On-call structural engineering and facilities design services

Client Name
Tilcon Connecticut, Inc.
Connecticut, USA
  • Civil & structural engineering


SLR provides engineering, design, structural inspection, and construction inspection services to Tilcon on an ongoing basis.


Work includes design of new and rehabilitated and expanded existing asphalt, sand, concrete, and aggregate plants throughout Connecticut.

Our most recent biannual inspection was for steel piers, railroad trestle and terminal building at Tilcon-owned property on the Branford Steam Railroad Line. The 345-foot long substructure consists of 10 spans with two concrete abutments and nine steel pier bents.

The railroad delivers crushed stone from the quarry to the Pine Orchard Marine Terminal where it is loaded onto barges serving coastal Connecticut, New York City, and Long Island. Based on our inspections we prepare plans and details for repairs aimed at safety and preservation of facility service life. Our designers work with Tilcon during off-season periods to implement the periodic improvements.

We routinely perform design of foundations for various plant projects; the most recent of which includes design of a new 500 tons-per-hour (TPH) Stationary Ultraplant and Sand Plant in North Branford, Connecticut. The foundations required over 1,200 cubic yards of concrete at the Ultraplant completed in 2018 and 700 cubic yards of concrete at the Sand Plant completed in 2019.

Our design team coordinated closely with the manufacturer for precision layout and stub-ups for numerous premanufactured components.

Additional project work included rehabilitations at the Danbury, Waterbury, and Hamden asphalt plants. The existing stacks at these plants were 32 feet above grade, but a recent air quality code change required these stacks to be extended vertically by 48 feet.

The design of the foundations was critical, as the existing footings were within inches of the new silo and weigh scale. The firm provided shop drawing review and consultation during construction. Due to the close proximity of the plant, deep excavation and pile driving was not feasible so new foundation on micropiles was designed to resist wind loads while minimising effects of vibration on adjacent footings.


SLR provided complete site design services for civil engineering and landscape architecture. We assisted in the regulatory process for local, county, and state approvals. This included participation in the preparation of both the Draught Environmental Impact Statement (DES) and Final Environmental Impact Statement (FEIS) in accordance with requirements of the State Environmental Quality Review Act (SEQR). Close coordination with Westchester County Department of Highways and the Town of Harrison continues during construction.