Complex sentence: The Main shaft went to the twenty nine hundred foot level with men working on all levels each working shift, the Brace-man was required to send equipment to the plat at each level, the plat is the area around the shaft at each level.
Split into simpler sentences: The Main shaft went to the twenty nine hundred foot level with men working on all levels each working shift. The Brace-man was required to send equipment to the plat at each level, the plat is the area around the shaft at each level.