Latest news

Being a partner of the industry and as one of the leading innovators of the market, we are continuously developing our products as well as ourselves and we always are implementing new ideas. What’s new? Which patent applications have been made recently? Which technologies are we using?

In the category „Latest news“, you will find the answers to these and many other questions. Because as a partner oft he international automotive idustry, we always have some interesting news for you. So it is worth it to frequently have an eye on these categories.

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Special rail vehicles are required for the construction and maintenance of track systems and overhead lines. This includes, for example, rail-mounted fire-fighting and rescue vehicles, crane trucks as well as rail milling machines. Vehicles with wheel flange, rail head or flank lubrication systems, with suction devices for cleaning ruts, with contact wire and track measuring devices, with snow clearing attachments and high-pressure water systems for cleaning points or for the contact wire de-icing device are also part of this special area of rail transport. The field is highly diverse and technically very demanding, as these vehicles are always high-precision custom solutions for very special tasks and areas of application ...
Cleff specialises particularly in the development and production of windows and doors for these special vehicles used in international rail transport. From our numerous references in this field, we would like to present our reference project for the Austrian company Linsinger, founded in 1939, which we equipped a rail milling train with access doors. The example clearly shows that this is a system delivery, which means that the door, door window and the entire lock and hinge technology come from a single source: manufactured by Cleff in Wuppertal. Every component of such a door is subjected to a series of tests in order to ensure that the individual components function reliably in the long term. Another project was a locomotive door with integrated heated windscreen and windscreen wipers as well as windscreen washer nozzles.
This example also shows the structural complexity and the technical demands with which we, as a supplier, meet the manufacturers of special rail vehicles. As you can imagine, a door of this kind is often only manufactured in manageable quantities – and this is perhaps another thing that sets us apart from our competitors on the market: We are decidedly happy to produce small series – with the same commitment and demand for perfection as we do for the large-scale orders we receive.

Do you need a window or door solution for your special rail transport vehicle? Contact us and tell us about your requirements – we will swiftly ensure that the solution you need is tailored to your individual situation.

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When local public transport carriages are outdated, they can be rebuilt with the help of a partial or complete refurbishment and restored to their best for many years of everyday mobility. Cleff supports these refurbishment processes with vehicle windows, vehicle doors, partitions and a large number of spare parts, such as new handles, glass with add-on parts and seals. Typically, it takes several years before a vehicle is refurbished after it was originally equipped. Over this time, we have often optimised processes and improved materials, which means that spare parts can possibly be used in better quality than the original parts.
We are open to all refurbishment projects, whether they involve vehicle windows - as is currently the case with the "Durability BR 481" project for the refurbishment of the Berlin S-Bahn (urban railway) series 481 - or smaller projects such as the refurbishment of an island train or a small railway. The logistical processes of our company allow us to deliver on schedule, making it easier for you to plan your individual project.

Discover new perspectives for your vehicle refurbishment - with Cleff by your side as a reliable partner for spare parts refurbishment.


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The new 5-spindle-CNC metal-cutting machine
It mills, it drills and it cuts threads: our new CNC-controlled metal-cutting machine will be able to do all that. We expect this high-performance "newcomer" in our company's machine park in spring 2023. Technophile readers will already know the process: The 5-axis metal-cutting machine can process components in the X, Y and Z axes as well as in an additional swivel or rotation axis - and simultaneously, of course. With the new investment, we will also be able to machine even larger window frames in the future: Dimensions of 3,000 mm x 2,000 mm x 650 mm can then be subjected to mechanical machining processes without any problems.
This investment is not a "mere" replacement investment, but will enable us to produce even larger window frames in the future and thus to proactively meet the increased market requirements. 
The stronger drive power of our new 5-axis machine is also accompanied by an increase in machining performance - which enables us to take account of the constant pressure on prices.
Incidentally, our old machine, which already had CNC-controlled 5-axis technology, will not be scrapped, but will be put on the second-hand market, where it can certainly be productive for many years to come in another company. 

The new wet separator 
Wherever work is done, as the saying goes, swarfs fall and dust is raised - and in our production, especially in the grinding shop, quite a lot of it is produced ...
In order to reduce dust exposure in the premises - for employees and the environment - as much as possible, these dusts are extracted and bound in a water bath - in the so-called wet separator.
Our wet separator was also getting on in years and in order to be able to subject the dust-laden air directly at the workplace to maximum cleaning performance, we installed a new wet separator in 2022.
However, our requirement was not to interrupt ongoing operations during the installation of the new wet separator.
This required a temporary "bypass solution", with a mobile unit taking over the cleaning function while the old system was dismantled and the new separator installed.
The dismantling and installation of the new separator was completed within one week. This required perfect planning by all the crafts involved in the work. During commissioning, the guaranteed data were checked - and more than fulfilled. In addition, the new wet separator now develops significantly lower noise emission values.

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A spirit of optimism has guided us throughout the year 2022, at the end of which we can look back on numerous successful projects with pride. Having said that, we fully appreciate that many of our accomplishments would not have been possible without you, the customers and suppliers of the Cleff company. We would like to thank you from the bottom of our hearts for everything and assure you that you can keep counting on the Cleff brand in the new year - and thereby on our unremitting reliability, proactive approach and flexibility. Each year, people from less privileged backgrounds also count on us - which is why we support the Burgholz children‘s hospice and the Wuppertal food bank.
We wish you, your families and employees a truly merry Christmas season and may you embark on a happy new year in 2023 - with health, happiness, success and, of course, optimism!
For more information, please go to: and 

