An apparatus for loading shipping containers onto and off of a truck or trailer bed. The rake device further includes a rake head secured to the first end portion of the elongated stem, with the rake head being generally disposed in a first plane, such that the first plane and the main portion define an acute angle therebetween. Random access is possible even if the GOP interval is lengthened. Additionally, fan speed may be calculated from pulses which are intended to identify the fan. Moreover, a tag is assigned to each of the words indicating a mapping between each of the words and one of the fields, and the words along with the assigned tags are stored in the storage unit.