The railway's iconic images are of its beautiful double-arched brick and stone bridges. Unfortunately, this photo only shows the top arch of this particular bridge. Still, I like its poetry.
The UNESCO honor is for the engineering achievements of the railway's designer, a young genius (he took the exams for a doctorate in mathematics at age 18), Carl Ritter von Ghega. He is credited with designing the world's first Alpine railway, the Semmering Railway from Gloggnitz to Mürzzuschlag. The 41 km railway route, which had been thought impossible to traverse, was constructed between 1848 and 1854 by 20,000 workers, 5,000 of them transported daily from Vienna. With 14 tunnels, 16 viaducts and more than 100 bridges, Von Ghega preferred to use bricks and stones rather than iron and steel for the majority of his bridges. He was knighted ('Ritter' denotes knighthood) before the railway's completion in 1854.
It's unusual to see monuments to engineers but the train station at Semmering has a massive one to von Ghega.
A few views from the train:
I'd only be guessing if I were to tell you the function of these wheels above the tracks. I think they have something to do with the electrical lines above the train.
The inside of the train before the other passengers arrived: