By Kevin M. Arft and Steven Hammerschmidt, Contributing Authors
At nearly two miles long, the venerable Fred Hartman Bridge is a critical piece of infrastructure for the Baytown and La Porte communities in Texas. The bridge carries over 90,000 vehicles daily, including 12,000 trucks, on eight lanes of State Highway 146.
The bridge plays a significant role in the regional and state economies, facilitating efficient transportation across the Houston Ship Channel, one of the nation’s busiest waterways, and supporting Port Houston commerce.
Constructed in 1995, the Fred Hartman Bridge is unique among Texas structures because of its 1,250-foot-long cable-stayed main unit supported by twin 440-foot-tall, M-shaped concrete pylons. The bridge replaced the Baytown Tunnel, which was removed to deepen the ship channel for larger vessels.
The bridge is currently the longest cable-stayed bridge in Texas and the 77th longest bridge in the world. Named after Fred Hartman, a prominent local newspaper editor, this regional landmark stands as a testament to engineering. The bridge’s complex cable design underscores its importance and distinguishes it from other structures in the area.
Soon after the bridge opened, the support cables experienced excessive vibration above allowable tolerances in certain wind and rain conditions. A study was performed and as a result, dampers were installed near the lower anchorage of each cable to successfully dampen the vibrations.
After nearly 30 years of use, the Texas Department of Transportation (TxDOT) has embarked on a proactive approach to preserve and extend the bridge’s life.
TxDOT contracted with GFT Inc. in late 2022 to perform a detailed bridge condition assessment as part of its maintenance plan. Regular maintenance has been performed on key bridge components over the years, such as repairs to the deck, the large modular deck joints and the access elevators within the pylons.
While the bridge’s major components have "fair to good" condition ratings based on previous inspections, more comprehensive, longer-term repairs were required.
Why This Assessment Matters
The assessment documented the bridge’s structural health, identified maintenance needs and established a baseline condition to monitor against future evaluations. While the bridge undergoes biennial routine safety inspections and hands-on inspections of its non-redundant steel tension members (NSTM), TxDOT sought a comprehensive assessment of the entire structure, including hands-on access to hard-to-reach areas and complex features. The assessment required specialized access for inspection of cables, anchorages, pylons and other specific components.
Located in the Texas Gulf Coast region, the bridge endures heightened environmental risks from coastal conditions, such as corrosion from high humidity and salt exposure, as well as strong winds from tropical storms and hurricanes.
These environmental factors increase maintenance requirements, particularly in structurally critical areas like cables, cable anchorages and NSTM connections. Maintaining safe access for the assessment crew while minimizing traffic disruptions on and below the bridge was a challenge that required extensive planning before engineers could deploy to the field.
Preparation for the assessment involved hiring a traffic control company to manage lane closures, deploying various pieces of specialized equipment (e.g., bucket trucks, under-bridge inspection vehicles, and safety boats), and employing rope access teams to reach difficult-to-access areas on the bridge’s pylons and cables.
The GFT team coordinated daily with TxDOT, the U.S. Coast Guard, and the traffic control company to ensure safe access to the bridge for equipment and personnel while limiting roadway and maritime disruptions.
According to the Greater Houston Port Bureau, the Houston Ship Channel is one of the nation’s busiest waterways. On average, it handles about 50 deep-draft vessel movements per day, with the capacity to manage surges exceeding 90 ships daily. Additionally, approximately 400 tugs transit the channel each day, transporting around 635 barges.
Coordinating the movement of inspection personnel and equipment with the Coast Guard was required to ensure continuous safe operation of the channel while performing the bridge assessment.
Innovation and Expertise
Before the main field assessment, GFT unmanned aerial vehicle (UAV or drone) pilots captured photographs and videos of the bridge cables and pylons to supplement and focus the efforts of the field assessment team.
Nearly 30 inspection engineers performed the field assessment over three weeks in early 2023. A 16-person rope access team, trained in Society of Professional Rope Access Technicians (SPRAT) techniques, accessed the exterior faces of the bridge pylons and the full length of select cables where using a boom lift or bucket truck were not feasible. Rope access reduced the number of lanes closed and mitigated the high cost of mobilizing and operating large cranes and aerial lift vehicles.
To inspect the pre-selected cables, rope access inspectors conducted hands-on observations by descending the cables and deviating the ropes as needed to access all pylon faces, including sloped portions, using tensioned guidelines.
A survey team collected precise horizontal and vertical data points on the bridge to compare with original construction records and establish monitoring targets for future assessments. While structural movement of a bridge under loading, especially one as large as Fred Hartman, is inherent to its design and function, tracking this movement is critical for monitoring its health.
Ultrasonic testing of select cable ends was performed to verify previous acoustic monitoring results and check for corrosion. Accelerometers also were used for operational modal analysis (OMA), providing baseline data on cable forces and vibration modes for future comparisons.
Lessons Learned
The assessment revealed no critical or significant structural issues but identified components requiring maintenance and repair, such as the concrete deck, deck expansion joints, steel protective coating and cable protective tape systems. These findings align with expectations for a bridge of this type and age.
The assessment data was compiled into a detailed report for TxDOT, summarizing findings and providing maintenance and repair recommendations to guide long-term preservation planning. The results were consistent with prior inspections, confirming the bridge's overall good condition while identifying minor, isolated deficiencies.
The recommendations will help TxDOT prioritize maintenance funds, mitigate future deterioration and enhance the bridge’s safety and longevity.
Additionally, GFT partnered with TxDOT to develop complex member inspection procedures for the Fred Hartman Bridge to help ensure compliance with the newly adopted Specification for National Bridge Inspection (SNBI). This document defines special inspection requirements for the bridge’s unique features, including cables, anchorages, electrical systems, and elevators.
Looking Forward
Maintaining the Fred Hartman Bridge underscores TxDOT’s dedication to proactive infrastructure management, ensuring the safety and functionality of critical structures while advancing Texas’ goals for sustainable, long-term infrastructure preservation.
This assessment exemplifies a proactive and thorough approach to complex structure maintenance, serving as a model for TxDOT’s stewardship of other iconic bridges across the Lone Star State.
This project’s integration of advanced testing and rope access techniques provides a practical framework for preserving large, complex bridges in challenging coastal environments.
Moving forward, TxDOT will implement the recommended maintenance and repairs outlined in the assessment, with an ongoing preservation design project reinforcing this commitment to the bridge’s longevity and legacy. RB
Kevin M. Arft, P.E., is a bridge team leader at GFT. Steven Hammerschmidt, P.E., serves as manager – rope access program, GFT.
