About Us

The consulting engineering firm of Richland Engineering Limited was founded in 1968. Headquartered in Mansfield, Ohio, we are a limited partnership managed by three senior partners:

Patrick R. Schwan, P.E.


Partrick Schwan has been working in the engineering industry for over 25 years. Patrick graduated from Ohio Northern University with a Bachelor of Science in Civil Engineering. As manager of the Transportation Department, Patrick develops and manages transportation projects. These projects include: roadway, airport, and municipal projects, as well as handling ODOT Pre-qualifications for design and construction engineering. Patrick is a licensed engineer in both Ohio and Maryland, and is a Certified Erosion and Sediment Control Professional.

David L. Rinehart, P.E.


David has been working in the industry for over 30 years. David graduated from Ohio State University with a Bachelor of Science in Civil Engineering. He later went on to receive his Master’s from Ashland University. He is currently the head of the Structures Department, where he inspects, analyzes, and designs bridges. David is a Registered Professional Engineer in the state of Ohio. 

David H. Timmer, P.E.


David has been working the industry for over 40 years. He received his Bachelor of Arts in Secondary Education from Eastern Kentucky University and then a Bachelor of Science in Civil Engineering from Ohio State University. As a Structural Engineer and Senior Partner, David aids contractors by designing retaining walls and cofferdams, develops demolition and erection plans, as well as analyzing existing structures to determine if they can support construction loads. David also works on stabilizing hillsides along with feasibility studies to see if a type of work can be practically done.

These senior partners bring numerous years of experience to the firm’s expertise in engineering. To perpetuate Richland Engineering for many years to come, associate partners have been added to the firm, from whom will come the future managers of Richland Engineering Limited:

Robert McAuley, P.S.

Robert has been working in the industry for over 30 years. He currently manages the Surveying Department. Robert and his team work together to determine what form of surveying is needed and then gathers it. Together they work closely with the Ohio Department of Transportation and the Right of Way Department for project planning and preparation. He holds his Professional Surveying license and is a member of the Professional Land Surveyors Of Ohio group. 

David Warholic

With of 36 years experience in the industry, David Warholic is a vital member of the team. He attended Cleveland State University to study Civil Engineering. He currently is the Senior Highway Designer,  responsible for detailed highway project plan development and coordination, and quality oversight for highway disciplines on ODOT Design-Build Projects. David is a Certified Professional in Erosion and Sediment Control (CPESC).

Richland Engineering Limited has an experienced professional staff of Civil Engineers, Structural Engineers, Highway Engineers, Traffic Engineers, Airport Engineers, Sanitary Engineers, Surveyors, and Inspectors. Areas of specialty include:

  • Airports
  • Highways
  • Municipal
  • Structures
  • Survey

Highly-qualified design technicians, CAD technicians, computer specialists, and clerical staff support the professional staff. The total team is geared to develop the solution to our client’s projects with total in-house teamwork.

Since its founding, the firm has been tested by hundreds of successful projects. During each project, we build a close working relationship with our client. This allows us to better determine the full scope of the project, and to find better solutions.

At Richland Engineering Limited, our people speak for our firm. We believe our employees are our best corporate communicators. Through their abilities and attitudes, our clients have learned that they can depend on Richland Engineering Limited, trust the firm’s judgment, rely on its expertise in all the services the firm offers, and respect the integrity of the partners of the firm.