| Depends on how steep. 4% is no problem for modern traction. Just look at this https://de.wikipedia.org/wiki/Datei:Wiedtalbrücke_Blickricht... which is used at 300kph by electric multiple units like the german Inter City Expres. I've rode over this at about 330kph shortly after opening, it's slightly noticable, but not like a roller-coaster at all, as one might think. Meanwhile this is also used by more conventional electrical engines for passenger trains up to 250kph, also in 'pusher' mode, and short freight trains, no longer than 700m, at anything between 160 to 200kph during nights. According to Wikipedia 'the Bakersfield–Palmdale section of the line will cross Tehachapi Pass, roughly parallelling the Union Pacific Railroad's Mojave Subdivision. Due to its heavy freight traffic and sharp curves (including the famous Tehachapi Loop), there is no current passenger service through the pass. While the proposed high-speed rail alignment will not include any long tunnels comparable to those in Pacheco Pass, it has nine shorter tunnels and several viaducts more than 200 feet (61 m) high. The maximum grade through the pass would be - 2.8 - percent, making it the steepest portion of the Phase 1 route.' Easy peasy. Edit: TL;DR? All of this is explained here https://en.wikipedia.org/wiki/Brightline_West |
