PROTECTING TRADE
When Admiral Fisher took office as First Sea Lord in 1904, the British cruiser fleet included large armoured cruisers intended to work with the battle fleet or to deal with large enemy raiders, medium cruisers for trade protection and station work, and smaller cruisers intended for purposes ranging from Empire defence to linking scouts with the main fleet. Radio obviated many such functions, so that Fisher envisaged a fleet in which battlecruisers would scout and perhaps also form part of a battle line. Through 1909 the only cruisers he built were intended either as destroyer leaders (for independent flotilla operations blockading German destroyer bases) and as scouts for coastal defence destroyers. Because of their destroyer functions, these ships have been dealt within a previous volume devoted to British destroyers.
The Bristol class
Work on a ‘new Boadicea began late in 1907, six such ships being planned for the 1908/9 programme, including one to be built at the Royal Dockyard, Pembroke.1 HMS Boadicea was essentially a destroyer leader, but the new cruiser was much more powerful. The principal role was understood to be to meet the new German Third Class Cruisers. That meant a variety of roles. For the fleet, it meant backing up blockading destroyers against a stronger German cruiser threat. Earlier, slower German cruisers would have been ineffective against fast British destroyers, but the newer ones could run down the British destroyers. It also meant trade protection, as the German ships could operate against British trade from the German colonies. During the First World War several of them did just that, Emden and Königsberg becoming famous in that role. Probably the ships involved were the first German turbine cruisers, the prototype Stettin and then Dresden and Emden, all armed with ten 4.1in/40 guns, displacing around 3,300–3,600 metric tons. Design speed was 23–24kts, increasing to 25.5–26kts in the next (Kolberg) class. Initial instructions (2 November 1907) were to design a 4,000-tonner capable of 25kts, armed with twelve 4in guns, with 50 per cent more fuel (coal and oil) than a Boadicea (the latest Scout), with a protective deck but no side armour, and with four months’ stores. There was no apparent interest in higher speed to overmatch the latest German cruisers. DNC could meet these requirements on the desired displacement, with the same protection as Boadicea (½in deck throughout with 1in slopes over the machinery, and a 4in conning tower).2 The Board provisionally approved the 410-foot version of the 4,000-tonner, but DNC asked for more options with thicker armour decks: (A) with 1in flat and 1½in slope only over machinery and magazines (4,150 tons) and (B) with 1in flat and 2in slopes (4,300 tons). A detailed drawing showed a 420ft (pp) x 44ft x 14ft 9in ship (4,300 tons). The design showed two 4in guns side by side at each end plus three in the waist on each side, blocked from firing across the ship by the boiler casing. The new ships were rated as Second Class Protected Cruisers because they were powerful enough to fight the last British cruisers with that rating, the Diana class. These ships were too big to build at Pembroke (a ship had to be docked within six months of launching, and the yard had no dock large enough), so in January 1908 it was decided that one of the six 1908/9 cruisers would be a smaller repeat Boadicea, the others being built at private yards.
Glasgow is shown with funnels raised, and with the pre-1914 arrangement of searchlights aft on a bandstand.
HMS Newcastle shows the effect of short funnels in this 19 August 1910 photograph.
It was proposed to replace the deck tubes with a submerged torpedo room.3 That in turn cleared deck space for another two 4in guns, for a total of fourteen. These changes were decided early in January 1908. DNC sketched a 4,600-tonner with the desired heavier armour (1in flat, 2in slope), the larger gun battery, and the submerged tubes.
Controller considered a 4in battery on a ship this size weak; for a few more tons she could have 6in guns at the ends plus the eight broadside 4in. The 6in was considered the natural gun for a relatively small cruiser, because it was the largest whose shell could be handled by a single man, hence the largest which did not require a powered hoist and elaborate loading arrangements.4 That also made the 6in the natural armament of armed merchant ships and other raiders which could be commissioned in significant numbers in wartime.
In mid-January DNC ordered Legends prepared for this alternative, as well as for four 6in (guns paired alongside each other at the ends) and four 4in, and for six 6in and eight 12pdrs (3in guns: 6in paired at the ends, with another pair of 6in guns, one on each side abaft the break of the forecastle, and the 12pdrs on the broadside abaft them).5 Although on 18 January the Board approved the version with single 6in at the ends (4,400 tons), Controller asked DNC to work out a slightly larger ship with two more waist 4in guns and a protected ammunition supply (3in tubes at the ends and in the waist). DNC thought that would add about 250 tons.6 In addition to the 6in and 4in guns, the ship was to be armed with a Maxim machine gun (later increased to four).
