Mielec 2025-07-03
Hybrid Multiple Unit (HZT).
The Hybrid Multiple Unit Impuls 2 type 36WEh is the first Polish train that, in addition to an electric drive powered by a 3 kV DC traction network, also has a diesel drive in the form of an MTU PowerPack system. This system allows the train to move along tracks without electric traction.
The HZT Impuls 2 type 36WEh train was created in Nowy Sącz in secret and was developed entirely by Polish engineers and technicians. The vehicle is not only innovative, but above all practical and fits perfectly into the Polish railway network. As of December 31, 2018, the length of active railway lines in Poland was 19,200 km, including 11,900 km electrified. In the times of the People’s Republic of Poland, it was planned to electrify the entire railway network. However, the national economy, ineptly run by the communists, could not carry out this plan. The HZT Impuls 2 type 36WEh vehicle uses innovative technologies that were combined into an efficiently operating system.
In 2019, the vehicle was officially presented during the 13th International TRAKO 2019 Fair in Gdańsk. During this fair, NEWAG S.A. received the main prize in the prestigious competition named after engineer Ernest Malinowski, for products and technical innovations used in the railway industry. The Hybrid Traction Unit Impuls 2 type 36WEh was distinguished in the competition.
HZT NEWAG IMPULS 2 type 36WEh is the newest and most modern traction unit in the world, which is already used in Poland by several regional railways. This vehicle has stopped the creation of further blank spots on the map of the Polish Railway Network, which excluded a significant part of Polish society from access to this means of transport. The first vehicles of this type were purchased by: the West Pomeranian Voivodeship, the Lower Silesian Voivodeship, the Łódź Voivodeship, the Wielkopolska Voivodeship and the Podkarpackie Voivodeship.
HZT NEWAG IMPULS 2 type 36WEh is a three-car train that moves at a speed of 160 km/h under electric traction, and thanks to combustion engines, on routes without wires, moves at a speed of 120 km/h. These are parameters that perfectly fit into Polish tracks. The train takes 330 passengers on board, and importantly, it is adapted for people with limited mobility. Passengers have at their disposal: WIFI, 230 V AC electrical sockets, USB ports, air conditioning, a place to transport a bicycle, a modern passenger information system, window tables, luggage racks, toilets in a closed system.
HZT NEWAG IMPULS 2 type 36WEhb-003:
The 36WEhb-003 train was built in 2023, for the Podkarpackie Province. The train has three cars: EVN: 90 51 2 440 094-6 (PL-PREG A), EVN: 90 51 2 440 096-1 (PL-PREG C), EVN: 90 51 2 440 095-3 (PL-PREG B). The first run of the train was on November 28, 2023. The train has the PolRegio livery of the Podkarpackie province; white-blue-green.
The train consists of three cars. Axle arrangement Bo’2’2’Bo. Own weight 110,000 kg. Gross weight 130,000 kg. Maximum axle load on the track 200 kN. Number of passengers up to 330 people. Length with couplers 59.30 m. Height with folded pantographs 4.21 m. Width 2.84 m. Rated power 1 600 kW. Power supply 3 kV DC. Entrance door light 1.30 m. Entrance threshold height from the railhead 0.76 m. The train can be operated at ambient temperatures from -25 to +40 degrees Celsius. Maximum operating speed; 120 km/h – in diesel mode, 160 km/h – in electric mode. Starting acceleration; ≥0.4m/s² – in diesel mode, ≥1.1 m/s² – in electric mode. Kinematic gauge PN-EN 15273-2:2013. Rail gauge 1435 mm. LED lighting. Total number of seats 308. Rated power 4 x 400 kW. Electric heating, automatic temperature control, air conditioning. Bogie spacing 16.30 m. Wheelbase in drive bogies 2.50 m. Wheelbase in trailer bogies 2.90 m. Track width 1435 mm. Diameter of new wheels 0.84 m. Closed toilet according to TSI PRM. There is a defibrillator on board.
What is the difference between the NEWAG 36WEh and NEWAG 36WEhb hybrid trains?
The NEWAG 36WEh and NEWAG 36WEhb hybrid trains are two versions of electric-diesel multiple units (hybrid EZTs) manufactured by NEWAG in Nowy Sącz. Both belong to the Impuls 2 train family, but differ in several aspects, mainly related to the configuration of the drive and power supply system:
HZT 36WEh is a classic hybrid version, with an electric drive and an additional diesel module (usually in the form of one or two diesel engines). It can operate both under the traction network (3 kV DC) and on non-electrified lines.
HZT 36WEhb is a more advanced variant, with more power in diesel mode and/or an improved operating mode switching system. The letter “b” denotes a modified version, for example in terms of: the number of combustion engines (often two instead of one), the power of the generators, slightly different equipment.
Both versions are 3-unit units, i.e. the standard configuration for the “36WE” designation. The HZT 36WEhb trains were ordered by the following Podkarpackie and Lublin provinces, as a newer version with corrections based on experience with the 36WEh. Each province orders a slightly different train specification.
PowerPack.
The PowerPack series 1800 and 1600 were designed as a compact and flat structure specifically for installation under the floor or on the roof of the traction vehicle. Thanks to this, each PowerPack can be individually configured to the requirements of a given rolling stock manufacturer.
