G forces, Car Crashes and T. rex

[Sim Koning <simkoning@msn.com>]

   I've been doing what I can to read up on G forces, the effect they have on 
the human body and how that might relate to giant theropods and other 
dinosaurs. From what I remember of Farlow's calculation's, a T. rex's torso 
dropped in a deadfall would impact at about 6 Gs, while the (765lb?) head would 
impact at about 14 Gs. The calculations for G forces during a fall while moving 
20 metres per second were 9 Gs for the body and 16 for the head. Alexander 
(1996) then evaluated this argument and speculated based on car crash studies 
that if a 70-kg human can survive a 15G car crash, than a 6000 kg tyrannosaur 
should be able to survive a 3.4 G deceleration. Here is where I have a problem: 
The reality seems to be that humans can survive close to 45Gs of rapid 
deceleration (John Stapp, 46.2 Gs on a rocket sled). Plus vehicle crash 
research indicates a tolerance of 15, 25 to 45Gs depending on direction and 
duration. In extreme cases indy car drivers have survived 100G crashes!
 
ftp://ftp.rta.nato.int/PubFullText/RTO/EN/RTO-EN-HFM-113/EN-HFM-113-06.pdf   
 
  So shouldn't the estimated G force tolerance for a T. rex be closer to 10 to 
20 Gs or am I way off here?
 
Simeon Koning