If you have several projects that share users (i.e an multiple experiment projects, etc.) you can
request a group to be created, so that you can have folks in the group, and put the group on
the projects, and only add people once. You do need to make a servicedesk request to the
redmine admins to get a group created, and say who should be able to update it.

Once the group is created at your request, you can manage the group; but it's
slightly non-obvious how:

  • log in to Redmine
  • click on the "My account" link in the upper right corner
    in the black band
  • in the upper right of the white frame there is a "Group" link,
    follow that.
  • click on the group name there
  • pick the Users tab, and add/remove users as needed.

So if you make new subprojects, just search for your group name in the
users list and pick that group and a role (i.e. Developer) and
add it, and all the folks will appear.