This is a class BB 475000 series (also known as SNCF BB 75000 series) diesel locomotive. It looks almost identical
to an Alstom Prima electric locomotive, just that it has no pantographs on the roof. This model was co-developed by Siemens of Germany and
Alstom of France. The electrical components are similar to what is used in the Siemens EuroRunner/Hercules locomotives of for example the
Austrian class Br2016 and the bogies and much of the outer looks are similar to Alstom's Prima locomotives. The machine has a top speed of
120 km/h, a power rating of 2000 kW and is powered by an MTU diesel engine.
Picture from close to the Aulnay sous Bois station from a moving train - sorry for the poor quality - 4.3.2014 by Ilkka Siissalo.