The Army Corps of Engineers rented obsolete equipment from Baguio gold miners for a nominal fee and made do with condemned TNT from the Ordnance Department. The explosive delivered was in powder form, and had to be wrapped into makeshift cartridges using magazine pages, which were placed into holes drilled into the rock. Labor was provided by the Philippine Commonwealth in the form of 1,000 convicts from the Bilibid Prison in Manila. A company of engineers from the Philippine Scouts worked on the construction as foremen and clerks.