Once the passages were cleared, engineers had to construct ten heavy bridges (using MTU bridgelayers, TMM bridgelayers and pontoon bridges), five light bridges, ten pontoon bridges and 35 ferries. The passages had to be opened in five to seven hours, immediately followed by the ferries, then the bridges two hours later, all the while under enemy fire. Of the heavy bridges, the Egyptians had only two Soviet-made PMP heavy folding bridges, which could be erected in a shorter time than most other bridges in their inventory, saving a few critical hours. These bridges were also much easier to repair. The speed with which the engineers cleared the passages and laid the bridges and ferries would affect the course of the entire operation. Engineers also had to man the boats that would cross the assault infantry initially. Finally, they had to breach the minefields around Israeli defenses for the assault infantry.