Abstract: A housing structure is provided for supporting vertically stacked horizontally extending arrays of forwardly removable disk drives in a very compact arrangement. The housing has spaced apart vertical walls with opposite side surface grooves having laterally projecting elastomeric bumper members therein. Pairs of front and rear disk drives are joined with elongated support plates disposed on their opposite sides and having spaced apart sloping side edge portions. The support plates are slidingly received in the wall grooves and wedgingly engage the resilient bumpers in a manner restraining movement of the inserted disk drives along three mutually perpendicular axes. Latch structures lock the inserted drives in the housing and releasably maintain resilient insertion forces on the tandem drive assemblies. A fan system draws cooling air through vertical gaps between the drives, and operational drive heat is conducted via the support plates into the vertical housing walls.