The coil rests on two lower beams of 20 x 20 cm crosssection and a length t = 320 cm. The loaded length from each beam on top is r = 210 cm. With the extension of (t  r) = 110 cm and the load of 8.5 t the necessary section modulus for each beam of about 1150 cm³ is obtained from the diagram in Figure 16. The same situation applies to the upper beams loaded directly by the coil with r = 100 cm.
The beams have a section modulus of 1217 cm³ (Table 1). Also the extension of 110 cm is well within permissible limits.
dimensions in cm 
10 x 10 
12 x 12 
15 x 15 
20 x 20 
section modulus in cm³ 
152 
263 
513 
1217 
Table 1: Section modules of timber beams (with 3 % shrinkage)