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At present, for instance, windows and doors are being built for 50 new Toshiba hybrid-diesel-battery locomotives HDB 800. Toshiba sets standards in terms of environmental friendliness with the crucial future technology of hybrid propulsion: namely, the CO2 emissions of the Toshiba HDB 800 are significantly reduced. These alternative propulsion concepts make it possible to work more resource-efficiently in the marshalling yards. The result is annual energy savings of at least 30% and the saving of 1 million litres of diesel fuel per year. What's more, the brand-new Toshiba hybrid locomotives are easier to operate thanks to the incorporation of the state-of-the-art technology.We in Wuppertal are also delighted about this forward-looking order and the great trust that has placed in the Cleff brand.This is because the locomotive combines high European and Japanese engineering standards, including being equipped with the latest technologies, such as the SCiB™ Lithium titanate battery system1 certified by TÜV Rheinland, which satisfies numerous quality and quantity-based safety requirements.Cleff's system deliveries also have to ensure safety when it comes to the driver's entrance door. Our door system delivery for the new Toshiba HDB 800 locomotives not only includes the door, but also its individual components such as the door frame, hinges, lock, handle, seals and windows. This is why all components are carefully matched to each other by our designers. New doors are subjected to host of tests at our in-house inspection and test centre, thus guaranteeing a permanently flawless function and maximum safety with regard to a wide range of loads.

1 SCiB™ is a trademark of Toshiba Corporation registered in Japan as well as other countries.

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As a system partner, Cleff is responsible for the supply of individual window and door solutions for driver's cabs of locomotives.
Here, we offer window solutions with different functions such as integrated wipers, wire and layer heaters.
Furthermore, when it comes to window construction for locomotives, the Cleff brand stands for
• the fulfilment of different transmission requirements
• coatings for noise and cold reduction
• integrated heating conductors with semi-transparent cover print as protection
• solutions for passive mobile radio support
• glass with scratch and shatter protection films
and much more.
All side windows as well as front and rear windows for locomotives can be adapted to the respective requirements and needs of our customers.
Cleff door solutions benefit from our extensive experience as a system supplier, which includes lock systems and hinge technology as well as door frames in the respective system scope.
The following applies to both product groups: We develop solutions for the most wide-ranging installation spaces – and in all conceivable forms.

Simply talk to us about your needs and we would be happy to advise you.

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You are probably wondering what kind of "good design" could be applied to our products in the first place. Good design is a fixed factor in the consumer sector, e.g. for household or hi-fi appliances - but also fo vehicle windows and doors or partition walls ...?.

Our answer is simple: design does a lot more than just some attractive shape and the right proportions. For us, product design also means perfect ergonomics, because a door, window or emergency exit handle, for example, can only be operated smoothly if it has the right shape - and under certain circumstances it can save lives. Many of our company's products also have to be designed in a way that is understandable to the layman and resistant to tampering because they are used in public transport.
To this end, design ideas play an important role. Product design can also provide valuable ideas for constructive solutions in the area of pre-design. Sometimes even tooling costs can be reduced through alternative design approaches.
And last but not least: good product design usually sells better and tops off the often sophisticated overall design of a vehicle. Especially in terms of the total development costs of a new product, such costs are relatively reasonable. For example, Cleff can implement design drafts as 3D-printed parts quickly and cost-effectively at an early stage of development. They are then used, for example, for pre-testing and for checking the functionalities. In addition, ergonomic aspects and aesthetic appeal are also evaluated very positively.

That is why our development work is often backed up by well-versed partners with many years of experience in the design industry. Together with them, we prevent possible "operational oblivion" and at the same time, create compelling solutions for our customers.
Do you need a special handle - perhaps even with an integrated logo, a hinge or a special profile solution albeit with an impressive design?

We will be more than happy to discuss product development and design with you. All you have to do is get in touch with us.

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International rail transport involves high loads. Punctuality in rail transport, be it local or long-distance, safety and operational readiness of the vehicles, depends on the quality of the individual products used to constitute a rail vehicle. Cleff contributes to this with vehicle windows and doors, partition wall systems and the timely delivery of spare parts, e.g. for refurbishment. Our full range of products in the field of functional glazing has resulted in numerous cooperations with leading manufacturers of rail vehicles in recent years.
Regardless of whether this involves driver boarding doors, partition wall systems or a complete side window system with hinged and sliding windows. The range of services is not limited to individual products, however, but also includes solutions for technically complex systems: For example, the door frame, handle, hinge and lock system are combined to form a door system solution developed and produced from a single source – and thus perfectly harmonised.
As a result, the Cleff brand has stood for expertise in products for rail traffic for well over 85 years. And we are committed to reliable and trustworthy partnerships with manufacturers and transport companies throughout Europe. A team of 85 employees at our site in Wuppertal develops, produces and tests sophisticated solutions for the demanding everyday life of rail transport. Our quality claim: We provide safety and durability of rail products in large and small series.
In the field of spare parts for rail vehicles, our customers can expect a broad portfolio of rubber profiles/seals, glass with add-on parts, aluminium parts, handles, accessories and much more. Over the past decades, Cleff has gained a reputation as a contact partner for vehicle refurbishment, specialising in products for rail transport. Not only does the quality of the spare parts from Cleff often meet OEM quality, it even surpasses it, as numerous products are constantly revised and adapted to the respective current technical standards.
As a glass supplier, Cleff offers a wealth of expertise in the handling of glass as a material and all the properties required by the modern railway industry. The range of glass on offer is diverse and the depth of expertise in the advice we offer on the possible uses of glass and its desired properties is high – we are in the position to provide just that thanks to the technical skill of the experts at Cleff.

International rail transport requires new products, spare parts and glass for a wide variety of rail vehicles – for which we are a quality-oriented contact partner. This is the contribution we make in terms of reliability and safety in rail transport.