On 17 February Controller told DNC (Philip Watts) to pursue this 4,650-ton design. On 13 May he added that all of the guns should protected with 3in shields (in previous designs the guns were not protected at all); estimated displacement rose to 4,700 tons. Further proposed detail changes would add another 120 tons. They included installing a 9ft rangefinder in a control position at the head of the foremast (with the guns having follow-the-pointer sights), fitting the 6in guns to have 1° rather than ½° depression; fitting the after 4in guns so that they could fire right aft; mounting four machine guns (Maxims) instead of one; adding a second searchlight (projector) on the after platform or engine room hatch; adding a 6ft screen (with open ports) between the upper deck guns, and across the deck in wake of the engine hatch; and installing magazine cooling (already provided in the Boadicea class). These changes would require another foot of beam. Watt particularly disliked the proposed screen, which he considered a possible shell trap which increased target area. The weight involved could be used instead to thicken the conning tower from 4in to 6in and also to thicken the deck over the steering gear from ¾in to 1½in. In rough weather the screens could trap water and this topweight would menace the ship. The screens were approved as a means of protecting guns on the off-side of the ship from the blast of guns when trained well off the beam; the gunnery school (HMS Excellent) estimated that without them the maximum training arc for broadside guns would be only 45°. Ultimately the conning tower was thickened to 6in. It was decided to save money by making the protective deck of nickel steel rather than non-cemented armour, experiments having shown no advantage for the latter.
Glasgow was a Bristol class cruiser. The 18in underwater broadside tubes were mounted well aft, abreast the mainmast, the starboard tube being mounted forward of the port tube. The elevation drawing was simplified somewhat by excluding the radio aerial rig, two multi-strand arrays rigged from the upper yards. It also omits the extensive coaling rig. The poles extending horizontally from the sides of the forecastle (and on the port side abreast the sick bay) supported ‘sun screens’. When not in use they were stowed beneath the 35ft steam cutter. The two 16ft dinghies were stowed atop the 35ft cutter when the ship was at sea. The main changes during the First World War were slight enlargement of the fire-control platform (but the pole foremast was retained) and the addition of one 3in anti-aircraft gun. Several ships of this class had their main topmasts removed in wartime. In addition to the usual small arms for shore parties, the ship had fifty cutlasses stowed in the overhead of the passageway abreast the captain’s cabin. (A D Baker III)
Watts considered the ships better subdivided than most unarmoured ships, and pointed out that all the main hold bulkheads were unpierced. Machinery spaces were redesigned between July and September 1908 for better subdivision. The engine space was divided into five compartments, three side by side forward of two spaces. The centre one of the three side by side contained the turbines driving the inner shafts, the turbines driving the outer shafts being in the two outer spaces. The other two compartments housed pumps and condensers. This arrangement protected the ship more than in the past against being disabled by a single shell penetrating the machinery spaces. The ‘tween deck spaces above the armoured deck was much more subdivided than in the past, making it less likely that the ship would lose stability or buoyancy due to riddling of her side. Of forty-one separate watertight compartments between the upper and protective decks, twenty were coal bunkers, three were offices and officers’ cabins, six were crew accommodation, and twelve were washplaces, store rooms, etc. DNC argued that although any unarmoured ship was more vulnerable to loss of stability, he had considerably reduced that risk. By late September, weight saving in the detailed design had made it possible to increase conning tower protection from 4in to 6in, and to provide 2in over the steering gear.
The Bristol class had funnels raised to reduce smoking; this also improved boiler draught. HMS Gloucester is shown shortly before the First World War, with identifying funnel bands. Note the marked difference between the large 6in guns at the ends and the broadside 4in guns. The objects visible on the compass platform are an open chart table and a rangefinder.
HMS Gloucester was one of the initial group of ‘Town’ class cruisers designed partly to protect British trade, a reversion to an earlier cruiser function. She is shown as completed, with short funnels which smoked her bridge.
The version with two 6in and ten 4in guns was reported to the Board as the ‘New 2nd class Protected Cruiser’, the Legend dated 30 May 1908 and submitted in June 1908. The new ship followed Boadicea in having engine rooms arranged so that either could operate if the other were bilged.7 A different arrangement was being considered to this end. Required speed was 25kts, roughly that of a battlecruiser. At the outset, the Board clearly called for range, since it asked for 50 per cent more fuel (coal and oil) capacity than that of the earlier ship (about two and a quarter that of Amethyst, the last conventional small cruiser, and nearly four times that of the destroyer-leading Scouts). Compared to Boadicea, the new ship was given a block of coal stowage forward of the machinery, for extra protection. Similarly, her torpedo tubes were placed below the waterline, where they were considered protected, rather than unprotected above water. Gun armament was changed from an all-4in battery (and only six guns), suited to fighting or supporting destroyers, to a pair of 6in guns at the ends plus ten 4in guns along the sides. In contrast to Boadicea, all the guns were shielded. The new ship was far larger, 4,800 tons rather than 3,300 tons. As the designation applied, protection was limited to an armour deck. The Board approved this design on 7 July 1908.
