Combined lubricated sterntube seals

Simplex combined lubricated sterntube seals are designed for shaft bearings that need to withstand the harshest of conditions. These oil/grease lubricated seals are designed to protect the bearings against sediments and marine growth. They comply with industry classification requirements and are type-approved by all major classification societies.

Dredger (BD)

Aft lip seal with constant grease and oil lubrication for operation in high-sediment loaded water.

FPSO/FSO (BRD)

Aft lip seal with constant grease and oil lubrication, special design for long operating intervals.

Water-lubricated sterntube seals

Simplex water-lubricated sterntube seals are designed for water-lubricated sterntubes. Under the influence of increasingly strict environmental requirements, this type of lubrication is becoming more and more popular. Water lubrication is by far the most environmentally friendly solution for lubricating propeller shaft bearings and is thus compliant with current legislation such as the VGP 2013 (Vessel General Permit) regulations. The modular design of the water-lubricated sealing system allows servicing work to be carried out very quickly and safely.

Depending on the specific application and our customers´requirements, the following Simplex seals can be combined with the Simplex BlueRun sterntube solutions providing a complete package.

Simplan

Mechanical fwd seal for water lubricated sterntubes with additional pneumatic seal.

Constant sealing pressure

Unique materials technology

Practically maintenance-free

Cost savings through less docking time

Data sheet

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Simplex Basic
water-lubricated (ZW-P),
SC3 – fwd seal

2-ring forward sterntube sealing system for water-lubricated sterntubes. Equipped with an additional inflatable static seal (Pneumostop).

Available as a split and not-split version

Reliable equipment covering the whole range of shaft diameters

Increased service life of the sealing rings and liner without external components, thanks to reliable lubrication by water circulation

Customized solution for all new build and retrofit requirements

Data sheet

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Carboplan Surface

Mechanical face-type seal for water-lubricated sterntubes. Equipped with an additional inflatable static seal (Pneumostop).

Corrosion and wear-resistant thanks to silicon carbide (SIC) sealing ring material

Special design for deep draughts and larger shaft diameters

Data sheet

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Water-lubricated sterntube bushes

The maritime industry is controlled by strict rules and regulations, whether environmental requirements or construction specifications. These stipulations play a decisive role whenever new vessels are designed and built or when older vessels are retrofitted to the latest technical and ecological standards.

For this reason, water-lubricated sterntube systems, including polymer bushes, are becoming increasingly popular for marine applications. These solutions have turned out to fulfill the most stringent environmental requirements, such as the VGP 2013 or Polar Code.

Sterntube bush

The Simplex BlueRun product range includes water-lubricated polymer bearing bushes, TWP, which have been designed for a long service life

For all types of water-lubricated sterntube systems: for fresh and sea water as well as for open and closed systems

No need to remove the shaft in order to exchange the bearings by using the split version

Available for shaft diameters up to 500 mm

Data sheet

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Bush in bush

Simplex carrier bushes are fixed to the sterntube and are suitable for the Simplex BlueRun bushes.

Data sheet

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Water quality system

Thanks to the Simplex BlueRun water quality system the seawater is cleaned by filtration and then pumped through the sterntube bushes for lubrication, cooling and flushing purposes.

No overheating

Any solids are reliably removed

Designed to operate on a standalone basis or fully integrated into the ship´s control and monitoring systems. The system can be operated in an unmanned engine room

The water quality system consists of two pumps (one standby). A single filter is connected to them

Constant measurement of temperature, pressure and flow rate of the water. All measurement results will be shown on the system’s display

Data sheet

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Tail shaft monitoring

The tail shaft monitoring system provides reliable information about how the bushes are wearing, thereby allowing early replacement planning.

Two sensors are installed in the upper side of the bearing bush and are connected to an evaluation unit

Contactless measurement of bush wear

Data sheet

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Sterntube seal accessories

The requirements for the operation of a ship determine the individual design of our Simplex shaft components. In addition to maximum reliability, safety and efficiency on-board, SKF Marine offers an extensive program of Simplex supporting units for condition monitoring, oil supply, cooling and operation.

In combination with the proven products from SKF Marine, our customers receive complete solutions from a single source for everything related to the shaft assembly.

Active circulation unit

Equipment for continuous oil circulation and refreshment of the aft seal lube oil. The system provides optimized lubrication of the seal rings for enhanced aft seal performance.

Contaminants in the oil, such as water, air or particles, will be transferred from the aft seal to the aft seal tank for further lube oil maintenance and condition monitoring

Condition monitoring equipment for the lubricant is available upon request

Data sheet

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Air Pressure Control Unit AFT Seal Tank

The unit regulates air supply to increase the head pressure of the aft seal tank - based on the vessel's draught. No manual changeover of tanks at different installation heights is required.

Equipment is designed for vessels with high and variable draught, such as tankers

Direct Forced Lubrication Unit

This system provides the constant oil circulation of the sterntube lube oil. The cooler and filter helps to ensure optimal temperature and cleanliness of the lube oil before entering the sterntube.

