There’s a lot of oddball railway vehicles out there, but the “Straßenroller” (“street scooter”) of Germany are something else altogether – a trailer designed to move railway freight wagons by road.
Also nicknamed “Culemeyer” after their inventor, there isn’t much written about Straßenroller in English, but German-language Wikipedia has a long article on them. Here’s the story of how they came to be:
Due to the increasing transport demands on the German Reichsbahn in the 1930s, technical solutions were sought in order to be able to meet these demands. One reason for this was the increasing motorization of road vehicles, which led to an increasing number of transport options using trucks. The freight transport options of the railways therefore had to compete with those of trucks. The small number of vehicles owned by the German Reichsbahn Company (DRG) was not enough to compete. Therefore, options were sought to attract companies that were not located near a railway siding to rail transport. The “door-to-door” concept offered customers the opportunity to receive containers of various sizes in so-called container transport or various freight wagons on site.
The Reichsbahn senior engineer Johann Culemeyer – responsible for mechanical engineering at the DRG – developed a trailer for transporting railway wagons based on these requirements. This road vehicle, the Straßenroller, enabled freight wagons and heavy loads to be transported economically and easily on the road.
A freight wagon could be transported from a freight yard to a company by road on a Straßenroller. This made it possible to transport goods in a wagon to and from a company that did not have a rail connection. The goods could be loaded and unloaded directly into the wagon, or fuel could be pumped directly from the tank wagon into the tanks of a gas station. When loading was finished, the wagon was put back on the tracks and could be transported over the rails again. It was also possible to park a freight wagon at a customer who did not have his own tracks. For this purpose, a mobile frame, the “mobile drop-off track”, was parked directly on the customer’s premises. The mobile drop-off track was a rectangular steel frame onto which a wagon was dropped off from a Straßenroller.
Under the motto “Bringing the railway to your home”, the DRG advertised the transport of freight wagons and the overland transport of heavy goods using the Straßenroller in its advertising brochure at the time. The Straßenroller was registered with the patent office on November 29, 1931 under the name “Mobile connecting track”; the patent was granted on November 9, 1933. On April 27, 1933, the Straßenroller and its possible uses were officially presented to the press and companies at the Anhalter freight station in Berlin.
The special road tractors used to tow them.
The Kaelble company, which had already provided the 72 hp Z4 Express tractor, delivered the newly developed three-axle tractor “Z6R/1” with a 100 hp diesel engine in 1933, and Henschel delivered the three-axle tractor “33 D O” with a 100 hp petrol engine, both with solid rubber tires. In 1934, Kaelble delivered its successor, the “Z6R” with pneumatic tires, and in 1935, Henschel delivered the “33 G 0” with a 100 hp diesel engine and pneumatic tires. Since the turning circle of these tractors was too large for city traffic, Kaelble developed the two-axle “Z4GR”, which became the standard tractor for city traffic from 1934 onwards. Due to the increasing number of orders and heavier loads, Kaelble delivered the three-axle tractors of the type “Z6RL” to the Deutsche Reichsbahn in 1937; the revised version, the “Z6R2A100”, followed in 1938, and the two-axle vehicles of the type “Z6GN125” were added in 1939.
How wagons were loaded and unloaded.
The Straßenroller, with a deadweight of around 10 tonnes and a load capacity of 32 tonnes, can transport a wagon with a payload of 20 tonnes and a deadweight of 11 tonnes. The maximum speed for transport with the Straßenroller was limited to 25 km/h for safety reasons.
It consists of two individual chassis that are connected to one another by a movable guide rod. Each individual frame is used to accommodate one axle of the railway wagon. The frames can be pulled apart to the axle spacing of the wagon. Each individual frame has eight wheels with highly elastic tyres; each of the wheels is movable. All wheels are connected to one another by a steering rod so that they can be steered into a circular arc for cornering.
The dimensions of a chassis without attachments are 3000 mm long, 2000 mm wide and 150 mm ground clearance. The maximum width across the wheel hubs is around 2821 mm.
After the wagon has been pulled onto the Straßenroller, it is lowered to transport height by a manually driven hydraulic lowering device. The lowering device was omitted from later Straßenrollern in order to save time when loading. The braking system is a combined air-oil brake and consists of a single-chamber pneumatic cylinder and two oil pressure pumps, each of which acts on two wheels of a single frame.
Their entry to service:
After a year of testing the Straßenroller on the grounds of the Berlin Anhalter freight station, the first official transport of freight wagons with a Straßenroller was opened on October 12, 1933 in Viersen on the Lower Rhine . The customer for this regular service was the “Kaiser’s Kaffeegeschäft GmbH”, which had built its own settling track system with transfer tables on the grounds of the chocolate factory and a permanent settling system with a turntable in the courtyard of the boiler house. The same year, the textile factory “Pongs & Zahn” in Viersen- Rahser and the “Benzin-Großhandels-Gesellschaft Heinrich Jansen” followed.
