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Civil & Marine

Melvin Price Locks & Dam Main Lock Overlook Alterations

Alton, Illinois

Completing renovations on the Mississippi’s largest lock & dam during an immovable 90-day closure


Civil & Marine

Key Services




Virtual Design & Construction

Delivery Method
General Contracting (GC)
Self Perform %
Work Hours

The challenge

Ц faced a multifaceted challenge in the major alterations of two overlook buildings at Melvin Price Locks & Dam. The project, set within a tight three-month winter lock closure window, involved renovating reinforced concrete buildings situated above critical lift gate machinery. The intricate design required shifting the building face back by 4.5 feet, enabling the removal and replacement of newly fabricated lift gates. The logistical challenge was compounded by the site’s location, 14.5 feet above the lock wall, demanding careful demolition and reconstruction amid severe access restrictions. The need to protect the sensitive machinery added complexity, requiring innovative solutions for structural support during demolition.

Key Facts

Keystone Award Winner, Associated General Contractors of Missouri

Planning started more than a year before construction to ensure all materials and processes were in place

SLC3 Best Practices Award Winner, Materials Management

Challenge met

Ц addressed the complexities by designing and implementing a comprehensive solution. A temporary shoring system was devised to support the structures during demolition, optimizing the reuse of existing reinforcing steel. Working primarily from barge-based floating plants due to access restrictions, Ц meticulously executed significant concrete demolition, removal, and relocation of columns, beams, slabs, and walls. The project seamlessly integrated removal and replacement of lift gates, a historic first for the 34-year-old lock complex. Beyond structural intricacies, Ц delivered building fit-out, low voltage electrical and HVAC system renovations, and upgrades to the medium voltage power distribution. The result was a successful overhaul within the challenging constraints, demonstrating Ц’s capacity for innovation in intricate and critical infrastructure projects.

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