An anchorage was built on each side of the Narrows, with each anchorage measuring long by wide, and containing a combined of steel and concrete. Each anchorage contained sixty-six large holes for the cables. The bases of each anchorage are built on glacial sands, reaching below ground level on the Brooklyn side, and below ground level on the Staten Island side. Foundation work for the -Narrows Bridge was well underway by 1960, as visitors were able to see the anchorages. A concrete workers' strike in mid-1961 threatened the timely completion of the Staten Island anchorage, which had only been partially filled with concrete. This strike lasted several months and affected many projects under the city.