Example of Computing Tower Leg Load and Height of Leg (For Flat Slab)

• W = Width of Slab Area
• L = Length of Slab Area
• F.H. (Floor Height) = Top of Slab to Top of Slab

EXAMPLE ONLY

Example: Height of Leg – 10′ (1 – 4′ and 1 – 6′ High Frame)

Maximum Leg Capacity — 11,600 lbs.

Example above — Height of Frame and Extensions — 11’10”

1. Frame requirements preferred 1 – 4′ and 1 – 6′ plus 30″ extension tube extended 14″ on bottom and Screwjacks on top. Capacity as per Table #4 = 11,600 lbs. (Table 4, and not Table 5, is used because extension tube is only replacing Jack as extension is only 14″)

2. Frame requirements alternate 1 – 6′ frame plus 48″ extension tubes on bottom, plus 48″ Extension Tubes plus Screwjacks on top. Capacity as per Table 5 = 4500 lbs.

EXAMPLE ALTERNATE

Showing the use of one 6′ frame and extension tubes instead of one 4′ frame and one 6′ frame. Also how to calculate load capacity.

NOTE: 321/4″ = Lower Extension Tube Extension

14″ = Jack Replacement (if Jack were used) Height of Extension Tube, for Load Calculating Purposes = 18″.

Use Table number 5, Section B at 20″ extension, as top extension tube governs because there is no Jack at bottom and therefore 14″ can be deducted from extension of 32 1/4″ making bottom extension for capacity purposes only 18″ long, which is shorter than 20″ at top, and as extension tubes are used at the top and more than 14″ (testing length) at the bottom, you must use Table number 5 Section B which gives a capacity of 5000lbs. per leg.

A big reduction from using a 2 frame high tower (interbraced) with a capacity of 11,600 lbs.)