Baku train that will start service in 3rd quarter of 2019 has crossed Turkish/Georgian border on Sunday.

Baku train cars have special wheelsets that can both run on standard gauge with 1435 mm width and on broad gauge with 1520 mm width without need of changing bogies.

TheDBAG/RAFIL type V gauge-changing wheelsets use special gauge changing track to move between standard and broad gauge without need of any interchange. This is one of the two systems which allow interoperability.

The below animation prepared by Talgo, which uses this system in its high speed trains, shows how system works:

Similar to system above, Baku train set had been pushed by TCDD loco at Akhalkalaki towards this special track. On the other side of the track, loco of Azerbaijan Railways was waiting to pull the railcars and complete the gauge change.

Though systems allows continuous run, different locos will pull the rail cars on two sides of the track. Thus train will have to stop for a while to attach to new loco. But passengers will not have to get off the train nor will wait for long time.

The first pass of Baku train cars was so cautious and slow, but successfully.