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... we offer the full range with driver boarding doors, boarding partitions,
partition wall systems - in the passenger area and the driver's cab - as well as the complete system glazing. When it comes to functional glazing, we develop and produce driver's cab windows in different variants such as flush/semi-flush, horizontal/vertical sliding, mechanical and electromechanical. We offer glazing from toughened safety glass to insulating glass. In addition, we offer hinged windows, sliding windows and windows with holders for passenger information, door windows, front and rear windows for trams and much more. We perform all relevant tests at our company or together with strong network partners.
The advantage: You receive all deliveries vehicle-related and pre-commissioned from a single source. This reduces your workload and simplifies communication, because you always have competent contact persons who are familiar with your project at all levels.
Do you need modern side glazing for your new local transport rail vehicles? Simply ask about the possibilities that Cleff also offers you for new partition walls.
Do you need front and rear windows? Why not also discuss additional glazing options for your new vehicles? You will certainly be surprised how extensive the development and production potential is here in Wuppertal. This is also one of the reasons we have been a long-standing cooperation partner of Stadler Rail AG, Alstom Bombardier, Siemens, Heiterblick and DÜWAG. They all rely on the many advantages that our services "from a single source" offer them.
Especially when it comes to the complete fitting out of trams with windows, doors and partitions, we are sure to be able to win you over with our design expertise and strong production performance.
You are warmly invited to visit Cleff in Wuppertal.


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Do you need glass? A lot of glass ... or a little glass? In any case, glass for vehicle glazing? Then we should get together and have a talk about it ...
Not only does Cleff manufacture complete functional glazing, but we also supply the right glass for your individual requirements. Glass has many possibilities – and this is what we offer and as a partner for glass supply, we have evolved into a permanent fixture in the supply sector over the last few years.
You define the requirements for the glass of your choice and we will provide the appropriate offer. For glass in various colours and shapes, with and without imitation etching, as toughened safety glass / laminated safety glass / ISO and stepped ISO, as bullet-proof glass, with coatings for light transmission, for climate optimisation and noise reduction, with ceramic printing or dot patterns, with coloured printing, tinting, foiling, anti-reflective coatings on one or both sides and much more.

Do you need your glass to have even more special properties? We would be delighted to inform you personally about what we can do for you in terms of glass, because it is impossible to list all the possibilities here.

So talk to us about glass – and discover Cleff as a supply partner for glass in a wide variety of designs.

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Every vehicle window and every vehicle door is only as good and reliable as the rubber profiles that accompany them.
This is where the choice of the proper profiles and materials comes into play. Because wind pressure – especially in the case of two-way traffic – extreme changes between low and high temperatures, strong cleaning agents that regularly act on the windows and doors with steam jet equipment – rubber profiles have to withstand all this and "keep tight" at the same time. Additionally, tolerances have to be taken into account that quickly add up when components are "lined up" and can be partially compensated for by rubber profiles.
Cleff also focuses on high quality in this respect. Following Aristotle's guiding principle "The whole is greater than the sum of its parts", we pay particular attention to the quality of every component and each material that is used in newly designed functional glazing or vehicle doors. And s particular attention must be paid to the quality of the rubber profiles used: they must not become brittle or lose their elasticity, and at the same time they must remain dimensionally stable for years in order to reliably fulfil their function.
Our many decades of experience in handling rubber profiles and our selection of the right types of rubber guarantee our customers the long-lasting function of these extremely important components. And of course, Cleff rubber profiles are also available for refurbishment and in the aftermarket business for rail and commercial vehicles: Replacing ageing profiles is easy and if the glazing is "still good", replacing the rubber profiles often gives the glazing a second life.

We would be happy to assist you whenever you need to replace the profiles in your vehicles. Regardless of whether this involves a rail, commercial or special vehicle, or cable, nostalgia or island railway. Cleff brand rubber profiles are always available for small or large series.

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We wish you a perfect start to the new year.
Tumultuous times are certainly behind us all, but now we are getting back on track and looking forward to the new year with renewed confidence, and the Cleff company is approaching the new year 2022 with fresh vigour.
Our teams in administration and production are already looking forward to interesting projects. Some of them have already been added to our order books and we see many exciting tasks in the development of new products and refurbishment ahead of us. The rail transport sector will certainly play a vital role again in the new year - and we will keep you informed about all the company's news here.
We look forward to working together with you again in more familiar "waters". Team and Zoom conferences have enriched the working world, shortened distances and made communication easier. Much of this will certainly remain, as it makes sense and saves valuable time. However, we all have definitely missed the personal contacts that so greatly enrich our professional lives. Soon we will surely be able to meet each other again more often. This is something we are very happy about and look forward to visits and discussions with you in a more personal atmosphere.
We would be happy to discuss your project on-site at your company or in a personal meeting at our premises. Also, if you would like to become acquainted with the Cleff company in Wuppertal and would like to gain an insight into our company and our products, simply make an appointment with us.
We look forward to seeing you in the new year 2022.


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... is now behind us. 2021 has once again moved the entire world like hardly any other in the past decades.
We have all learned that health is our greatest asset in life. Many have managed to weather these past months well, but several of us have also had to go through some decidedly painful, personal experiences. And who would have thought at the beginning of 2020 that the Corona crisis would be with us for so long?

The Cleff company has weathered this period well. Our employees are healthy. That is the most important consideration.
From an economic perspective, we owe our continued success in 2021 to long-standing customer relationships, intensive acquisition efforts and our team, which has pulled together and performed extremely well during a volatile time of unpredictable market changes, uncertain supply chains, rising material and energy costs.

