VOSSLOH Rolling Stock’s DE 18 four-axle mixed traffic entered the market in 2014 and since then over 145 1.8MW units have been sold to customers across Europe, performing tasks ranging from l from operating cargo and shunting services to construction and logistics, including salvage operations.
A batch of 10 DE 18s is currently being built for customers in Italy following secure DE 18 type approval by the European Union Agency for Railways (ERA) in June 2021. Presentation runs have also occurred in Sweden and Norway and Vossloh Rolling Stock expects certification here, including with ETCS Level 2 Baseline 3, in 2023. It is also considering potential sales in Eastern Europe.
As rail operators become increasingly aware of their environmental performance as well as the rising cost of diesel fuel, Vossloh Rolling Stock is introducing a range of new features to improve the sustainability of its locomotives, including the DE 18.
Vossloh Rolling Stock has designed its locomotives in a modular way, which means that different components and systems can be installed according to customer needs.
A notable development is the introduction of batteries in the SmartHybrid version of the DE 18, where battery operation can replace diesel engines for last mile applications and in sensitive areas such as tunnels, depots and stations, reducing potentially energy costs by around 10%. The locomotive debuted at InnoTrans in 2018 and in September 2021 Vossloh Rolling Stock’s won a contract with Nexrail to supply 50 units, with production currently underway at its Kiel plant. The locomotives will run mainly in France, Belgium and Luxembourg, with delivery expected to begin in 2023.
The DE 18 SmartHybrid is equipped with a 1.8 MW diesel engine. However, unlike the previous version of the locomotive, the 1000 liter tank of the 4 kW auxiliary diesel engine has been replaced by 144 kW NMC lithium-ion batteries placed under the chassis of the locomotive. The battery can undertake more than 7,000 charging cycles, giving it a lifespan of approximately 8 to 10 years. It provides approximately one hour of emission-free operation and fuel savings of 20-50%.
The batteries can be charged using an external 400V 3ac power source or the diesel engine, taking six hours using an external supply without electric preheating or faster if there is heating with the speed depends on the temperature. Using the diesel engine allows the battery to be charged in 20 minutes while trickle charging using the on-board static converter takes four hours.
Once the battery has reached the end of its life, it can be replaced relatively easily. It is possible to install a more powerful battery or switch back to diesel.
The use of the Plug-In Hybrid option makes it possible to prolong the stopping phases of the diesel engine by operating all the auxiliary systems on the traction battery. According to Vossloh Rolling Stock, using the battery for low power operation requiring less than 400kW is more efficient than using the diesel engine and potentially reduces usage by 40-50%, increasing maintenance intervals.
Diesel remains the essential fuel for many locomotives due to the flexibility it offers. Nevertheless, work is underway to reduce its consumption and the impact on the environment.
Fuel consumption varies greatly depending on the tasks performed by the locomotive. The greatest savings are realized if a diesel-electric traction system is used. However, Vossloh Rolling Stock has developed several additional functions and intelligent operating modes to further reduce consumption and emissions, which are available as options for customers to improve the performance of the DE 18.
These include Vossloh Eco Drive, which supports economical driving by providing detailed information on fuel consumption according to different parameters: per hour, per kilometer, daily consumption and total consumption. There is also a limit value sensor and an energy meter recording daily consumption. Additionally, a Performance Button Eco can allow the DE 18 to operate at its maximum power output of 1.8 MW. Normal operation takes place with an output of 1.5 MW, which saves energy.
On the other hand, an Eco mode switch can limit diesel engine output to 1.2 MW, again providing more efficient engine management. The driver activates this setting using the driver console. In addition to improving performance and reducing fuel consumption, engine tuning helps reduce maintenance costs – reduced production means longer periods between engine overhauls. This is particularly advantageous during shunting operations, which do not require maximum power output.
