when tunneling under the surface of Mars became a focus in the
story. Rather than build on the surface, exposed to the violent
elements, my characters tunnel underground. Unknown to everyone, the winds have another trick up its sleeve.
Here's a couple of paragraphs from the book:
"It was a slow process, using these digging tools. They were first developed on the Moon and had to run on low oxygen using special fuels and oils that could take the freezing temperatures. Many times one of these machines broke a front pinnacle or a gear would strip. Even when this happened, the vibration did not stop. Either the ahman’s implements continued, or if they stopped, the human machines were still boring away. About fifty to a hundred feet a day could be dug depending on how soft the soil was, how fast the mechanical screw delivered dirt and muck into the transport carts to the surface, and waiting during down times for new cutting parts after they wore out. Stand time, as it was termed, was the final time everything held together and their work was finished in a particular spot.
The tunnel had been opened up to allow space below the Interview Room to retract if need be. Ahmans and humans worked together, still in their atmospheric suits, to place wiring, lights, sewer connections and communication devices throughout the tunnels. The height of the tunnels grew to twenty feet. The walls were then covered with a mixture of polypropylene plastic and Mars cement from heating the frozen soil, a recipe the ahmans gladly shared." - A Nation