The primary purpose of this work is to experimentally investigate the damping coefficient of a viscous damper, intended to be used in railway applications to reduce noise emission. The viscous shock absorber used in this study is a commercial vehicle damper to which minor modifications were added. This investigation was focused on detecting the variation in the damping coefficient value over a wide range of frequencies. The experimental setup tends to simulate the railway vibration represented by a strong steel metal sheet structure attached to a shaker from its lower side. The shaker itself is connected to the damper rod through a dual acceleration-force sensor. A sinusoidal load with wide range of frequencies was applied by the shaker to the top of the damper's rod. Both acceleration and force time-responses were collected, stored and analyzed to extract the Force-Displacement and the Force-Velocity graphs. Based on the damping coefficients obtained for the different values of excitation frequencies, the results show that the damping coefficient is not constant and depends on the excitation frequency.