When 100-year-old bronze doors at the Missouri State Capitol became inoperable, the State of Missouri faced an engineering challenge that had nothing to do with standard construction: How do you safely remove, transport, and restore two 7,500-pound doors that measure 6 feet wide by 18 feet tall?
The answer required custom rigging systems, specialized scaffolding, precise coordination, and the kind of engineering expertise that separates contractors who can handle complex historic work from those who can’t.
The Challenge
The two monumental bi-fold bronze doors guard the entrance to the Grand Stair at the Missouri State Capitol. After a century of use, they had become inoperable and needed expert restoration.
But these aren’t doors you can simply unbolt and load onto a truck. Each door weighs more than 7,500 pounds. They’re positioned under a portico at the top of exterior stairs. And they’re irreplaceable historic artifacts that couldn’t be damaged during removal or transport.
The Custom Engineering Solution
Prost Builders’ team designed a complete rigging and support system specifically for this project:
- Five-ton trolley rail system to move the doors horizontally from underneath the portico to the top of the south stairs
- Custom scaffolding and supports to provide safe working platforms and structural bracing during removal
- Specialized rigging to distribute the weight safely while protecting the bronze surfaces
- A-frame truck supports custom-built to transport the doors safely to New Jersey for restoration by bronze door specialist firm Olek, Inc.
This wasn’t equipment you rent from a supplier. It was engineered specifically for this project based on the doors’ weight, dimensions, location, and the building’s historic nature.
Why This Required Engineering Expertise
Most general contractors coordinate subcontractors. They don’t design custom rigging systems or engineer specialized support structures.
This project required professional engineers who could:
- Calculate load paths and structural requirements. Moving 7,500 pounds through a historic building requires understanding how forces transfer through existing structures.
- Design safe rigging systems. The doors had to be supported at multiple points to prevent stress concentrations that could damage the bronze or bend the frames.
- Account for historic preservation requirements. Every attachment point, every support structure, every piece of rigging had to be designed to avoid damaging historic materials.
- Coordinate with restoration specialists. The entire removal and transport process had to meet the requirements of the bronze restoration firm who would do the actual restoration work.
Part of a Larger Capitol Preservation Program
The bronze doors project was one of six historic renovation and restoration projects Prost Builders has completed at the Missouri State Capitol in recent years.
Other projects included:
- The Great Window stained glass restoration ($3.4 million)
- Stained glass laylight and 34 roof skylights restoration
- Various structural and architectural preservation work
The State of Missouri keeps returning to Prost Builders for Capitol work because historic preservation at this level requires contractors with demonstrated expertise, not just construction experience.
The Restoration Process
After the Prost team successfully removed the doors and transported them to New Jersey, restoration specialists at Olek, Inc. began detailed work to return the doors to functional condition while preserving their historic character.
The project timeline had to coordinate with state government operations and the governor’s inauguration schedule. When restoration was complete, the doors and their strengthened framework were carefully reinstalled — just in time for the inauguration ceremony.
Project Leadership
Project Manager Drew Wilde and Superintendent Cory Hoelscher led the Prost team through the complex removal and reinstallation process. Drew Wilde also managed several other high-profile historic preservation projects, including the Kirk Building renovation at Truman State University.
What This Reveals About Historic Preservation
Projects like the bronze doors restoration show why historic preservation requires different capabilities than standard construction or renovation.
- Engineering matters more than construction experience. Knowing how to pour concrete or frame walls doesn’t prepare you to design rigging systems for 7,500-pound historic artifacts.
- Every project is unique. There’s no standard procedure for removing monumental bronze doors. The solution has to be engineered specifically for that project’s conditions.
- Preservation expertise is specialized. Understanding how to work with historic materials, coordinate with restoration specialists, and meet preservation standards requires experience that most contractors simply don’t have.
- Accountability increases with irreplaceability. When you’re responsible for irreplaceable historic artifacts, there’s no room for “we’ll figure it out as we go.” Everything must be planned, engineered, and executed with precision.
The Bigger Picture
As one of the largest design-build general contractors in Missouri, Prost Builders has built a reputation for successfully completing historic renovation and restoration projects throughout the state.
This expertise didn’t develop overnight. It came from decades of working on landmark buildings, learning from specialized restoration consultants, investing in engineering capabilities, and building relationships with preservation authorities.
When you’re responsible for a state capitol, a historic courthouse, a landmark academic building, or any structure that represents community heritage, the contractor you choose makes a lasting difference.
What This Means for Your Historic Building
If you’re planning work on a historic building — whether it’s exterior restoration, structural reinforcement, or adaptive reuse — look for contractors who:
- Have professional engineers on staff who can design solutions for unique preservation challenges
- Can demonstrate completed preservation projects with verifiable references (not just old building renovations, but actual preservation work)
- Understand coordination with specialists like restoration consultants, preservation architects, and specialized subcontractors
- Have relationships with preservation authorities and understand state and federal preservation standards
- Can provide examples of custom solutions they’ve engineered for previous preservation projects
- Standard construction expertise isn’t enough for landmark preservation. These projects require specialized knowledge, engineering capabilities, and a track record of protecting irreplaceable assets.
Planning restoration or renovation work on a historic building? Contact us to discuss how our preservation expertise and engineering capabilities can help protect your building’s historic character. Or learn more about our historic preservation work.