He and a cousin, 19, who also is a smuggler, were huddled together in a new imported car, one of the fruits of the trade, parked outside a friend’s house. It was a chilly desert night, the sky shocked with stars, and the young men were wired and nervous, smoking one cigarette after another.

Image Many people in Rafah still rely on the smugglers tunnels. Credit... The New York Times

The broad outlines of the tunnels are well known from the Gaza side. They are about 6 feet high and 3 feet wide. They are typically 65 feet or so below the surface, have pulley systems and lighting and ventilation. The Hamas government charges for the electricity used.

Little discussed is how the tunnels work on the Egyptian side, and why state security has been so unsuccessful in finding them. They are begun in Gaza in full view of Egypt’s border guards, after all, and nearly everyone here admits to either working in the tunnels or being related to someone who is.

The young men say that most people no longer have the tunnels come up inside their homes, because if they are caught they have no room for denial, and the whole family could be imprisoned. The openings are lined with tarps and filled with sand. When the tunnel owner in Gaza wants to make a run, he phones and the young men assemble a small group of trusted partners. They then dig out the sand, pull out the plastic tarps and pass through food, clothing or whatever has been ordered.

“It is a family affair, but not everyone knows where the hole is,” said the 19-year-old. “There are only a very few people you can trust and rely on. You make a deal with four or five other guys and that’s it, it stays between you.”

The young men said that most tunnels also have a pipe running through, a couple of inches in diameter. They said the pipes were used to funnel fuel, mostly diesel, to Gaza. Even when Israeli bombs managed to damage the tunnel entrances, or cause a collapse, the pipes were often undamaged and the fuel smuggling went on uninterrupted. They said they did not know anyone who smuggled weapons — only food, fuel and clothing.