L2 -- crane runway beam span or building column bay spacing
It's common that a building has different column bay spacings.
In Crane-1 data input, user already input the max. column bay spacing of the
building as L1.
In Crane-2 data input, user can input the L1 bay's neighbor column bay spacing
as L2 here as shown below.
The input of L2 will NOT affect crane runway beam design as long as the L1 input
is the max. column bay spacing of the whole buiilding.
The input of L2 may affect the crane beam supporting column's vertical point
load and point moment caused by the crane moving load.
The different combinations of L1 and L2 input may impact the crane beam
supporting column's vertical point load and point moment caused by the crane
moving load.
When there are different column bay spacings in a building, user may try different
L1 and L2 combinations, say L1=30' L2=20' and L1=20' L2=30' to get different
sets of crane beam supporting column's vertical point load and point moment and
use the max. one for design.
