This photo show one of this cranes mounted in what looks to be a Mineapolis-Moline GTS tractor, and they refered crane as a "Fowler crane".
Found in a page about the machines used in ‘LEIGH CREEK – THE OLD TOWN PROJECT’, with a lot of personal photos. They have a lot of other interesting photos too.
https://leighcreek-theoldtownproject.squarespace.com
Source:
https://leighcreek-theoldtownproject...erations-1940s
https://leighcreek-theoldtownproject...erations-1950s
https://leighcreek-theoldtownproject...-power-station