Within Teamwork Projects, you can choose to add a user as a site administrator.
A site admin will have the same permissions as a site owner and can perform all the same actions.
To change a user to a site admin, click on the 'People' section of your Teamwork Projects site:
You will now be presented with a list of people who are added to the site. To the far right of the person you want to make a site admin you will see a pencil icon, select this to edit their profile:
You can then choose the 'Permissions' tab and the option for 'is this user an administrator' can be toggled on and off:
Note: When you toggle this on, the permissions that were showing will now be removed as they will automatically have these as an administrator.
You can then see who is a site admin on the list of people. They will be indicated with a green key icon:
For more information, see: Project administrators