On Friday May 17th 2019, the Ingeokring organized an excursion to the RijnlandRoute in Leiden.
After all the participants arrived, Anne Bäcker (Arthe C&S) started her presentations: first, about the design of the tunnel, its concrete segments, and the cross passages, all this in relation to then challenging geology of the area. Furthermore, she gave us a tour guide before entering the site of the TBM launch shaft.
But before we actually went to the launch shaft site, we had an archaeological intermezzo: René Isarin ( RijnlandRoute / Provincie Zuid-Holland) explained why and how the Romans established in the Leiden area 2000 years ago. This is due to the archaeological excavations in the sandy deposits along the river Old Rhine: many objects, and rudiments of Roman residences, fortresses, and road sections have been discovered.
He described how the Romans set up their settlements and how they build their roads. For example: the majority of their roads along the Limes border (along the Dutch part of the Rhine) have been strengthened with oak trees dated from exactly the same year! This indicates an early demonstration of a design process concerning harvesting trees and logistical challenges.
After putting on the necessary PPEs, it was time for moment suprême: walking around the depths of the launch shaft, we had a clear and close view on the assembly of the TBM. The tail shield, cutter head and the gantry: all of it could still be gazed in full glory. Still, because within a few weeks (beginning of July) the TBM will be crawling through the Leiden subsoils.
After a group photo has been made on top of the TBM ballast embankment, the excursion had to come to an end unfortunately; many (geo)technical questions were still wanted to be asked eagerly.
The Ingeokring would like to thank Anne and René for their captivating presentations, the hostess of the RijnlandRoute Informatiecentrum for her patience, and – last but not least – Comol5 for their hospitality!
For more information and current visuals about the on-going project, visit the contractors combination’s (Comol5) website (in Dutch).