The world is full of paradoxes, and so should alternate history be. Tom's excellent "Operation Unicorn" is masterful at showing how a victory in one quarter can lead to or be balanced by a defeat in another. Everything is complex and inter-related, and rarely in OTL does a victory lead to a victory lead to a victory and so on. Sometimes a victory can be the cause of ultimate defeat...
I considered using the Scarborough raid as the POD for this, but decided that OTL events around and in the wake of Dogger Bank gave me a surer footing on the matter. True, Unrestricted Submarine Warfare was being put forward by Pohl (Chief of the German Naval Staff) in November 1914, but at that point it did not have the backing required. Perhaps, had Warrender caught Hipper after the Scarborough raid (and he had a good chance to, after Ingenohl went home with the rest of the HSF) then matters might have come to a head. But I can feel a bit more sure-footed if we use Dogger Bank, since in OTL that was the catalyst anyway
The Battle of Dogger Bank occurred on 24th January 1915, so this is where our tail begins. Singnalling confusion in OTL caused the British battlecruisers to break off their pursuit of their German counterparts, and return to focus on the already-dommed Blucher. The essence of the signalling confusion was Beatty's seemingly-inexplicable decision to turn away from the Germans on a North-Easterly course. Damage to the Lion precluded the possibility of using the wireless since the dynamos were all shut down, whilst the signal halywards had been reduced to two. Beatty therefore could only use brief signals, and not explain himself. To the other captains the whole thing was mysterious, and they tried to second-guess what he wanted, and why. In the final resort, once command had devolved by default to Admiral Moore on the New Zealand, he continued to try to second-guess Beatty and issued orders on the basis of what he assumed was being asked.
And all this because Beatty thought he saw a periscope ! Which, considering the scope and subject matter of this thread, is really rather ironic. Let us, therefore, remove this outbreak of periscopitis (no one else on Lion's bridge saw anything and one assumes it was a nervous reaction from the admiral who had just had his flagship shot up around him, and was understandably anxious about whether the whole battle was in fact a trap). In the alternative I am proposing, Beatty doesn't see a shadow out of the corner of his eye, or whatever he mistook for a periscope, and allows the pursuit of the German battlecruisers to continue. The Blucher is clearly doomed, and can be left for later - it is the badly-damaged Seydlitz, and the damaged Derfflinger which are the prizes here.
Thus the Battle of Dogger Bank is a tremendous British victory - the Blucher, Seydlitz and Derfflinger are sunk, along with the German destroyers which Hipper throws into action in an attempt to drive off the pursuit (OTL he gave this order then rescinded it after the British turnaway which he assumed was in response). Moltke and escorting cruisers flee home, but Hipper is dead, and the German battlecruiser force shattered. The Kaiser is apoplectic (which is surprisingly hard to spell) and although he doesn't do a Hitler-like "Scrap the fleet" rant, there are elements of it in his ravings.
OTL the decision was made to begin Unrestricted Submarine Warfare on 4th February, with the offensive beginning in earnest on the 22nd. Presumably these are more or less the earliest dates possible, give or take a few days at the start. One assumes there were various councils, meetings, discussions etc, but here the Kaiser is likely to be more forceful, and to meet less opposition so the dates could be advanced by a few days. I doubt the interval can be much-changed, since it presumably is made up of time to get the submarines on station, responding to new orders etc. If we advance things by a couple of days, then USW could begin on the 19th February, the same day as the Allied attempt to force the Dardanelles begins.
OTL the problem is three-fold -
-1- not enough submarines to properly pursue the offensive
-2- not enough new submarines being built to replace losses, or allow for a gradual increase in the offensive
-3- the protests of the United States (and other neutrals)
OTL again (since we are dealing with divergences we need to know what really happened) the first period of USW lasted from the latter part of February 1915 to early June 1915; on the 7th May the Lusitania was sunk, and on the 5th June under US pressure, Germany decreed that it would no longer attack large liners.
This second period of USW lasted from early June to the end of August, when after the sinking of the Arabic on the 19th August, and increased US pressure, Germany decreed on the 27th August that it would no longer attack any liners whatsoever *(which considering that converted liners were being used as armed merchant cruisers and troopships was a bit of a blow). The third stage of USW staggered into September, before it was formally ended.
With the advantage of hindsight one can wonder what a reluctant US declaration of war in 1915 would be like - there would not have been the build-up that had occurred before the OTL declaration in 1917, and various problems would remain unresolved - not least the US intervention in Mexico, and the lack of an army. There are also, of course, less US dreadnought battleships around to risk sending to Europe.