As the year draws to a close, we would like to extend our special gratitude to our customers, whom we were able to support in numerous challenging projects – and, of course, to our suppliers and service providers, who have faithfully stood by our side. And despite the fact that the crisis will probably continue to take its toll on all of us, we are certain that the future will be bright. We remain confident and trust in bright prospects for the new year because we all continue to stand together – and especially in these extraordinary times.
Looking ahead now, we look forward to spending time with all of you in the new year.

In this spirit, we wish you a wonderful Advent season and a happy, healthy Christmas among your family, friends and loved ones. We start 2022 with optimism and energy and wish you a wonderful start to the new year.

In accordance with the latest standards... goes without saying that our design team also works this way.

The design engineers at Cleff use modern CAD systems at their workstations; in doing so, we take into consideration the growing qualification requirements of complex designs in the development stage. The design of vehicle windows, doors and partition systems is heavily influenced by complex calculations. Special material properties also play a role; in particular, the interaction of different materials, such as glass, rubber and aluminium. Due to the advanced functionality of windows and doors, which generally involves “folding”, “rotating” and “sliding”, taking into account sensitive tolerances is also required. Simulators are also frequently needed in order to be able to test the flawless operation of new designs in the development stage.

In addition to their pure design capabilities, CAD systems help to ensure the verification of finite elements. They can also perform numerous calculations that make individual, specific product requirements verifiable.

And 3D visualisations can also be generated quickly. This way, our customers get a “preview” of new products. To further help arrive at decisions, we also use a 3D printer. This is used to produce individual parts quickly and cheaply and in outstanding quality. As a result, the design and function of parts can be conclusively tested.

Product development is supplemented by the possibility of numerous tests of partial production steps or on the finished product. These tests are carried out in our own test centre or together with our network partners.

Cleff offers development competency from a single source.

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Graffiti is an irritating problem, and many transport companies must invest a great deal of time and money to remove the “artwork” created primarily on local commuter, suburban and underground trains.
We counter this with effective anti-graffiti coatings for windows and doors, which simplify the removal of graffiti and keep locomotives and rail carriages clean. Graffiti paints of wide-ranging qualities do not adhere to surfaces as well and are also easier to remove, even if cleaning takes place at longer intervals.

The coatings also permit simplified cleaning outdoors; for example, with steam-jet cleaners. The result is the possibility of a more thorough and faster cleaning process that is also more economical and benefits the environment due to the reduced use of water and cleaning products.

Windows and partition walls in buses and trains are often subject to scratching. The emergency hammer found in carriages is the “tool” used to accomplish this. We counter this form of vandalism with highly-effective scratch-resistant films, which can be applied to windows and transparent partitions in trains. Cleff ensures that its products are durable.
We will be happy to show you the options for added protection against vandalism and for simplified vehicle cleaning through coatings and films – both solutions are useful both for original equipment and for the complete or partial renovation of buses and trains.

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Company founder Carl Wilhelm Cleff was an expert in machining, polishing and anodizing aluminium strips for the bodies of large vehicles and passenger cars. Known back then as "Leisten-Cleff", since 1935 the company had been producing mouldings with a decorative but also functional character: These mouldings covered, for example, the weld seams on the car bodies.
Framed windows, especially the common, hinged windshields for trucks, were made of milled brass profiles at that time. Backed by years of experience with aluminium profiles, Carl Wilhelm Cleff began manufacturing frames for vehicle windows from extruded aluminium profiles. This proved to have two decisive advantages: Production became more inexpensive and bending became easier - and the aluminium-framed vehicle windows manufactured by Carl Wilhelm Cleff became a success – fuelled by the advancing motorisation of the 1950s "economic miracle years."

In the period that followed, the functions of vehicle windows were further developed and became significantly more complex. Under the Cleff brand, the so-called "functional windows" emerged, with a wide variety of sliding or folding functions. From synthetic windows to armored glazing with a thickness of 40 mm, Cleff now developed and produced individual windows in a wide variety of shapes. Later, complex system packages and partition walls, e.g. for rail-bound vehicles, were also added to the company's product range.
Today, the Cleff brand represents a comprehensive product portfolio with functional glazing (except windscreens), partition systems, vehicle doors and spare parts – in small and large series.
The basic construction principle in vehicle window manufacturing, namely the use of extruded aluminum profiles, has remained unchanged to this day.

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They divide interiors in many local public transport vehicles and shield entry and exit areas. In combination with grab handles, partition wall systems are essential for the safety of a vehicle. Monitors that can be mounted on partition walls can also be used for advertising and passenger information. Partition walls are characterised by a high degree of stability and provide transparency - glass elements guarantee an unobstructed view through a bus, underground or suburban train carriage. At the same time, vehicle partitions have a high degree of stability, as there is often room for prams, bicycles or wheelchairs next to them. Partition walls are the inconspicuous companions of mobility in modern local and long-distance transport.
Partition wall systems from the Cleff company are developed specifically for each customer and adapted to the high stresses of daily use. The choice of special glass provides safety for passengers and foiling can further customise the appearance or provide additional scratch resistance. And there are virtually no limits to the customised design of partition walls.

You can learn all about the possibilities of a technically sophisticated and durable solution for your new partition wall system during a consultation with our experts. We can support your project for the initial installation or a refurbishment - in both small and large series.

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...this part of our work is extremely important to us. When you understand the stresses that windows and doors in vehicles are exposed to, then it quickly becomes clear that the surface treatment must meet the highest standards. The high thermal loads that vehicles are exposed to in the hot and cold regions of the world are one example. Cleff produces vehicle windows and doors that are used worldwide. After their service life in the temperate climate regions, many vehicles can expect a “second life” in more southerly climes.

Therefore, the vehicles equipped with our windows and doors, whether trams, buses, small vans, emergency vehicles or special-purpose vehicles – depending on the area of use – must be able to withstand both Arctic and tropical temperatures, endure high humidity, offer rust protection, particularly in coastal areas, and resist changing pressure conditions. Thus, the perfectly treated surfaces of our products ensure not only a permanently attractive appearance, but also perfect functionality.

