The fuel crisis

[Dave Saxton]

I'm finding that the operations of the German warships throughout WWII was based a great deal on the supply of fuel, and the problems of how to provide it to warships during operations. The German Navy had finite fuel supplies for warships from the very beginning of the war. This was particularly true of fuel oil. Diesel was easier to come by. Often operations had to be postponed until the supply could be built up. A major operation like Rhine Exersice would of had to be planned months in advance, with a careful sheparding of almost all availbable stocks, and the pre-placement of tankers and so forth. These logistacal problems may help explain some of Adm Lutjens decisions.

For the first part of the war, the primary supplier of fuel to the German war machine, and also high grade fuel oil to the Navy, was actually the Soviet Union. With the attack on the Soviet Union the Germans would cut off their main fuel source. This may have been a factor in Raeder pushing so hard the deployment of the turbine battleships to raiding during the first part of 1941? Hitler was gambling that he would gain direct control of the Russian oil fields within 5 months, but he never would.

After Barbarossa, virtually the only source for high grade fuel oil was Romania. The Italian fleet was also dependant on this same source. The Italian fleet was virtually immobilized thereafter. It was hoped that the Ploiesti refineries could supply the German fleet with 46,000 tons of fuel per month, and that was less than 1/2 the actual need. However, even that quota was never remotely obtained. During some periods, the monthly supply was less than 10% of the needs. In April and May 1942, the German Navy (even destroyers) was ordered to cease all operations temporarily. Potential operations by the Tirpitz could not be sanctioned most of the time. The Tirpitz standing ready was really a bluff due to the fuel situation. I don't know if the Allies ever understood high tight the German Navy's fuel situation in the Artic really was?

This caused the transfer of the two remaining diesel burning Panzer ships to Norway, despite the fact the Germans themselves now considered them poorly suited to front line duty, especially the anti aircraft capablities.

To better understand the course of the naval war in the Atlantic, the Artic, and the Med, the fuel situation must be taken into account.

[RF]

Hello Dave,

Britain's Ministry of Economic Warfare was very well aware of the critical fuel position in Germany, as well as the shortages of certain strategic raw materials such as rubber, cotton and tungsten, among others.
That is why the Royal Navy paid so much attention to intercepting blockade runners and mounted the ''cockleshell'' raid on merchant shipping in Bordeaux, and the RAF Photographic Unit was ordered to photograph every German merchant ship in Axis ports - to identify potential blockade runners, raiders and naval supply ships.

The KM's problems were down to Hitler, but to an extent they were also culpable. Hitler failed to provide for Germany's long term fuel supplies, and the ersatz substitutes - such as oil extraction from coal - were very expensive and not very efficient. The South Africans under apartheid did much better in that respect, using Sasol.
The KM was culpable in that they used such fuel hungry ships. The diesel technology was there, indeed it was a German invention in the first place (by Rudolph Diesel), yet they persisted in pushing for high pressure oil turbines in the big ships. More focussed, strategic based planning could have overcome all of this.

One the major ironies of WW2 - the Axis was always short of fuel, especially the Afrika Korps - yet that unit was sitting on top of some of the world's largest oilfields that would have eliminated the fuel problem and greater strengthened the Italian economy. However it was to be the likes of Gadaffi who were to later benefit. I am of course referring to the oilfields of Libya.

[dunmunro]

KM ships were also fuel hogs:

This is a post I just made on another board.


"Regarding shipboard bunkerage and range, the problem of high fuel consumption cannot be overlooked. British counterparts of comparable type used less than half the fuel of the German cruisers, and even at forced speed they used less than 40% less than the German installations-and with more reliability. Moreover, auxiliary machinery in British cruisers used less fuel, had a more favourable warming period, were more economical in terms of personnel and were easier to repair. This was true not only for British heavy cruisers but also for capital ships: for example HMS King George V, of 37000 tonnes displacement and with 3759 tons of Bunkerage capacity, could steam for 4500nm at 20 knots and 2540 miles at 27 knots."

Heavy Cruisers of the Admiral Hipper class (Koop p.202)

Bismarck's range with 7300 usable tons of fuel:

approx 8300nm at 20knots and 5200nm at 27 knots. (Anatomy of the Ship - Bismarck)

Using data from HMS Howe in British BBs, KGV's range with 3530 tons of fuel would be 4700nm @ 20knots and 2650nm @ 27knots, but regardless, Bismarck's range indicates a higher consumption at a given speed, especially at 20knots. RN Town class cruisers had a design range of 7000nm @ 16knots with about 2000 tons of OF versus about 6800nm @ 16knots with 4200 tons of OF for Prinz Eugen.

[RF]

The KM ships with the greatest fuel economy were some (but not all ) of the hilfskreuzer, and given that they were not purpose built it does indicate what might have been achieved if they had been.

[Dave Saxton]

I know that turbine ships consume more fuel than diesel powered ships. However, the diesel powered ships were not as fast as the turbined powered ships.

A few years ago, I did a quick calculation of the actual fuel consumption of Tirpitz during Operation Sport Palace, and the results were very surprizing. The Tirpitz used significantly less fuel than expected up to 25 knots speed.

viewtopic.php?f=9&t=316

The fuel consumption of the Tirpitz wasn't out of line compared to other turbine battleships. Other nations with ample fuel reserves could use turbine power with out much trouble, but for Germany, diesel power, in retrospec, was a better way to go.

[Bgile]

The KM ships with the greatest fuel economy were some (but not all ) of the hilfskreuzer, and given that they were not purpose built it does indicate what might have been achieved if they had been.

The merchant raiders began life as merchant ships, and were originally designed (as are all merchant vessels) with fuel economy as a primary consideration. That is why they made good merchant raiders. "purpose building" them would have been unlikely to help fuel economy at all.

[RF]

I'm not so sure.

The KM had plans for the construction of ''Spahkreuzer'' reconnaisence light cruisers, a smaller version of the ''K'' classe light cruisers (including the odd turret arrangement) and diesel engined ''Atlantic'' destroyers which on paper should have had great fuel economy, as well as diesel engined battleships.
Of course these plans never came anywhere near to starting (I believe M.A.N. did develop prototype diesel engines for one destroyer of which one is in preservation) but the potential was there.

Incidently the Kormoran was equipped with a set of proto-type diesel electric engines for which Steiermark was supposed to be the test ship. These had very great fuel efficiency but the engines had a problem which only became apparent after some two months at sea - the bearings for the engines had been constructed of too light a metal. As far as I am aware these particular engines were unique and never entered formal production - they were too cumbersome for use on submarines, so their development was abandoned.
However I do recall that M.A.N. did develop a smaller but very reliable diesel engine for the S boats, of which quite a lot of detail is given on the Prinz Eugen website.

[Tiornu]

Gun disposition in the Spahkreuzer was fairly conventional: six guns in centerline twin mounts, usually with two of the mounts aft. Resemblance to the "K's" is slight.

[RF]

From the proposed designs of these reconnaisance cruisers that I have seen they do seem to resemble the K classe in both outline and intended role. I realise that these designs come more than ten years after the K classe ships were designed.