[T3] A new T-34 owner?

Jim Adney jadney at vwtype3.org
Sun Jul 3 10:09:10 PDT 2011


On 3 Jul 2011 at 13:55, jaransont3 at comcast.net wrote:

> From: "Jim Adney" <jadney at vwtype3.org> 

> On 1 Jul 2011 at 15:19, jaransont3 at comcast.net wrote: 
> 
> > A 35mph front crash into a fixed object generates approximately a 25g 
> > decceleration!  The number can be much higher at higher speeds, 
> > depemnding on what you hit.  Federal Motor Vehicle Safety Standards 
> > (FMVSS) require testing at 25g front impact, 20g rear impact and seat 
> > belt pull testing at 16Kn (3500lbs) on both the lap and shoulder belts 
> > simultaneously.  This means the outer fixed end of the belt sees about 
> > 7000lbs of load in this quasi-static test. 
> 
> Don't you mean the INNER end here? 
> 
> *************************** 

> Actually, both the inner and outer lower anchors see the same load
> (assuming the retractor and fixed end share a common anchor point)
> since both the shoulder and lap belts each act on those anchors. 

I guess I wasn't thinking about 3-points with a retractor.

If you assume a retractor, and assume the "quasi-static" situation 
where the shoulder belt tension is everywhere equal, then you would 
certainly get 3500# from each one, both applied to that lower outer 
anchor point. BUT do the vector addition, and the sum would come to 
something slightly less than 7000.  ;-)

Once I start to think about vectors, however, I have to admit that 
the same thing would apply to the inner anchor point.

Still, I'll agree that considering the angle between the vectors, 
7000 is probably a pretty good number for each point, even the outer 
upper!

This all gives me one more reason to like the '70-1 belts best.  ;-)

-- 
*******************************
Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
*******************************




More information about the type3-vwtype3.org mailing list