You can expect complete expertise from us: in the surface treatment of window frames and doors/door frames, e.g., decorative surfaces, 5-layer finishes and powder coatings – and with a variety of surface textures and colours. At Cleff, the corrosion resistance and durability of window frames and doors/door frames is always a priority.

Special coatings such as anti-graffiti coatings and scratch-resistant films also ensure that our products are easy to clean and prevent vandalism.


We advise you not only on the products themselves, but also on selecting the right surface treatment.

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Nestled in the beautiful countryside of the Bergisches Land region, infamous for its exciting excursions, Wuppertal is an active and culturally open-minded industrial city on the outskirts of the Ruhr region. Our city is also the (elective) home of countless prominent personalities of the past and present: Well-known names such as Friedrich Bayer, Ferdinand Sauerbruch, Friedrich Engels, Johannes Rau, Pina Bausch and Tom Tykwer are closely associated with Wuppertal.

From an economic point of view, we have valued our location since the company was founded 85 years ago, because Wuppertal enjoys a central position: within Germany as well as Europe. Our delivery processes benefit greatly from this outstanding location. The proximity to the most important trade fair centers and, of course, to our customers in Germany, the Netherlands, France and Belgium is a major asset. Being this close to our customers is particularly beneficial in terms of personal contact, which is often required in the case of complex developments. We also have a proven network of suppliers and service providers in the region, which has evolved over decades and with whom we cooperate in a true spirit of trust.
Development and production are closely linked at the Wuppertal site and thus stand for our commitment to "Made in Germany". Cleff has never even contemplated a possibly more cheaply priced production abroad. In doing so, we assume our social responsibility, employ people in the region and train young people to become competent specialists.

Last but not least, the immediate proximity to the Ruhr area has shaped us Wuppertalers: Here, "a spoken promise" still means a lot. This is taken seriously and is of greatest importance to us.

Aerial photo of Wuppertal at night: ©Jonathan Webb /

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Along with vehicle windows, vehicle doors are certainly one of the core competences of our company. They are used for a wide variety of purposes, and we can refer to references in the most diverse areas: In the case of locomotives, for example, sophisticated solutions are required for access doors that have to meet high demands in terms of pressure tightness. In addition, we also develop and produce vehicle doors for completely different commercial vehicles such as fire engines and snow groomers. Other applications include engine room doors and doors for watercraft. Many vehicle doors have special features, such as "panic handles", which are designed to allow quick opening in dangerous situations.

Many years of experience with a wide range of customer requirements and the ensuing design alternatives have helped us to evolve into a team of highly skilled experts in the field of vehicle door development. This is also demonstrated by complete door systems that Cleff develops for customers as part of system deliveries, because often it is not just a matter of developing a door, but also the matching frame of the vehicle door, including all the necessary components such as handles, hinges and lock technology.

Our customers supply the design specifications for the door opening on their vehicles - we supply all the components of a door solution for this interface on the vehicle - perfectly matched to customer requirements and tested in our in-house test centre in accordance with the relevant standards.
Let us introduce you to Cleff as an experienced door developer for your vehicles.

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... the Cleff company is supporting the modernisation project with the renewal of the side glazing.

Since 2019, the Berlin S-Bahn (urban railway) has been modernising all trains of the BR 481 series, which is scheduled to last several years and the continued operation is ensured by the project "Longevity BR 481".
The appearance of the modernised vehicles will be adapted to the new S-Bahn (urban railway) trains. Paint, upholstery, floor panels and floor coverings will therefore be renewed in the same design. However, the 481 series will also be technically optimised:
For example, corrosion damage is being repaired, mechanical and electrical components are being replaced or reworked and new door leaves are being installed on the entrances. The retrofitting of additional horizontal grab rails, special markings for passengers with restricted mobility, tactile door opening buttons and the installation of a video surveillance system will thus increase safety and comfort in the vehicles. The sum of all measures can permanently prevent aging-related malfunctions and make the trains fit for the years to come.

The side window systems of the trains will also be modernised: This part of the 481 fleet renovation is significantly accompanied by the Cleff company: the scope of supply of the system includes the hinged windows and the pressure frames. These pressure frames are inserted into the window cut-outs of the carriage body structure, glued and serve to hold the clamping rubber frame and the keder profile, which are also part of our company's scope of delivery, as well as the windows.
Originally, the pressure frames consisted of a plastic profile frame that was supported on the vehicle body in precisely defined dimensions. In order to better accommodate possible tolerances of the car bodies in the future, an optimised solution, i. e. a coated subframe, was developed by the Cleff company.

However, this exemplary and extremely extensive refurbishment project is not only about improving the quality in all areas with a new design, better technology and more accessibility and making the trains technically fit for the future. Rather, the modernisation takes into account environmental aspects: the vehicles are given a "second life" as many people now have more reasons to switch to the railway again.

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... is an essential contribution to the best possible surface quality.  Since 2020, the new cleaning system at Cleff has ensured the thorough degreasing of e.g. vehicle window frames, thus creating optimal conditions for the subsequent process of powder coating.


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All quality tests can be carried out at our company and at partner companies: Quickly and reliably – and above all in accordance with our own high standards. That is why we have our own test centre for a large number of tests.

