The size of the Boulder Canyon Project necessitated a broad array of innovations in construction engineering and management which had enormous impacts on all of the large scale projects that followed it. Major milestones were achieved in mass concrete handling and placement across a large and sometimes treacherous job site; equally challenging problems with forming and pouring structural concrete elements for the project, such as the intake towers, penstocks, spillways, and outlet works; steel penstock fabrication and placement; and establishment of basic job site safety precautions that became increasingly common thereafter, including on-site medical care the provision of hard hats to all workers.