All 3 look forged, maybe some kind of hammer blow open ends.  Biggest 1 weighs 40 lbs. Opening size and thickness noted on cardboard. Thats a 1' scale for size comparison. 
Anyone seen anything like these?

That is some really unique boat anchors.

Be careful about hanging those on the wall.

Wow!!! Those are impressive!! First thing that comes to mind would be for a ship, or, shipyard????? Regards, Lou

Large steam engine or railroad "slug" wrenches ? But those aren't usually open end.

Do slug wrenches have that taper to the shank?
Would the hammer tend to deflect?
I'm thinking that the hole is related to some form of attachment.

Quote from: leg17 on September 09, 2018, 03:28:15 PM
Do slug wrenches have that taper to the shank?
Would the hammer tend to deflect?
I'm thinking that the hole is related to some form of attachment.

my thoughts too, some kind bigass cheater bar made to fit the taper, then pinned.  2 wrenches have flat edges, while other has radius edge along taper. 

Railroad??

Boy, you could do some serious nut-rounding-off with those!

Motor mount wrenches for a Russian Soyuz rocket. I saw Howard Wolowitz holding on to one during launching.

EvilDr235

Think of large stationary engines like power plants, pipeline compressors, etc.  Box end won't work on a stuffing nut for a valve or rotating shaft.  Hole was for pin for a chain & clevis attached to some external power source (maybe a large lever or block & tackle -- the space where the wrench itself had to work might have been somewhat constricted). 

yep, my thinking too. big cheater bar would be angled/offset to bring the pull back to horizontal or vertical, not on a 45* axis.   Socket of the bar could be tapered and wrench would be pinned into it.  Tapered fittings wouldn't bind together if pinned slightly loose.  Hole diameter not big enough for clevis/pin torque that might be applied.