Decatur Park District
Scovill Zoo Train Design, Decatur, Illinois
Chastain provided concept planning, design and construction engineering services on the 1,663' extension of the Scovill Zoo train. The extension doubled the length of the existing track, and included a 500' long prefabricated truss bridge and 450' of
precast modular retaining wall. The new track followed the bluff of Lake Decatur, and provided scenic views of the lake and the Beach House located across the lake from the zoo. It also connected the Children's Museum, which allows visitors of the museum to ride the train and visit the zoo. A new parking lot with LED lighting was provided to the museum as part of the project. Work included earth excavation, constructing new 24" gauge 20 lb. rail track atop ballast, 500' prefabricated truss bridge atop 48" diameter drilled shaft hammerhead piers, riprap below bridge for erosion protection, modular precast concrete retaining wall of up to 10' exposed height, pedestrian fence, HMA parking lot, PCC sidewalks (stamped and standard), LED lighting, and tree removal. Scope of services included project management, preliminary engineering with concept plans, design engineering for site plan/railroad/structural, cost estimates, initial construction layout, construction documentation, on-site construction observation, pay estimates, and project close-out. The terrain in which this project was located was challenging both from a design aspect, as well as constructability. The bridge is located over 35' above the ravine adjacent to the lake, which a few hundred feet away from the end of the bridge a cut of over 9' was needed and the precast modular retaining wall used to retain the soil due to an existing building that was to remain. The alignment also followed the edge of the lake bluff, so soil stability was verified and track guardrails were used in case of a derailment along the bluff. The project was let for bid in May 2018 with a winning bid of $2.06M, and the project was completed ahead of schedule and at a cost of $2.11M. An additional $65K was added to the awarded contract as additional work requested by the Client, including other railroad track repairs, additional fencing, gabion baskets, builder's risk, and additional grading work.