Frequently Asked Questions

体育投注注册To solve the problem of soul-destroying traffic, roads must go 3D, which means either flying cars or tunnels are needed. Unlike flying cars, tunnels are weatherproof, out of sight, and won't fall on your head. A large network of tunnels many levels deep would help alleviate congestion in any city. No matter how large a city grows, more levels can always be added.

体育投注注册Created by Elon Musk, founder of Tesla and SpaceX, The Boring Company (TBC) constructs safe, fast-to-dig, and low-cost transportation, utility, and freight tunnels. Our public transportation solution, Loop, is designed to be the fastest and safest system ever.

体育投注注册Select one of the following topics below to learn more.




Why Tunnels?

体育投注注册Benefits of tunneling include:

  1. Unlimited capacity: There is no practical limit to how many layers of tunnels can be built, so any current or future capacity outcome can be achieved. This flexibility contrasts with a surface system, where adding a lane to the road is often difficult.

  2. Minimal land use体育投注注册: Tunnels minimize the use of valuable surface land. Tunnels also do not conflict with currently operating transportation systems, such as roads and sidewalks.

  3. Minimal surface impact体育投注注册: Tunnel construction and operation do not create any discernible surface noise or vibration. Tunnel construction and operation are invisible, silent, and undetectable.

  4. Weatherproof operation体育投注注册: Rain, snow, wind, and surface temperatures do not affect system operation.

  5. Flexible architecture体育投注注册: Architecture can flexibly support different types of transportation (public transportation, moving sidewalks, pedestrian walkways, and freight).

  6. Future expansion: For the reasons listed above, it is much simpler to extend a tunnel-based system than a surface-based system.

Why hasn't this been done before?

体育投注注册Currently, tunnels are really expensive to dig, with many projects costing between $100 million and $1 billion per mile. In order to make vast tunnel networks feasible, tunneling costs must be reduced by a factor of more than 10, with TBC's Loop tunnels currently priced at approximately $10 million per mile. 

Tunnel Boring Machines (TBMs)


What kind of Tunnel Boring Machines (TBMs) does TBC have?

TBC has iterated through three generations of TBMs – Godot (off-the-shelf TBM), Godot+ (50% faster than Godot), and Prufrock (pictured above). Each TBM was developed to further increase tunneling speed and reduce tunneling cost.

体育投注注册Prufrock has been designed to launch directly from the surface and will achieve speeds of more than 10x faster than Godot.

How fast are TBMs?

体育投注注册Standard TBMs typically dig one mile in 8-12 weeks, which is approximately 14x slower than a garden snail (depending on which snail, of course). 

体育投注注册Prufrock has initially been designed to tunnel greater than one mile per week, with the longer term goal of tunneling at 1/10 of human walking speed, which is 7 miles per day.

How are we increasing tunneling speed?

体育投注注册Prufrock, our third generation TBM, has incorporated the following design changes and modifications: 

1. Surface launch and porpoising: Launching the TBM directly from the surface eliminates the need to excavate a TBM launch pit, which is expensive and slow. Instead, Prufrock arrives on a truck, tilts down, and is mining within 48 hours. Porpoising allows the TBM to emerge at-grade without necessitating the excavation of an expensive TBM retrieval pit.

Prufrock 2.PNG

2. Continuous mining体育投注注册: Installing the tunnel’s precast segments simultaneously with mining eliminates the need to stop the TBM every five feet (these stoppages are standard on soft-soil TBMs).

3. Tripling the TBM’s power: Combining tripling the machine’s power output with the appropriate upgrades in cooling systems. More power = more speed.

4. Eliminating rail: Utilizing rubber-wheeled segment trucks instead of traditional rail-based locomotives. This eliminates the time-consuming rail installation and maintenance, along with certain safety hazards, such as derails.


How are we reducing the cost of tunneling?

TBC is reducing tunneling costs to below $10 million per mile through a number of improvements and innovations, including:

  1. Vertical integrating:体育投注注册 Producing TBMs, electric construction vehicles, and the tunnel’s precast concrete lining in-house.

  2. Reducing and standardizing the tunnel diameter: Reducing the tunnel diameter to 12 feet, a 30% - 60% reduction relative to standard transportation tunnel diameters. Maintaining the same tunnel diameter for all projects in order to avoid "reinventing the wheel" each time TBC designs a project and construction process.

  3. Repurposing dirt体育投注注册: Developing alternative methods of excavated tunnel dirt reuse, including repurposing the muck as bricks and pavers for housing projects and embankment beautification.

  4. Designing and using all-electric tunneling equipment体育投注注册: Constructing the tunnel using all-electric tunneling equipment, including an all-electric segment liner truck (formerly an all-electric locomotive), resulting in a cleaner tunnel with simpler ventilation requirements due to the lack of diesel fumes.

Loop System

What is Loop?

Loop is an all-electric, zero-emissions, high-speed underground public transportation system in which passengers are transported via compatible Autonomous Electric Vehicles (AEVs) at up to 150 miles per hour through Main Artery Tunnels between stations. AEVs are Tesla vehicles (Model S, 3, and X) that operate autonomously within the Loop system.

What type of stations are there?

体育投注注册There are three station types: surface stations, subsurface stations, and subsurface open-air stations.

Surface Station

体育投注注册Subsurface Station

Open-air Station

What is the ridership capacity of Loop?

