Axiom Engineers: Commissioning

Caldecott Bore 4 Tunnel, State Route 24 Berkeley Hills

This Caltrans project involved construction of a two-lane bore and a new Operations Maintenance Center (OMC). The new bore allows for four lanes of west-bound traffic to Oakland on State Route 24 and is connected to the existing bore 3 via pedestrian cross passages.

The commissioned systems included all electrical distribution from both of the 12KV PG& E connections at the east and west substations to the 120V panelboards.
This included all medium voltage switchgear, circuit breakers, motor control centers, emergency generators, transformers and the automatic switching logic between the two substations.
Other commissioned electrical systems included radio rebroadcast, fire protection, battery chargers, carbon monoxide and nitric oxide detection, tunnel lighting controls, traffic control systems, and call boxes.
Commissioned mechanical systems included tunnel ventilation, cross passage ventilation, OMC HVAC, fire protection standpipe and dry fire protection.
Additional commissioned services included integration testing of all systems and operator response.

The Caldecott Tunnel
The Caldecott Tunnel gets its name from Thomas E. Caldecott (1878–1951), mayor of Berkeley from 1930–1932, member of the Alameda County Board of Supervisors 1933-1945, and president of Joint Highway District 13, which built the first two bores.

Project Summary

• 4,200 ft. long integrated with existing tunnels
• Linear heat detection activation of jet fans and traffic control systems
• Automatic primary power interlocks between substations
• Emergency generators and automatic transfer switches
• Integrated emergency response plan
• Tunnel ventilation system with nineteen 200hp jet fans and associated motor control centers
• Integration of controls with existing tunnel controls

Project Accomplishments

• Significant testing of automatic power transfer systems
• Numerous emergency response plan improvements for effective operator emergency reactions
• Correction of numerous deficiencies in power system and operator training
• Correction of incorrect circuit breaker ratings and trip unit settings
• Correction of numerous control system reporting inaccuracies

Selected Projects

LEED® 2.0 Commercial Interiors
LEED® 2.2 New Construction
LEED® Existing Buildings: Portola Hotel & Spa
CSUMB Dining Commons
Caldecott Bore 4 Tunnel
Doyle Dr. and Highways 101 and 1 Tunnel
East San Jose Carnegie Branch Library
Live Oak Community Resources Center
Monterey Peninsula College, Student Center
Naval Postgraduate School, Boiler Replacement
Nordic Naturals
Presidio of Monterey
Vandenberg Air Force Base
West Valley College Campus Centers