On the Job: Tappan Zee Bridge, New York

The Tappan Zee Bridge is in the middle of a massive reconstruction project and VIBCO is part of the job.

A Short History of the Tappan Zee Bridge

The first Tappan Zee Bridge was built from 1951 to 1953. The project cost approximately $8 million (about $61 million in today’s dollars) and was seen as an ambitious project to connect north New Jersey to New York City. Once completed, the new influx of commuter traffic that could easily travel from New York to New Jersey and vice versa spurred businesses and real estate developers to set up company branches and housing, providing commuters with ample new job opportunities.

The newness of the Tappan Zee was short lived. By 1960, not even a decade after its completion, reports and studies on the bridge revealed that officials and contractor companies had cut corners. The bridge’s finish was beginning to deteriorate, other parts of the bridge were built well below acceptable building standard. Moreover, the original Tappan Zee was designed to be nonredundant, meaning that there was little to no support built into the bridge to help stabilize and secure it should a massive shot hit the bridge jeopardizing it’s structural integrity. For comparison, a suspension bridge’s cable supports are a form of redundancy in engineering.

Since 2013, a brand new Tappan Zee Bridge has been under construction. Discussions about the project began back in 1999 and spanned almost a decade before any actions were taken. Almost “$88 million in taxpayer dollars was spent, 430 meetings were held, 150 concepts were considered” according to the project overview section of the Tappan Zee Bridge’s website. The project was stuck in a decade-long limbo.

It wouldn’t be until 2011 when New York Governor Andrew Cuomo with help of President Obama’s newly passed Design-Build legislation was the project finally able to leave the discussion room and finally begin construction.

According to the Tappan Zee Bridge’s website, the project is:

• Designed to last 100 years without major structural maintenance
• Projected to cost 3.1 billion dollars over 5 years (April 2018 is the projected unveiling date)
• Expected to meet or exceed environmental standards

On the Job: VIBCO and the New Tappan Zee Bridge

VIBCO began working with the Tappan Zee Bridge contracting company back in 2014. The Tappan Zee contractors contacted VIBCO to explore the idea of using external vibrators on the bridge's pillar and pylon construction.

Prior to contacting VIBCO, the Tappan Zee Bridge contractors were using internal vibrators to consolidate their concrete pours and experienced a myriad of problems with the internal vibrators they were using. Among the recurring problems were:

• Inconsistencies in consolidation from pour to pour
• Voids and rock pockets
• Unable to get in between the structure’s heavy rebar structure without getting damaged
• Achieving a substandard finish

Moreover, the internals weren’t long enough to reach the full length of the climbing forms.

VIBCO supplied the Tappan Zee workers with our external electric vibrators on the bridge's 16 North and South Main Span Towers and for their pylon pours. The bridge was using OM Engineering climbing concrete forms.

After the first use, all the problems mentioned above were no more. The vibrators mounted effortlessly onto the bridge’s climbing forms and once activated delivered the smooth, professional finish the contractors were looking for as well as the consistency from concrete pour to concrete pour.

Earlier this month, we paid a visit at the request of the Tappan Zee contractors to the job site for some additional consultation.

Check out more VIBCO case studies, field stories and product applications under our On the Job section.