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Marine Services

A global partner for marine support

For over 60 years Bruinhof Marine has supplied, commissioned and serviced marine propulsion gearboxes and drive component parts for drive (shaft) generators, dredge pumps, jet pumps and cutter drives.

Our staff offers extensive know-how and many years of experience with the former Lohmann + Stolterfoht and the current Flender NAVILUS marine gear units and their associated couplings, clutches and ancillary parts such as; lubrication, cooling, temperature and pressure monitoring and control systems.

Brochure: Marine Services

Products & Parts

Flexibility for all applications

Flender has been building high-quality, reliable, standard and customised gear unit solutions for a wide range of marine applications for decades. These are developed within the well-known and established modular gear unit system NAVILUS ®.

We attach great importance to our dialogue with shipyards and operating companies. Our customers know that we take their requirements very seriously and we ensure, through our industry knowledge and expertise, that these are addressed in full when developing new solutions. At the heart of which is our tried and tested technology.

In the marine propulsion technology sector, it is important to operate a ship’s main engine over long periods at the most efficient operating point possible and at the same time, reduce emissions to a minimum. This is especially important for applications with multiple uses, i.e. different propulsion profiles. The central objectives of which are; low operating and life-cycle costs, minimum environmental impact, as well as achieving the highest levels of reliability and safety.

Your benefits at a glance

  • Flexible drive concept
  • Custom power ratings
  • Low / minimal noise generation
  • Low vibration
  • High efficiency
  • Optimum power-to-weight ratio
  • High quality, availability and reliability
  • Worldwide service
  • Our industry experience and competence


  • Single-engine ships
  • Twin-engine ships
  • (Two-gear) PTO, PTI, PTH
  • Dredger (cutter head drives, suction and presser drives, jet pump drives)
  • Ships with low-speed diesel engines (Generator)
  • 2-Speed applications on chemical tankers, superyachts, seismic-, fishing-, and rescue vessels
>Product page: Navy & Shipbuilding


  • Clutch torques of up to 304 kNm
  • Pneumatic switchable
  • Reliably interrupts or establishes the flow of power

Experience since 1964 - proven reliability

The PNEUMAFLEX clutch is a combination unit comprising a double conical friction clutch and highly elastic coupling. The clutch components comprise two inner friction cones which are pressed against two outer friction conical faces via the pneumatically actuated clutch cylinder.

The elastic part comprises rubber elements arranged in parallel which are completely optimized enhancing the coupling's reliability and performance significantly.

Due to the high torsional flexibility of the rubber elements, PNEUMAFLEX KA clutches shift resonance (torsional vibration) between the natural frequencies of the system and the exciting frequencies of the driving and driven machines across the operational speed range. Due to their high damping qualities, they also reduce the residual vibration amplitude and thus protect the valuable assets.

Moreover, the clutch compensates center mismatch, in both axial as well as angular misalignment, for connecting machinery elements (engines, gearboxes, generators, etc.) within a predetermined tolerance range. Additionally, the rubber elements effectively isolate structure-borne noise.

Your benefits at a glance

  • Combination of a dry friction clutch and highly elastic coupling without short-lived idle bearing system
  • Complete separation of primary and secondary sides
  • Backlash-free, no wear of components subject to backlash
  • Smooth and easily controllable engaging operation
  • Protects the propulsion system against overloads if a slip monitoring unit is used
  • Clutches of type KAP can be vertically removed


  • Torsionally stiff clutch torques up to 1400 kNm
  • Pneumatic switchable

Smooth engagement

The PNEUMASTAR is a torsionally stiff, double-cone, friction clutch. The clutch components consist of two inner and two outer friction cones which are pneumatically pressed against the outer tapered friction faces via a pneumatically operated clutching cylinder. Rubber sleeve springs form the torsionally stiff portion of the clutch.

Due to the high resilience of the rubber sleeve springs, the PNEUMASTAR clutch is capable of effectively compensating radial, axial and angular misalignments within predetermined limits. Moreover, as the clutching components are moved over the rubber sleeve springs during the actuation of the clutch, wear through axial sliding movement between the various contacting parts is avoided.

