In a message dated 2008/10/09, cjburch@........... writes:

> I'm confused by the recent messages that imply that a pendulum with a LIGO 
> X-
> suspension should be designed with the center of mass above the platform 
> suspended by the crossed flexures. 

Hi Chuck,

       There are two possible types of long period crossed wire suspension 
systems. One has the mass positioned below the suspended plate. The LIGO system 
has the mass positioned above the suspended plate, just below the position 
where wires cross. This is much more compact.

       Regards,

       Chris Chapman   
In a me=
ssage dated 2008/10/09, cjburch@........... writes:



I'm confused by the recent mess=
ages that imply that a pendulum with a LIGO X-

suspension should be designed with the center of mass above the platform 
suspended by the crossed flexures. 




Hi Chuck,



       There are two possible types of long pe=
riod crossed wire suspension systems. One has the mass positioned below the=20=
suspended plate. The LIGO system has the mass positioned above the suspended=
 plate, just below the position where wires cross. This is much more compact=
..



       Regards,



       Chris Chapman