This is a flat plate of iron immediately inside the furnace door and is
used in many boilers in order to insure the more perfect combustion of
the coal.
When the fresh fuel is laid on, it is placed on the dead plate instead
of on the grate; in this position the coal is coked, the gases from
the coal being ignited as they pass over the already intensely hot
fuel in the furnace, the fuel from the dead plate is pushed forward to
make place for another charge to be put on the dead plate. But more
frequently, as elsewhere described, the fuel is thrown over and across
the dead plate directly upon the hot fire.