German naval building commitments continued to include battleships and battlecruisers that would never see service, or if they did would never see action. What I am proposing is that the Kaiser demands that anything which cannot be completed in 12 months or so be cancelled - this would allow the Lutzow to complete, and (with the usual optimistic lies of people caught in a corner) work on Baden and Bayern to continue. But not only would the Ersatz Hertha and the Mackensens, Sachsen and Wurttemberg, be delayed, they would be effectively cancelled. The Ersatz Yorcks will never get off paper, and no material is going to be gathered for these ships. Thus, slips, resources and manpower is going to be available for a major building effort to expand the submarine fleet
A comparison with Britain might be useful here. When Fisher returned to the Admiralty in November 1914 he convened a conference to look at Royal Naval building and threw a huge number of new contracts about. Specifically relevant here, he demanded new construction on submarines, not sign-off on new construction, but the start of new construction. He also threw large orders to Bethlehem for additional submarines, which were delivered within six months. Whilst its unlikely that the Germans know the details of any of this, they do have the capacity to crash-build such units if they can gather the will to do so.
Hopefully, I am giving them that will. Six months for new construction would take us into August, but a dedication to construction would mean that existing contracts would get a boost, and that new submarines capable of pursuing the offensive would be available somewhat earlier than OTL.
In addition, in the face of the loss of face (I hate it when that happens!) of Dogger Bank, Germany is less concerned with the reaction of the USA. It is increasingly clear that Wilson's neutrality favours the Entente powers, and that the USA is making credit and armaments available. Sure, there were words to the effect that the USA would trade with anyone, but how can Germany or Austria-Hungary manage this in the face of the British blockade? Its obvious that the US is aware of this, and that Wilson is aware that his policies favour the Entente. Its not too large a step for German leaders over Summer 1915 to reckon that even if the USA is pushed into a declaration of war the actual help that it can give the Entente powers won't be much more than they are already giving them. Perhaps twelve months later it would, but by that time USW can have won the war
The knock-on from Dogger Bank is unlikely to change much in terms of dates of anything in the first part of 1915 - Italy will sign the Treaty of London on 26th April, and will declare war around a month later. Possibly it will be slightly earlier than OTL, both due to Dogger Bank and to what might be happening in the Dardanelles
Operations there began on the 19th February, and in OTL the landings at Gallipoli took place on the 25th April. What one has to wonder though, is whether the removal of two additional German battlecruisers has had any effect on British policy - OTL the decision to send the Queen Elizabeth and two older battlecruisers to the Dardanelles caused major arguments within the British naval heirarchy, based on considerations and fears of relative strength back in the North Sea. Here, that ratio is better, tho one assumes that in addition to Lion, another two British battlecruisers probably need urgent and perhaps lengthy dockyard treatment after Dogger Bank. Thus, overall, the active ratio may not be much altered. I do think, tho, that the boost of Dogger Bank and the existence, even if in dockyard hands, of a superiority in numbers, would have lessened the force of the argument.
Paradoxically, that might have led to the Queen Elizabeth remaining at the Dardanelles longer and being torpedoed. Paradoxically back (!), she is likely to survive, and the German focus on attacking her will in turn mean that a couple of old battleships that were sunk in OTL survive, and that British prestige is not damaged by their loss. The limping into dockyard hands of the Queen Elizabeth looks like a blow but is not as bad as it could have been
Thus things are not MUCH changed - yes to a few dates, yes to a few details, but the operation to pass the Straits still fails, and the landings at Gallipoli take place. Italy views things as clearly flowing the Entente's way, and enters the war, probably a week or so earlier than OTL since it would take somewhat less to convince everyone in this scenario.
Meanwhile Handelskrieg (literally "trade warfare" but applied by the Germans to USW) continues unabated. Large liners continue to be targets, and perhaps we can posit another one sunk in July, with American loss of life. This ratchets up the pressure, already at the boil after the Germans apparently ignored US protests over the Lusitania. But high Summer is when USW can really begin to come into its own as numbers of submarines available start to increase dramatically, and beter materiele, better tactics, etc all have an added effect.
The pre-dreadnoughts are probably also decommissioned in this scenario too. What use a load of old battleships when the decision has been made to win the war under the sea ? No doubt this causes resignations and argument, but it does free up a large number of crews for the submarines. Utilising the Kiel Canal, the High Seas Fleet can continue to maintain a dual focus on the Bight and the Baltic, and the loss of the older ships simply means that it has given up on the idea of forcing a battle in the North Sea in favourable circumstances - Dogger Bank will be cited to show that favourable circumstances are not likely to occur !
Late August would see a substantial increase in the number of submarines at sea at any one time, but also likely see the US decision to enter the war. In German eyes it would become a race - to starve Britain out over the next few months before the US can make their entry into the war count.
Best Regards
Grey Wolf