Elon Musk's Boring Company is reportedly pitching companies on wider tunnels to carry shipping containers, but the bigger hole could drive up costs considerably

• The Boring Company is reportedly looking to build wider tunnels than its current 12-foot standard.
• A presentation seen by Bloomberg shows two shipping containers side by side in a 21-foot tunnel.
• Experts said the change is feasible, but could make projects substantially more expensive.

The Boring Company, Elon Musk's drilling startup, has reportedly been pitching companies on a new wider tunnel, a new presentation obtained by Bloomberg shows.

According to the pitch, the new tunnels would be 21 feet in diameter, up from the company's standard of 12 feet, and be wide enough to allow a pair of standard shipping containers to pass together, side by side.

The company did not reply to Insider's request for confirmation or comment.

While most media coverage of Boring has focused on passenger transportation, it currently offers a freight solution on its website using its 12-foot tunnel, which it says "barely" fits 9.6-foot-tall containers on a specialized transporter platform.

In the presentation for the larger tunnels, single and double configurations are shown with respectively sized battery-powered freight carriers.

Experts told Bloomberg that the idea has the potential to be successful if the costs are well-managed.

Anne Goodchild, founding director of the Supply Chain Transportation & Logistics Center at the University of Washington, called the concept "totally doable," but said that surface roads are often still an attractive, relatively low cost alternative to tunnels.

The Boring Company says its loop tunnels cost about $10 million per mile on average, but its recently completed project in Las Vegas cost $47 million for a 1.7-mile loop. The company says many traditional tunnel projects range from $100 million to $1 billion per mile.

Tom Groark, executive director of a trade organization for the heavy construction industry called the Moles, said costs of drilling tend to increase at a faster rate than the width of the tunnel, largely because of the challenge of getting all the material out of the hole.

Even so, he said Boring's marketing of a standard size for every project helps keep equipment expenses in check.

"They're making the job fit the machine, and that's huge," Groark said.

Another startup in Switzerland is aiming to move freight via underground tunnel networks, but unlike the Boring proposal, it uses custom-designed autonomous modules, rather than the globally adopted shipping container.