[en] A large aperture 2 m x 2 m neutron time-of-flight spectrometer is described consisting of 145 plastic scintillator blocks, each 270 mm deep and 153 x 153 mm² in area. Details are presented of the design, the construction and the on-line data acquisition and monitoring system. Its performance is briefly summarized: detection efficiency > approximately 20%, time-of-flight and spatial resolution (standard deviation) approximately 1.1 ns and approximately 0.9 blocks respectively. The counter operated successfully for four years in conjunction with a high resolution electron spectrometer to measure electroproduction processes with a nucleon in the final state. Although it was designed for the detection of neutrons of kinetic energy between 30 and 500 MeV, it was well suited also for the detection of high energy protons. (Auth.)