Section · Technology

The machine, broken open.

A walk through how Warwick Tunnelling's microTBM is being designed — what it has to do, the constraints that shape it, and the subsystems we're building to get it underground.

Status
CAD Phase
Build phase: TBA
Cutterhead Ø
≥ 500 mm
Tunnel length
≥ 30 m
Drive
Electric
Control
6DOF · remote
01Approach

The Not-a-Boring Competition is deceptively simple: dig a half-metre-diameter, thirty-metre tunnel, faster than anyone else. The brief hides an enormous amount of mechanical, electrical, geotechnical, and operational engineering — and that's the whole point.

Our design philosophy is first-principles, low parts-count, tightly scoped. We are taking inspiration from the teams that have done well before us — Penn Hyperloop's 294-part discipline, TUM Boring's hardened mechanical reliability — and adapting them to our team size, our workshop, and the geology beneath the Midlands.

What follows is the current state of our subsystem design as the team builds out the first CAD revision.

02Subsystems

What it takes to dig.

01 / Excavation

Cutterhead

The face of the machine. A rotating cutterhead breaks the soil at the tunnel face; geometry, cutter selection, and torque management determine how fast we can advance without stalling, blocking, or damaging the head.

Diameter
≥ 500 mm
Drive
Electric motor + gearbox
Cutter type
TBD — soil-dependent
02 / Propulsion

Thrust System

The TBM has to push itself forwards against the cutterhead reaction force. Our propulsion sub-team is designing the launch structure, thrust reaction frame, and advance mechanism to keep the machine on alignment under load.

Method
Hydraulic thrust
Reaction
Concrete launch pit
Advance
TBD
03 / Spoil Removal

Muck Handling

Excavated soil has to leave the tunnel as fast as the cutterhead produces it. We're evaluating slurry, vacuum, and screw-conveyor options against soil conditions, length, and complexity budget.

Method
Under evaluation
Conditioning
Foam or polymer
Surface plant
Skid-mounted
04 / Navigation

Guidance & Alignment

Competition rules require the machine to break through within 0.5 m of the nominal alignment, while reporting full 6-degree-of-freedom state at all times. Our navigation subsystem combines IMU, encoder, and laser-target reference data.

State
6DOF, ≥ 0.1 Hz
Reference
Laser target + IMU
Tolerance
0.5 m at breakthrough
05 / Control

Electronics & Software

Remotely operated from the surface. PLC-based control, redundant E-stops, sensor telemetry across all subsystems, and an operator interface designed to be legible under pressure on dig day.

Architecture
PLC + microcontroller
Comms
Wired, surface ⇄ TBM
E-stop
Hardware + software
06 / Tunnel Support

Lining

The tunnel has to stay open behind the machine. We're designing a lightweight, sequentially-deployable support system that can be installed without halting forward progress.

Type
Segmental — under design
Material
TBD
Install
In-tunnel, automated
03Roadmap

From concept to dig day.

  1. Sept 2025 Preliminary Design Briefing Initial concept, approach, and subsystem strategy submitted to The Boring Company.
  2. Nov 2025 Final Design Package Complete engineering package — geometry, FEA, electronics, controls, manufacturing plan.
  3. Winter 2025 Final Design Presentation Live defence of the design to TBC's panel of advisors.
  4. Spring 2026 Mining Readiness Review Hardware on the bench. Safety, operational, and reliability sign-off.
  5. Spring 2026 Competition Week — Bastrop, TX On-site tests and dig day. The machine has to bore.
04Constraints

The rules we have to live inside.

REQ.01 Tunnel cross-section ≥ 0.2 m² (equivalent to 0.5 m diameter circle).
REQ.02 Straight-line distance ≥ 30 m between fully-underground entry and breakthrough.
REQ.03 Breakthrough within 0.5 m of the nominal alignment, or accept time penalty.
REQ.04 Tunnel crown depth > 0.5 m at its deepest point.
REQ.05 6DOF state reported at all times, telemetry rate ≥ 0.1 Hz.
REQ.06 Remotely controlled from the surface — no humans in the tunnel during operation.
REQ.07 No combustion engines, no explosives. Electric drive only.
REQ.08 No surface settlement or heave due to tunnelling — penalised in scoring.