Tappan Zee Bridge, Design and Technical Oversight

KPFF designed, and is currently providing technical oversight for the construction, testing and commissioning of six (6) under bridge inspection travelers for the new Tappan Zee bridge. This twin cable-stayed bridge crossing New York’s Hudson River was completed in 2017 and consists of one 1140’ main span and two 467.5’ back. Each span is equipped with two rail mounted, self-propelled. under bridge inspection platforms (“travelers”) that facilitate maintenance of the bridge. KPFF was initially tasked only with completing the design of the traveler trolley and drive system, making use of components already purchased by the client. As the project progressed, KPFF was asked to assume full design responsibility for the traveler system and to provide the client with technical support to facilitate fabrication, testing, installation and commissioning. As part of this work, KPFF has provided technical assistance in selecting and sourcing mechanical, structural and controls system fabrication services. We are currently assisting the client and their fabricator to plan and support full off-site testing and commissioning of the travelers prior to delivery and installation onto the bridge.