Like all TGV variants, the KTX-I is a permanently coupled trainset that consists of two traction heads, that is powered end cars carrying no passengers, flanking a fixed set of passenger cars or trailers that are articulated with Jacobs bogies between them.
 Though the KTX-I is based on the TGV Réseau, it has 18 instead of 8 passenger cars, making them the longest member of the TGV family with a monobloc configuration, that is a single set of articulated cars.
The two normal (non-Jacobs) bogies next to the traction heads under the two extreme passenger cars are motorised, like on the TGV Sud-Est.
Further traits differentiating the KTX-I from all European variants are the supply voltage frequency of 60 Hz (instead of 50 Hz), rotating seats in the First Class sections, the lack of any bar or restaurant cars.
Original plans in 1993 proposed a new "showel nose" design, with the underside of the nose closer to the track, for better aerodynamics in tunnels; however, the final design was only a slightly modified version of another TGV export version, the AVE Class 100 for Spain.

The trains are pressure-sealed to reduce passenger discomfort from pressure variations during tunnel passages.
Windows are triple-glazed, with a thickness of 29 mm (1.1 in).
 Seat distance is 930 mm (36.6 in) in Standard Class cars, 1,120 mm (44.1 in) in First Class cars.
All passenger compartments are equipped with ceiling-mounted video displays, on-board audio systems, phones and vending machines.
Like all TGV variants, the KTX-I is a permanently coupled trainset that consists of two traction heads, that is powered end cars carrying no passengers, flanking a fixed set of passenger cars or trailers that are articulated with Jacobs bogies between them.  Though the KTX-I is based on the TGV Réseau, it has 18 instead of 8 passenger cars, making them the longest member of the TGV family with a monobloc configuration, that is a single set of articulated cars. The two normal (non-Jacobs) bogies next to the traction heads under the two extreme passenger cars are motorised, like on the TGV Sud-Est. Further traits differentiating the KTX-I from all European variants are the supply voltage frequency of 60 Hz (instead of 50 Hz), rotating seats in the First Class sections, the lack of any bar or restaurant cars. Original plans in 1993 proposed a new "showel nose" design, with the underside of the nose closer to the track, for better aerodynamics in tunnels; however, the final design was only a slightly modified version of another TGV export version, the AVE Class 100 for Spain.
The trains are pressure-sealed to reduce passenger discomfort from pressure variations during tunnel passages. Windows are triple-glazed, with a thickness of 29 mm (1.1 in).  Seat distance is 930 mm (36.6 in) in Standard Class cars, 1,120 mm (44.1 in) in First Class cars. All passenger compartments are equipped with ceiling-mounted video displays, on-board audio systems, phones and vending machines.
KTX-I