Re: coupler size list

To fit the full size emergency knuckle we had to grind off about 3/8" from each end of the pin boss. As this knuckle extends further out from the coupler, no further modification was necessary. The emergency knockle will still work in a full size coupler, though it sets a little below center. As Bret noted, these knuckles are fixed in the closed position so no changes to the latch mechanism are needed. It takes about a minute to pull the 3/4 knuckle and insert the modified emergency knuckle. (Not counting the time to lug the thing from wherever it is.)

Other styles of full size couplers in use on the S.V. include Janney, National, and Simplex. The outside dimensions of these vary considerably but they all mate perfictly. We even have two thoroughly modern shelf couplers, from a standard Ga. tank car, and they easily couple with the older types. They look rather strange in a narrow ga. consist however.