"bolt on spud blades for better traction and bigger footprint", a sentence that only makes sense when discussing a WW1 tank

http://1914-1918.invisionzone.com/forums/topic/173218-ww1-military-motors-1916-set-x-50-cards/?do=findComment&comment=2358901
http://1914-1918.invisionzone.com/forums/topic/173218-ww1-military-motors-1916-set-x-50-cards/?do=findComment&comment=2359307