Two Trams Coupled Tail to Tail: Prague Revives a 1983 Trick to Get Through the Autumn Closures

After more than four decades, Prague is putting back into passenger service pairs of T3 trams coupled back to back. Zdopravy.cz reported on 26 August that, according to the enthusiast account Tramvaje v České republice, the arrangement — known as PX — should appear with passengers on line 19 over the last weekend of August.

The principle is simple and slightly odd. Two trams are joined at their rear ends, so the set can reverse direction anywhere, with no need for a loop: after the change of direction the rear car becomes the front one. Passengers only ever use the car leading the way.

Why now

DPP had not answered Zdopravy.cz's questions about the PX sets at the time of publication. The preparations were confirmed to the paper by Filip Drápal, spokesman for Prague Integrated Transport (PID), who put the reasoning in terms of fleet cover rather than novelty:

Nasazení částečně nízkopodlažního vozidla formou dvojice vozů spřažených zády k sobě připravují kolegové z DPP, aby v době zvýšeného vypravení obousměrných tramvají KT8 existovala i v budoucnu technicky ověřená záložní varianta pro vypravení spoje, pro který by standardní obousměrná tramvaj již nebyla k dispozici.

— Filip Drápal, spokesman, PID

In other words: this is a spare wheel. Two coupled sets of the partly low-floor T3R.PLF type are to stand by as an operational reserve, and their use is not meant to be routine. Drápal told the paper that after the verification running, "Případné nasazení po ověřovacím provozu se očekává naprosto minimální."

The pressure comes from the calendar. Several tram closures now overlap, and each of them raises the call on the bidirectional KT8D5 cars — the trams that can reverse without a loop and are therefore what a closure needs. The repair of the Spojovací turning circle runs from 11.30pm on 28 August to about 4.30am on 12 September, with lines 9, 11 and 98 diverted to the Žižkov depot, a temporary Spojovací stop opening on Hartigova, and buses 146 and X98 covering the Kněžská luka–Spojovací section. And from 29 August the longer closure between Olšanské náměstí and Nákladové nádraží Žižkov begins. Both need vehicles that can turn round on the spot.

An accounting footnote worth noticing

There is a quiet detail in how the set is paid for. It takes two trams to run, but as ordered capacity it counts as one. "S DPP je dále dohodnuto, že se s ohledem na nabídku cestujících účtuje v tomto případě vůz jako sólo," Drápal said — the billing follows the seats actually offered to passengers, which is one car's worth, not the metal deployed.

That is the correct way round, and it is also the reason the arrangement stays a fallback rather than a habit: the operator commits two vehicles and two drivers' worth of vehicle to deliver the capacity of one.

The last time

Prague last ran sets like this with passengers in 1983. According to DPP's own historical material, a special line 45 operated in the PX arrangement from 17 October to 16 November 1983 between Výstaviště and the Trojská stop. Two T3 cars were joined at the rear and, as now, only the leading car was open to passengers.

The configuration is not unique to Prague. Brno ran back-to-back T3 pairs on line x12 during the 2025 closure of Kounicova street. Olomouc uses the same principle on a longer-term basis with its VarioLF plus/o cars, which are built for it and have doors on both sides.

What makes the Prague case worth recording is not the hardware but what it reveals. A network that has to reach four decades back for a way to turn a tram round is a network running its bidirectional fleet close to the limit — and the autumn closure programme has not finished yet.