Some years ago I read "The ship that changed the world" by Dan van der Vat (a good read). What struck me was he used different dates to the usual accepted storyline for the signing of the Ottoman German Alliance and for the influences of the two warships mentioned. Since then I have trawled the net looking for the detail of what actually happened. I have found an interesting site at http://www.dardanelles.co.uk
which I recommend to the members of this forum.
The site contains the text of the book "Straits: British policy towards the Ottoman Empire and the origins of the Dardanelles Campaign" by Geoffrey Miller. This book and two others by Mr Miller are accessible free on line. The other books are also of interest: "Superior Force" about the cruise of SMS Goeben; and "The Millstone" about the Anglo French naval alliance and Britain's entry into World War One. All of these books contain significant references to the source material. I have not followed up the source documents but some may like to.
The time line suggested in Straits expands on that put forward by van der Vat.
During June 1914 Djemal Pasha (Ottoman minister of marine) visits France seeking an alliance. There he meets Captain Raouf Bey, who had been appointed Captain of the Sultan Osman (later HMS Agincourt) . Raouf says that the shipyard was acting strangely always looking for a delay. Raouf had been staying on Tyneside to "oversee" completion.
Towards the end of July Admiral Wilson of the Admiralty seeks legal advice from the Foreign Office concerning taking over the ship. This highlights the importance of preventing the Ottomans hoisting their flag onboard.
On the 30th of July 1914 a small conference was held by Churchill to discuss the advice of the Attorney General about the legalities of taking over the ships. Churchill then telephoned Armstrongs (the builders) to inform them the Ottomans could not hoist their flag nor move the ship (nor the second dreadnought building at another yard). Interestingly it was considered and decided not necessary to inform the Ottoman Ambassador.
On the 1st of August the Ottomans make the final payment for the Sultan Osman and this information is sent to the yard. Captain Raouf is "invited" to the directors offices of the yard and informed he cannot hoist his flag, nor will the ship be leaving the yard. He telephones the Ottoman ambassador in London who seeks a meeting at the Foreign Office. There he is informed that the Admiralty had taken possession of the ship. He sends a telegram to Constantinople.
The fractions making up the government there were actually involved in a heated debate. Present were the Pro-German minister of war Enver, the minister of the interior Talaat, the Grand Vizier Said Halim, the finance minister Djavid, and the minister of marine Djemal. Enver speaks out for an alliance with Germany, Djavid argues against, the others do not become involved. Finally Enver produces the telegram from London which ends the argument.
One can also look at the instructions sent to SMS Goeben during this time. On the 1st August a rumour passes around Constantinople that the Russian Black Sea fleet will attack the Bosporus. The German ambassador sends a telegram to Berlin asking for the dispatch of Goeben. On the 2nd of August Berlin replies that Goeben is required elsewhere. It is in the afternoon that the German ambassador declares the alliance signed.
Goeben's involvement in turning the Ottoman Empire to war with Russia is another post.
I cannot recommend Geoffrey Millers works highly enough.