CREC press news release

Firth of Forth Tunnel as proposed by Scottish Greens.  image: Deltix Transport Consultancy (from Rail for All report commissioned by Greens)

Barcelona L9 Metro line Vinals, CC BY-SA 3.0, via Wikimedia Commons

Altona tunnel Hamburg, from Implenia

J.Kumar is winner of Metro Rail Contractor of the Year 2020 image cover of J.Kumar annual report

Ontario Line subway - Metrolinx

Faroe Islands Eysturoy Tunnel I did the composition and some markings by using screen shots of Duckduckgo map.

NCC Faroe Islands Eysturoy Tunnel  - image by NCC

Eysturoy Tunnel Depth Diagram By Rennohokwerda1 - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=97378062

NCC Faroe Islands Eysturoy tunnel roundabout (image by NCC)