154. System Tenon Engineering, Part 1: Standard Molded Stems
Not long ago, a friend sent me an interesting technical question that bears consideration for everyone who likes to geek about System pipes: I’ve seen a lot of old De Luxe Systems from Peterson, spanning most of the 20th century. I’ve seen a lot fewer Standard Systems. I understand from the book that the Standard Systems never had the bone (later aluminum) chimney. Were those System Standard stems just tapered all the way down? The current version has that little stepped tenon, and for the life of me, I can’t understand what that really achieves. If it’s just about increasing the length of the stem, wouldn’t a natural taper all the way down look better? I’m just wondering if you know when Standard Systems developed that tenon thing. There’s a lot to unpack here. One good place to begin is always at the beginning, so take a look at the Patent Standard and Premier System tenons illustration at the top, from the 1896 catalog. While there were the four mouthpiece styles available on what we now call the Standard and Premier grades, notice that the ABC and AC are light: these are screw-in bone extensions (or “chimneys” as the old Kapps hands called them). The AB and A, on the other hand, which are dark, are extensions molded into the stem itself. The chart is meant to represent shouldered and tapered, Standard and Premier (or what we now call Standard and Premier). I'\ll look at the screw-in Premier and De Luxe chimneys at some point in the near future. For now, let’s look at the molded extensions: why are they there? what function do they serve? The biggest problem with any army mount is, of course, turbulence, as any good pipe artisan will tell you. I’m sure Charles Peterson knew this, which is why he designed these step-down extensions to have a conical, tapered shape that extends to, or to just below, the air hole in the stummel, as you can see in the 309 demonstrator pictured above. Look at the photo from the 1906 catalog above. The taper isn’t as obvious as in the 1896 illustration, but that’s probably because of the length of it. That is, the Morse taper on both the A and AB, seen from a side perspective like this, is quite graduate. Much more gradual, inf act, than recent generations of mouthpieces. This would allow the tenon to fit more deeply (and hence more securely) into the mortise. A tight fit, preventing any air to escape from the juncture between tenon and mortise, is necessary for the best performance of any army mount, and even more so of the System, which has to contend with the demands of the reservoir. This detail from the 1937 catalog is one of the best insofar as showing the taper of the original Patent-style molded vulcanite Standard System tenon. It also shows the higher shoulders and graceful curves of the A and AB respectively as compared to…