I'm a little confused about the construction of this plane. I can see no real purpose for the way the bottom has been made more narrow than the rest of the body. It can't be used as a rabbet plane because the sole is coffin shaped just like the body. The blade is the same width as the sole but the mortise is a quarter of an inch wider than the blade. I assume its been modified but I can't figure out why.

The strangest things turn up here...

You can't mortice, you can't use it as a rabbit, it's just a plain blade...so..what does it do that it didn't do before?...apparently nothing

The sides are a different depth , so it's useless as a depth stop, and where did all the wood go on the heel?

How odd...

Perhaps someone's idea of lowering friction?

Quote from: rusty on November 25, 2012, 09:09:21 PM
The strangest things turn up here...

You can't mortice, you can't use it as a rabbit, it's just a plain blade...so..what does it do that it didn't do before?...apparently nothing

The sides are a different depth , so it's useless as a depth stop, and where did all the wood go on the heel?

How odd...

Perhaps someone's idea of lowering friction?

Or had to use it in a tight place to make repairs to something that was otherwise inaccessable

It most likely was done, in fact, to use as a rabbet plane.  I've seen it done, and it does work.  My 18th Century carriage maker's rabbet plane is made very much like this. 

Our carpenter was had himself a smoothing plane *and* a rabbet plane, all in one tool.  If the cap iron got in the way somehow, he could have made a second wedge to secure the blade without the cap iron. 

Quote from: Branson on November 25, 2012, 11:57:02 PM
It most likely was done, in fact, to use as a rabbet plane.  I've seen it done, and it does work.  My 18th Century carriage maker's rabbet plane is made very much like this.   

Would it have worked as a rabbet plane with the rounded sides? I would think it would have been impossible to cut a straight rabbet that way.

Quote from: WiebeLC on November 26, 2012, 12:33:00 AM
Would it have worked as a rabbet plane with the rounded sides? I would think it would have been impossible to cut a straight rabbet that way.

I hadn't noticed the curve in the plane's sole, but that rather confirms my opinion.  It appears to be one version of a coachmaker's rabbet, made to be  used for curved work.  The Stanley #68 coachmaker's rabbet spoke shave also has curved sides for just that reason (see picture).   I have two brass shop made rabbet spoke shaves, both of which have curved soles.  Carriage and coachmakers often dealt with curved work. 

Thanks for the info. I hadn't thought about it that way.

Would Sandusky have made it this way or is modified?

I figured out today that it would have cut a rabbet with a radius of 1'8".