The ICE 1 was the first mass-produced high-speed train in Germany. It was created in the 1980s when the TGV was growing in popularity in France and the Shinkansen had been operating in Japan for several decades. It is a train set consisting of one power car without seats at each end of the train and non-powered coaches. For this reason, the German term “Triebkopf” (“traction head”) is used for the motor cars.

This was preceded by the InterCityExperimental, which was built only once in 1983. In 1988, a world record for rail vehicles was set at 406.9 km/h.

The basis for the power cars was the class 120, which was the first series-produced locomotive in Germany to be powered by three-phase motors. When not worn, the wheels have a relatively small diameter of 1,040 mm. This made it possible to keep the overall height of the powered end cars at the same level as the coaches to ensure a uniform appearance of the train. Braking is usually done by means of dynamic brakes in the power cars and disc brakes in all coaches. All cars also have magnetic track brakes only for emergency braking.

The sets are approved for speeds of 280 km/h, but were initially only used up to 250 km/h after they went into service in 1991. From 1995 they were allowed to operate at their maximum permitted speed as planned, but this was reversed three years later. Only since 2006 have some been running again at 280 km/h.

A number of nine to 14 coaches can be selected for the train formation, which was often used in the beginning. It should be noted, however, that a train with the maximum number of cars only allows operation up to 250 km/h due to the limited power. All ICE 1 trains now have twelve coaches, consisting of three first-class cars, a dining car (on-board restaurant) and seven second-class cars.

The power cars are forming the class 401, with the running number of one being 500 higher than that of the other. The first and second class coaches form the classes 801 and 802, the second class coaches with a service compartment form the class 803 and the dining cars form the class 804.

From 1989, the first lot of 41 sets was produced, followed by a further 19 pieces until 1993. Later, some ICE 2 cars were ordered for the ICE 1 because there were temporarily too few seats in second class.

One train was destroyed in the serious accident in Eschede in 1998, apart from this all the others are still in use, which were redesigned between 2005 and 2008. This not only included a comprehensive technical overhaul, especially of the power cars, but also a conversion of the passenger compartments to a modern design. At the same time, the number of seats was increased, but this was at the expense of comfort. On its previous routes, the ICE 1 has been replaced by the ICE 4 since 2017, but thanks to another modernization campaign started in 2019, the ICE 1 will still run until around 2030.

Since the large capacity of the ICE 1 proved to be too inflexible with lower passenger numbers, a train half as long was tendered. The tender was won by a consortium whose members partly corresponded to the manufacturers of the ICE 1. The ICE 2 consists of a powered end car, six trailers and a control car. The power car largely corresponds to that of the ICE 1 and additionally has a Scharfenberg coupling to couple two trains together if necessary. The weight of the trailers has been significantly reduced compared to the predecessor. Between 2010 and 2013 the trains underwent a redesign so that they can still be used until 2030 or longer.

The ICE T is a multiple unit with tilting technology that was originally designed for use as an IC. A tilting system was installed for driving on upgraded routes with tighter curves and the maximum speed was set at 230 km/h. There is the seven-car class 411, of which 60 multiple units were built, and the five-car class 415, of which only eleven were built. The latter is mainly used to supplement the seven-car trains when there is a high volume of passengers. The development took place together with the ICE TD, which is diesel-electrically driven. Both can be distinguished from the ICE 3 by the shorter nose. As with the ICE 3, the vehicle was created in a cooperation between Siemens and Bombardier (initially Adtranz). In this case, Alstom joined them with its Italian subsidiaries.

The ICE T is powered on four or three center cars, of which each bogie has one powered axle. The pantographs and converters are housed in the non-powered control cars for better weight distribution. As with the class 610, the tilting technology system comes from Fiat and was the cause of operational problems for a long time. Several times it was only possible to travel without tilting technology and in some cases the trains had to be parked completely. In 2008, when the train had been in service for nine years, problems were discovered with the axles caused by the higher centrifugal loads when driving through curves at high speeds. This led to additional temporary mothballing and a sharp reduction in maintenance intervals. This meant considerable additional investments for the DB and a serious impact on the image. Nevertheless, they stuck to the procurement of a second series and later eliminated all problems.

