As the 8th largest engineering firm in the entire St. Louis region, TWM provides civil and structural engineering and geospatial services to both public and private sector clients throughout the Midwest and Southeast including Illinois, Missouri, and Tennessee. We draw upon the extensive knowledge, skills, and experience of our licensed professionals, as well as our support staff, to tackle design challenges with accurate and cost-effective solutions. Due to the solid reputation TWM has built over the last 78 years for being able to get the job done right, we proudly retain approximately 95% of our clients’ business. We care deeply about providing our clients with Exceptional Service. Nothing Less.


TWM’s roots date back to 1946 – the year engineer and land surveyor A. Yorker Wade founded the Wade Engineering Company in Belleville, IL, a small community about 15 miles east of downtown St. Louis, MO. An original staff of three worked out of Wade’s home until 1953 when they relocated to a small commercial center the company developed at the intersection of Lebanon Avenue and IL Route 161. To this day, locals still refer to it as Wade Square.

Yorker Wade eventually sold the firm to his son Jerry and another surveyor Bill Moerchen. Meanwhile, Rollie Thouvenot, the younger brother of Bill’s wife, had started working for the firm while still a teen – cutting brush for the surveyors as a summer job. Working his way through the ranks, he eventually became president in 1987, and the firm was subsequently incorporated under the names of those three founders. In 2003, TWM began an Employee Stock Ownership Plan (ESOP), a trust which holds the company stock in each employee’s name, and in subsequent years, the ESOP continued to purchase additional shares. In 2017, TWM became 100% ESOP owned.

From these humble beginnings TWM has grown to the firm it is today, with corporate headquarters in Swansea, IL and 10 additional branch offices. The firm is large enough to take on major projects, but still close enough to its roots to remember the importance of honesty, integrity, trust, and doing business on a handshake. The firm’s ESOP ownership means that every client works with an owner and will benefit from that person’s vested interest in seeing the firm and its clients succeed.


If you want every employee to know your mission by heart, then make it concise, notable, and bold. If you want them to live it every day, make sure your clients know it and remember it as well.  In 2004 we shortened our mission statement to just four words. We offer those pivotal four words to you as our promise.



Over the years, TWM and the firm’s work have been recognized as exemplary on local, state, and national levels. Below is a partial list of recent honors.

  • 2024 ACEC Missouri Grand Award | Transportation
    Missouri Route 100 Rehabilitation | St. Louis, MO

  • 2020 ACEC Merit Award | Transportation
    IL River Bridge District | East St. Louis, IL

  • 2019 ACEC Merit Award | Waste & Stormwater
    South Side Park Lift Station and Relief Sewers | Belleville, IL

  • 2016 ACEC Honor Award & National Recognition Award | Transportation
    First IL Diverging Diamond Interchange | Marion, IL

  • 2015 ACEC Honor Award & National Recognition Award | Waste & Stormwater
    Water Treatment Facility Expansion | Belleville, IL

  • 2012 ACEC Merit Award | Structural Systems
    MetroBikeLink Signature Bridge | Swansea, IL

  • 2011 ACEC Honor Award & National Recognition Award | Surveying & Mapping Technology
    3D Scanning of Rock City Business Complex National Archives & Records Administration/National Personnel Records Center Annex II | Valmeyer, IL


Read more about the projects we work on, and how we fulfill our promise and mission of Exceptional Service. Nothing Less.


Celebrating Success: TWM Named A Finalist For Best Places To Work

TWM has been named a 2024 Finalist by the St. Louis Business Journal as one of the Best Places to Work. Nearly 200 St. Louis-area companies were nominated, with 83 selected as top emp [...]

By |April 18th, 2024|Categories: News|Tags: , |0 Comments

Honoring TWM’s Legacy: Reflecting on the Passing of William Moerchen, One of our Founders

It’s with deep sadness that we announce the passing of William Moerchen. Bill was one of the three owners and founders of Thouvenot, Wade, and Moerchen (TWM), but he was also so much [...]

By |March 28th, 2024|Categories: News|Tags: , |0 Comments
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