WWI Without America

[BlondieBC]

I think he thought that because it wasn't centrally directed from bases in Germany with high powered radios like in WW2 that it wasn't possible, but like you said commander coordinated by themselves at sea with their lower powered radios just fine.
Dönitz gained experience in WW1 doing just that and made it doctrine in WW2.

Pre war, the Germans had a radio in West Africa that could broadcast to all of South America, so it is not he shore to ship. Are you talking about the U-boat to shore range? While less certain on this one, i believe the U-boats sent messages reporting on their patrol as they rounded Scotland. I look at this a good bit for my TL. There would have been radio issues in the first weeks or perhaps even months of the war, but this was because a U-boat was viewed as a day-time torpedo boat that was to be used within 100-200 miles of port. Doctrine normally had them return to in or near port each night when the torpedo boats would go out. So there is no need for longer range radios. As time passed, they increased the range of the radios as the need arose.

And even assuming that I am 100% wrong on this stuff. Lets look is what is possible if you want to do wolf pack with central co-ordination. Zeppelins are 100% immune to aircraft over water until mid 1917. They have 100+ hour range. You can fit a large radio on them, and they are effectively 5000 foot tall tower.

I see immense doctrinal issues in figuring out wolf packs. But if went back in time and were limited to not giving any new technologies, it would be easier to do wolf packs in WW1 than WW2. For most of the war, once a U-boat dives, it is as safe as an Ohio class submarine. U-boats can break contract if discovered near 100% of time. IOTL in WW2, most contacts were found by submarines not scouting aircraft. You can cover this as well as Germans did IOTL in WW2 ITTL with Zeppelins. If you can fly to East Africa, you can do round trip to west of British Isles. Radios had the range. Torpedoes were more reliable, even though really both would mostly be using deck guns until convoys got more efficient. Both wars have issues with broken codes. U-boats have enough speed to follow on surface at distance.

I know I got a lot of flak when I did a wolfpack attack on the Grand Fleet to open my TL, but I have yet to have anyone explain to me why it could not be done with minor changes to OTL.

 

[Mikestone8]

U-boats certainly had ship to shore wireless by 1917. In The Victory at Sea, Admiral Sims remarks on how much advantage the Allies got from listening in to the subs' conversations. According to him they were chattering all the time.

 

[BlondieBC]

Wasn't submarine range and speed also an issue in WWI?

To the west of the British Isles?

OK, U-19 a prewar boat. Surface 15.4. Submerged 9.5. Range 7600 miles at 8 knots. Now to VIIC. Speed 17.7/7.6. Range 8500 at 10 knots.

So we are looking at 2.3 knots maximum and 2 at max fuel usage. Ranges overlap, but the older boat is faster underwater. Now this might be an issue in WW2, but ship moved slower in WW1. There was a gradual increase in speed of ships over the interwar years. Something like 30% of ships count and 10% of ships are sail. The only issue will be these U-boats will have trouble catching fast ships such as refrigerator ships and luxury liners traveling at full speed. But U-boats of WW2 also have issue with fastest merchants.

To give you an indication of how adequate this is. I looked up the actual speed used by used by the Grand Fleet in the first days of the war. It was in the 9-12 knot range from memory (6 knots below slowest ship in fleet). For example, Duncans' travel at 19, KE 7 at 18.5.

And don't forget the big help. You will be following a convoy using coal. If you have to dive or slow down due to escorts, you have a good chance of picking up the coal cloud which will lead you to a target.

http://uboat.net/wwi/types/?type=U+19

http://uboat.net/types/viic.htm

 

[BlondieBC]

Main limit on submarine range was the supply of torpedoes. Once these ran out the sub had to return to base, which could be a longish journey from the waters off southern Ireland up around the north of Scotland.

As a result, iirc, only a comparatively small minority of u-boats were on station at any given moment.

Well, it is about 1/3 of the number on station. The numbers used to plan for WW2 were from WW1 were correct. It would take about 300 U-boats with 100 on station to break the UK in WW1. In the Med, you had nearer to 50% on station.

And I am not so sure on Torpedoes numbers. Take the two largest classes U-31 (early war model) had 6. U-93 class was up to 16 which was more a 1917 model. The VIIC had 14 torpedoes. Yes, it would be an issue, but even without changes it is manageable. Sure with 6 torpedoes you have to come home faster, but you can largely ignore UK escorts ships and airplanes that would make the trip harder in WW2.

Now to get to the number of torpedoes. I guess we have to guess what % hit. The average long range freighter is in the 3,000 to 10,000 ton range. So with 50% and minimum tonnage, it is 10,000 per patrol. With 75% and max tonnage it is 40,000 tons per patrol. Each time you cycle out with 300 ships, you are might be sinking 3,000,000 tons to 12,000,000 tons. It does not look like a torpedo issue. Isn't the UK merchant fleet only 20 million tons? And the Germans could have built ships with more torpedoes. Again to me, it does not look like technology issues, but leadership issues. The Germans had a naval weapon which could win the war, but did not figure out how to use it in the right way.

