Oilers, Tankers, Supply Ships, and Troßschiffe

[gregorianchant]

I am trying to better understand the distinctions between ships we label as Tankers, Oilers, and Supply Ships, or more importantly to better understand the distinctions between German auxiliary ships in capabilities/functions.

I know Oilers were used to refuel ships while at sea with liquid fuel (naval oil or diesel oil), and Tankers are generally used to transport liquid fuel or crude oil from port to port. However, I have also seen reference to Tankers being used to refuel ships at sea, including the Wollin and Weissenburg which appear to generally be labeled as Tankers as opposed to Oilers. I have also seen naval Oilers defined as also carrying dry cargo, such as ammunition, food, repair parts, etc., and that appears to have been the case with ships like the Jan Wellen, Esso Hamburg, Gedania, etc. which are often referred to as Oilers when serving with the Kriegsmarine. So is the main distinction between Oilers and Tankers that Oilers also carry other (dry) supplies to ships, and the ability to efficiently transfer those dry supplies to ships at sea? Or are Oilers that carry dry supplies a subset of Oilers (a Replenishment Oiler)? I have seen the same ship referred to as a Tanker in one spot and an Oiler in another spot, so perhaps there is no agreed/consistent terminology?

With respect to the Dithmarschen class of ships, the Germans classified them as “Troßschiffe”. I have seen Dithmarschen class ships described as a “navy replenishment oiler”, a “supply ship”, and also as a “combination oiler and supply vessel”. But if Oilers generally contain dry supplies in addition to fuel, then aren’t all Oilers also supply vessels too in that they contain dry cargo supplies? I do see on ww2db.com that the Dithmarschen class is described as serving “several roles, including tanker, repair ship, ammunition ship, dry cargo ship, and hospital ship” and I have found other references to this class of ship having repair rooms and being able to serve as a hospital ship, so perhaps the Dithmarschen class truly aren’t classical naval Oilers and more of a fleet depot supply ship? (The NavalPedia book on the Kriegsmarine classifies them as “Fleet Oilers”, but lumps them in with other ships that appear to be oilers and that don't have repair or hospital facilities.)

Would appreciate any thoughts/insights on the above. Thank you in advance!

[RandJS]

Hello,

In this context, I feel the term Oiler and Tanker may be used interchangably other than KM purpose built vs merchant built. The KM added storage containers on deck of a number of ships, thus adding to their cargo carrying capacity.

Meanwhile, the Dithmarschen class were true supply ships. In additon to Diesel/Fuel oil, they carried lube oil, fresh and potable water, they carried AV gas on deck.They had refrigerated/frozen cargo capacity, as well as stores of ammunition and torpedoes. They also had medical facilities, repair capabilities and carried other naval stores as well.

Regards,
RandJS

[RandJS]

Hello,

Dithmarschen 12/1940
Heizol oil 9930 t
schmierol 383 t
destillat 500 t
frischwasser 381 t
trinkwasser 118 t
muniton 332 t
proviant 393 t

Franken 4/1945
at least 2700 t fuel,
1,000 rnds 15cm for Nurnberg
1,000 rnds 15cm for Destroyers
1,750 rnds 12.7 cm for Destroyers
undetermined amount 2cm

I also have the figures for Nordmark 11/1940 somewhere...
Nordmark was able to assist in repair of tanker Eurofeld's machinery problems while at sea...

Hope this helps,
RandJS

[RandJS]

More:

Freighter Alstertor as supply ship:

"The forward holds were converted into prison cells for between 300 and 350 prisoners"
"Extra tanks containing either oil or water were fitted on deck. Containers measuring 6 square yards were also placed on the main deck to store large caliber ammunition and torpedo parts."
• 1,500 5.9 in shells for the raiders
• A large number of smaller caliber shells.
• 10 torpedoes
• 20 leather oil supply hoses, approximately 22 yards long.
• 2 Arado Ar 196 Seaplanes.
• Many provisions e.g., tinned goods and sacks of potatoes.
• 50 scuttling charges.

Cheers,
RandJS

[gregorianchant]

Hi RandJS,

Thanks and you must be right about “tanker” and “oiler” being mostly used interchangeably. In doing some further looking, I do see a distinction being made between on one hand a Replenishment Oiler or Tanker--a ship carrying fuel in fuel tanks and dry cargo in cargo holds capable of underway replenishment at see (https://en.wikipedia.org/wiki/Replenishment_oiler)--and on the other hand just an oiler or tanker that is primarily used to transfer fuel between ports/bases. I think I was mistakenly thinking an “oiler” was a Replenishment Oiler/Tanker and a “tanker” was a regular/non-replenishment tanker, but I don’t think that is true.

