he platform raised and ready to be moved sidewise to position it over the trailer tank; FIG. 1 1 is top plan view of the trailer; FIG. 12 is a top plan view of the trailer of FIG. 8 with the platform extended; FIGS. 13 and 14 are fragmentary detailed sections substantially on lines 13-13 and 14-14 of FIG. 12; and FIG. 15 is a side view in longitudinal section showing the platform lowered into carr