Abstract: A tier forming and handling device for forming and handling sequential tiers of lumber from a flow of elongate boards translated on a first conveyor in a first flow direction, wherein the boards are aligned along their length generally perpendicularly to the first flow direction, having a mat forming mechanism for collecting, by selectively actuable hook stops, the flow of elongate boards against the hook stops so as to form a mat of lumber having a downstream end adjacent the hook stops and an upstream end whereagainst the flow of elongate boards may continue to collect into abutting adjacent array; a mat separator for separating, along the first conveyor, at a selectively adjustable separation location, a tier of lumber from the downstream end of the mat of lumber; and, a variable speed tier accelerator for conveying and selectively variably accelerating the tier of lumber, once separated along the first conveyor, from the first conveyor to a hoist stacker, wherein the selectively adjustable separation loca