National Dutch Railroad Company Archives
The very first Dutch railway opened in 1839 and ran between Amsterdam and nearby Haarlem. It was built by the Hollandsche IJzeren Spoorweg Maatschappij (HIJSM or HSM), which was founded in 1837 by private investors.
These investors had primarily commercial interests. They wanted to establish a "high speed" connection between the ports of Rotterdam and Amsterdam, and Germany. But because of endless disputes over land it took the company until 1847 to complete the railroad between Amsterdam and Rotterdam alone.
In the mean time another private railroad company saw the light in 1843: the Nederlandsche Rhijnspoorweg-Maatschappij (NRS) had started to build a railroad between Amsterdam and Utrecht. In 1845 this railroad was extended to Arnhem by the same company and finally connected to German railroads in 1856. In 1860 yet another railroad company started that constructed the railroad between Utrecht, Zwolle and Kampen: the Nederlandsche Centraal-Spoorweg-Maatschappij (NCS).
Birth Of Dutch Railroad Company
Despite the effort of these three major companies and many smaller ones, the Dutch railroad network had fallen hopelessly behind the huge modern networks that were being constructed in Britain and the United States.
Therefore the Dutch government issued a new law in 1860 commissioning the construction of ten large railroads to connect all provinces to the railroad network. This network would not be exploited by the Dutch state but by a private company, the Maatschappij tot Exploitatie van Staatsspoorwegen (SS).
Between 1860 and 1938 the HSM and SS became the largest railroad companies in the country systematically buying out smaller companies. Finally, the two merged in 1938 resulting in the N.V. Nederlandse Spoorwegen, of which the Dutch state was the sole stakeholder. It remained that way until the privatization of 1995.
Railroad Personnel Records
If you get lucky, one of your ancestors was employed by the N.V. Nederlandse Spoorwegen or one of it's predecessors. Why? Because the provincial archive of Utrecht hosts this company's vast archives (over 160 meters long!) including staff records, railway photographs and drawings of tracks, equipment and buildings.
Although not digitally available you can request information on ancestors directly at the archive by e-mail. They will send you the requested information for a reasonable fee. You can ask your questions in English.
Railroads In The Dutch Indies
Don't forget that until WW2 Indonesia was a Dutch colony. Railroads were build there also, often under the direction of Dutch army officials or technicians. If your Dutch ancestor was working for a Dutch railroad company in Indonesia you will not find him in the Utrecht archive. In that case, you best turn to the National Archives which holds some of the Indonesian railroad company archives for the colonial era. These collections are not digitally searchable yet but you can send them a research request in English via e-mail.