They had a pretty good show on this on the History channel. They showed how the Tyrians rammed a ship loaded with explosives into the first causeway and destroyed it with fire. Alexandar almost gave up at that point but then became even more resolved to take the island. The second causeway was built at an angle from the mainland to the island and protected by a fleet which Alexandar put together in order to checkmate the Tyrian fleet.
They showed how the Tyrians rammed a ship loaded with explosives into the first causeway and destroyed it with fire.There were various flammable materials, used for Greek fire, but AFAIK there were *no* explosives available at that time.
Re post #6, it is amazing what a leader with resolve can do for you, but then again Alexander did not have chiquahuas like Reid, Kerry, Murtha and the DBM nipping at his ankles every day.