......... It would be interesting to know the engineering that goes into making sure the building could handle the
shock load of a heavily loaded
lineset traveling at speed getting E-Stopped........
The engineering that goes into a building is of course the combined work of the Architect, Structural Engineer and
Theatre Consultant. Companies like JR
Clancy,
ETC, Vortek et. al. have done extensive engineering studies on how their rigging works (or doesn't) with building structures. That's one of the reasons that the
Prodigy was designed with the compression tube as part of the
base design. Many school auditoriums and theatres have been designed and built without a consultant and have roof structures that are less than ideal for supporting
theatre rigging, especially in terms of lateral loading, thus the tube. All the rigging companies offer backbones or stiffeners with their powered rigging, The
prodigy is just the first one to make it part of the
base design and have the absence of a backbone/tube be the option rather than the norm.
As far as the
shock loading engineering, it's just math. Math and making sure all the parameters are allowed for. Snow load, wind shear, wind up lift, harmonic vibration from the
shock load(s), how many
shock loads could happen simultaneously and of what magnitude. Total weight imposed on the building structure by the structure itself, total weight of installed equipment such as transformers, roof mounted air handling units, microwave or radio towers
etc. finally add in the total static loading of the
theatre and
stage equipment with the potential
dynamic loading figured in. Once they have all the pieces together they crunch the numbers and see if the forces balance out. Part of the equation is you want to
build the structure "Just" strong enough with adequate allowable
safety margins, but no stronger (unless planning for future expansion) because it add a LOT of cost to a building to make it taller or stronger or have a greater span. When there is no
theatre consultant, the tendency is to under estimate the loads the
stage equipment will add to the picture. Once the mistake has been made, it is difficult and expensive to correct. Say the roof structure won't support the load. Easy, just
build a
grid or add some beams below the roof to support the rigging. But wait, now we have to add structure to the side walls to support the added steel. If the rigging adds lateral loading we also have to beef up the side wall that takes the loading. Now we've added a lot of wight that the side walls have to support, might need to beef up the back wall and the supporting structure holding up the
proscenium. Now the
foundation is over loaded and we have to work on that.......... As you can see, it's like pulling a loose thread on a knit sweater, once you start, it just keeps going.