This might be the start of a book on the subject.
Methusalech was afraid. This was his normal emotion every time King Hezekiah called him in for a progress report on the tunnel. It was not that the King made him feel that way, it was just that he seemed to be continually bringing him bad news.
The King understood the difficulty of what he had asked. No one had done anything like this before. Even the Egyptians with all their building projects hadn’t attempted something as peculiar as this. Methusalech spent a lot of time before the LORD praying for guidance as a result.
God’s faithfulness was shown in the continual flow of the spring which was named “Bursting Forth” (Gihon). It was an ancient name. The first book of the Torah said that one of the 4 rivers of Paradise was called the same. The people of Jerusalem liked to think that their Bursting Forth was somehow the same river as the one that watered Paradise like the Tigris and Euphrates were also thought to be somehow related to their counterparts. Methusalech thought all this unlikely considering how much the great Flood had changed the face of the earth since then.
The great thing was that it never stopped flowing and producing enough water for all their needs.
Then the King had his dreams and revelations. One of them warned him that the Assyrians were going to come and take over the land. The second told him to not let the Bursting Forth waters be accessible to just anyone. He had a picture of the spring being like the city’s wife, she shouldn’t be available to any stranger but only to the city itself.
Then he had a dream of a tunnel with gently flowing waters (Shiloah) in it. And that’s when he called in Methusalech.
They had been digging for 6 months now and things were not going well. The original plan was to dig a straight line through the bedrock with two teams. One team was to start at the place where they were to collect the water (the Pool of Shiloah). The other was to start at the Gihon spring itself.
The problem was trying to dig in a straight line.
Methusalech realised early that they were going to have problems direction finding when deep underground. There were no stars or landmarks to go by, nothing but a general sense that they were going in the right direction.
The team that started from the pool end had already gone through several changes of direction. In some ways it wasn’t so difficult for them since they were not going under the mountain to the same extent. In theory they should be able to hear the men at the top thumping their big instruments. But the ground carried the sounds in all sorts of strange ways so they kept changing direction as they heard it change.
The Team that started from the Gihon spring had been led by Ahimoah. He was a good man. The original intention had been to bring the spring waters straight to the other side of the mountain of Ophel and then go down from there. However it was taking too long and the mountain rock was too hard. So they decided to change direction and head south instead. It would have helped if they could know what south meant under that much rock.