Did this hit the read/write heads scratch the magnetic disks?
You managed to hit three hard disks simultaneously?
If you're absolutely determined to find out if the platters are scratched, first copy all the data on to new drives (2013 drives are 11 years old and way outside any warranty period). Next, remove the cover from the hard disk. Disassemble the platters so you can view both sides of each platter. Check with high power microsocope for scratches. Regardless of condition, smash the platters with a large hammer and dispose of carefully.
A less destructive test would be to download a trial copy of Hard Disk Sentinel and run a surface read scan. This can take ages on a big drive, e.g. 2 to 8 hours. If the result looks like this, you've got serious problems. You won't know for certain if the platters are scratched, but at least you might learn if the drives are going bad.
https://www.hdsentinel.com/help/en/61_surfacetest.html
