Can anyone identify this tool?

[Singularity]

It looks as though it least temporarily was affixed to something via the circular ring of holes with witness marks??

[s/v Jedi]

My guess is a device to wind up the spring for the starter-cord of an outboard

[SaltyMetals]

i reckon it is for getting stones out of horses' hooves.
Andrew

[ArmyDaveNY]

I think it is a tuning tool for the Turbo Encabulator! It might be used to adjust the dingle arm.

https://www.youtube.com/watch?v=rLDgQg6bq7o

[Wulf]

Or maybe the previous PO just placed it there to play with the new owner? Kind of like the Halloween skeleton buried under my back porch...������

[boat driver]

Originally Posted by s/v Jedi

My guess is a device to wind up the spring for the starter-cord of an outboard

yes- put winch handle in it to hold in lap-
I agree.

[roland stockham]

Does that socket fit the nut on the front of the engine? If so could be a home built hand cranking system

[Mikeiso1192]

Anything my Dad couldn't recognize was classified as a Manglewurzle so that's what it must be. Haha

[freakytiki]

Its definitely a thingamajigger

[ArmyDaveNY]

Are you able to ask the previous owner?

[deblen]

Originally Posted by s/v Jedi

My guess is a device to wind up the spring for the starter-cord of an outboard

https://www.youtube.com/watch?v=UNoG-OJfKxo

[Boatyarddog]

Originally Posted by Nyaminyami

When I recently bought my boat I found this piece of kit amongst a miscellany.
It measures 180 x 170 x 45mm and has a square key on one side and a splined key on the other.
All steel construction. It weighs 5 kgs.
Could it be something to align/fit drive or propshaft to gearbox, or gearbox to engine?

I am loath to throw it away but also really don't like having redundant/useless kit aboard.

Any ideas?
Thanks in advance.

Maybe it was used to tighten or loosen that sometimes difficult to access castillated nut on a coupler, or flange, placed between the drive and shaft coupling, the nuts and sliding squares adjusted to accommodate supporting bars to keep it steady and not rotate. A 1/2" torque wrench or breaker bar then used to loosen or tension the nut.
Interesting tool though.
Cheers
SV Cloud Duster

[Comogene]

If I recall correctly, a Birchwood 33 is a trawler. Looks awfully similar to a door locking mechanism.

[Offshore1960]

I see the word Top is etched in one of the faces close to an edge. A purpose made tool for sure. I would certainly keep it and one day you will realize what it's for.

[Brewgyver]

Originally Posted by Chuck Hawley

OK, I am thinking it's a torque multiplier of some sort. Perhaps with a 3:1 or 4:1 gear reduction. Put the winch handle in one side and get a slower, more powerful drive for a socket on the other side. However, this would require a large arm to hold the frame of the device to keep it from turning. In other words, you need to restrain the outside from turning.

Chuck

The square is female, not male, so it would have to be the driven side. Plus, there are no through pins on the plates to indicate that there are any gears within. From the overhead pic, it would appear that the socket is simply a 12 point socket, but I don't think the square drive is actually used.
The bolts with heads on opposing sides are threaded through stationary nuts (one is clearly welded in place), and the ends of the bolts appear to bear against the large pieces of machine key stock, which in turn appear to be attached via pin to either side of the socket in the center. It looks like it was made to make fine rotational adjustments via the 12 point socket. Hard to imagine why, though, maybe holding an engine crank in a precise position?