Founded in 2012 and located in Campellsburg, Kentucky, Rabbit Hole Distillery produces approximately 27,000 barrels of fine spirits annually. Frost Engineering & Consulting was enlisted for structural engineering services to design an innovative, high-density solution for storing approximately 25,000 whiskey barrels within a minimal space of 10,800 sq. ft. Frost also partnered with structural engineering researchers at the University of Notre Dame to address the challenges of constructing rickhouses more quickly and at less expense while also reducing exposure to growing insurance costs and hazards like fire and wind-storms.

The Frost-ND team, working in collaboration with metal racking industry partners, accelerated the optimization of the design, fabrication, and installation of light-gauge steel storage rack products for use in constructing rack-supported barreled spirits rickhouses by experimentally validating the performance of semi-rigid “moment frame” connections to quantify the range of rotational stiffnesses, strengths, and reliabilities of these components.  Semi-rigid “moment frame” connections have historically been used in various other materials, such as hot-rolled steel and reinforced concrete, to solve one of the most fundamental challenges of structural framing, which is to provide lateral stability and stiffness while avoiding clashes with access paths, utilities, and architectural features.

Reverse cyclic testing and subsequent statistical reliability analysis was performed in accordance with the standards that govern light-gauge steel rack design and testing, including RMI/ANSI MH16.1 Section 9.6, AISI S100 Commentary Chapter K, and FEMA 460 Appendix A. Historical testing of similar products by others using these standards was largely targeted to seismic performance. The Frost-ND team understood that a likely governing condition in Central Kentucky would be the initial unloaded condition of the rickhouses under lateral wind forces when frame connections would be more flexible – and potentially weaker – absent the load of barrels. Therefore, the Frost-ND team modified the test procedures to better represent the unique conditions faced by rickhouse owners in Kentucky.

Frost designed a schematic structural solution, designed and executed an experimental validation testing program, and completed a final structural design of the foundations and framing for two barreled spirit rickhouses, each with an approximate construction cost of $5 million. In addition to the high-density storage capacity, a unique feature of the rickhouse design is that the 500-ton racking structure supports the building facade and roof.

The Frost engineering team addressed the range of storage and environmental challenges at Rabbit Hole Distillery with a customized, innovative and efficient solution.