This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Thames tunnel shield. Diagram of the tunnelling shield used to construct the Thames Tunnel London Contemporary image th century probably from the Illustrated London News Tunnel construction Tunnelling equipment The Illustrated London News Thames Tunnel PDArt
Page 2023 Free-images.com. All images are Public Domain