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The San Francisco/Oakland Bay Bridge is not only a critical piece of infrastructure, but a marvel of modern engineering. The work involved in constructing the iconic self-anchored suspension span of this bridge included the use of innovative techniques that pushed the boundaries of modern construction. In this post, we’ll dive into some of the most fascinating aspects of the project, including cable band installation, suspender rope installation, and load transfer works that were essential during construction.

Cable Band Erection

Following installation of the PWS (Prefabricated parallel Wire Strands) that made up the main cable, and compaction of those 137 strands, attention turned to cable band erection. There were a total of 114 cable bands, each unique due to varying slope and rotation of the main cable. The cable bands were composed of two halves that were fastened together with 2” diameter bolts and tensioned to a predetermined load.

Suspender Rope Erection

Of the 114 cable bands, 100 had a pair suspender ropes.  Various methods were used to erect the suspenders, depending on the height above the deck.  For locations that a crane could not reach, a custom designed frame was fabricated that allowed a winch to pull the suspender into position.  The center of each suspender rope was marked during fabrication to verify suspender was properly placed during installation.

Load Transfer

Suspender Rope Jacking

The load transfer operation was a critical phase during the Bay Bridge’s construction.  During this operation the permanent suspender ropes were sequentially tensioned to transfer the weight of the bridge deck from the temporary truss to the main cable.  To perform this operation, engineers utilized a jacking system consisting of friction clamp weldments, threaded rods, and jacking beams at each suspender location to connect the suspenders to the bridge superstructure.

The friction clamp weldment was comprised of thick steel plates with machined surfaces secured to each suspender rope using eighteen 1.25” diameter A490 bolts.  The friction clamps were connected to a lower jacking beam using 4 high-strength all-thread rods.  The jacking beams were equipped with two hydraulic jacks.  Each individual system was capable of supporting the maximum load transfer design load of 800 tons, lifting the bridge superstructure, and permanently connecting the suspender to the bridge superstructure.

These jacking systems were vital to equalize the loads during jacking operations, ensuring the structural integrity of the suspender ropes.  The precision required in this process was remarkable, as each jacking location needed to lift and transfer the load incrementally to avoid putting excess strain on the structure during the load transfer operation. 

Jacking Saddle & Tower Adjustments

A unique aspect of the SAS span was it’s continuous main cable; each end of the cable was anchored into the deck at the east end and wrapped around the west pier.  This imposed challenges as the main cable was loaded during load transfer.  Prior to cable erection, the permanent tower was “pulled” approximately 20” west.  To perform this operation, ten 2.25” strands  were connected between the top of the tower to the adjacent island. Jacks on the lower end of the strands were used to manipulate the movement of the tower.  During load transfer, the jacks were adjusted to allow the tower to move at predetermined increments in order to balance the horizontal reactions from the cable.

Additionally, the cable between the two west deviation saddles needed to be adjusted during load transfer to maintain equal tension with the side span cable.  The jacking saddle, positioned between the two deviation saddles, was used to perform this operation.  At each of the jacking saddle’s four legs, four 300T jacks were used to adjust the location of the jacking saddle.  Throughout load transfer, the jacking saddle was sequentially “pushed” a distance of approximately 5’-5”.

In total, the team managed to jack and transfer the load in multiple stages, demonstrating incredible precision and control in their engineering methods. It’s a testament to the planning and expertise involved in constructing a bridge of this magnitude.

The Unsung Heroes of Bridge Engineering

The construction of the San Francisco/Oakland Bay Bridge is a testament to the power of modern engineering. Each phase of the project required careful planning, precision execution, and immense technical expertise. These complex processes were integral in ensuring that the bridge could handle the immense loads placed upon it, while also standing as a symbol of engineering excellence for generations to come.

The next time you drive across the Bay Bridge, remember the countless hours of engineering and ultimately the successful load transfer process, that made this marvel of modern construction possible.

