Item No. 8g_supp
Meeting Date: November 17, 2026

Satellite Transit System Controls Project
Amendment Authorization (CIP #801043)

Purpose & Scope
Project Purpose: Life Cycle Extension project of the STS's Control System to include the
replacement of obsolete software, hardware, radios and associated components.
Project Scope:

Phase 1- Construction

Phase 2 - Equipment
Automatic
Train Control
System

Fiber Optic Loop /
Electrical Construction

21 Cars

- Software
- Hardware
- Network
- Radios
- Certification
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Operational Impacts

B20
N13

• Nightly STS Shutdowns
• North Loop from 12AM to 6AM
• South Loop from 11PM to 5AM

S1A

DA

• Shuttle Track from 10PM to 6AM
• Active Construction and Operational 
Readiness (COR) plan
• Busing / Wayfinding
• NSAT: D Annex ground board to Gate
N13 
• SSAT: B20 hardstand gates to Gate S1A
• Limited STS car availability during transition
from existing to new system.
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Project Budget and Schedule
Current Budget:

$78,240,000

Schedule Milestones:

This Request:

$4,700,000

Revised Budget:

$82,940,000

• Construction Auth: Q3, 2021
• South Loop In Use: Q2, 2027
• North Loop in Use: Q1, 2028
• Substantial Completion: Q3, 2028

The request supports the Port's
obligations for construction
completion and closeout
The project is funded by the
Airport Development Fund

Schedule extended by 31 months
due to a construction contractor
defaulting and additional
manufacturing delays.
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Project Photos
Temporary Controls Center

Maintenance Bays

1.8 Miles of Conduit

New Controls Equipment

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Project Photos

Old Vehicle Coupler

Communications Retrofit

Vehicle Dynamic Testing

Replacement Vehicle Coupler

Temporary Controls Center

Vehicle Retrofit Work

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Action Requested
Request Commission authorization for the Executive Director to:
(1) Increase the Capital Improvement project budget and
authorization for the STS Controls Renewal and Upgrade project
(CIP#801043) at Seattle-Tacoma International Airport (SEA) by
$4,700,000;
(2) Execute related project change orders, amendments, work
authorizations, purchases, contracts and other actions necessary
in support of the project.
The amount of this request is $4,700,000 for a revised total
estimated project cost not to exceed $82,940,000.
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Questions?

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