in additional detail below the traveling head 32 includes guides 68 a and 68 b mounted on an upper portion of the traveling head 32 and guides 68 c and 68 d mounted on a lower portion of the traveling head 32 the function of the guides 68 a 68 b 68 c and 68 d will be described in additional detail below 0022 fig5 depicts the lower jack 30 located in a lower tower section 70 which is formed by a plurality of vertical and horizontal structural members in a conventional manner the lower tower section 70 includes two vertically spaced opposed rails 72 a and 72 b as well as two vertically spaced opposed rails 74 a and 74 b spaced from the rails 72 a and 72 b each of the guides 68 a and 68 d of the lower jack 30 extend between the rails 72 a and 72 b in engagement therewith and each of the guides 68 b and 68 c extend between the rails 74 a and 74 b in engagement therewith to permit vertical movement of the traveling head 32 relative to the lower tower section 70 the hydraulic cylinder 34 a is mounted between the rails 72 a and 72 b and is attached between the rails 72 a and 72 b at a point 76 and the hydraulic cylinder 34 b is mounted between the rails 74 a and.