The Brightline train project is more than just a transportation venture; it’s a historic feat of engineering and a testament to modern innovation. Stretching across miles of diverse terrain in Florida, this project connects the state’s major cities within an easy and quick route. Since its initial opening in 2018, the line has continued to grow, carrying over 2 million passengers in 2023. Today, Brightline’s maximum operating speed is 125 mph. The trains cover the 235-mile route from Miami to Orlando in 3 hours and 25 minutes, with an average speed of 69 mph.

Bridging the Gap: A Construction Marvel

At the heart of the Brightline project is the construction of 28 bridges, a crucial element in its design. These bridges are not just structures but symbols of connectivity and progress. The primary objective was to replace existing and outdated bridges with larger and more efficient ones, incorporating an additional track for rail traffic at each water crossing. This enhancement allowed both Brightline Trains and Florida East Coast Railway (FECR) to operate on two rail lines instead of one. Notably, four of the 28 bridges were of historical significance, namely the Eau Gallie River (Melbourne, FL), Crane Creek (Melbourne, FL), Turkey Creek (Palm Bay, FL), and Sebastian River (Sebastian, FL). These particular bridges posed the greatest challenges due to their size and complexity, requiring a meticulously coordinated approach.

Navigating Challenges: The Power of Innovation

Building a project of this scale is not without its challenges. The Brightline construction teams faced numerous obstacles, from difficult terrain to unpredictable weather conditions. However, these challenges were met with cutting-edge solutions and a workforce dedicated to overcoming any hurdles.

One of the major challenges was constructing the bridge foundations deep into the riverbed, ensuring stability and durability. This task required advanced machinery and techniques, including the use of large-diameter pilings driven deep into the ground. The project also demanded close coordination with environmental experts to protect the surrounding ecosystem, demonstrating a commitment to sustainable development. Another main challenge faced by the team involved coordinating with the railroad flaggers responsible for ensuring safety along the active railroad corridor, along with not impacting existing FECR rail traffic. Effective and constant communication was crucial with all members of the project team to mitigate any potential risks and ensure the smooth progress of the project.

Celebrating Success: A Community Effort

The Brightline project is not just about the engineering, it’s also a story of community and collaboration. The workforce behind this project includes hundreds of skilled workers, engineers, and planners, all contributing their expertise to bring this vision to life.

Moreover, the Brightline project is set to have a lasting impact on the communities it connects. By providing a fast, efficient, and reliable mode of transportation, it will open up new opportunities for economic growth, tourism, and cultural exchange. The project is poised to revolutionize travel in the region, making it easier for people to commute, explore, and engage with the world around them.

Looking Ahead: A Bright Future

As the Brightline project nears completion, it stands as a beacon of what’s possible when innovation meets determination. The rail line is now a tangible connection that will serve generations to come. The journey of Brightline is far from over; it’s a continuous path of progress that will shape the future of transportation in the region. The Brightline train project is a journey into history, one that honors the past while embracing the future.  Our JBC team’s involvement in this project was a pivotal part in the success of the Brightline High Speed Passenger Train transit from Miami, FL to Orlando, FL in 2023, making history as the first private US passenger rail line in 100 years.

In the world of civil engineering, certain projects stand out not only for their scale but also for their intricate design and technical challenges. The Queensferry Crossing in Edinburgh, Scotland, is one such project. This monumental bridge, spanning the Firth of Forth, is a testament to modern engineering, innovation, and perseverance.

A Cable-Stayed Colossus

The Queensferry Crossing is not your typical bridge. With a total length of 2,638 meters, it boasts a central cable-stayed bridge (CSB) that spans 2,090 meters. This design ensures that the bridge is both strong and flexible, capable of withstanding the harsh conditions of the North Sea while providing a vital transport link between Edinburgh and the surrounding regions. The bridge stands at a whopping 210 meters at its highest point making it the tallest bridge in the UK. The Queensferry Crossing was completed and opened in August of 2017.

Construction of the CSB required careful consideration of the bridge’s weight and stability. The segments were built with a combination of concrete and steel, ensuring that the structure could bear the significant loads placed upon it. By January 2016, 60 out of the 110 deck segments had been installed, highlighting the relentless progress of the construction team.