The internal combustion drive is provided by MTU 4000 series diesel engines with a power of 390 kW. The 36WEh trains are equipped with two power units called PowerPack. Each of them consists of a 6-cylinder, in-line MTU diesel engine with turbocharging, with a power of 390 kW. The engine can work with a hydromechanical ZF traction transmission or with a power generator. The latter solution is used in Impuls 2 type 36WEh trains. The engine also has auxiliary devices such as: engine cooler, alternator, air conditioning compressor and air intake and exhaust system. These engines are characterized by; high reliability, ease of maintenance, long periods between repairs and low specific fuel consumption. The transmission is optimized for speeds up to 120 km/h. The MTU 4000 series diesel engines are manufactured in 6H, 8V, 12V, 16V and 20V cylinder configurations, and are suitable for installation in a wide range of locomotives, DMUs and HZTs. They use MTU Common Rail fuel injection. The diesel engines have a good power-to-weight ratio. In the HZT Impuls 2 train, the internal combustion engine drives a 360 kW generator, which provides a voltage of 2,700 V to 3,050 V.
The MTU PowerPack uses engines; 6H1800 or 12V1600, which are located centrally. The rotational speed of the engine shaft is transmitted either to the gearbox or to the traction generator. On the opposite side of the PowerPack is the cooling system and optional other equipment: on-board generator, air compressors, air conditioning, CaPos. The exhaust system is on one side of the internal combustion engine, and the air intake is on the other side of the engine. The whole rests on a single frame, which can be mounted under the floor of the wagon body or on its roof. The unit can be equipped with hydraulic, mechanical or electric transmissions. Thanks to its compact design, the PowerPack has a Plug & Play configuration, which allows for quick assembly or disassembly and easy access to components. This solution also reduces the weight of the entire unit. MTU PowerPack has electronic control of the most important operating parameters of the unit, which allows for ongoing monitoring of the technical condition of the drive unit. MTU PowerPack meets the EPA Tier 3, 4i and EU Stage IIIB standards. MTU PowerPack has applied selective catalytic reduction (SCR) technology, or in Polish, reduction of nitrogen oxides NOx. Without a doubt, the drive has a low vibration level and an acceptable noise level.
MTU PowerPack with a power of 2 x 390 kW is installed, for example, in PESA Link and NEWAG 222M Impuls trains. The same drive unit is installed in foreign Bombardier Turbo Star trains. On the other hand, 1 to 4 PowerPack 390 kW drive units are installed in Alstom Lint 54 passenger trains; depending on the number of wagons.
MTU also offers Hybrid PowerPack. This is a system additionally equipped with batteries, with a power of 30.6 kWh to 122.4 kWh. This solution has a mechanical transmission and an electric motor or only an electric motor.
Description of HZT NEWAG IMPULS 2 type 36WEh.
HZT NEWAG IMPULS 2 type 36WEh is a train consisting of three wagons, with their markings being as follows; The first carriage “A”, the second carriage middle “C”, the third carriage end “B”. The train has all the features of the EZT Impuls 2 type 36WE. These features include an economical driver’s cabin with the possibility of adding a place for an assistant. The cabin has individual air conditioning and heating. A fridge, kettle, microwave, sink and additional cabinets can be installed. The mechanic’s cabin has separate doors leading from the outside, both on one and the other side. In the previous EZT Impuls 1 there were no such doors. There is only one door from the passenger part to the cabin. There is no door between the cabin and the engine room part, which increases the noise level in the cabin.
Switching from the traction network to diesel traction is simple. We set the direction of travel to Zero. On the systems screen, in the device tab, we give the operating mode window. We lower the pantograph. After a few seconds, we turn on the diesel mode on the screen. When the electronics switch, we return to the main screen and use the same lever from the pantograph to start the PowerPack. You have to remember to activate the fast switch. It all takes a dozen or so seconds. We do the same thing in reverse. The pantographs are placed on the middle section of the train.
The floor in the Impuls 2 vehicle is at a height of 0.62 m, and above the bogies 0.76 m. However, in the first and last carriage, where the PowerPack is under the floor, it is higher. Individual carriages can be equipped with a different number of passenger doors. Type 36WEh has one pair of passenger entrance doors in each carriage. This extends the passenger exchange time, but increases the number of seats. The door clearance is 1.30 m. An additional advantage is the reduced number of door automation systems. The interior of the train was designed in consultation with Koleje Wielkopolskie. The entire train is Class 2. The middle carriage is adapted for the travel of disabled people and the transport of bicycles and baby carriages.
In the middle section there is one large toilet in a closed system. The toilet doors are opened manually, because in Impuls 1 trains the automation was failing. The toilet is adapted to serve disabled passengers and is equipped with a baby changing table.
The electric drive motors have a power of 400 or 500 kW. The 36WEh vehicle uses 4 x 400 kW traction electric motors. These are three-phase asynchronous motors and are electronically controlled by an inverter. There is one inverter for each bogie. The mechanical transmissions are two-stage.
The vehicle is equipped with automatic Scharfenberg type couplers. A novelty is the covers, which are easy to unlock and move upwards, because they are permanently connected to the coupler. There is no possibility of losing them.
Written by Karol Placha Hetman