCP 1414 XG (7860 kW)
Shipyard: Gdynia Shipyard, Poland
Owner: Rigel Schiffahrt, Germany
2 Open Top Container Vessel, Type 168 A
1 x SCP 1294 XG (8400 kW)
Shipyard: Sietas-Werft, Germany
3 RoPax ferry NORRÖNA
2 x SCP 1294 XG (10,800 kW each)
Shipyard: Flender Werft AG, Germany
Owner: Smyril Line, Faroe Islands
4 Offshore Supply Vessel C. LIBERTY
2 x SCP 0774 ZG (2110 kW each)
2 x STT 1010 T-LK CP (1000 kW)
Shipyard: North American Fabricators, USA
Owner: Edison Chouest Offshore, USA
2
3
5 EGV BERLIN
2 x SCP 1414 XG (5280 kW each)
Shipyard: Flensburger
Schiffbaugesellschaft, Germany
Owner: German Navy
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6 Passenger/Container vessel ZI YU LAN
1 x SCP 1544 XG (15,000 kW)
Shipyard: Aker-MTW, Germany
Owner: Shanghai Shipping Corporation,
PR China
7 AHSV HADI XI
2 x SCP 0714 XG (2025 kW each)
Shipyard: Keppel Singmarine, Singapore
Owner: Hadi H. Al-Hammam Establishment
– Marine Services, Saudi Arabia
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8 Atlantik 488, 1 x SCP 119 4 AW (5300 kW)
Shipyard: Volkswerft GmbH Stralsund,
Germany
Owner: Murmansk Trawler Fleet Co.,
Russia
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9 RoRo vessel AKDENÍZ
2 x SCP 1294 XG (8100 kW each)
Shipyard: Flensburger Schiffbau-
Gesellschaft, Germany
Owner: UND Roro Isletmeri AS, Turkey
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SCHOTTEL for the Shipping World
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Constant customer support
Professional commissioning world-wide
Preventive maintenance and repairs
Close-knit sales and service network
Our product information provides you with explanations and data for planning plants incorporating units from our current programme.
On account of the modifications associated with upgrading, the contents of a specific edition will remain valid for a limited time only.
Binding for the application concerned are the data given in our tender specification.
VPR-525/05 e . Printed in the Federal Republic of Germany
Innovators in steerable propulsion
SCHOTTEL-Schiffsmaschinen GmbH · Kanalstr. 18 · D-23970 Wismar / Germany
Tel.: + 49 (0) 38 41 / 204-0 · Fax: + 49 (0) 38 41 / 204-333 · eMail: info-ssw@schottel.de · www.schottel.de