Unit available as loose supply or ready-mounted on a frame

Air Pressure Control Unit Gravity Tank

Regulates air supply to increase the head pressure of the sterntube gravity tank. This equipment is standard design for vessels whose structure and layout do not allow for installation of the gravity tank at the required height.

Available as a basic version or an advanced system with redundancy control for twin shaft vessels

Lube Oil Unit

The high pressure hydraulic pump provides the required hydrostatic oil pressure at the lubrication pockets of the bush and intermediate shaftline bearings. The combination of customised bearing design and directed oil pressure keeps the shaft floating in all bearings, even at very low speed or with frequent changes of the rotating direction, thus minimizing wear in the bearing.

Application: Sterntube bush bearing – Intermediate shaft bearing – Radial bearing of thrust bearing

Net protection

A potential risk posed by fishing nets or lines floating on the surface of the sea is that they can be drawn in by the propeller and become entangled – they can then find their way into the seal and damage the sealing rings.

If a sterntube seal becomes damaged and oil enters the seawater as a result, the ship will not be allowed to continue its journey and must be docked for immediate repair. High docking costs and potential contractual penalties through noncompliance with delivery deadlines can have serious consequences.

Net protector

Dirt, net and rope protection ring for effective aft seal protection against dirt, fishing nets and lines.

For all Simplex seal generations and types

For new-build and retrofit; sufficient installation length provided

Dirt and net protection ring, fully split

Positioned in front of first sealing ring

Data sheet

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Net cutter

Knife blades for aft seal protection against fishing nets and lines.

For all Simplex seal generations and types

For new-build and retrofit; sufficient installation length provided

Net or line cutting knives fixed on to the rope guard or propeller

Made from stainless steel

Data sheet

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Net pick-up

Net and rope collecting ring for aft seal protection against fishing nets and lines.

For all Simplex seal generations and types

For new-build and retrofit

Net collecting ring is fully split

Complementary component to the aft seal

Data sheet

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Intermediate shaft bearings

The operational efficiency of a machine or plant is determined above all by the quality of the bearings used in all rotating applications. This applies in particular to the line-shafting of ship propulsion plants. The Simplex bearings were developed especially for this purpose as short, plain bearings.

Intermediate Shaft Bearing

Simplex bearings disposed of a short shell length. They can be precisely aligned to avoid edge loading. The running porperties of the bearing metal have been optimized with a technically highly advanced bonding of bearing metal and shell. The vital lubrication of the bearing is safeguarded in the Simplex bearing at all times, even at low shaft speeds.

Oil lubricated shaft bearing, plummer block or tunnel bearing design is available

Temperature sensing and monitoring systems included

Cooling systems available for unfavourable operating conditions

Data sheet

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Simplex high-load thrust bearings

The Simplex high-load thrust bearings (HL) are single-collar bearings for absorbing the thrust loads produced by the ship's propeller.
 Other applications, such as with turbines, air blowers, cutter suction dredgers and centrifugal pumps, are also possible. If required, the bearing's internal parts can also be fitted into gearboxes or, by using flange-type casings, onto engines and motors. Of course, the Simplex HL thrust bearings are manufactured in accordance with the rules of all international classification societies.

High load thrust bearing

Single-collar axial thrust bearing for taking up thrust loads produced by the ship's propeller.

For any type of propeller (CPP or FPP)

Temperature sensor (Pt 100) fitted at the upper thrust pads in both thrust directions

Simplex HL thrust bearings from size 500 upwards only as axial bearings due to more precise alignment of the separate radial bearing after thrust bearing foundation

Data sheet

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Simplex sterntube bushes

The Simplex sterntube bushes have been proven over decades of shipboard operation. 

While merchant shipping generally benefits from the standard design of Simplex sterntube bushes - cast-iron/lead-based white metal (GG-20) - the bushes intended for ships subjected to higher stresses, such as icebreakers, are made of nodular cast-iron/tin-based white metal (GGG-40). The intercrystalline bonding of the materials provides the highest possible quality and durability. The length of a bush is determined by the rules of the respective classification society.

Available in different material combinations of bushes and white metal lining

Bushes available up to 2,800 mm in length and with outside diameter of 1,200 mm

Sterntube bush

Simplex sterntube bushes in combination with Simplex seals as the ideal solution for oil lubricated sterntubes.

Available in different material combinations of bushes and white metal lining

Data sheet

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Bush in bush

Bush in bush version with sterntube bush in assembly bush.
Assembly bush: inside finish-machined and outside rough-machined with seal flange ring.
Inlay bush: inside and outside finish-machined for easy exchange.

True customized turnkey solution ready for installation for all vessel sizes and all vessel types

Certified by all major classification societies

Data sheet

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Simplex sterntube solutions

The Simplex FlexiTube and SternTube provide customers with precision technology in a complete package solution, including sterntube bushes, patented sealing packages and installation supervision.

For designing a customized sterntube solution, SKF Marine only needs to know the type of hull, the sterntube length and the diameter of the propeller shaft. Thanks to an intelligent module design we are able to deliver customized stern tubes for vessels of all types and sizes.

