A quick search gets me this article: https://tmg110.tripod.com/impger1.htm
Then, a whole mess of antique imperial flags for sale.
From the above link comes this item:
"From 1871 to 1893, naval auxiliary vessels flew the war ensign with a blue anchor added below the canton. Thereafter they flew a variant of the black-white-red national flag with an imperial crown over an anchor, both gold, on a white disk. Also adopted in 1893 was an ensign for merchant ships commanded by naval reserve officers: a black-white-red national flag with a large Iron Cross at the hoist."
Images of these flags appear in the linked article.
I assume the tugs would fall under "naval auxiliary?" You indicate they are in a certain department of the Imperial Navy. I don't think they're "merchant ships commanded by naval reserve officers," but that is perhaps possible.
No idea what the SMS VULKAN would fly...if anything.
Good day all!
as some may know --
I am actually coming to the end of a lengthy on/off project... 2013 -- 2022 ( !! )
14 pages of pain ... can be read at the link below--or skip fwd to page 13....
The SMS VULKAN, as in 1919---in the process of being towed away
from the mouth of the Elbe River ( Hamburg) to Harwich in England for breaking up/scrapping.
( war reparations-- ( and vessel obsolete/ superseded -ergo no interest to the English or the Germans...
So --to the question of flags...--
Both ocean going Tugs , one German RETTER ( 1885 ) and one ex-Dutch SCHELDE 1906 are in the employ of the 'Sea -transport department' of the Imperial Navy-- but neither vessel is offensively or otherwise armed --
.==> what Ensign--if any would they have flown ? Naval ?
.......==> indeed were any ships of the Navy flying their ensigns at this time?
I would think --that the VULKAN herself-- would not fly a Naval Ensign?
==> --having already been discarded by the Navy for breaking--and in any case being towed and not under her own power...?
I have only 1 x image of the Schelde (i) ( ex Dutch ) in 1918-- there is a 'flaglet' hoisted off the gaff--
but it appears to be very small and not of the size I would expect of an Ensign?
I have had a couple of suggestions on the MW forum -- but with knowledge -- more is always more!! and I thank you in advance for any further insights ! Regards Jim Baumann