## Tuesday, June 07, 2016 ... /////

### New longest Czech railway tunnel gets topologically completed

This video of a "walkthrough" was added on September 10th, 2016.

I have been following the construction of the new railway "Tunnel Ejpovice" (Kyšice-Chlum) near Pilsen very carefully. An hour ago, we could finally witness the moment when the impressive German machine Herrenknecht TBM S-799 nicknamed Viktorie (probably after the best soccer team in Czechia, FC Viktoria Pilsen) – whose sibling was recently used somewhere underneath London as well and they seemed to be more proud about it than we are – finally changed the topology of the Pilsner region.

As we liked do scream when we were drilling the holes for the ethernet wires for the Internet at our student hostels in Prague in 1993, "penetration"! I've actually taught my fellow workers to scream "orgasm" but let's not be picky.

There will be two independent tunnels. The second opening of the first tube, i.e. the Southern tunnel, has finally emerged beneath the Chlum Hill in Pilsen, one mile from our home. (Chlum itself meant a "hill covered by forest" in archaic Czech.) Nice catering including 3 glasses of champagne, a beer, a lunch, and three pies were prepared for the relevant people – Metrostav workers, directors, mayors and other important municipal politicians, and high energy physics bloggers. The European Union that has contributed to this $160 million project has therefore earned a small unimportant plus in my statistics. ;-) The tunnel is 4.15 kilometers long – much longer than 1.75 km, the length of the longest operational Czech railway tunnel at this moment. The TBM gadget (tunnel boring machine) will be drawn back to the beginning hole in the village of Kyšice (which I also monitored last year when the construction was getting started) and Viktorie will dig the second, Northern tunnel from the same direction, hopefully more quickly than the first tube because they are already experienced. It takes some 90 minutes for the fastest trains to get from the Pilsen main train station to the Prague main train station. The awkward detour around the Chlum Hill in Pilsen is the main (but not only) reason why the trains are so much slower than the cars and buses. Regular bus lines only need 50 minutes to get from the center of Pilsen to the Western suburbs of Prague. After all the$1.2 billion improvements of the Prague-Pilsen-Cheb railway tracks and the speed is increased, the time needed to get from Pilsen to Prague should drop almost by 50%.

(YouTube allows you to take a train from Pilsen to Prague-Smíchov for free. I've taken that train about 200+200 times in my life. If you haven't, you're recommended to watch this highly entertaining 80-minute movie LOL.)

I have lots of photographs and short videos I took but this video shows pretty much the same things we could see and someone could quickly create a more professional film than I could. ;-) See also iDNES.cz with two videos, denik.cz, novinky.cz, Qap, and CN.cz. Or the 2010 eight-minute visualization of the modernization of the railway tracks between Pilsen and Rokycany.

It's probably not infinitely difficult but I am impressed how cheap the tunnels are and how accurately they were able to hit the target. The accuracy is surely much better than one meter. There should be some extra event on Saturday – I was told that there could be some projection stunt, perhaps a modest version of the Prague Astronomical Clock 600th anniversary show.

A previous blog post was dedicated to the Blanka Tunnel for cars in Prague.

The speed of the construction seems to be identical to that in the LEP-LHC tunnel at CERN – below 10 meters a day in average. The excavation for the LEP-LHC tunnel was done by three TBMs, so it's about 9 km per TBM, and it took 3 years (1985-1988). That's pretty much the same speed as 1.35 years for 4.15 kilometers of the Southern tunnel that just arrived to Pilsen. Note that the LHC tunnel was Europe's largest civil engineering project before the Channel Tunnel was built.

Colliders come and go, the tunnel stays. In 2000 when this song was shot, the collider in the tunnel was LEP while the LHC was the name of the band (Les Horribles Cernettes). Today, the collider in the tunnel is the LHC and the cernette is a 750 GeV particle that the collider may have discovered but we will only know when the already-processed data are publicized. By extrapolation, in 2032, the collider in the tunnel will be called the Cernette and the string excitations it will discover will be named LEP.

The latest portions of the Pilsner tunnel took much more time than expected. The rock under the Chlum Hill was a rather hard spilite because Chlum used to be a volcano, we were told. The knives of the TBM had to be replaced twice as often here. The diameter of the TBM is 9.9 meters and during the construction of the 4.1 km cylinder, it had to rotate 450,000 times.