The product name for Deutsche Bahn's system of non-high-speed long-range train connections (abbreviated: IC).
Derived from the Trans Europa Expresses (TEE), the first ICs were run by Deutsche Bundesbahn in 1971 ("IC '71" programme). Then, InterCitys were first-class only and ran in two-hour intervals; they were also the first German trains to achieve 200 km/h on schedule, either through traction by 103-series locos or with ET 403 EMUs.
Although immensely successful, DB sought to improve IC attractivity and introduced second-class compartments on some ICs in 1976. With the "IC '79" programme in 1979, a second class was introduced on all IC trains; the tightest ICs connections changed from two-hour to hourly intervals; the IC network was subsequently enlarged by its extension to 6 lines in the 1985 "IC '85" programme and the integration of the international EuroCity (EC) system into the national IC system in 1987.
The InterCity system lost its status as Deutsche Bundesbahn's premium product with the introduction of the InterCity Express (ICE) in 1991. It has de facto become the regular net of long-range connections with the demise of the InterRegio system and the subsequent conversion of most InterRegio lines into IC lines in 2002.
The standard InterCity train is a push-pull train consisting of a 200-km/h-capable locomotive (now that the days of the 103 are over, usually a 101 or a 120, though the latter are scheduled to go out of service someday soon; diesel ICs are rare), some (usually one or two) first-class cars, the BordBistro (snack bar car) between the classes, and the second-class cars, the last of which is a cab car (usually with some room for bicycles).
InterCity cars are supposed to be air-conditioned and somewhat pressure-resistant (closed WC system), i.e. 200-km/h-capable. Currently, there are open-seating cars (Apmz/Bpmz), quasi-compartment cars (Bvmz) and compartment cars (Avmz) in service (for the meaning of the designations, see Deutsche Bahn passenger car designations). Unfortunately, because the InterRegio system was "integrated" into the InterCity system, many InterRegio cars with a new paint job are also in use. They are generally inferior to genuine IC cars.
Because most of the currently running IC material was built before 1990, Deutsche Bahn is at the moment implementing a huge (and sorely needed) renovation and acquisition programme. For the moment, 1305 IC cars (including 107 cab cars) are being refurbished (for example, equipped with Passenger Information Systems and electronic seat-reservation displays) at a cost of about 200 million euros. For the future, about 1000 new IC cars will be acquired; they are supposed to have replaced all existing long-range cars by 2015 -- at a total cost of somewhat between 0.9 and 2 billion euros.
Unlike (except for rare prototypes) the older ones, the new IC cars will feature pneumatic suspension. Otherwise, their design will be pretty conservative: single-decker cars, all open seating with two seats to each side of the aisle. Designers promise an ICE-like interior with "lots of wood and glass and leather seats for the first class". We shall see -- the first prototypes will be out in 2004.
Together with the new and refurbished material, a new operations concept is to be introduced where IC units (loco+cars+cab), once coupled, are not separated in regular service, i.e. operated like ICEs.
As of DB's 2002/2003 schedule, the following 23 IC and integrated EC lines exist:
Note that lots of the lines branch, which has been indicated by parentheses and slashes. Note also that, obviously, there is a lot of "cities" in and around Germany - the IC network plan looks a lot like a tube map, in fact.
IC train numbers are four-digit numbers beginning with the line code; for ECs, it's the same, but the numbers are three-digit only. InterCity trains haven't got names anymore; some EuroCity trains operated by foreign railway operators still may have names.
In 2002, the IC system changed its livery; IC trains are now painted almost, but not quite white with a fire-engine-red strip below the windows (like ICEs). Again, foreigner-operated EC trains usually differ.