  Hadronic showers are characterized by a rich particle structure in the
spatial as well as in the time domain. The prompt component comes from
relativistic fragments that deposit energy at the ns scale, while late
components are associated predominantly with neutrons in the cascade. To
measure the impact of these late components, two experiments, based on gaseous
and plastic active layers with steel and tungsten absorbers, were set up. The
different choice for the material of the active layers produces distinct
responses to neutrons, and consequently to late energy depositions. After
discussing the technical aspects of these systems, we present a comparison of
the signals, read out with fast digitizers with deep buffers, and provide
detailed information of the time structure of hadronic showers over a long
sampling window.