The limitation of emissions during shunting is also reflected in the addition of the start-stop function of the VED engine to the DE 18. Studies have shown that diesel shunting can spend up to 80% of its life idling. Previously, limiting restarts was justified by reducing wear on the starter motor and the risk of the engine temperature dropping below 60°C and depleting the batteries and air tanks. VED allows the engine to restart without any wear. The engine automatically shuts down after a set idling period and restarts occur on demand or if certain conditions are met. In addition to limiting emissions, the feature should reduce required maintenance.
Introducing the latest developments in diesel traction can also significantly reduce emissions. A prototype of a DE 18 that meets EU Stage V emissions requirements will be presented at InnoTrans this month.
The 12V 4000 Stage V engine was supplied by MTU and the engine can also be certified to run on HVO biofuels made from hydrogenated vegetable oils to EN 590 and paraffinic diesel to EN 15940. biofuels reduce CO2 emissions of up to 55% compared to fossil fuels, and a reduction of up to 95% is expected with the second generation (PTX), which should be available before 2030.
According to Vossloh Rolling Stock, the use of HVO has no significant implications for engine operation or maintenance schedule. There are also no differences in terms of storage and distribution compared to fossil fuels and no significant increase in costs for freight carriers. In addition, the compatibility of DE 18 with European standards allows an immediate transition to these types of alternative fuels. Delivery is possible by truck to existing refueling sites and it is possible to mix HVO and biofuels with diesel in any ratio.
Modularity and durability are also at the heart of the DM 20, the newest locomotive platform from Vossloh Rolling Stock and the first to be equipped with a pantograph to collect traction current from the overhead wire.
Designed for freight operations as well as shunting, infrastructure work and rescue operations, the DM 20 has found favor with the market: Paribus Rail Investment Management has ordered up to 50 locomotives on behalf of Rive Private Investment in 2021 while Vossloh Rolling Stock secured another order for two initial units with Rail Innovators and Port of Rotterdam Authority. In December 2021, the company secured its largest order to date, a deal with DB Cargo for 50 hybrid units with options for an additional 200 locomotives. Delivery of the DM 20s, which will be used for freight operations in Germany, will begin in 2024.
Vossloh Rolling Stock says their primary focus for the DM 20 is to provide flexible traction options to their customers. Each locomotive has two different sources of traction, diesel and electric. The supplier indicates that it is also possible to update and adapt the traction system as needed, even after several years of use.
Three variants have been manufactured so far: the DM 20-EBB, the DM 20-EDD and the DM 20-BDD, the latter option chosen by DB.
E means high voltage and B electric traction. The DM 20-EBB can take traction current at 15/25kV ac and 1.5kV dc. D stands for diesel traction, the DM 20-EDD being equipped with two 480 kW diesel engines. The two diesel engines deliver 750 kW of continuous power to the wheels and 850 kW with time limitation, which Vossloh Rolling Stock says is comparable to existing locomotive types.
A high-voltage system is not installed on the DM 20-BDD, which is equipped with two diesel engines as well as a 160 kWh lithium titanate (LTO) battery for energy storage, located under the locomotive chassis. Here, the AC traction system supplies 2.5 MW to the wheels, which is supplemented by 300 kW from the battery under the floor, represented by the letter B.
Although not yet in production, a DM 20-EBB locomotive is feasible where the two 350 kW LTO batteries provide 500 kW to supplement the power of the AC traction system at the wheels.
In addition to adaptable traction systems, Vossloh Rolling Stock says the DM 20 is ready for future upgrade to other technologies as they emerge, including digital automatic couplers (DACs), cameras for obstacle detection and augmented reality to support maintenance activities. Work is also underway to introduce condition monitoring services for the DM 20.
Sensors and GPS tracking devices installed on the locomotive will continuously transmit data to assess the condition of critical components using limit values and monitoring logs. Additionally, Vossloh Rolling Stock plans to use augmented reality techniques to assist technicians, improving the accuracy and consistency of maintenance work.
The supplier says this is part of its effort to provide a flexible locomotive platform that can adapt to future needs. In a competitive market and with increasingly environmentally conscious customers, these appear to be essential conditions for future success.