Elon Musk’s Boring Company will expand its existing test tunnel for another 2 miles after it was granted a permission to dig holes underneath Hawthorne in California. The Hawthorne City Council leaders voted 4-1 in favor of Boring Company to dig a tunnel and build an underground test track north of SpaceX headquarters.

Boring Company test track

Musk and his engineers are already conducting tests using their test tunnel underneath the SpaceX compound. In order to conduct longer test runs, building a longer track is important. Brett Horton, who oversees The Boring Company operations, said that they are using pieces of machinery used for digging sewage lines.

With the permission from Hawthorne City Council, another two miles will be added to their tests tracks allowing a more rigorous testing of their “electric sleds.” The sleds were developed to carry cars along the network of tunnels in as fast as 130 miles per hour.

Currently, the existing tunnel underneath the SpaceX compound is located along Crenshaw Boulevard. In addition to the tunnel and the electric sled, reports say that Boring Company’s car elevator prototype is also being testing in the area. Cars will use the car elevator to transfer from city roads to Musk’s underground tunnels.

Aside from posting official 3D rendering of the what the Underground tunnel system will look like, Musk also posted proof that the Boring Company is on the right track. Earlier this year, the billionaire posted a photo of the equipment called “Godot” used to dig tunnels.

Last month, he posted another video showing a Tesla Model S being lowered into an electric sled.

Building the track

Due to the advancements in the operations, Horton said that the underground construction will be “undetectable.” This is mainly because of the depth at about 44-feet below the ground. He added that no one on the surface would be able to see, hear or feel any digging that will happen underground.

Despite that, the Boring Company’s spokesperson assured the public that they will closely monitor any unpleasant effects of the digging. They are willing to halt operations if there are evident changes on the surface like ground subsiding by more than half an inch.

The company hopes to tests the electric sled or skate on the extended 13.5-foot in diameter tunnel once it is completed. The extension is also considered as an opportunity to improve the current tunnel-boring machine used by the company.