We check the following for you:

  • Pressure cycle testing in accordance with UIC 566 section
  • Testing of the air tightness of doors in accordance with DIN EN 14752
  • Water tightness test of doors following DIN EN 14752
  • Wind resistance to wind load according to DIN EN 12211:2016
  • Air permeability according to or based on DIN EN 1026:2016
  • Water tightness against driving rain in accordance with DIN EN 1027:2016
  • Durability test according to or based on DIN EN 1191:2012
  • Smoke protection test according to DIN EN 1634-3:2009
  • Soft body impact test according to e.g. NF F01-492 and NF P08-301
  • Calculation of sound reduction at windows and doors according to e.g. ASTM E2611-17
  • Measurement of sound insulation on windows and doors according to DIN EN ISO 10140
  • Static strength verifications and fatigue strength verifications according to DIN EN 12633-1
  • Fatigue strength verifications for vibration loads according to DIN EN 61373
  • FEM calculations for load assumptions and strength verifications

But our test centre can do even more: As a service offer, we at Cleff accompany your test series under professional guidance and make all meaningful test results available to you. Get to know the test centre. Simply make an appointment and tell us your individual test task. Together we will make your products standard-compliant and thus future-proof.

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One aspect of window and door construction is still purely manual ability. However, we always aim for the highest degree of absolute perfection with regards to precision fit, durability and surface quality, even in mechanical processing methods. We are therefore working on continually improving all production opportunities.
Our machine fleet has therefore been expanded, with the help of a high investment amount, to include two new CNC processing centres with 4-axle technology and a bending machine from the latest generation, amongst other things.
We do not just meet the demands for modern and reasonably priced product designs for vehicle windows and doors; we will also be able to satisfy our customers' individual wishes with regards to the mechanics (e.g. opening and closing mechanisms) and shaping of our products even more in future.
A high number of complex start-up projects will now be executed successfully with the help of new approaches to tools in the company. Further investments are planned …

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On the occasion of our anniversary year, we have opened up our archives and would like to share something special with you today: The "yellow giant", which was put into service by ADAC Südbayern in 1962 as a support vehicle Cleff had already equipped numerous vehicles with windows for the vehicle manufacturer Gottlob Auwärter throughout the years of what history books call the "economic miracle". 
The semi-trailer of the "yellow giant" (12 metres long and 2.5 metres wide) had space for a conference and meeting room, an office with a small kitchenette and a customer area with a counter. The towing vehicle was a Mercedes-Benz LPS 328/36 (5,070 cc six-cylinder engine with 110 hp) and the semi-trailer served as a mobile ADAC office. In addition to a 220-volt vehicle electrical system with an AC generator and emergency power batteries, it was equipped with the latest state-of-the-art communications technology at the time, such as a telephone system, a loudspeaker system on the roof connected to a Philips tape recorder, a record player and a microphone. For almost ten years, the vehicle served ADAC at trade fairs, exhibitions and sporting events in southern Bavaria to support ADAC members and to offer them eye testes and response tests. It was ultimately sold in 1971 and decommissioned another 30 years later.
But only for the time being ... because from 2010 to 2012, the complex full restoration of the semi-trailer train took place, which had meanwhile "matured" into a fully fledged "class-5" wreck – and our company was absolutely delighted to accompany this restoration in the area of windowing.
All windows (plastic glazing and real glass windows) were replaced or reconditioned, the frames newly anodized and provided with new seals. An exciting and demanding task, because the vehicle windows from the 50s and 60s often tend to have a rounded shape. We were particularly proud to discover that we still had the original window handles on our shelves - which meant we did not have to reproduce them, but were able to supply brand new "old" handles directly from our stock.
After having been put into service again by ADAC Südbayern in 2012, the "yellow giant" can now be admired at many ADAC events and at events supported by ADAC, e.g. as a historical support vehicle.
The "yellow giant" is just one of the vehicles that Cleff equipped with individual windowing in former days; numerous other developments were also made for the Auwärter brand Neoplan. If historical vehicles are to be equipped with new windows as part of a restoration project, we would be pleased to assist you. And – as the "yellow giant" has shown – it is even possible for us to "conjure up" individual window profiles, seals or handles for your vehicle from our stock again! This means you can carry out your vehicle restorations and overhauls with greatest ease.
(Photos: ©ADAC Südbayern)

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Cleff has equipped the new PistenBully type 300 Polar Antarctic with vehicle windows. 20 of these tracked vehicles, distinguished by their exceptionally high manoeuvrability, thrust and reliability, will be delivered to the Antarctic in the coming weeks to perform their service under the most extreme conditions. The PistenBully vehicles have been in service in the polar region for more than 30 years. Their overall construction is specially designed for the extreme conditions in the perpetual ice and they have since become an indispensable asset in the Antarctic for expedition and research teams from more than 15 nations.
Not only are the special vehicles, which have been further developed into true "polar all-rounders", used as supply, clearing, towing or construction vehicles, but they can even be used as vehicle for overnight accommodation – and that in temperatures as low as 50 degrees Celsius below zero. This makes it clear what stresses our windows are subjected to in terms of material quality, tightness and insulation in these vehicles.

We have been partnering with Kässbohrer Geländefahrzeug AG, which celebrated its 50th anniversary in 2019, as a supplier for various vehicle series for decades. Kässbohrer Geländefahrzeug AG develops and produces tracked vehicles for a wide variety of applications pursuant to the very highest quality standards - standards that we at Cleff are happy to meet: With the supply of vehicle windows and doors, which must also function reliably under special conditions.

You can find more about the PistenBully 300 Polar Antarctic here:

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On 3 June 2020, we showed numerous representatives of regional and supra-regional public utility companies the way to do this with a product showcase of our new glass divider for city buses.
The Driver Protection System, or DPS for short, is a glass divider built on the swivelling ticketing area next to the driver area of modern city buses. In this period marked by the Coronavirus, the system offers increased protection for the driver in terms of hygiene. Cut-outs in the glass enable the ticket to be issued or payment to be made. The divider can also play a part in protecting the driver from attacks. This requires the use of laminated safety glass. The DPS uses anti-glare glass in various designs (which are related to the remaining reflection) as standard to minimise reflections.

