In two cases British cruisers were built specifically to run down fast cruisers built by the United States explicitly to operate as raiders in wartime, in accordance with settled US naval policy. In 1854 the US Navy announced plans to build five large steam frigates and one large steam corvette, and the Royal Navy responded with large fast frigates of its own. It turned out that the US ships were not nearly as fast as had been expected. The British ships were not repeated because they were so expensive; commerce protection, certainly as then understood, demanded numbers. During the American Civil War, Confederate raiders like CSS Alabama devastated Union merchant shipping. The Union response was a series of what were expected to be very fast cruisers capable of running such raiders down. They were also potential commerce raiders, and again they demanded a British response. It came in the form of a program for six large fast steam frigates, only three of which were ultimately built (Inconstant, Raleigh, and Shah). Again they were too expensive to be constructed in any numbers.
It is not clear when British naval officers realized that the combination of an explosion in the sheer number of British merchant ships and the nature of steam power (in the 1870s and early 1880s cruisers could not match the endurance of merchant steamers) made the old convoy policy obsolete. Nor was the lesson of the Napoleonic Wars entirely clear. One witness before the Carnarvon Commission, an experienced and thoughtful shipowner, explained that a convoy attacked by overwhelming force would be annihilated – as had happened on several occasions. An effective convoy defence would have required that each convoy be escorted by a force capable of beating off the most powerful enemy ships. It may be that the ability simply to crush an enemy’s ports seemed for a time a sufficient guarantee against large-scale commerce raiding.
The first internal document formally laying out the desired cruiser force seems to have been a statement prepared by First Naval Lord Admiral Milne in December 1874 for the First Lord, in connection with the First Lord’s attempt to frame a rational naval program.6 Milne’s paper on unarmoured ships was written to help the First Lord frame estimates. It is impossible to say whether it reflected widely-accepted ideas, which were not expressed on paper because they were not worth writing down. Explaining the navy’s thinking to a civilian First Lord was a different proposition.
Milne mentioned both the need to protect the trade on which the country relied, and also what might now be called presence missions, such as suppressing the slave trade and piracy. Milne distinguished between the main fleet, which for him included fast frigates and corvettes, for general war and also for commerce protection, and smaller unarmoured ships for foreign and home service, surveying, despatch duty, and coast guard service. He also produced a paper on trade protection, perhaps the earliest one formally to advocate what was later called a policy of patrolling focal areas. ‘It is well known to foreign nations that our trade is our great point of weakness, and that it is open to the attack of the cruizers of any enemy.’ Recent intelligence showed that the Russians had planned to attack the Australasian trade during the 1863 crisis.
Milne argued that any seaman trying to destroy British trade would know the main trade routes, and would seek targets in particular places where they were concentrated. He identified eighteen such places, Each of these eighteen stations should be occupied by two or three ships, making a total of forty to fifty cruisers. Adding reliefs ‘and separate ships for obtaining information’ gave the total of fifty to sixty cruisers he sought.7 By cruisers Milne meant frigates and corvettes, which he thought would soon be rerated as cruisers of the first, second, and third classes. Only a few of them were really fast.
Milne proposed a fleet of 20 frigates, 25 to 30 first-class corvettes, and 30 second-class corvettes, aside from lesser craft (sloops and gunboats). He considered this a low estimate, and pointed out that a quarter would probably always be under repair or defective at any time. However, the figures seem to have been unaffordably high, so in a marginal note Milne called for a war establishment of 30 frigates and 25 corvettes, a total of 55 such ships. Actual numbers were falling rapidly. Of 26 frigates on the Navy List, 14 were fit only for harbour service, and of the remaining 12, 6 would have to be repaired or replaced within four years. Against a wartime requirement for 30 corvettes, 32 were on the list, but 11 had already been condemned. Of the remaining 21, 14 were in commission, and Milne expected three to be found unfit within three years. Another seven sloops had been commissioned as second-class corvettes, six of which had recently been repaired. No frigates were building, but three first-class and nine second-class corvettes were under construction, in addition to nine sloops and lesser vessels not considered in this book.
Milne pointed to the destruction of US commerce by Confederate raiders, most famously CSS Alabama, only about a decade before. He pointed to the failure of the US Navy to find sufficient ships to run down this Confederate raider. The British cruiser force was shrinking as the wooden ships of the 1850s and 1860s were being condemned much faster than they were replaced. Since 1 January 1868, 19 frigates had been stricken, and 3 built; 16 corvettes had been stricken, and 12 built; and 19 sloops had been stricken, and 12 built. As a minimum, Milne wanted an immediate program of six Boadicea class frigates to be laid down in 1875, another six following in 1876. The 1875 proposal was apparently vetoed by the Cabinet.
Focal area defence was part of a larger strategy. French bases abroad would be attacked so that they could not be used as bases for commerce raiders. The troopships used for such attacks would be convoyed, and some other unusually valuable ships might also be protected directly. The issue of convoy was whether such protection could be or would be extended to the mass of merchant shipping. The conclusion was clearly that such extension was impossible and unaffordable.
The enemy force which got to the focal areas had to be restricted; the British had to neutralize the French battleships. That was not too difficult in European waters, but it became far more difficult as the French gained colonies in Africa and in Asia. The British had to station their own armoured ships in the Far East specifically because a single French armoured ship could destroy the unarmoured cruisers which would execute the trade protection mission in wartime. Hence the British (and French) policy of building second-class armoured ships, many of them classed as armoured cruisers, for foreign service. The nature of these ships is obvious partly because their Ships’ Covers are clearly marked ‘second-class ironclad’ rather than ‘armoured cruiser’.
Milne also pointed to the varied peacetime (presence) roles of unarmoured British warships, such as presence missions for the Foreign Office and suppression of piracy and of the slave trade. He was embarrassed that he could not provide ships; there was no reserve apart from the Channel Squadron and the Detached Squadron.
It is not clear to what extent Iris and Mercury were intended to meet Milne’s needs. Certainly he did not get the large cruiser program he wanted. The British cruiser program continued to consist mainly of relatively slow corvettes through the early 1880s.
In the aftermath of the 1878 crisis with Russia the Carnarvon Committee met to examine the ability of the Empire to maintain the food supply of the United Kingdom in the face of foreign attacks on British trade. It spent relatively little of its effort examining naval efforts to deal with enemy commerce raiders, concentrating instead on the defence of British colonies and coaling stations. Most of the world’s steaming coal was in exactly these places. Without coal, an enemy raider would soon be rendered immobile.8 The Carnarvon Committee did collect statements from some prominent shipowners attacking the earlier trade protection tactic of convoy, which had apparently already been abandoned.
In 1885 the Foreign Intelligence Committee (now in effect a naval staff) issued a comparison of trade protection by focal area patrol and convoy.9 The unpleasant reality was that the Royal Navy had no cruisers capable of working with really fast merchant ships. Very few had the combination of speed and high-speed endurance needed to convoy even 10kt freighters, which were quite common by that time. Even sailing merchant ships would be difficult to convoy, because they might easily be becalmed. Their