This is really annoying as i cant find an adequate response, and i was sure i was going to. I have looked through Pollards 'The British Shipbuilding Industry 1870-1914'. Buxtons 'The warship builders', Slavens 'British Shipbuilding'. As well as a few more British Shipbuilding books by Alan Johnman, Hugh Murphy, Hugo Lorenz, Leslie Jones, Hugh Peebles. And a specific chapter on Technological advancements and the relations between the Admiralty and private Industry by Hugh Murphy in Bryan Ranfts 'Technical Change and British Naval Policy 1860-1939. Plus an interesting article by Mathew Seligman on the high speed liner threats and policy prior to the First World War, and.........Dont know! nothing.

Well nearly nothing..

I suspect that it is a mix of things. Firstly, by the design and building of the Kaiser and Konig class of Battleship which (please forgive me this small crime) according to Wikipedia had Parson Steam Turbines, Parsons design was not new and not under lock and key. The scale of the impact that Parsons turbines had on marine technology and shipbuilding meant that it wasnt a secret. Parsons had (according to both Pollard and Buxton) licensed the design and concept to anyone who had the money. The company recognised that the influence and scale of the design was going to far outstrip their ability to manufacture them, and unless the company capitalised on its intellectual property rights and sold licenses freely (for the right price) people were just going to evade patents and copy it, or even develop something better. So by 1905 there is a long list of companies producing 'Parsons' steam turbines. Although i hasten to say this list looks mightily 'British'.

This links to the second issue. Any one of the books listed above could describe in great detail the twisted and gnarled hydra beast of conflicting vertical and horizontal ownership of shipping, shipbuilding, steel, marine engineering, arms firms that criss-crossed the whole globe. Once patents reach the major conglomerates of either arms or shipbuilding than its not an outside bet that a substantial number of builders around the globe could draw on those same patents. It was a myriad of ownership not too unlike modern day multi-nationals

Plus there were competitors to compete with. American, French, Swedish contemporaries all able to offer similar propulsion systems and all offering their own patent to those with money.

Adding to this was the growing arms free for all of the period. Turkey, Brazil, Chile, Russia, Japan, Argentina, Greece are all buying Battleships or major warships from British Yards or the US. It is a buyers market. Warship exports are at the time major parts of British exports and economy and to a substantial effect prop up the profitability of the arms and shipbuilding sectors. Arms exports are promoted and fast tracked.

So basically 'Parsons' turbines might be just a name like a 'Hoover' with the actual engines made by Dennys, or Vickers or maybe German AG Vulcan? But im honestly not sure. This is why im annoyed. This is isnt unusual to this specific issue and type. My area of research touched upon naval arms and shipbuilding outputs and exports in the interwar years. One of the major headaches is disentangling actually who built what for whom. Especially in relation to foreign built ships using British equipment. Often British boilers, engines and machinery are cited but can often be built under license from either the main shipbuilder or by a third party.

And it doesnt really answer your question as to why? Why was this allowed? Well in part its because this was not a state arms secret or development. Parsons turbines was purely a commercial venture with obviously industry and global wide impact. The commercial exploitation of steam turbines was being explored quicker than then naval side. Yet of course having said that the naval application and importance was obvious from the outset. The Royal Navy and the British government part financially supported the White Star Muritania and Lusitania being equipped with large 'experimental' parson turbines as early as 1902 in part because the Admiralty wished to explore the idea of arming large merchant ships and to equip themselves to defeat large fast German merchant ships like Kaiser Willhelm der Grosse. So the strategic control and application of superior steam turbines was already understood.

So why?......I dont know. I presume because no one said they shouldnt. It was peace, it was a commercial business, it was a commercial item that was either purchased and payed for as part of a wider British push on maritime exports, or via patent license. It was a buyers market. Parsons monopoly wasnt going to last for ever..best cash in. I have also little doubt that those at the top of British trade and industry would have seen this as an absolute win. An example of British maritime engineering dominance, not trading secrets with an enemy.

I think ideally i would need to look at some official Parsons History if there is one. Also something exploring the granting of export and arms licenses.

This is all very unsatisfactory. I dont know the answer and i dont know where to find it without doing more research than im willing to sanction. Normally i wouldnt have even have commented with such a "shrug" of an answer, but i spent a few hours on this so im writing out of stubbornness.