We have achieved the impressive feat of adapting our new system to various vehicle types from renowned city bus manufacturers - all in just a few weeks. These bus types are a representative cross-section of the vehicle types used by almost all German transport companies, and were available at our product showcase.

Impressive active driver protection and economic benefits

Our new divider is not only a question of occupational safety, with the DPS also offering economical benefits. The isolation of the driver’s work area means there are no longer any cash takings. The Driver Protection System is a significant step towards normalising economical driving operations: safe boarding in the driver’s area can be resumed, and therefore the purchase and checking of tickets.

Strong interest across Germany

The guests present - crew, buyers and workshop managers - did not only come from the immediate surroundings such as the Ennepe-Ruhr area, Solingen, Remscheid, Dortmund and Bochum, but also from Berlin (BVG), Münster and Cologne (KVG). We used the product showcase to introduce an innovative, technical development which will able to gain attention across Europe. A DPS pilot project is currently being implemented with the Wuppertaler Stadtwerke public utility company and the product has already proven itself to be ready for series production. The prerequisites for this are TÜV approval and obtaining a positive assessment from driving trials by Wuppertaler Stadtwerke.

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... and now it’s ready for use by our customers: the side-hung window has ISO glazing and places high demands on its design due to the heavy weight resulting from its dimensions. The window weighs in at approx. 40 kg – 20 kg of which is accounted for by the glazing alone. The viewing area measures 800 mm x 660 mm.
The weight of the window glass (28 mm laminated safety glass/toughened safety glass ISO) combined with the window’s dimensions could quickly result in imprecise opening and closing if the design wasn’t as sophisticated as it is, i.e. the window snags when opening and no longer closes precisely and tightly.
This problem has been eliminated through the use of a two-point lock and opening via an integrated gas strut. The new side-hung window also offers a latch position at 10°, which can be fixed using the ergonomic rotary handle.
The opening angle is also restricted to 90°.


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This week Cleff produced its largest ever sliding window for use in the rail industry. The dimensions (external dimensions) of 2028 mm wide x 1317 mm high with an opening clearance of 1644 mm wide x 445 mm high are unusual and require complex and extensive preparation work – particularly with regards to the weight of the countersunk part, which weighs approx. 30 kg due to the window’s dimensions.
Ergonomics was the main focus of our development: the countersunk part, in other words the extremely heavy sliding area of the window, had to be user-friendly and easy for passengers to move.
This was achieved through our proprietary “Soft Elevation System” (SES), which significantly reduces the opening and closing forces thereby allows even heavy window elements to open and close effortlessly.
The design and implementation of a large, yet easy to operate window: another exciting challenge we were glad to face.

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A special construction feature was implemented for one of our long-standing customers. The top-hung windows were
intended to be closed by the passengers – but only to be opened by the driver. We complied with this special wish of our
customer with a respective construction feature: now the window can only be opened by the driver with a key tool. The
background of this necessary construction change was the special climatic and safety technical requirements for the
window and its design.


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Motorhomes place high demands on all aspects of functionality, design and longevity. This also applies without limitation to the driver and passenger windows in our product range.
The windows on the driver’s side for fully integrated motorhomes should not of course require too great a sliding effort to open and close them. At the same time, the window should not suddenly open or close “by itself”, e.g. when braking or accelerating. In addition, one of the requirements was to exactly measure the construction and range of movement of the window handle in order not to affect the function of the blinds situated in front of the window. The constructive solution of the window mechanics and the ergonomic design of the handle – with very little construction space available – was the main focus of this development in order to ensure a good compromise between comfort when using the handle and the best possible level of safety.

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The year 2020 has begun, which is also a very special year for us. Since 1935, the Wuppertal-based company Cleff has been finding answers to questions such as: What is the best window solution for your vehicle?
What is the best door design to ensure that it functions safely and reliably in the long term?
Is there a large selection of spare parts for your train, commuter train, bus or passenger ship?

These questions are just as important today for many international vehicle manufacturers as they were 85 years ago – and Cleff provides answers with flexibility, fair prices and reliable delivery of high-quality products – today, just as we did back then. Our optimal and individual solutions have ensured the company‘s continued existence for decades – be it for small, medium and large quantities.

Feel free to download our anniversary brochure „Producing vehicle windows and doors since 1935 – Over the course of time“. Discover how our company has developed over the past 85 years and learn more about our exciting company history from 1935 to the present day. Join us in our anniversary year and celebrate 85 years of vehicle windows and doors from Wuppertal with us at Innotrans 2020 in Berlin in September.

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For more than 80 years, Cleff has been the brand for individual vehicle windows and doors.
Starting with the compilation of all customer wishes and the planned usage, continuing with the meticulous in-house construction and development, into which we incorporate the empirical values of decades of experience, up to the initial sampling and serial production: the Cleff company illustrates the entire development and production process. This also includes, e.g. the possibility for pressure cycle testing according to the UIC in our in-house test centre. Do you need a small series for a nostalgic train? No problem.
You want trains or busses equipped with a bigger series of innovative windows? We will be pleased to take this on. Your locomotives require doors with numerous functions? Cleff is your partner to contact.
Regardless of which vehicle you wish to refurbish – the Cleff company will supply you.
And the range of services extends even further. Cleff also offers complete solutions with a comprehensive range such as door frames, locking systems and gaskets – profit from the product range of an experienced full-service company to supply your system needs.

