Known for their sediment-gnashing and rock-pulverizing talents, these titans of industry don’t necessarily mesh with their namesakes of queens, activists and mayors. But tunneling tradition dictates that subterranean work can’t begin until the gargantuan tunnel boring machines are given a name — and the work is no walk in the park.

To dig massive tunnels that can reach five stories tall, boring machines are equipped with a massive rotating wheel, called the “cutting head,” which is made of rotating discs that carve out the rock. The crushed rock is churned onto a conveyor belt and sent to the surface. While the machine bores the tunnel, it also builds it by injecting a mixture of sand, ash and cement on the walls of the tunnel. Modern machines can complete between four to 10 feet per hour. Here’s a look at a few machines behind famous digs around the world:

Big Becky

Namesake: Sir Adam Beck, Canadian politician and founder of the Hydro-Electric Power Commission of Ontario.

Project: In 2006, the Niagara Tunnel Project began with Big Becky, who chewed her way through more than six miles of rock. The result was The Niagara Tunnel, which will provide electricity to 160,000 homes by adding 1,600 gigawatt-hours of power per year to the Canadian grid.

Size: Big Becky weighs in at 4,000 tons and stands 45 feet tall.


Namesake: Harriet Tubman, African-American abolitionist and humanitarian, chosen by the Miami-Dade County Girl Scouts.

Project: To ease traffic congestion to the Port of Miami, Harriet carved out a tunnel that will get 16,000 vehicles from the port on Dodge Island to the mainland much faster.

Size: Harriet weighs in at 265 tons and spans the length of an entire football field.

Interesting Fact: This boring machine is equipped with 500 to 700 sensors that can communicate with the operating crew and transmit real-time updates on the machine’s progress and tunnel conditions.


Namesake: Named for Bertha Knight Landes, Seattle’s only female mayor.

Project: Bertha was tasked with carving out the two-mile Alaskan Way Viaduct replacement tunnel, which will carry motorists on State Route 99 under downtown Seattle.

Size: Bertha weighs in at 900 tons and is more than 300 feet long.

Interesting Fact: You can follow Bertha on Twitter! @BerthaDigsSR99

The London Underground Eight

Namesakes: The UK government commissioned a team of eight tunnel boring machines to carve out tunnels under London . They were named for Ada Lovelace, one of the first female computer scientists; Phyllis Pearsall, creator of the London A-Z street atlas; Queen Victoria; Queen Elizabeth; Mary Horsley, wife of 19th century railway engineer Isambard Kingdom Brunel; Sophia Kingdom, wife of Marc Isambard Brunel, a French-born engineer who built the first tunnel under the Thames; and Jessica Ennis-Hill and Ellie Simmonds, gold medallists from the 2012 London Olympics and Paralympics.

Project: The eight tunneling machines were used to construct new rail tunnels under London that would fit within the existing railway network and, once built, be able to relieve some of London’s commuter congestion by adding additional lines.

Size: Each of these ladies weighed in at 1,000 tons and were more than 400 feet long.

Interesting Fact: The force generated by these machines is equivalent to force required to lift more than 2,900 London taxis.