Pneumatic operation of the clutch enables speedy and precise manoeuvring, which is a prerequisite for use in the marine application.

Your benefits at a glance

  • For stiff, but interchangeable connections
  • Backlash-free, no wear to components subject to backlash
  • Smooth and easily controllable engaging operation
  • A range of clutch types are available with different connections

Clutch Control Unit (Box 70/PFA 8600)

There is an electro-pneumatically operated remote clutch control device available for PNEUMAFLEX and PNEUMASTAR clutches, which performs the following functions:

  • Adjustment of the engaging time
  • Compressed air failure alarm signal
  • Automatic disengagement of blocking of clutch operation if the standard solenoid valves have been actuated by external interlocking devices
  • Automatic changeover from engaging air pressure to working air pressure
  • Automatic disengagement of the clutch if the working air pressure falls below the value required for slip free torque transmission

The pneumatic control system might lose a bit in functionality over time due to various ambient conditions on board. Air leakage, dirt, even grease or oil in the valves or hoses inside the box may lead to catastrophic events such as a frozen clutch or failure in engaging / dis-engaging, resulting in reduced operational reliability.

To prevent this from happening, only a minimal investment is required with the introduction of the Flender B.V. developed “Swivelling Control Panel”. The “Swivelling Control Panel” enables an exchange system to be created on board. With a spare panel you will no longer suffer operational downtime due to malfunction and you can rely on our services to repair the damaged panel at our workshop. Defective panels are assessed; malfunctioning items quoted and following final customer approval are replaced. Repair costs are therefore cost effective and limited to replaced components.

Electronic Slippage Monitoring Device CA

Clutch slippage is checked by the electronic monitoring device CA which has been designed to:

  • indicate clutch-slippage as a result of overload
  • operate contact free
  • Identify impermissible load at an early stage
  • offer additional safety to prevent damage due to overload

The slippage monitoring device CA indicates on PNEUMAFLEX and PNEUMASTAR clutches, inadmissible clutch-slippage. The monitoring function of the unit is based on measuring the speed difference between the primary and secondary part of the clutch.

The monitoring unit is maintenance-free, contact-free and therefore does not suffer mechanical wear. A high degree of functional reliability is ensured by making use of integrated circuits.


  • Highly elastic shaft coupling for torque of up to 928 kNm
  • Alignment compensation
  • Excellent damping capability

Flexible solution for shaft connections

The elastic rubber elements were completely optimized significantly enhancing the coupling's reliability and performance. The most significant feature of the coupling is its rubber high torsionally flexible elements. Moreover, the coupling compensates center mismatch, axial as well as angular misalignment of the shafts and machinery elements, to be connected (engines, gearboxes, generators etc.) within a predetermined tolerance range.

The coupling is especially suited for use in diesel engine propulsion systems and installations where torsional vibration must be considered.

Various rubber hardness grades effectively address the natural frequencies arising in the respective drive system.

SPIROFLEX KS couplings shift resonance (torsional vibration) between the natural frequencies of the system and the exciting frequencies of the driving and driven machines. Due to their high damping qualities they also reduce the residual vibration amplitude and thus protect the valuable plant. Additionally, the rubber elements isolate structure-borne noise effectively.

Sizes KS 100 to KS 370 are designed with ring elements EJN while sizes KS 390 to KS 530 are fitted with four EJK segments which together form a ring element.

Your benefits at a glance

  • Elements can be removed radially
  • Exclusively features frictionally locked connection
  • Backlash-free torque transmission
  • Flywheel connecting dimensions acc. to DIN 6288

DENTILUS gear couplings

  • Easy to mount / dismantle
  • Two-piece housing

High performance, low maintenance

DENTILUS gear couplings of the AS-, AG- and AV- type, formerly branded as Lohmann & Stolterfoht, are designed with crowned teeth and are used where torques must be transmitted through shafts that are subject to movement in all axis’s. The gear couplings can compensate angular, radial and axial misalignments.Bruinhof Marine utilizes these couplings for marine applications such as generators, (dredge/jet) pumps, cutter drive shafts and other shaft-to-shaft connections.

