>> Is there a direct train route from ZRH-Interlakken Ost and if so, which train is it?
You will always have at least one transfer between Zürich Flughafen (airport) and Interlaken Ost.
The fastest route involves a transfer at Bern. The most scenic route involves a transfer at Luzern, but takes about an hour longer. If you can spare the time, I would definitely recommend the route via Luzern instead of via Bern. Here is a description of it:
Sit on the right if you can. Leaving Luzern, the train soon reaches an arm of the Vierwaldstättersee/Lake Lucerne. Then it passes the Pilatus cogwheel train station at Alpnachstad (on the right), and travels along the shore of the Sarnersee (Lake Sarn) at lakeside level. If the weather is pleasant, there will likely be some hikers on the walking path which circles the lake and is about the only thing separating the train from the lake for most of the way. There are lovely views across the lake to mountains, meadows, woods and villages on the other side.
From Giswil, the train climbs steeply up to the Brünig Pass, providing elevated views over the Lungernersee (Lake Lungern) with its pretty villages, meadows and mountains.
At Brünig-Hasliberg station, the train reaches the highest point of the Golden Pass route between Luzern and Interlaken Ost (1,002 metres above sea level), having climbed over 500 metres in altitude since leaving Giswil. At some times of the year, Brünig-Hasliberg is under snow.
During the descent from Brünig-Hasliberg to Meiringen, a wide, level-floored valley with scattered buildings and a very straight river running through it is visible far below. The river is the Aare River, which here has been straightened and looks like a canal.
At Meiringen, the train changes direction, and passengers sitting on the right are now on the left. However, there's no need to move to the other side of the train, because the best views from Meiringen to Interlaken Ost are on the left.
Leaving Meiringen, the train travels alongside the straight Aare River seen earlier from high above on the Brünig Pass, and shortly reaches another lake, the Brienzersee, along which it travels to Interlaken Ost.
Here is a height profile of Golden Pass route Luzern to Interlaken Ost
Whether you choose the fast route via Bern, or the scenic route via Luzern, transfers are easy.
- At Bern, the transfer will usually be between platforms 5 and 6, which are two sides of the same platform.
- At Luzern, you just walk up the platform to the front of the train and along the main councourse to your next platform, which is on the same level. You can wheel your luggage onto the train through a door level with the platform - look for a door with a wheelchair logo on it.