Approach Viaducts: Engineering Precision

The Queensferry Crossing isn’t just about the main span; it also features two approach viaducts on either side. The Approach Viaduct North (AVN) and the Approach Viaduct South (AVS) are essential for connecting the bridge to the existing road networks. These viaducts were constructed in stages, with each section meticulously aligned to ensure a smooth transition onto the main bridge. AVS was launched in 12 phases onto V-Shaped piers and sits at 525 meters long.  AVN is made up of two different cross section types: parallel twin composite decks, and a single composite deck with 12 single deck segments and 8 twin deck segments. AVN sits at 221 meters long.

A key challenge in the construction of the approach viaducts was minimizing disruption to the surrounding communities and environment. The team employed innovative techniques such as launching girders from a fabrication facility directly onto the piers, significantly reducing the need for onsite construction.

Towers: The Heart of the Bridge

Rising high above the Firth of Forth, the three towers of the Queensferry Crossing are perhaps the most striking feature of the bridge. These towers, each reaching heights from 207-210 meters, were designed to anchor the cables that support the bridge deck. The reinforced towers start at bedrock nearly 40 meters below the water.

Constructing the towers was no easy feat. The reinforced concrete structures were built in segments, with each new segment being added only after the previous one had set. They were built in 4-meter sections using climbing formworks, or jumpforms, with a total of 54 lifts per tower. This incremental approach ensured the stability of the towers as they grew taller. The towers also had to be resilient enough to withstand the fierce winds that regularly sweep across the waterway. Due to the Scotland’s famous variable weather, the towers featured all-weather “bird-cages” so work could continue in all types of climates.

Making History Overseas

The construction of the Queensferry Crossing was a global effort. The bridge’s design and construction involved companies from across Europe, including Spain, Germany, and the UK. This international collaboration brought together some of the brightest minds in engineering to tackle the numerous challenges presented by the project.

From the initial design phase to the final stages of construction, the project required meticulous planning and execution. By Spring 2017, the Queensferry Crossing was on track to be completed, marking a major milestone in the history of Scottish infrastructure.

A Lasting Impression on the Community

The Queensferry Crossing is more than just a bridge; it’s a crucial component of Scotland’s transport network. The bridge connects the motorway networks on either side of the Firth of Forth, providing a vital link for commuters and freight transport alike. With the completion of the bridge, traffic flow across the waterway improved significantly, reducing congestion and travel times for commuters coming in and out of the city. This iconic bridge stands as a testament to a global effort in engineering in construction and will continue to serve the people of Scotland for years to come.

In the world of transportation research and development, Florida’s SunTrax stands as a beacon of innovation. As the first state-of-the-art facility of its kind in the United States, SunTrax is dedicated to advancing technologies in safe, controlled environments, with a particular focus on autonomous and connected vehicles.

A Cutting-Edge Facility with a Vision

Located in Central Florida, the SunTrax Connected and Automated Vehicle (CAV) Test Facility is a sprawling complex with over 475 acres of space dedicated to testing the future of transportation. This facility is specifically designed to support the testing and development of emerging transportation technologies, providing a controlled environment where innovators can push the boundaries of what’s possible.

SunTrax’s primary feature is its dedicated high-speed oval track, which is an impressive 2.25 miles long. This track is surrounded by a variety of other testing environments, making it a versatile location for various automotive and infrastructure tests.

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Overcoming Challenges in Construction and Innovation

The development of SunTrax was not without its challenges. The project required innovative solutions to unique problems, including the integration of sophisticated technology into the infrastructure. From the use of specialized construction techniques to the deployment of cutting-edge communication systems, every aspect of SunTrax was meticulously planned to ensure it could meet the demands of modern transportation testing.

One of the most significant challenges was the global COVID-19 pandemic, which struck during the construction phase. Despite this, the team at SunTrax continued to push forward, implementing rigorous safety protocols and adapting to new work environments to keep the project on track.

Innovation at the Core

Innovation is at the heart of SunTrax’s mission. The facility was designed not just as a testing ground, but as a hub for research, development, and collaboration. It features dedicated areas for testing various aspects of autonomous vehicles, including sensors, control systems, and infrastructure interaction.