Your benefits at a glance

  • Suitable for reverse operations
  • Quiet operation due to head centering
  • Special design for vertical operation available
  • Large permissible finish bore
  • Easy replacement of seals with split cover
  • High level of operational reliability due to high quality materials
  • Long service life with low levels of maintenance
  • High ambient temperatures possible
  • Interchangeable with preceding series

AXILUS thrust- and RADILUS shaft bearings

  • Bearing design tailored especially for shipbuilding applications
  • Self-lubricating operation, despite highly inclined positions
  • Noise and vibrations during operation are generally low

Absorbing the propeller thrust

The wide range of LRL/LRH RADILUS shaft bearings and LAR/LAK AXILUS thrust bearings, formerly branded as Lohmann + Stolterfoht, are designed for either intermediate radial shaft support, or to take over axial thrust force out of the driven machine, or both at the same time. The bearings are supplied with white metal linings in the shell and suitable for shaft diameters between 110 and 850 mm. Various configurations are available, such as with / without built-in cooler, shaft load monitoring equipment, forced lubrication and similar features.

Your benefits at a glance

  • Self-lubricated
  • Low maintenance
  • Reliable
> Brochure: RADILUS LRL
> Brochure: AXILUS LAR
> Brochure: AXILUS LAK


Expert commissioning by Flender specialists for smooth operation of your installation

Complex equipment needs to be expertly installed and commissioned to ensure its long lifetime. Flender B.V. / Bruinhof Marine offers an experienced commissioning team to provide customers with a service which covering; installation check, alarm testing, sensor calibrating and load- & performance trials.

Your benefits at a glance

  • Highly flexible service and an excellent cost-benefit ratio thanks to specialized trained personnel
  • Extensive product know-how

Maintenance ensures optimum availability of industrial plants around the world

Inspection and preventive maintenance need to be carried out regularly, especially on machinery operating continuously in a harsh environment. The goal of inspection service is to identify and assess the actual equipment condition by either visual inspection or endoscopic inspection of the internals. A final report with recommendations is included.

To resolve unplanned equipment downtimes as quickly as possible, we are offering a fault correction service for your equipment worldwide – in the form of a team of experienced service specialists. The scope of the service includes troubleshooting, error cause identification, repair or replacement of defective components and the provision of a final report.

Your benefits at a glance

  • Improved plant availability
  • Repairs on the high-quality level of the manufacturer
  • Transparency of services carried out and the parts used through repair reports

Preventive maintenance secures your machine performance

Maximize your equipment availability by choosing our preventive maintenance service. Regular maintenance measures based on the products' age and operating hours, will help you to keep equipment in the optimal operating condition.

Your benefits at a glance

  • Scheduled maintenance downtime instead of unscheduled production outages
  • Planning of inspection and preventive maintenance intervals to suit operating conditions
  • Optimum plant and machine performance


To avoid damage to gear units and to prevent failures, the first symptoms should be detected early. Therefore, for optimal reliability of your drive, we offer you our condition monitoring, DIAGNOSTEX®. As a specialist for gear units we will ensure your drive is well maintained through means of analysis, diagnostics and inspection.

We apply the following possible methods: whether telediagnostics, mobile vibration analyses, acceptance measurements or load and torque measurements, inspections, endoscopy – condition monitoring means above all to have the right feeling for your operation.

We offer you the best technologies for condition-oriented maintenance of your drive to prevent problems before they can exist. Continuously online with remote assistance and analysis from our side or offline upon a visit from one of our engineers, all depending on your level of participation.


With online condition monitoring, we offer you a diagnostics instrument that is precisely tailored to your needs. Our remote diagnostic services allow condition-based maintenance of your standard and application-specific gear units. The diagnostics know-how of our gear unit experts, combined with the DIAGNOSTEX 2000 and DIAGNOSTEX 4000 hardware, represent a decisive step toward non-stop plant availability. Both remote service products offer you online data collection and recording as well as transmission of the measured data to our Remote Expert Center via secure data links.