FlexiTube

Complete sterntube with white metal bush bearings, completely piped and ready to install. Design allows compensation of axial movement. Should a temperature differential between the water and the sterntube cause the sterntube to expand, the FlexiTube is able to compensate for this due to its sliding fit forward mounting point. This means that the ship’s hull structure will not suffer stress cracking.

Interfaces adapted to the shaft seal

Connection box for monitoring system

One interchangeable temperature sensor

Two bearings (three for SR-Type) fitted in our workshop

Integrated pipes for shaft seals (if required)

One integrated oil sampling pipe

Connections for filling of sterntube oil and air outlet

Connections for filling of epoxy resin and air outlet

Package for securing the epoxy resin filling horizontally and vertically as well as for alignment

Patented sealing package to secure the epoxy resin filling

Complete o-ring and bolt kit

True turnkey sterntube solution

SternTube

Complete sterntube with white metal bush bearings, completely piped and ready to install.

Bulkhead seals

Where bulkhead openings for shafts need to be sealed to protect adjoining spaces against flooding, Simplex bulkhead seals offer the optimum solution. Our list of references includes sealing solutions for chemical and product tankers as well as for gas tankers and offshore vessels. Our special gas-tight bulkhead seals are also available for explosion hazard areas. The latest generation of Simplex bulkhead seals operates well under the highest shaft speeds and is especially designed for offshore supply vessels with long shafts and multiple bulkhead openings.

Centrax

The Centrax bulkhead seal is used exclusively on ships for sealing rotating shafts against bulkheads to avoid flooding related compartments in the event of an accident. Radial and axial movements of the shaft are easily absorbed by the bulkhead seal.

Self-lubricating, no additional lubrication needed

Practically maintenance-free

Centrax S

The Centrax S bulkhead seal is based on the Simplex Centrax design. In order to provide additional compensation for large radial displacements of the shaft, the Centrax S consists of an inside and outside casing.
The inside ring is inserted into an outside housing ring. Radial shaft movements, such as shocks for instance, are easily absorbed by the bulkhead seal.

Self-lubricating, no additional lubrication needed

Practically maintenance-free

Simplex

Two sealing rings face each other, thereby acting as a barrier chamber which is filled with oil. This chamber is connnected to a 15/30 l oil tank and permanent lubrication and cooling of the oil is ensured by means of a circulator.
A special solution for high shaft speeds is delivered by a back-to-back arrangement of the sealing rings in combination with applicative grease.

Available as a completely axially split version

Designed for in-situ overhaul

Simplex rudder stock seals

Simplex rudder stock seals exclusively seal oscillating rudder stock shafts against oil or water.

For straightforward locations we manufacture easy-to-fit packing glands consisting of split-ring elements. For more awkward locations, for example in the region of the waterline, we offer our Simplex rudder stock seal which matches the Simplex sterntube seal in terms of its design and size availability.

We offer standardized types of rudder stock seals which can be supplied with grease or oil lubrication depending on the customer’s specification. As for all our seals, we also offer customized versions of the rudderstock seal.

Simplex Upper rudder stock seal

The Simplex Upper rudder stock seal is located at the upper end of the rudder shaft, installed at the top of the rudder stock trunk, thus operating in the steering gear room.

Simplex Lower rudder stock seal

The Simplex Lower rudder stock seal is located at the lower end of the rudder shaft. It can either be installed at the bottom of the rudder stock trunk thus operating in the seawater. We also offer a version that is designed to protect against sea water and is for installation inside the coker unit.

Simplex services

We provide support for your ship throughout its life cycle – taking care of it every step of the way with professional planning, regular dockings, emergency servicing and quality spare parts. Our comprehensive service for Simplex shaft components, e.g. sterntube seals, bushes, tunnel bearings and plummer blocks, ensures that your vessel is optimally equipped, maintained and always ready for operation – worldwide and 24/7.

Worldwide service network for maritime customers

Available 24 hours a day, 365 days a year

Direct contact by service email: service@skf-marine.com

Qualified SKF service stations with trained and certified experts

Highly professional staff for efficient service and customer support

Initial Consultation

Complimentary initial consultation, planning, technical support for new-build and retrofit

Close coordination with the customer and the shipyard during construction

Advice on country-specific provisions and regulations, for example in USA waters

Initial installation of components

Commissioning of the components on board

Alignment control

Product training for the crew

Data sheet

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Regular docking service

Optimal replacement parts based on the ship´s history

Outstanding OEM quality

High availability of replacement parts and express delivery

Qualified service technicians worldwide

Standardised service reports worldwide

Data sheet

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Vessel operation service

Maintenance and functional checks for all components

Technical advice, fault diagnostics and system optimisation

Service information provided on a regular basis

Data sheet

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Emergency service

24/7 hotline with technical support

Emergency service support

Highest availability of standardcomponents and spare parts

Additional express production capacities

Underwater repair service

Data sheet

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Spare parts

Central warehouse in Hamburg plus two more in Singapore and Shanghai

Short notice production of spare parts: 98% of already delivered parts can be reproduced within a very short time

Speedy delivery thanks to airport security clearance

Constant quality checks, ongoing development

Specially-developed tools for spare parts installation

Data sheet

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