体育投注注册Loop ridership is a function of the number, size, and spacing of stations.  Generally, high-volume Loop systems target 10,000 people/hour. If a system requires greater ridership, additional tunnels can be constructed.  If a system requires much lower ridership, the tunnel system remains the same, and smaller, less expensive stations are constructed.

How much would a trip cost?

Fare prices are project-specific but will be comparable to or lower than current public transportation fares.

How is Loop different from a subway?

Loop is an express public transportation system that resembles an underground highway more than a subway system.

Passengers arrive directly at their final destination without stopping by traveling through a Main Artery Tunnel and using side tunnels for AEV entry/exit.

To put it another way, if a subway line had 100 stops, a train would typically stop at each station, so the trip between Stop 1 and Stop 100 would be long. In contrast, Loop passengers travel directly to their destination, anywhere between Stop 1 to Stop 100, without stopping at the intermediate stations. The express system allows Loop AEVs to travel faster than conventional subway cars (up to 150 mph vs. up to 65 mph).

How does Loop avoid congestion at entry/exit points?

Unlike a subway, there is no practical upper limit to the number of stations that can be built along the tunnel route because stations can be as small as two parking spaces. Since stations require such a small footprint, they can easily be integrated in busy city centers, parking garages, and residential communities. This high density of stations will distribute AEV and foot traffic across many access points, providing more convenient entry and exit locations and reducing congestion in populated areas. If needed, larger stations can be built to increase ridership capacity.

How does Loop allow riders to stay safe during the COVID-19 pandemic?

Unlike standard public transportation systems, Loop vehicles carry small numbers of passengers (as low as one). This allows Loop passengers to travel with people they know and reduces the risk of exposure to airborne diseases presented by crowds.  Additionally, rider high-touch surfaces are well understood within Loop vehicles, which can then be cleaned and disinfected between rides.

What is Hyperloop, and how is it different from Loop?

体育投注注册Hyperloop is an ultra-high-speed underground public transportation system in which passengers are transported at 600+ mph within a vacuum-sealed tunnel. Whereas Loop is used for shorter intra-city routes, Hyperloop will be used for longer inter-city routes.

TBC’s current tunnels are designed and built in preparation for their eventual transition to Hyperloop.



Vehicle Safety

AEVs (Tesla Model S, 3, and X) have achieved NHTSA’s top rating of 5 stars and have the lowest probability of injury among all vehicles tested.

How do people evacuate? 

体育投注注册Like subways, Loop tunnels will have emergency exits along the tunnel route. However, unlike most subway systems, Loop has no internal hazards (e.g. a 600 volt third rail), and the entire paved surface serves as an emergency walkway; the egress path is thus safe and wide (despite the reduced tunnel diameter).

What if there is a fire? 

体育投注注册The risk of fire is very low in the Loop system as the tunnel lining is non-flammable (concrete) and no flammable materials are added. Additionally, there is no live electric third rail, minimizing potential fire sources and eliminating the potentially dangerous effects of (unlikely) water intrusion, as AEVs can safely handle some rain. In the unlikely case that a fire does occur, the tunnel’s ventilation system will remove the smoke to allow passengers to safely evacuate.

What other safety features does Loop have?

Safety features/system include:

  1. 体育投注注册Wide walkway for emergency egress,

  2. 体育投注注册Real-time gas and smoke detection,

  3. 体育投注注册Ventilation system designed to NFPA standards, and

  4. 体育投注注册Direct communications within tunnel to Control Center via tunnel intercoms, cell service, and WiFi.

What about earthquakes?

体育投注注册When designed properly, tunnels are some of the safest places to be during an earthquake. From a structural safety standpoint, the tunnel moves uniformly with the ground, in contrast to how surface structures react to earthquakes. Additionally, a large amount of earthquake damage is caused by falling debris, which does not happen inside of tunnels. Some examples:

  • 1994 Northridge Earthquake: No damage to LA subway tunnels.

  • 1989 Loma Prieta (Northern California) Earthquake体育投注注册: No damage to tunnels, which were used to transport rescue personnel.

  • 1985 Mexico City Earthquake体育投注注册: No damage to tunnels, which were used to transport rescue personnel.


Tunnel Photo #1.jpg

What about utilities?

体育投注注册With a typical minimum depth of 30 feet, our tunnels are well beneath most utilities, which are typically less than 10 feet below the surface. In circumstances where a utility is located deeper, the tunnel depth is increased accordingly.

Is there disruptive surface vibration or noise during tunneling?

No. Once a tunnel boring machine is below approximately two tunnel diameters, or 28 feet, the tunneling process is almost impossible to detect, especially in soft soil. The tunnel operation is inaudible, and there is typically more surface vibration felt from a pedestrian walking nearby than from the TBM operating 30+ feet below.

What do you do with all that dirt?

体育投注注册In typical tunneling projects, excavated dirt is shipped offsite to disposal locations. This process is costly, time-consuming, noisy, and environmentally-unsustainable. We recycle a portion of the muck into useful bricks and pavers to be used to build anything from affordable housing to patios. This is not a new concept, as buildings have been constructed from earth for thousands of years including, according to recent evidence, the Pyramids. These earth blocks can potentially be used as a portion of the tunnel lining itself, which is typically built from concrete. Since concrete production accounts for 4.5% of the world’s greenhouse gas emissions, earth blocks would reduce both environmental impact and tunneling costs.

How can I share feedback?

We welcome comments and questions about the company, TBM technology, and our projects. Please email communityfeedback@sizepro-works.com体育投注注册 to share your feedback.