Tubes within tube and shell heat exchangers are supported at intermediate points by plates. Flow-induced vibration can cause tubes to impact and rub against these supports, or other tubes, and can result in tube fretting-wear. The tube-to-support dynamic interaction, which consists of dynamic contact forces and tube motion, is used to relate single-span wear data to real heat exchanger configurations consisting of multi-span tube bundles. This paper describes the technique used to measure tube-to-support dynamic forces in the Chalk River Nuclear Laboratories impact fretting-wear test facility and reports test results that validate the technique. The force measurement technique is shown to provide a reasonable measure of dynamic contact forces.