I have 3 excavators, a 311 CU, 307, and just bough a 305C CR. I quizzed the cat salesman on how to chain down the 305. Cat has a sticker on the front of the machine explaining how to do it. It is not in compliance with the DOT's rules, I have been pulled over 7 times concerning chaining equipment down. The last time I laid into the officer verbally, have not been pulled over since.
Getting back to the 305. Cat recommends chaining to the ends of the blade and to the hole in the center frame. This does not meet DOT standards since you are chaining to an implement. You cannot chain to a rubber track and I also disagree about chaining to a steel track pad. It is not what I consider the Frame.
BTW, I asked the cat salesman to find out about how to chain down the 305 so it meets DOT standards. He still has not gotten back to me!