DX Mobile

Mobile services offer a flexible and cost-effective solution for standard and application-specific gear units. Measurements are carried out using hand-held devices on site by Flender service professionals at regular intervals or when required e.g. in troubleshooting cases. Data evaluation and diagnosis are carried out by our competent expert team.

Your benefits at a glance

  • Qualified data evaluation and diagnostics by competent experts
  • Specific recommendations for action as well as early warnings in the event of a fault
  • Reduced maintenance costs through early detection of wear-related anomalies
  • Ability to schedule repairs
> Flyer: Gear units in focus. Process under control.
> Product page: Diagnostic Services

Bruinhof Marine

Center of Competence

Due to a global corporate level focus on the marine business, Flender B.V. in Rotterdam (NL) has been assigned as the international center of competence for all marine mechanical drives and lifecycle related support. This includes responsibility for worldwide repair, service, modernization-modification and commissioning, parts supply and technical support for all current Flender and former Lohmann + Stolterfoht Marine drive systems and components, consisting of gear units, couplings/clutches, oil supply systems and journal bearings. With the global Flender network behind us, our team’s footprint has extended. We can now offer our customers the benefits of a global player on a local scale.

Just one phone call away

We have access to a global inventory of genuine spare parts and databases. With this historical installed base drive information, whereas at the same time we strive for the presence of local knowledge and spreading of our passion and dedication. With that philosophy we tend to be only just one phone call away, willing to contribute to the highest level of operational reliability for our customers.

Bruinhof through the years

Since 1956 Bruinhof B.V. has supplied, commissioned and serviced reliable Lohmann + Stolterfoht marine mechanical propulsion systems and other drive components for drive (shaft) generators, dredge pumps, jet pumps and cutter drives for the BeNeLux market. In 1998 the Lohmann + Stolterfoht decided to return to their core business. In doing so the products for marine gear units, couplings/clutches and slide/thrust bearings was sold to several other manufacturing companies.

A. Friedrich Flender AG took over the gear unit portfolio and as such Bruinhof B.V. became part of that transaction, becoming their lifecycle support partner. The Lohmann + Stolterfoht NAVILUS range was re-branded as Flender NAVILUS. The DENTILUS gear couplings were sold to Malmedie Solingen and the AXILUS and RADILUS shaftline bearings acquired by Renk Hannover. The Spiroflex, Pneumaflex and Pneumastar products became part of the Bosch Rexroth portfolio (today ZF). Despite all these changes, and due to the extensive knowledge on product lifecycle, the new portfolio owners reinstated Bruinhof B.V. as their product and service representative.

As a result of the Siemens AG takeover of Flender in 2005, Bruinhof B.V. have been integrated into Siemens Netherlands N.V. with effect from February 2009.

Through a renewed global marine business engagement at corporate level as well as a focus on lifecycle services in 2011, Bruinhof Marine was assigned as the international center of competence for all marine mechanical drives and associated lifecycle support by Siemens.

Bruinhof Marine therefore became responsible for worldwide repair, service, modernization-modification, commissioning, parts supply and technical support for all current Flender and former Lohmann + Stolterfoht Marine drive systems and components. This comprises gearboxes, couplings/clutches, oil supply systems/heat exchangers and journal bearings.

To fulfil a role in the changing market, faced with increasingly fierce competition from Asia and price pressure from overcapacity, Siemens decided to transform their Mechanical Drives Business Unit into a standalone company within Siemens. In September 2018 Bruinhof Marine became a new legal entity as Flender B.V.

Flender B.V.

Bruinhof Marine

Postal address:

PO Box 9607
3007 AP Rotterdam
The Netherlands

Visiting address:

Boterdiep 37
3077 AW Rotterdam
The Netherlands
> Maps

Billing address:

Attn.: Accounts payable
PO Box 9607
3007 AP Rotterdam
The Netherlands

Contact details

Phone: +31 (0)10 800 9454
Marine Spare Parts:
Marine Field Service:

Bank details

Bank account: Flender B.V.
IBAN nr: NL50DEUT0265246571
VAT nr: NL 858144438B01

Registered at the Chamber of Commerce in Rotterdam as nr. 70106401