On Thursday, December 7, 2017 at 9:30:08 AM UTC-5, Kevin Neave wrote:
Does anyone out there know how German Glider Manufacturers calculate the
max weak link strength for winching?

Presumanbly this is also related to the max winch speed

For example in the UK the max winch speed of a K13 depends on which weak
link (Brown or Black) is being used

Regards

KN

Download CS22 (previously JAR22) and search for "weak link" using find function.
"CS 22.583 Winch-launching" describes the conditions.
TOST also has a table on weak link strength on p. 16 of their catalogue giving rated load (in decaNewton). Multiply by 2.2481 to get Pounds.
Gliding New Zealand has a useful "advisory circular weak links" with examples and a rule of thumb.