BDC motor has 8 brushes -- Why?

[Ed Walti]

I've got this large dc 36v 65 amp motor and is has 8 brushes. Can someone please educate me why it would have this many?

 

[Wee-Lamm]

https://www.physicsforums.com/threads/2-pole-4-pole-8-pole-motors.509564/

 

[jim hardy]

Gives 8 amps per brush.

How're they arranged ? four sets of two like below ?
How big are they ?
https://commons.wikimedia.org/wiki/File:Commutator-of-DC-traction-motor-01.jpg