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In particular, nostalgic trains or busses for sightseeing tours need individual windows and doors. The same applies to special and commercial vehicles … the Cleff company supplies windows and doors for trains, busses and ships – but also offers small series for vehicles which are seldom used, or used just once, and are therefore highly individual. The island railway or the city train for tourists most likely arose as an individual production – the requirements on their windows and doors are correspondingly special – and therefore a "case" for us. And we dedicate ourselves to such tasks with the same quality requirements and love for detail as is used in the serial production of new vehicles.

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With our spare parts, we are able to offer you the possibility to exchange defective parts – and thus also a complete refurbishment of your vehicle. These spare parts are often even better than the original, as they are partly newly constructed, comply with new norms or use better materials – e.g. with regard to fire protection. The Cleff spare part offer is particularly interesting, for example, for local transport operators, who want to impart “new life” into their vehicles. In the field of railway transport in particular, we are able to prolong the service life of the vehicle fleet – and for historical vehicles we even offer spare parts with a historical charm, which are, however, state of the art in terms of modern technology.
The offer comprises all types of rubber elements and gaskets, aluminium parts, handles, fittings and glass with attachments.
If you need individual spare parts for older vehicles or decide to refurbish and restore your vehicle fleet, then we are your partner to contact.

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Currently, “AI” and Industry 4.0 are the focus of many discussions. At the Cleff company, we are also having a tendency toward more automation, but there are still regions of industry where clearly defined boundaries set the limits. We also encounter these limits, as our daily work is defined by a high level of manual craftsmanship – and this will continue to be the case. Window construction does not only need manual dexterity, but rather the right “feeling“ for materials and construction parts, which can only evolve after many years of working in window construction.
An example: Our staff in assembly bring window frames in the right form with exactly targeted blows with a hammer and can thus align frames with exact tolerances.
Only a few employees have this highly specialised ability after a lot of experience – and thus the above-mentioned “feeling” is only able to develop after many years of working in window construction. An ability, which even the most ingenious robots are not able to perform, even today …
The same also applies to construction: numerous developments are determined by creativity. Many vehicle doors require very individual solutions on account of the special installation situation and the high demands, e.g. on their pressure tightness. In this case, considerable constructive creativity is needed in order to provide acceptable results which can be implemented and keep the cost aspects in mind at the same time.
Individual developments, as they are offered by the Cleff company, always rely on the individual expertise of our staff in construction and assembly – and we are proud to have such talented employees and their individual abilities.

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This is not just the epitome of engineering design and technical pioneering spirit, but also the landmark of Wuppertal since 1901: the Wuppertal suspension railway.
Enjoy a breath-taking view and a continuously changing view of the town when sitting in the bright blue carriages – through windows made by Cleff. After all, the entire functional glazing with the windscreen and rear window, side glass panes, flush window top-hung windows and partitions stem from our production, produced for the manufacturer of the “new suspension railway“: the company Vossloh-Kiepe/Stadler.
As a “ traditional Wuppertal manufacturer“ of vehicle glazing, we are naturally proud that our products now accompany the “Schwebebahn” on each journey it makes.
We wish the “Schwebebahn” and all who travel on it a pleasant trip … and enjoy the view!
You can find more about the history of the Wuppertal suspension railway and some of the interesting stories about it here:


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In Wuppertal, we have also demonstrated a special closeness to Bauhaus and its world famous approach to design. The unusual commitment of the Wuppertal paint manufacturer Herberts, which already brought famous Bauhaus followers, such as Oskar Schlemmer, to Wuppertal is reflected in that both industry and schools of applied arts promised a lot from modern design.

And finally, the Cleff company also stands for the tradition of good design in Wuppertal: we already sponsored a design competition in collaboration with the Bergisch University and Polytechnic in Wuppertal in the 1980’s. Good design is an important component of numerous developments at Cleff today, e.g. the aesthetics of a window or a door have to comply with the overall design requirements of the complete vehicle. Similarly, there is a lot to consider at the human/functional interface: for example, windows and door handles are subject to the high requirements of user-friendly ergonomics and the lay understanding of function – which may even be of life-saving significance.

However, product design can provide even more than this: through creative ideas, it could allow material savings and simplified production processes – which means a reduction in costs.

For this reason, we integrate from the outset experienced designers with many of these developments. They provide „fresh wind", query the basic processes and help to counteract operational blindness under certain circumstances.

100 years of Bauhaus is therefore an anniversary to remember - because even today we are still able to take advantage of the fundamental principles of Bauhaus.

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We thank you very much for the numerous visits at our booth on the InnoTrans 2018 in Berlin and the many inspiring discussions with our customers and suppliers.
We look forward to the next time in 2020.

The Team of Carl Wilhelm Cleff GmbH & Co KG


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We have been analysing, designing and programming for a long time and now, it is done: Our new web presence is going online! The new version features many alterations and advantages. So, it eases the precise dsicovery of projects for example and it brings our team to the fore. Furthermore, we are now able to picture many references easily. The design studio „Design Scholemann“, located in Gevelsberg, supported us for this project. They will also attend us in all further matters concerning the public image.

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At the end of 2017, we introduced an environmental management according to DIN EN 14001. To date, we have been certified within the program of Öko-Profit which is now being replaced by DIN EN 14001. We at Carl Wilhelm Cleff are comitted to improving the standards for the environment protection as well as for our employees by introducing the DIN EN 14001. Please find the corresponding certificate under the category „Download“.

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It has been a long time since Tuffi & co – and the characteristical orange waggons oft he Schwebebahn (an overhead railway) were as old as they were. Therefore, the municpal utilities of Wuppertal urgently needed some replacement. The sky blue waggons are in fact produced in Valencia, Spain but important components of the elegant design are produced in the hometown of the Schwebebahn: The frameless windows are produced at Carl Wilhelm Cleff. The local journals have reported about this – read more: link