What's In The Tunnel
Hard numbers for every utility system inside the 12-ft utilidor. These specifications address the full capacity requirements of the Colossus 2 and Colossus 2 South combined operations.
150 MW
Electrical Capacity
20,736
Fiber Strands
12,000 GPM
Chilled Water Flow
90 Trips/Day
Vehicle Transport
Power Distribution
150 MW
Total Electrical Capacity
How It Works
Four 13.8kV high-voltage feeders carry the bulk of power — 35 MW each — providing 140 MW of primary distribution capacity. Two 480V buses supply an additional 10 MW for local distribution and equipment power.
Underground routing eliminates weather-related outages and reduces transmission losses by 3%, saving $19.7M annually compared to overhead surface lines.
Total annual transfer capacity of 1,314,000 MWh — enough to power both data centers at full computational load 24/7/365.
Fiber Optic Network
20,736
Total Fiber Strands
How It Works
Six OS2 single-mode trunk cables, each carrying 3,456 strands, provide the backbone for data center interconnect (DCI) between Colossus 2 and Colossus 2 South.
Four primary trunks handle active traffic while two redundant trunks provide 100% failover capacity — 10,368 simultaneous 800G links with full redundancy.
Underground routing provides the shortest physical path between facilities, minimizing latency to under 10 microseconds — critical for distributed AI training workloads across both compute clusters.
Chilled Water Cooling
12,000 GPM
Total Flow Rate
How It Works
A 24-inch main supply pipe delivers 10,000 GPM of chilled water, with a 12-inch redundant supply adding 2,000 GPM failover capacity. Return piping mirrors this configuration with 18-inch main and 12-inch redundant lines.
85 MW of thermal cooling capacity derived from:
= 71.9M BTU/hr ≈ 85 MW thermal
Underground routing keeps chilled water insulated from ambient heat, maintaining efficiency that surface piping cannot match.
Vehicle Transport
6/hr
Vehicle Throughput
Tunnel vs. Surface
Tunnel
6/hr
8 min transit
No escorts needed
Weather-proof
Surface
2-3/hr
25 min transit
Armed escort required
Weather-dependent
The enclosed tunnel eliminates the need for armed security escorts, reduces transit time from 25 minutes to 8 minutes, and operates in all weather conditions. Each vehicle carries 2,000 lbs of payload — 8 to 12 GPU servers per trip — with autonomous electric operation.