The KTNF8 (KT4NF) Tram Unit

The new KTNF8 three-segment tram was created through the reconstruction and modernization of the old four-axle two-segment CKD TATRA KT4 tram.

A central low-floor segment was integrated between the two original segments. This tram is intended for unidirectional operation. The vehicle is driven from one driver's compartment.

General Information

Central low-floor segment

The inserted central low-floor segment is of light steel construction and preserves the structural character of the original KT4 vehicle. KTNF8

The body sections are connected with a combination of tried and tested RT6 tram joints, and a modification to the original KT4D under-frame. The lower ball hinge transfers load forces and is composed of a friction bearing with a spherical slip surface. The upper ball jinge is composed of a vertical connecting rod with two rubber-steel elements.

Standard bogies (mfg. by ALSTOM LBH GmbH), gauge 1200 mm, wheel diameter 410 mm. The vehicle body is connected to the bogies through a pivot and two slip surfaces on the sides. Two double-axle bogies can rotate through 12.5 degrees, and have 4 hydraulically controlled active disc brakes and 2 rail brakes. The primary suspension has rubber elements, and the secondary rubber rings with cylindrical coil springs.

The passenger compartment in the low-floor segment is connected to the KT4D area with stairs at either end. In light of the vehicle's design, the low-floor area is maximally utilized. The wheelchair section has folding seats in the side wall.

The door of the middle segment is in the centre of the vehicle. Under the door is a slide-out ramp controlled by the driver, which facilitates entry and exit for wheelchairs, baby carriages and persons of limited mobility.

Located on a vertical hand bar inside by the door is an integrated column that permits communication with the driver, control of the ramp, emergency brakes and emergency door opening.

The passenger compartment is heated with two electric heaters with fans, located below the seats.

The electrical systems are of type UA 37P, with TV14Z drive control. During startup, the TE036 A01 traction motors are run in low-loss mode by two pulse IGBT converters. During dynamic braking, the braking energy is fed back into the charging network. The driver's position has a display that shows information operational and fault conditions of the electrical system and instructions for further steps.

Technical Data: KTNF8 with low-floor segment

Gauge 1000 mm / 1435 mm
Coupler to coupler length 26 554 mm
Vehicle width 2 180 mm
Vehicle height above track 3 560 mm
Floor level above track 900 / 360 mm
Traction bogie wheelbase 1 900 mm
New wheel diameter 700 mm
Weight 29 800 kg
Min. turning radius 16 m
No. of seats 60 (inc. 3 folding)
Standing room (5 pers./m2) 92
Standing room (8 pers./m2) 154
No. of traction motors 4
Traction motor output 54 kW
Maximum speed 65 km/h
Maximum acceleration 1,2 m/s2

Technical Data: low-floor segment

Length 7 500 mm
Weight of central segment 9 300 kg
Bogie wheelbase 1 200 mm
Wheel diameter 410 mm
Floor level above track 360 mm
No. of seats 23 (inc. 3 folding)
Standing room (5 pers./m2) 25
Standing room (8 pers./m2) 42

Layout drawing