The drawings files are all in the :drawings: repository, not here.

See https://expo.survex.com/handbook/computing/repos.html

You do not need to know about the version control system for several common cave data surveying tasks,
the website has forms for uploading and reports which describe everything, e.g. see all 
darawings here 
https://expo.survex.com/dwgfiles/

and you can upload drawings with this form
https://expo.survex.com/dwgupload/