I thought it was because Dutch men were stereotyped as short. The same term is also used in track - a dutchman is a short piece of rail used to fill a gap, or when a rail breaks near the end and you just put another set of angle bars on the break until you can change it out, or bridge the break with one set of bars.
Returning to the air hose dutchmen, I have never heard of them being outlawed but that may well be, that point about their not being attached to the car sounds like something the Federales would come up with.
Sometimes you have a car which has excessive travel on the cushion draft gear, the hose is mounted wrong, or some other problem: every time you stretch the train out the hoses separate and you are in emergency. That gets old in a hurry, especially in winter, especially when it's a ways back in the train. On some roads locos carried a dutchman as standard equipment. It's a darn handy thing and makes a lot of sense, so if they have not banned it yet they soon will
Returning to the air hose dutchmen, I have never heard of them being outlawed but that may well be, that point about their not being attached to the car sounds like something the Federales would come up with.
Sometimes you have a car which has excessive travel on the cushion draft gear, the hose is mounted wrong, or some other problem: every time you stretch the train out the hoses separate and you are in emergency. That gets old in a hurry, especially in winter, especially when it's a ways back in the train. On some roads locos carried a dutchman as standard equipment. It's a darn handy thing and makes a lot of sense, so if they have not banned it yet they soon will