Therefore, an internal railway was built to connect the exhibition buildings on the Esplanade des Invalides with those under the Eiffel Tower.

The more than 3-kilometre (1.9 mi) long railway line began 250 metres (270 yd) from the Concorde Bridge at the Ministry of Foreign Affairs near the Seine.

It crossed the Esplanade des Invalides and followed the Quai d'Orsay on the banks of the Seine, within the fence of the Universal Exhibition, between the two rows of trees furthest away from the river.

The son of one of the concessionaires, Louis Gaillot, a young architect, gave them shapes of unusual originality and functionality.

The works were led by the Deputy Chief Engineer J. Charton, who was responsible for the metalworking and dealt in particular with the construction of the railway on the Champ de Mars.

Although the route was completely fenced-off to the public over most of its length, a low top speed of 10 kilometres per hour (6.2 mph) was set.

This maximum speed should even be reduced to 4 kilometres per hour (2.5 mph) at certain points along the route, especially at level crossings, where each train was preceded by a flagman.