The area of application of the ICE T basically covers two areas. One is ICE services that run on existing and upgraded routes with many curves. While the other ICE series without tilting technology have to reduce their speed significantly in many places, the ICE-T can travel at a higher speed. The other area includes services of the IC, which are now completed with a greater saving in travel time. From 2006, the ÖBB also used three seven-car ICE-T trains as class 4011. These ran routes within Austria and to Germany, some of which had previously been served by the 4010 “Transalpin” train sets. This phase ended in 2020, when the trains were returned to Deutsche Bahn and are now served by the Railjet, which also has a speed of 230 km/h.

The diesel-powered ICE TD was developed in parallel with the electric ICE T with tilting technology. With a 560 kW Cummins engine in each of the four cars, it achieved a record speed of 222 km/h. It was intended to significantly reduce travel time on non-electrified, winding routes with a maximum permitted speed of 200 km/h. Due to many technical problems, the 20 trains had to be temporarily parked, sometimes for several years at a time. The last trains used between Hamburg and Denmark were retired in 2017.

The ICE 3 MS was created due to the requirement for a train that can be used on four systems with alternating and direct current. After Siemens had developed the ICE 3 into the Velaro for export, the ICE 3 MS or Velaro D was created as the fourth version of this series. The trains are mainly used in traffic to France and are only allowed to use their maximum speed of 320 km/h there. They each consist of eight cars, every second car being powered on all four axles. It reaches 10,650 kW for a short time and 8,000 kW permanently. Only 6,000 or 4,200 kW are possible with direct current.

In 2008, Deutsche Bahn tendered a new generation of ICE multiple units with the working title ICx. They were initially to replace the 200 km/h InterCity and EuroCity sets and only after the delivery of a sufficient number also the aging ICE 1 and ICE 2. In addition to the largest possible number of seats, the tender also only required a maximum speed of 250 km/h and only optionally 280 km/h. For the first time in history, it was required that the industry bear the entire development costs and that payment should only be made after acceptance. The designs came from Alstom, among others, with the AGV and TGV Duplex that had already been developed.

Ultimately, Siemens emerged as the winner, with Bombardier as the supplier with a share of one third. As with the ICE 3, about every second car is powered on all four axles and achieves a continuous output of 1,650 kW. In contrast to the predecessor, however, the complete power train technology of the AC version is located in the power cars and is not split over several cars. Only in the case of the multi-system version is the machinery for operation under direct current located in the non-powered carriages. Some trains without multi-system equipment have also been used in Switzerland since 2019 and have additional pantographs with Swiss contact strips. The top speed was initially limited to 250 km/h.

In order to achieve the required capacity, the distance between the seats has been reduced compared to the earlier ICE trains. In addition, the usual car length of 26.40 m was abandoned in order to reduce the relative proportion of vestibules in the overall length with longer cars. This means that middle cars with a length of 28.75 m and end cars with a length of 29.10 m are now used. In order to achieve the necessary strength of the longer wagons, they are now made of steel again, using a new type of laser welding technology.

The first version presented in 2015 was the twelve-car ICE 4, which is 346 meters long and offers seating for 830 passengers. It has six powered cars and thus a continuous output of 9,900 kW. Since 2020, seven-car trains three powered cars have been in use. Since 2021, thirteen-car trains have also been running, which were created by adding another power car to a twelve-car train. In principle, the manufacturer has the option of combining trains from five to fourteen parts, provided that the respective combination successfully goes through an approval process.

After the introduction of the thirteen-car trains, the order includes a total of 37 seven-car trains, 50 twelve-car trains and 50 thirteen-car trains. The manufacturers currently assume that the production of the ordered trains will be completed by 2023. A change that only came into effect in 2021 was the increase in the maximum speed for twelve and thirteen-car trains to 265 km/h. Since the trains were already designed for this speed and reached 292 km/h during test runs, only the software had to be adapted and the new speed had to be written down in the driver's cabs in addition to the certification. The seven-car trains are still only allowed to travel 250 km/h because their equipment does not meet the required TSI safety level. According to an expert report, future trains with a maximum speed of 300 km/h will require a completely new type of train.

