AKN is a small private railroad company which operates some of Hamburg's S-Bahn lines on its own network. The main line of AKN runs from the Hamburg-Eidelstedt station via Kaltenkirchen to Neumünster, but there are also lines from Henstedt via Ulzburg to Norderstedt and from Elmshorn to Ulzburg. AKN lines are called A-Bahn lines in the Hamburg regional network. Roughly speaking the company is owned half and half by the city of Hamburg and the state of Schleswig-Holstein, although some individual people hold some shares.
This new train of Br622 is made by Alstom and it is of Alstom's type LINT 54.
Picture from Hamburg-Eidelstedt station 1.7.2019 by Ilkka Siissalo.

Another view of AKN's Br622 LINT.
Picture from Hamburg-Eidelstedt station 1.7.2019 by Ilkka Siissalo.

Before the new LINT trains AKN used on its main line A1 mainly these so called VTA trains. It is a fairly uncommon train type in Germany. It is also known as VT2A. They are from 1993 and they have Cummins diesels, which make them fairly slow to accelerate and therefore not very suitable for AKN's lines with frequent stops. They were built by what then was LHB, today Alstom.
Picture from Hamburg-Eidelstedt station 5.7.2013 by Ilkka Siissalo.

This one with the sickled metal coloured sides is a VTE train, also known as VT2E, a precursor of the VTA shown above. They were from the year 1976. AKN got rid of all of them 2015-16. Only five units are left in Germany now.
Picture from Hamburg-Eidelstedt station 5.7.2013 by Ilkka Siissalo.

Erixx is a private passenger train operator and a fully owned subsidiary of Osthannoversche Eisenbahnen OHE. They operate six local or regional train lines in Niederschsen and Bremen, but mostly centered around the city of Braunschweig. Erixx uses 27 trains of the type Alstom Lint 41, class Br622.
Picture of an Alstom Lint 41 of Erixx from Braunschweig 17.7.2018 by Ilkka Siissalo.

nordbahn Eisenbahngesellschaft is 50% owned by AKN described above. It operates on behalf of the states Schleswig-Holstein and Hamburg the lines Hamburg–Itzehoe, Hamburg–Wrist, Bad Oldesloe–Neumünster, Neumünster–Heide and Heide–Büsum. They use Stadler FLIRT and Alstom LINT trains. Here we see two FLIRT trains passing Hamburg-Eidelstedt at high speed.
Picture from Hamburg-Eidelstedt 1.7.2019 by Ilkka Siissalo.

Side view of the passing FLIRT units of nordbahn. The colours of these trains are specified by the payer, NAH.SH.
Picture from Hamburg-Eidelstedt 1.7.2019 by Ilkka Siissalo.

One of nordbahn's FLIRT trains is stopping at the small station of Tornesch. This is one of nordbahn's five coaches long FLIRT units called ET5. They also have six coach versions and call them ET6.
Picture 14.7.2019 by Ilkka Siissalo.

Rennsteigbahn GmbH & Co KG is a private rail company which now owns and takes care of the old and historic rail lines Ilmenau–Themar and Schleusingen–Suhl. This old class V22 diesel locomotive is from the communist East German times. It was delivered in 1972 as a V22 machine to PCK Schwedt - Petrolchemisches Kombinat Schwedt, VEB Otto Grotewohl Böhlen, a nationalised company within the East German state. Later it worked for the VEB Braunkohlenwerk "Erich Weinert" in Deuben and from 1990 onwards for MIBRAG - Vereinigte Mitteldeutsche Braunkohlenwerke AG in Zeitz. It still has the old MIBRAG sticker on its side but it was taken over by the RBG - Rennsteigbahn GmbH & Co. KG in 2007 and it has since been used in track maintenance work on the line.
Picture from Ilmenau 2.7.2019 by Ilkka Siissalo.

The same old V22 locomotive as shown above, combined with a tank wagon - apparently used for vegetation control poison sprayings (?) - together with an old Mitropa restaurant coach. What a combination ! But apparently it had been used in servicing the historic Rennsteigbahn rail line.
Picture from Ilmenau 2.7.2019 by Ilkka Siissalo.

The real "business" of Rennsteigbahn is to organise historic, touristic special train rides along the old and steep Rennsteig route using steam locomotives and old coaches. This second class coach of the type Cd-21b was used during the communist DR times as DR's number 541-317. It's from the early 1920s.
Picture from Ilmenau 2.7.2019 by Ilkka Siissalo.

The very old green passenger coach in the foreground is the same one that is pictured above. In the background is a fixed two coach set of classic DR doubledecker coaches as were used in suburban traffic of for example Erfurt and Dresden during the communist East German times. The blue coach in the background is an old first class express train coach, also from old communist times. The light yellow wagon in the background is an old snow plough.
Picture from Ilmenau 2.7.2019 by Ilkka Siissalo.

The old coach on the left marked "81 753 Berlin" was of the type Di-28b and it is from the year 1922. The other coaches in the picture are the same that are already shown above.
Picture from Ilmenau 2.7.2019 by Ilkka Siissalo.