Doubled collar ties?

[NM_Shooter]

Looking over other projects, and I found this one, which shows doubled collar ties on every other rafter.  How effective is this?

http://www.countryplans.com/cody.html

BTW... here is a nice presentation on roof framing...

people.morrisville.edu/~crovelp/Roof%20Framing.ppt

[Don_P]

Thats fine, you need to tie the rafters no more than 4' apart. If in high load areas remember the purpose of the tie is to prevent the rafter foot's horizontal thrust from tearing the building apart. This is the highest stress joint in the assembly, pull the trigger again, and again... Table R802.5.1(9) has minimum nail count for the heel joint splice.
http://windyhilllogworks.com/Calcs/Sloped%20Rafter%20Design%20for%20Bending1.htm

[John_C]

The caption says there will be a loft as well so those are doing more than holding the walls together.