Wiener Linien: Full Air-Conditioning of Public Transit Will Take Decades

Current Status of Air-Conditioning

Looking at subway cars, buses, and trams together, nearly 80 percent of all public transit vehicles in Vienna are air-conditioned, according to Wiener Linien. For buses, the rate has already reached 100 percent; for rail vehicles — that is, subway cars and trams — the share currently stands at 64 percent. Specifically, according to Wiener Linien, 49 of 163 subway trains are still in service without air conditioning, and for trams, it is 201 of 507 vehicles.

The complete equipping of the fleet with air conditioning will still take decades. The reason lies in the long service life of the older vehicles. The Silver Arrows in particular — the oldest subway models in the fleet — are designed for a service life of 45 years. This timeframe is also intended to be used. Since Wiener Linien has been purchasing only air-conditioned new vehicles for around 25 years, the share is increasing continuously, but only at the pace of natural fleet rotation.

Why the Transition Will Take Decades

On the subway, the Silver Arrows are the only models without air conditioning. For trams, it mainly concerns the Type E2. The U6 line is an exception: All vehicles there are already air-conditioned. On the other subway lines, the chance of boarding a cooled vehicle still depends on luck and on the specific train.

The trend is nevertheless positive: Ten years ago, only around 40 percent of the fleet was air-conditioned. The share has risen significantly since then. Every new Flexity tram — 13 more are to be added this year, according to Wiener Linien — and every new X-Wagon on the subway further increases the share of air-conditioned vehicles.

Technical Settings of the Air-Conditioning Systems

Wiener Linien vehicle technician Gerhart Siegl explains the technical background of the air-conditioning: "Von 36 Grad Außentemperatur in einen 20 Grad kühlen Zug zu steigen, wäre auch körperlich eine Belastung sowie energietechnisch problematisch und würde sehr viel Geld kosten." The air-conditioning systems in the vehicles are therefore set so that they do not lower the interior temperature too much.

Specifically, the following principle applies at Wiener Linien: Cooling kicks in above 25 degrees, ventilation between 18 and 25 degrees, and heating below 18 degrees. At an outside temperature of 35 degrees, the temperature inside the vehicle should be around 30 degrees. The air-conditioning systems therefore do not provide full cooling to a comfort level, but rather a moderate reduction of the interior temperature.

The fact that the doors open regularly at every stop poses an additional challenge for the air-conditioning. Gudrun Senk, Managing Director for the technical division at Wiener Linien, explains: "Fahrgäste verweilen relativ kurz, steigen aus und um." On the one hand, because the doors open regularly at stops; on the other, a "Wohlfühltemperatur" is needed that is as pleasant as possible for everyone.

Economic Framework Conditions

Gudrun Senk views the development as fundamentally positive: "Auch wenn wir auf der Schiene nicht so weit sind wie bei der Busflotte, ist die Tendenz der Klimatisierung stark steigend." The aim is to continuously increase passenger comfort. However: "Einen anvisierten Zeitraum kann Senk auf Nachfrage nicht nennen und erklärt: 'Die Erneuerung des Fuhrparks hängt von den wirtschaftlichen Rahmenbedingungen ab.'" In other words: How much is earned through operations and how much money is received as a subsidy from the City of Vienna.

The budgetary situation also plays a role. Senk acknowledges: "Das hängt davon ab, wie rasch wir unseren Fuhrpark erneuern können", she said. Of course, the decision has "auch mit der budgetären Situation zu tun". The air-conditioning of the entire fleet therefore depends not only on technical but also on financial framework conditions.

New App Labeling for Passengers

There is a new feature for passengers: Wiener Linien has introduced a label in its app that is meant to show whether the respective vehicle is air-conditioned. According to Senk, this was "ein großer Wunsch der Fahrgäste gewesen". This allows Viennese residents to specifically target air-conditioned vehicles when choosing their connection.

Wiener Linien's advice to passengers is: "Bitte die Fenster geschlossen halten." This applies even when temperatures feel warm. Anyone who discovers a defective air-conditioning system should report it via the contact form at helpcenter.wienerlinien.at or by phone via the Wiener Linien customer service at +43 1 7909 100.

Outlook on the Coming Heat Waves

The fact is: The chances of catching a non-cooled subway or tram have decreased in recent years, but have not fallen to zero. During heat waves like the current one, which is reaching Vienna these days with temperatures close to the 40-degree mark, a ride on a non-air-conditioned Silver Arrow or E2 tram can become a test of patience.

The Silver Arrows — once the showcase model of the Vienna subway — will continue to roll through the network for many years without air conditioning. Only when the last of these vehicles reach the end of their 45-year service life and are replaced by new X-Wagons will the Vienna subway fleet be fully air-conditioned. Until then, it remains partly a matter of chance for passengers whether they will enjoy a cooled car during the next heat wave.