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.'
Okay, but the I-5 doesn't bother with loops and tunnels. It just barrels right over the top of the mountains, including a 5-mile section of 6% grade according to the sign (https://www.crashforensics.com/tejonpass.cfm). Trucks struggle to crawl over the top at like 30 mph, with tires. It's not exactly a roller coaster hill to be overcome with inertia.
They have distributed traction, meaning powered bogies in every second wagon for the current variants. There is no 'engine/locomotive' in the classical sense. All of these also have electronic anti-slip/traction control.
Edit: Even if a quarter of the powered bogies are defect for whichever reason, the remaining ones still suffice to accelerate from full stop at 4% grade. By design. For current variants. It's a variable platform. They could use more powered bogies. Stronger motors. Whatever.
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