Thanks about answers. Maybe is better to ask, how the length is compared to eg. 1856 or 1870, because in 18xx-serie length depends so much about playing group?
I am member in 18xx Yahoo group, but only a lurker. I mostly hate these yahoo groups (it is hard to find what you are looking for), but definetely in that group there is much knowledge about issue. But it seems, that even here in BGG, is very good probability to get answers for questions concerning more rare 18xx incarnations.
I'd put it between 1870 and 1856. More towards 1870 in length. There are a couple of ways the early game can go that can change the length of the game (train rush bringing out the Swiss rail), and the early game will go much quicker with more experienced players.
Do note that the initial auctioning of the minor companies is different than 1870/1856, which can make that part of the game take a bit longer.