Trans-Danube, I think. And no indication in the word that capitäns is plural, so only one captain - the "s" is possessive.Probably apocryphal?!
Upper-Danube-Steam-Boat-Transport-Ferry-Company-number-one-captain's*-uniform.
If anyone can produce any evidence of there ever having been a steam ferry on the upper danube with more than one captain I'd be fascinated.
*I think you have a redundant "a".
(Sorry about the extra a - typo after finding the a-umlaut on the charmap...)
but I know that if referred the the "Ueber" it would say "NummerEinz (..) uniform" not the other way around.
Posts like this are so much more enjoyable when you've seen the combatants ride tandem to John O'Groats.