- GT4 (tram)
The GT4 (from German: Gelenktriebwagen 4-achsig, which translates as "4-axle articulated tramcar") is a tramway vehicle built by
Maschinenfabrik Esslingen .History
Only 380 were produced of which 350 were delivered to the Stuttgarter Strassenbahnen, the public transport operator of
Stuttgart . The remaining 30 vehicles were delivered toFreiburg (19),Neunkirchen (Saar) (8) andReutlingen (3). The 350 Stuttgart-vehicles were uni-directional, had three double-doors, and were built to 1000 mm gauge. The remaining cars were bi-directional and built with 1000 mm gauge, with the exception of the Neunkirchen cars, which were built to standard gauge. They also had four powered axles whereas two powered axles was the standard variant. Tram service in Neunkirchen was abandoned in 1978.Technics
The GT4 was developed because the longer 6-axle articulated trams, for instance the GT6, with Jacob's bogies were not suitable for the Stuttgart network. This network was rich in curves and varied gradients.
The joint construction is unique: Both rotary stands are connected by a carrier. In the center of the carrier, the joint rests. This carrier is linked at the inside of the rotary stands, so that it is pressed when driving along curves. This results in the joint pushing towards the outside of the curve and thus breaking the working of the car body.
On standard gauge vehicles only the inner axles on each bogie were powered, therefore the wheel notation was (1A)(A1). 2/3 of the vehicle weight were rested on both powered axles.
The bi-directional variants have a second driver's cab and additional side doors, unlike the uni-directional models.
Trailers
The GT4 can operate in double traction mode. Some vehicles had powered sidecars and therefore, no driver's cab. This was the case with 24 vehicles of the first series, 30 in the second series, 98 in the third and fourth series and eight in the fifth series, altogether 180 coaches were affected.
Sale to other cities
As Stuttgart put the
Stuttgart Stadtbahn standard gauge light rail system in operation from 1985 onwards, some surplus GT4 cars were sold to other cities:*
Iaşi (Romania ) - 61 cars
*Augsburg - 40 cars
* Halle - 38 cars
*Nordhausen - 12 cars
*Ulm ,Halberstadt ,Brandenburg an der Havel , Arad (Romania) and Kochi (Japan) - unspecified numbersSome vehicles were destroyed or damaged beyond repair during a great fire in the Feuerbach depot in Stuttgart in
1986 .The bi-directional cars originally delivered to Reutlingen were later rebuilt to uni-directional cars in the Stuttgart workshop.
In
1989 , a longer car set was rebuilt: Two unidirectional vehicles (SSB 714 and 735) were joined together as one bi-directional vehicle. The vehicle had no additional doors, so only the two doors in the direction of travel were usable.
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