The Stratton Lock Expansion Project (Fox River, Illinois, USA)
Joshua M. Repp, P.E., Project Manager, Bergmann Associates, Buffalo, NY, USA
The William G. Stratton Lock, formerly known as McHenry Lock, provides lockages for recreational boating traffic on the Fox River and has been in service since 1960. The Lock serves as the passageway between the Fox Chain of Lakes in northern Illinois, and the Fox River. An average of 15,000 boats pass through the aging locks annually. The lock originally measured approximately 18x60 feet and, due to its relatively small size, users often experienced high wait times.
An engineering study was conducted in 2012 to evaluate options to increase the capacity of the lock, including an alternative to expand the length of the lock or to construct a separate lock adjacent to the existing lock. A detailed comparison of each alternative was made, considering primary factors such as cost, construction schedule, flexibility and ease of operation, ingress and egress times for boaters, and ability to facilitate potential future renovations and maintenance needs. Expansion of the existing lock chamber in the downstream direction was selected, roughly doubling the length of the lock to 18x120 feet.
Design for the lock expansion included rehabilitation of the existing lock chamber, modifications to the existing lower gate monolith, installation of a new gate monolith, reconfiguration of filling/emptying systems, extension of lock walls, safety improvements, and new lock mechanical and electrical systems. The existing horizontally framed steel miter gates were to be repaired and the lower lock gate relocated to the new lower gate monolith. The design was completed in 2013 and the lock expansion project was constructed in the winter of 2014 at a cost of nearly $4 million dollars. The rehabilitated lock has been in service now for several years and, given its increased capacity, has greatly reduced wait times and enhanced the boating experience for recreational boating users on the Fox River.
The presentation will outline the alternatives considered during the study phase, discuss features of the lock expansion design, and discuss challenges encountered during construction. Photos and video of the pre and post construction conditions will be included.
A link showing the lock construction from above:
https://www.youtube.com/watch?v=bjAQWDL2TMs