Non-welded support plate member

A support plate comprising a plurality of elongated channel beams each having a generally U-shaped cross-section comprising a flat base portion and sidewalls, wherein the sidewalls each comprise a parallel portion and an inwardly sloping perforated portion which connects the parallel portion with the flat base portion and provide an open end to the channel beam opposite the base portion, said channel beams lying parallel to one another with at least part of the sidewalls adjacent the open ends of the channel beam in contact with the corresponding portion of the adjacent channel beam and releasably connected thereto by attachment means and wherein at least one of the inwardly sloping sidewall portions of at least one of the channel beams is provided with an end plate lying in a plane perpendicular to the length of the channel beam and located at the end thereof, said end plate being attached to the sloping sidewall portion of the channel beam and to the sloping sidewall portion of an adjacent channel beam so as to close off the gap between said sloping sidewall portions of adjacent channel beams.