On June 15, 1934, Straßenroller transport began in the town of Aschersleben ; the first customers were the “Werkzeug-Maschinenfabrik u. Eisengießerei Billeter u. Klunz AG” , followed by the Gebrüder Ludewig wool blanket factory. Straßenroller operation for the rolling bearing manufacturer Kugelfischer in Schweinfurt began on July 10, 1934, and between eight and ten freight wagon transports were carried out daily. On November 2, 1934, freight wagon transport began in Elmshorn, among others for the “Gebrüder Asmussen Presshefefabrik” and the “Gebrüder Rostock AG”.
Other major customers included the Osram company from Berlin and Continental Gummiwerke AG in Hanover. Osram had two sidings on Utrechter Strasse, which were connected to each other by a transfer table inside the building. The first companies in Baden to use the Straßenroller services were the Freiburg brewery Ganter and the silk thread factory Mez AG, from June 5, 1935. In Saxony, regular service began in January 1935 in the town of Pulsnitz , where the long-distance power station and the consumer cooperative were supplied from the freight station.
And the growth in traffic.
When the “Culemeyer” was put into operation in 1933 in the Viersen district, a delivery rate of around 30 wagons per week was expected; after just a few months, the peak value was 90 wagons per week. In the first year, a total of 4,284 transports were carried out.
From October 1933 to April 1938, around 163,000 freight wagons were transported for 140 customers. By July 1942, 500,000 freight wagons had already been transported by road.
In 1964 there were a total of 123 locations in West Germany and 120 in East Germany with regular Straßenroller service.
A number of different designs of Straßenroller were created.
The first Straßenrollern were built by the Gothaer Waggonfabrik AG (GWF) on behalf of the Deutsche Reichsbahn and according to the plans of Johann Culemeyer, while the one-part 12-wheeled Straßenroller was manufactured by both the Waggon-und Maschinenbau Aktiengesellschaft Görlitz (WUMAG) and GWF.
- Two-part 16-wheel: 31 tonne capacity, each half having two axles and eight solid rubber tires across two rows. Originally equipped with a lowering device to lower the loaded wagons to transport height, this was removed in 1935 increasing load capacity to 40 tonnes.
- Two-part 24-wheel: 100 tonne capacity, each half having three axles and 12 solid rubber tires across two rows.
- One-piece 12-wheel: 40 tonne capacity, six axles with only outer wheels.
From 1953 onwards, a new generation of Straßenrollern was developed on behalf of the DB by Siegener Eisenbahnbedarf AG (SEAG) and Waggon-und Maschinenbau GmbH Donauwörth (WMD). This one-piece Straßenroller was based on the DB design.
Sometimes multiple Straßenroller were used to transport large railway carriages.
The fleet continued to grow after their introduction.
In 1933, the Deutsche Reichsbahn owned two Straßenrollern, by the end of 1934 there were already 16 and by the end of 1935 there were 32 Straßenrollern. In 1939, the Deutsche Reichsbahn had 49 two-part 16-wheeled Straßenrollern in its inventory, but only four two-part 24-wheeled Straßenrollern.
By the end of 1945, the Deutsche Reichsbahn owned around 200 Straßenrollern of various designs, and in 1947 around 132 of these were still operational.
In 1949, the German Federal Railway took over around 153 two-part and eight one-part Straßenrollern from the stocks of the German Reichsbahn.
In 1964, the Deutsche Reichsbahn had 104 Straßenrollern for 40 t payload, 6 Straßenrollern for 80 t and 6 for 100 t payload.
Retriment of the original Straßenrollern commenced in the mid-1970s, with the Deutsche Bundesbahn discontinuing the delivery of freight wagons by road in 1987, following the growth in truck swap bodies and ISO containers for intermodal freight. However the tractor units and trailers were sold to private companies who continued operating them, for the delivery of specialised cargoes or for special transfers of railway vehicles.
Footnote: “Vagnbjörn” of Sweden
Statens Järnvägar in Sweden also operated special vehicles to transport rail wagons by road – they were called “Vagnbjörn” (“wagon bears”).
The Swedish Wikipedia page on them is sparse, but according to this page the first units arrived in the 1940s, and remained in service until around 2015.
More history on them can be found at the ‘Veteranlastbilar’ forums and this web page by Peter Löf, and hundreds of photos at the DigitaltMuseum.
Further reading
- More Straßenroller photos by evilcargo on Flickr.
- The French called these vehicles remorque porte-wagon (wagon carrier trailer)