 

[BlondieBC]

Did I forget to mention the Germans in WWI didn't have sub bases in Norway, Denmark, Holland, and France to operate from?

If you define ports capture as "technology", you have a minor point on if they can win. But how does leaving say Oslo make wolfpacking technologically possible but Hamburg makes it impossible? There are huge, huge issues in the German admiralty in WW1 preventing success. They are mostly mental though. Even without tinkering with build schedules or technology, the Germans could have starved the UK in WW1 without bringing in the USA into the war the vast majority of the time.

 

[BlondieBC]

U-boats certainly had ship to shore wireless by 1917. In The Victory at Sea, Admiral Sims remarks on how much advantage the Allies got from listening in to the subs' conversations. According to him they were chattering all the time.

Does he explain how it helped? As in examples or stats on U-boat sunk?

I looked at the actual copies of the codes and a sample couple of weeks of broken messages. The U-boat messages basically were just given as they rounded Scotland in and out. Basically as follows:

U-20. Rounding Scotland Outbound.


U-45 Returning from Patrol rounding Scotland. 5 Ships Sunk for 15,000 tons. 4 Torpedoes left and 5 days fuel.

So it provides some useful information but not a lot. It basically let them know how many U-boats were on merchant patrol and it would give them some idea of hit rate on torpedoes. I would assume the Admiralty had pretty good idea of number of ships lost each week to all causes. I don't see a war winner, but I will grant it is a clear flaw by the Germans. If one of the time they had surged from 3 to 30 U-boats on station in merchant warfare, they might have caught the merchant fleet off guard. But if I wrote a TL where I fixed the U-boat codes alone with no other changes, most people would have trouble telling it from OTL unless you happen to have memorized the number of ships sunk per month IOTL.

And triangulation of the transmission was a mixed blessing. Yes, it is useful to know that there is two U-boats NW of Belfast. But the average error was 50-75 miles on the location of the transmission and it took 10-12 to get ship on station, so it endup wasting a lot of resources of the RN chasing ghost. Take a 50 mile error on original location and U-boat moving at 8 knots, you are off by 130 nm by the time the ASW arrives. Now this is presumably balance partially by merchants steering clear of U-boats, but if given a location 60 miles off the actual, I question if this is a big issue. I will not even guarantee that tighter radio procedures and unbroken U-boat codes would actually help.

Now the Surface is a different matter, because the Germans might well ambush a subsection of the British Fleet to begin to even the odds. And without always knowing when the High Seas Fleet is in port, the RN admirals might either be less aggressive or pull even more resources to the North Sea.

Now the diplomatic code breaches were an absolute disaster.

 

[Mikestone8]

Does he explain how it helped? As in examples or stats on U-boat sunk?

He cites it mainly as a help in locating u-boats.

"For example, we would hear that the U-53 was talking just outside of Heligoland; this submarine would be immediately plotted on the chart. As the submarine made only about ten knots on the surface, in order to save fuel oil, and much less under the surface, we could draw a circle around this point, and rest assured that the boat must be somewhere within this circle at a given time. But in a few hours or a day we would hear from this same boat again; perhaps it was using its wireless or attacking a merchantman, or perhaps one of our vessels had spotted it on the surface. The news of this new location would justify the convoy officers in moving this submarine on our chart to this new position. Within a short time the convoy officers acquired an astonishingly intimate knowledge of these boats and the habits of their commanders - - "

 

[BlondieBC]

He cites it mainly as a help in locating u-boats.

"For example, we would hear that the U-53 was talking just outside of Heligoland; this submarine would be immediately plotted on the chart. As the submarine made only about ten knots on the surface, in order to save fuel oil, and much less under the surface, we could draw a circle around this point, and rest assured that the boat must b somewhere within this circle at a given time. But in a few hours or a day we would hear from this same boat again; perhaps it was using its wireless or attacking a merchantman, or perhaps one of our vessels had spotted us on the surface. The news of this new location would justify the convoy officers in moving this submarine on our chart to this new position. Within a short time the convoy officers acquired an astonishingly intimate knowledge of these boats and the habits of their commanders - - "

Thanks. The book I used most who had access to both UK and German archives indicated the average error was 50-75 miles (5-9 hours travel time). So the picture I have is the UK thought it had the U-boats within say an average circle of 10-30 miles and redirected convoys. The total error was likely over 100 miles assuming the U-boat was not patrolling in a limited patrol box. Add in enough fog of war, the UK could see it as big win, especially for the wartime leaders. Germany knows it is being triangulated, but figures it was not a big deal. It would take a lot of work to know if it was a big net gain for the UK.

Now with all the other mistakes the Germans made, I can easily see the U-boat commanders being very, very predictable. So once you triangulated them once, you could guess which patrol box they were in. It would also explain the inability of U-boats to show up at surface actions. The Germans were talking so much and predictable enough the Grand Fleet or Beatty simply sailed around them.