prevent the return motion until the load is to be released application_number US 32397394 A description although for illustration purposes the dryer shown is a web flotation dryer it should be understood by those skilled in the art that the present invention is applicable to other types of dryers such as roll support and arched dryers and equipment other than dryers which utilize load bearing retraction systems especially fluid cylinder retraction systems similarly although the dryer illustrated in the drawings includes three dryer zones the present invention is applicable to dryers having any number of dryer zones turning first to fig1 there is shown a split enclosure drying hood including an upper hood 10 and a lower hood 12 in the closed position a clearance gap 13 is formed between the hoods 10 12 in which the traveling web w is floatingly supported between upper and lower air bar arrays not shown in air receiving communication with the upper and lower hoods respectively the upper and lower hoods 10 12 can be further separated from one another with a retraction system in order to thread the web through the dryer or maintain or replace dryer internals such a system is conventional in the art and may for example include a guiding devices 15 16 in addition to the retraction cylinder rod 30 along with associated equipment the present invention is not limited to any particular retraction system the retraction system of the present invention comprises an air cylinder 20 in the embodiment shown three on each side of the dryer the actual number used can vary and depends in part on.