Bill Daniels wrote:

The FAR's allow a wide range of rope strengths. It behooves us to set the
rope strengths near the top of the allowable range. The greater danger is
the rope that breaks unexpectedly not one that fails to break under stress.

Be careful out there.

I rock climb, and in climbing they use load limiting devices to handle
peak stresses that might overload an anchor (or your body). Could they
be of use here?

http://www.yatesgear.com/climbing/screamer/

They work by having the stitching rip at a set maximum load. Once the
stitching is all ripped, they become a static load carrying device.

They can be manufactured to basically any configuration. Under another
project, I've had them manufactured to activate at 2000 LBs load. You
can put them in parallel to raise the activation force.

This could allow you to use a more robust tow line, counting on the
devices to provide peak load limiting.

Terrible news about the accident...

Mike Y.