SunTrax has also made significant strides in incorporating sustainability into its operations. The facility employs eco-friendly practices, ensuring that as it pushes the boundaries of technology, it also respects the environment.

Recognition for Excellence

SunTrax’s groundbreaking work has not gone unnoticed. The facility has garnered multiple awards, including:

• Project in Construction Award (Special Distinction) – 2023
• Jubilee Major Transportation Achievement Award – 2020
• President’s Award for Excellence – 2020
• West Use of Technology & Innovation – 2020

These accolades are a testament to SunTrax’s commitment to excellence and its role as a leader in the field of transportation innovation.

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A Look Ahead

As SunTrax continues to develop, it remains at the forefront of the transportation revolution. The facility is expected to expand its capabilities, incorporating new testing environments and technologies to accommodate the rapid advancements in autonomous and connected vehicles.

With its state-of-the-art facilities, commitment to innovation, and a clear vision for the future, SunTrax is not just a testing ground—it’s a launchpad for the next generation of transportation technology.

In the heart of Las Vegas, where innovation meets excitement, the High Roller stands as a testament to human engineering and the creativity of the city. Developed by Caesars Entertainment, the world’s largest gaming company, this impressive structure rises 550 feet (168 meters) above the ground. Upon completion, the Las Vegas High Roller became the tallest observation wheel in the world, holding that title until 2021 when the Ain Dubai (Eye of Dubai) opened. However, the Eye of Dubai has been out of operation since 2022. The High Roller is located on a sprawling 350-acre parcel just one block west of the iconic Las Vegas Strip, directly across from Caesars Palace. The $550 million project stands as an icon of the city’s skyline and a common attraction for the constant stream of visitors that make their way to the city.

Engineering and Building the Structure

The American Bridge Company team undertook the monumental task of constructing this engineering marvel. Their scope of work included the supply and erection of the 469-foot (143-meter) diameter wheel, which rests on a fixed spindle supported by four inclined steel legs. These legs stand approximately 283 feet (86 meters) above ground level and are reinforced by a transverse braced leg. The structure was designed by ARUP’s San Francisco team with help from their London Office.

The High Roller’s structure is a marvel of modern engineering. The four tubular steel legs, varying in diameter up to 9 feet (2.8 meters), were constructed first. These legs are anchored to concrete foundations and equipped with 13 tuned mass dampers to mitigate vibration. The total weight of the steel used in the support and brace leg system is a staggering 1,331.6 tons (1,208 metric tons).

The 545.6-ton (495 metric ton) hub, spindle, and bearing unit was erected in three pieces using a falsework truss designed by American Bridge. The hub and spindle assemblies, made of steel forgings with a heat-treated welded overlay, were meticulously assembled and positioned using cranes and precise skidding techniques.

Rim and Cable System

The rim of the High Roller, a tubular steel structure with a diameter of 6.6 feet (2 meters), was erected in 53-foot (16.1-meter) segments. These segments were bolted together with collar splices and supported by radial erection struts. As seen in the video above, the wheel was incrementally rotated and assembled using a 750-metric ton capacity Hydraulic Rotating Mechanism (HRM) designed by American Bridge and Enerpac.

The wheel’s cable spoke system, consisting of 112 locked coil spokes, was installed in two phases. The final cable tensioning ensured each cable achieved a force of 1,189 kilonewtons (267,300 pounds) within a tolerance of +/-10%, resulting in a final wheel tolerance within +/-25 millimeters (1 inch). In summary, that explains that the cables were tensioned to a specific force with a small allowable variation, leading to a very precise final structure.

A Global Effort

Constructing the High Roller required collaboration with specialty suppliers from around the world. Structural steel came from China, bearings from Sweden, gripper systems from the Netherlands, forgings and castings from Japan, cables from Italy, and tuned mass dampers from Germany. The erection engineering was performed by American Bridge engineers in Coraopolis and Las Vegas, while skilled labor and supervision were provided on-site. This global effort is a testament to the importance of this beloved attraction in the City that Never Sleeps.