3 Cent Nickel - Full Of Errors

I can try looking up the Cud attribution in 'The Cud Book' when I get home, but Cuds on these coins were very common because the metal was hard on the dies, and the dies had very short life spans as a consequence. As such, they are interesting, not too rare, but big ones can get a small premium.

This might help:

should be in classic errors

This may be a bit long, but it should be clearer that way.

OK, for starters let's examine how a normal coin is struck.

The feed fingers drop a planchet into the collar where it rests on the anvil die and the fingers move back out of the way. The hammer die comes down and strikes the coin. The hammer die goes back up. The anvil die rises pushing the coin out of the collar. The feed fingers push the struck coin out of the way. The anvil die drops back down. The fingers drop the next planchet in the collar and the cycle repeats.

Now for how the brockage is created. As above the planchet is dropped in and struck by the dies. But this time when the hammer die rises up, the coin sticks to it and come up out of the collar and stays stuck. The anvil rises and the fingers come forward but there is no coin to push out of the way. The anvil goes back down the planchet is dropped into the collar and the fingers go back. Now in this case the planchet is sitting on the anvil die, but up above it instead of the hammer die is a struck coin and it is same design and the anvil die but the die is incuse and the coin is raised. The hammer die comes down again and the planchet is truck between the anvil die and previously struck coin. When that coin then comes out of the collar it will look like the last picture that Coop posted. That is a full brockage.

If the coin continues to stick to the hammer die it will continue to strike brockages, but as it does so the coin on the hammer die will start spreading sideways and start wrapping itself around the die. As it does this the image facing the planchet in the collar is also "spreading out" and after a few strikes the the brockages being produced will look more like the first picture Coop posted. Personally I would not call this a brockage, I would call it struck through a late stage capped die. This is because the design of the die is starting to show through the intervening coin (die cap). If it continues to strike more planchets eventually the expanded reversed design disappears completely and more of the hammer die design shows through until it almost looks like a normal coin but slightly distorted like it was struck through a thin layer of foil (Which n fact it was.)

Another way a brockage can form is after the first coin is struck instead of sticking to the hammer die, the anvil die fails to rise up and push the coin out. Then when the fingers come forward they drop the planchet on top of the already struck coin still in the collar. When the dies come together again it will also form a brockage similar to the last one Coop posted, but it will also have a partial collar error (or possible even a full broadstrike) because the second coin can't fit down inside the collar.

And you can have a partial brockage. In this case go back to my first example but before the dies have a chance to com together and form a full brockage, the coin falls off of the hammer die and only partially overlaps the planchet in the collar. Now when the dies come together the coin in the collar will have the normal image from the anvil die, part of the image from the hammer die, and the rest of the coin will show the reversed incused image from the intervening coin. It will look something like Coop's second and third pictures except that those were also broadstrikes (The collar was forced down and not restraining the coin.)

Thanks for taking the time to write that Condor.
And continued thanks to COOP for always having a great didactic picture at the ready.