units the support frame further includes an adjustable compensation spring to adjust to forces applied to the support frame caused by uneven terrain the support frame is adapted for use with corner sweeping units application_number US 77566904 A description referring now to fig1 and 2 a center pivot irrigation system 10 is shown in accordance with the present invention wherein the system 10 is adapted to rotate about a center pivot 12 that serves as a water supply for an elevated boom 14 boom 14 is supported on a plurality of mobile support structures or towers 16 although these figures illustrate a center pivot irrigation system the present invention is not intended to be limited to center pivot irrigation systems additionally although only one boom 14 and three mobile towers 16 are shown the present invention is not intended to be limited to the number of booms or mobile tower structures the number of towers depends of the length of the boom which is dependent on the size of the area of land to be irrigated for example the span between mobile towers 16 is typically between about 130 to 140 ft however this length may vary as seen in fig1 and.