|The railway Lisbon-Porto was almost completed. The last major obstacle was the river Douro and it was necessary to solve the problem.
Proposals were asked with an international tender.
Only four companies accepted the challenge.
Eiffel win the contest with a revolutionary solution: a metallic arch spanning 160 m!
These are the prices of the proposals:
»»»» G. Eiffel 965 000 francs
Fives-Lille 1 410 000 francs
Soc. des Batignolles 1 895 000 francs
Mead, Wrightson & Cº 2 750 000 francs
Eiffel proposal had the best price but, more important, had the better structural solution, introducing a new concept for crossing these kind of large valleys.