Early HO scale couplers, Part 2

 In my first post on this topic, I described a number of the early couplers available in HO scale, from the Varney dummy coupler (an accurately shaped and sized coupler), to the other extreme, the Mantua loop coupler, and the good-looking but not very reliable Devore coupler. You can read that post here: https://modelingthesp.blogspot.com/2024/07/early-ho-couplers.html .

If you do read that post, you’ll find a discussion point by my friend Arved Grass, stating his belief that the initial Kadee metal coupler was the model MK. As I replied, that’s not true. It certainly is true that the MK coupler was the first Kadee magnetic coupler, and it was first advertised (as far as I can determine) in the December 1959 issue of Model Railroader, or MR.

But years earlier, the Kadee metal coupler head had been introduced, with a variety of coupler shanks, with model numbers from 4 to 7 (and later to 10), all called “K” couplers, not MK (probably “K” stood for Kadee). These had a straight trip pin, as you can see below (ad from page 12, October 1956 MR). I imagine the “good lookin’ ” phrase was with reference to the Mantua loops.

Or for a view of several cars with these straight pins, there is this photo (page 46, October 1957 MR):

And just to cinch the point, here is Kadee’s announcement of their new Model 10 or K-10 coupler (the same one shown above) for Athearn’s plastic freight cars, but in a very clear drawing (page 16, July 1957 MR):

In the previous post about early couplers (link in top paragraph of the present post), I had misremembered what the Kadee uncoupling ramp was like. I thought it was a converging throat to push the pins together. Actually, it was the opposite: a diamond shape that pushed the pins apart to uncouple the couplers. It could be raised electrically. Here’s a photo (page 41, May 1957 MR):

There were the familiar types K-4 and K-5 “for general use,” as the ad below says, along with several other types for specific rolling stock, up to type K-8 (ad from page 7, May 1956 MR):

But finally they did introduce the “Magna-matic” coupler, the one we have used ever since. As mentioned above, I believe this is the initial announcement in the December 1959 MR, page 25; it isn’t obvious here, but this coupler has the curved trip pin that is so familiar now.

So the straight-pin Kadees were all “K” models, and didn’t become “MK” (as shown above) until the end of 1959, when the above announcement was published. In what I hope isn’t  excessive clarity, this should now be a complete story.

Tony Thompson