After conferring with the chief engineers of the Second and Third field armies, Shazly became aware that IAF, despite heavy losses, had destroyed so many bridge sections that the Egyptians had lost the equivalent of three heavy bridges, leaving four bridges in reserve along with the five already laid in the canal. This gave rise to concerns about supply in the coming days and weeks. Shazly then discussed the possibility of constructing three bridges in the canal using earth and sand. This would make causeways impregnable against air strikes and artillery. The chief engineer of the Third Army, with whom he discussed the idea, was confident that, given enough bulldozers, the causeways could be constructed in one week.