The class 423 was the first in a series of S-Bahn multiple units that had been purchased since the late 1990s to replace the aging class 420. Although the latter had been built up to that point, it was a 1960's design and the first examples had already reached the end of their useful life.

In contrast to its predecessor, the class 423 consists of four instead of three cars with the same overall length. While each car previously had two bogies of its own, the middle cars now rest on shared Jakobs bogies. This is just one of the weight reduction measures used, which reduced the curb weight by a total of 24 tonnes with the same number of seats. With 50 kW less motor power, acceleration was also significantly improved compared to the newer, weight-optimized versions of the 420 series. Four of the five bogies have two powered axles. The gangways between the cars are now open, which, among other things, enables a better distribution of passengers. With now three instead of four double doors per side, the total number of doors remained the same to enable quick entry and exit.

The vehicles quickly got the nickname “Quietschie” (from the German word for “squeak”), which came about due to a special feature of the combined power and brake lever. When starting off quickly, this is responsible for brakes still being applied lightly when the power is already switched on and therefore make a squeaking noise.

The classes 424 and 425 followed in 1999, which are identical to the class 423 in terms of length and power train. The different classes can be explained by minor adjustments for different areas of application. The class 425 has a toilet, fewer doors and different entry heights so that it can also be used outside the actual S-Bahn network. Some classes have LZB and are allowed to run at 160 km/h. The class 426 is a two-car version of the 425 with two of the three bogies powered. This is used for routes with low passenger volume and to reinforce existing trains. The most modern variant is the class 422, which has been built for the Rhine-Ruhr S-Bahn since 2007. The most important change is the adaptation of the vehicle fronts to the latest crash standards, which has increased the overall length by around two meters with additional crumple zones and anti-climbing devices.

There were some delays in the certification, which were caused, among other things, by a lack of braking performance in bad weather, software problems and problems with the door locking systems. By 2010, over 600 trains had been completed, of which 462 belonged to the class 423. Since 2013, some trains have been optically adapted to the even more modern class 430, which, in addition to LED lighting and an expanded passenger information system, also includes improvements in accessibility.

The class 430 is a four-car multiple unit for S-Bahn trains that was developed jointly by Alstom and Bombardier as the successor to the class 422 and, above all, replaced the last trains of class 420. The model was originally only planned for use in the Stuttgart network, but later the production of the 422 for the Rhine-Ruhr network was also discontinued in favor of further development. Ultimately, however, the Stadler FLIRT 3 was ordered there. A second area of application was found for it with the S-Bahn Rhein-Main.

The class 430 is based directly on its predecessor, but has improvements in many areas. In principle, the same three-phase asynchronous traction motors were used, but they and the entire chassis were further optimized in terms of smooth running, background noise and energy efficiency. Energy recovery from the electric brakes is also standard and benefits from the strong acceleration and deceleration in S-Bahn operation. The train is still running on five bogies, three of which are designed as Jakobs bogies between the individual cars. Except for the central bogie, all axles are powered. The design has been updated inside and out and includes new crash standards, LED lighting and a modern passenger information system.

As with other new rail vehicles in recent years, there were several delays in the course of certification and introduction, which in this case largely affected the locking mechanism of the doors. Finally, regular operation in the Stuttgart network could be started by the turn of the year 2013/2014 and the first tests and training courses were due in the Rhine-Main area at that time. A total of 188 trains were built up to 2017 and in 2021 production for the Stuttgart network was restarted and new trains were also ordered for the S-bahn Rhein-Main, which are to be delivered in 2023. The existing trains have been optimized in terms of software over time, which means, for example, that aggregates that are not required are temporarily switched off and the opening times of the doors have been reduced. Some of the previous classes are also being adapted to the design of the 430 series.