This Wikipedia entry (https://en.wikipedia.org/wiki/MV_Esso_Hamburg) for Esso Hamburg (which it describes as a supply tanker) makes a distinction between “the naval oilers Uckermark and Ermland plus the tankers Schlettstadt, Adria and Friedrich Breme”, but the author may been trying to distinguish between purpose-built naval supply vessels and converted commercial tankers.

These former commercial tankers all appear to have been converted to replenishments oilers/tankers, carrying fuel and dry cargo:
• Ergerland
• Lothringen
• Gedania
• Esso Hamburg

The Esso Hamburg, according to https://en.wikipedia.org/wiki/MV_Esso_Hamburg, took the following supplies at one point in St. Nazaire:
• 7,400 tons of fuel oil - this was much less that the ship could hold but was sufficient for the ship to maintain the correct speed to complete the mission.
• 1,200 tons of Diesel oil for own consumption.
• 20 torpedoes in their crates.
• 2,000-3,000 tons of fresh water
• 300 tons of special boiler water.
• 2,500 20.5 cm. shells.
• Provisions for 2,000 men.

The following converted Norwegian whale factory ships (which seem to interchangeably be referred to as oilers or tankers in support of your prior comment) all appear to have carried fuel oil as well as ammo and other dry supplies to ships:
• Jan Wellem (a German whaler at the commencement of the war, but built in Norway)
• Ole Wegger
• Pelagos
• Sudmeer
• C.A. Larsen

The following are converted commercial class oilers/tankers which appear to have been used to fuel ships at sea, and assume but not sure they had the dry cargo capacity too:
• Schlettstadt
• Friedrich Breme
• Belchen
• Wollin
• Weissenburg
• Heidi
• Ill

I have found reference to a number of other commercial tankers captured or built in occupied countries converted to replenishment oilers/tankers:
• Jeverland (Danish)
• Ostfrieland (France)
• La Mayenne (France)
• La Baise (France)
• Karnten (Dutch)
• Spichern (Norwegian)

The Dithmarschen class ships clearly seem the cream of the crop, which is not surprising given purpose-built, and their repair and medical facilities, as well as refrigeration, etc. for dry cargo, distinguish it from oilers. It seems like that class fits the definition I have found for a Fleet Tender, but I see there were other German ships given that class name (like the Hela) which were much smaller with less cargo capacity and possibly more barracks capacity.

Best regards,

Greg

[RandJS]

Happy Holidays,

Additional information:

Medical Care on Nordmark included two major operations, thirty two minor operations and two procedures involving casting during 212 days at sea supporting Scheer, the raiders and several u-boats.

Nordmark conducted 41 refuelings/replenishments to 24 different vessels.


Cheers,
RandJS

[gregorianchant]

Interesting. The Wikipedia page on the Nordmark describes the Dithmarschen class as combining taker, repair ship, ammunition ship, and dry cargo ship, and then goes on to state they were equipped with a small hospital. So they definitely seemed to have functions/capabilities beyond what I think you'd find in an oiler or a fleet tender.

[stril]

Hello
The info found at Chronik des Seekrieg 1939-1945 is quite useful and should answer some of your. questions.
https://www.wlb-stuttgart.de/seekrieg/k ... frames.htm
regards
Stril

[ROLAND1369]

Also do not forget that this class of ship was quite well armed for defense. They had three 150 mm deck guns, two 37 mm and four 20 mm antiaircraft guns. with their trained naval gun crews they could take on any thing up to destroyers with a good chance of success.

[thaddeus_c]

the only equipment the Dithmarschen-class ships lacked was aircraft handling (at least I've never read any reference or even consideration given to adding that)

was a scaled down supply ship ever designed or even mentioned when the primary resupply task became u-boats?

[RandJS]

Hello,

Several standard merchant ships were modified to supply u-boats.
Python
90 torpedo
1,000 rnds 10.5cm
5,000 rnds 3.7cm
10,000 rnds 2 cm
1017 m3 diesel
56 m3 lube oil

Regards,
RandJS

[[email protected]]

New to this forum...On this day in 1944 the German tanker ROSSBACH was torpedoed and sunk by USS BURRFISH south of Muroto Zaki, Shikoku, smallest of Japan's four main islands.
Two years earlier, while sailing as MADRONO under the Norwegian flag, she had been captured by the German auxiliary cruiser THOR while on a ballast voyage from Melbourne to Abadan, Iran, and taken to Japan by a prize crew. There she took her new name and was managed from Hamburg.
No details known of crew when sunk. Can anyone help? Is this the best place to post this? Tom