Five of these Bristol class were built under the 1908/9 programme. They and their immediate successors were called the ‘Town’ class. Approval (on 16 January 1908) was subject to the demand that the cost of one repeat Boadicea and five of the new cruisers should not exceed that estimated for six improved Boadiceas. Estimated cost was £415,000, but shipbuilding conditions were bad, so builders bid low. These and the later versions of the design all had twelve boilers in three boiler rooms with four funnels, the middle pair being wider because they combined the uptakes from the after end of one boiler room with those from the fore end of the adjacent one. Each set of uptakes served two boilers set side by side, the stoking space in each boiler room being between two rows of boilers. Thus the foremost funnel was at the forward bulkhead of No. 1 boiler room, the aftermost at the after bulkhead of No. 3 boiler room. One of the five ships, HMS Bristol, had two-shaft Brown-Curtis turbines instead of the four-shaft Parsons turbines in the others. She had two engine rooms in tandem, each containing one turbine with its condenser on the other side of a longitudinal bulkhead (these bulkheads were on alternating sides, to suit the turbines driving the port and starboard shafts).
The following year the Board asked that the 4in guns be replaced with 6in, for a uniform battery of 6in. On 28 January Controller asked for ships with six or eight guns, equipped as private ships or flagships, all of which were to have 21in rather than 18in torpedo tubes if possible. The eight-gun alternative was chosen; estimated displacement was 4,950 tons. Blast screens would be omitted. Legends submitted on 3 February showed a 430ft, 4,990-ton ship or a similarly-armed 440ft, 5,280-ton flagship; 22,000shp engines would drive each at 24.75kts. Watts proposed reducing fuel at deep load to 1,450 tons to compensate for extra armament weight (150 tons) without enlarging the ship. In each case armament included two submerged tubes for short 21 in torpedoes. To get enough breadth for them, the tubes were moved to forward of the forward boiler room, the lower athwartships coal block (for protection) being eliminated. Watts considered the new cruisers the smallest which could accommodate the new torpedoes.
As the forward broadside 6in guns might be affected by spray, Watts relocated them to the lengthened forecastle. All three forecastle guns could fire right ahead, and the three after guns could fire right astern; the broadside was five 6in. More boilers (an additional boiler room) would be needed. In redesigning the ship, Watts lengthened the forecastle to provide sufficient space for all officer cabins, the lower deck being left clear for the crew. However, the Board had recently called for sufficient space for 15 per cent supernumeraries, and Watts wanted to know what complement he should allow for. In an accompanying note, Watts pointed out that to maintain the existing speed of 25kts, it would be necessary to add at least 400 to 600 tons. Alternatively, it would be far less expensive to retain the existing machinery and accept the loss of perhaps a quarter-knot. This might be no more than a nominal sacrifice, as many turbine ships were exceeding their rated horsepower and speed on trials (the state of turbine design was primitive, and reliable instruments, such as dynamometers, to measure output did not exist).
Controller proposed in mid-April that the eight-gun design be adopted for the 1909/10 ships. They would be fitted as flagships, accommodation being provided under an extended forecastle. Bunker capacity would be reduced by 150 tons as weight compensation. As Watts had recommended, the machinery would be unchanged, the slight loss of speed being accepted.
The completed design was submitted on 30 July 1909 and approved by the Board that day; Watts hoped to have building drawings ready for bidders by the end of August. Protection matched that of the Bristol class. Due to the loss of the lower coal block, fuel capacity was reduced from 1,600 tons to 1,500 tons, but ‘this is still a very large fuel supply for this class of vessel’. Length was the same as that of the Bristol (430ft), but beam increased from 47ft to 48/2ft and draft increased by 3in. At this stage displacement was given as 5,250 tons. On the basis of the cost estimate for the Bristols, Watt estimated that the new ships would cost £440,000, but shipbuilding conditions were still poor and he expected some reduction (though not as much as for the Bristols).
Four of these Dartmouth-class cruisers were built. As in the previous class, one ship (HMS Yarmouth) had two-shaft Brown-Curtis rather than four-shaft Parsons turbines. Although turbines were rated at 22,000shp, they often developed much more: three ships developed nearly 24,000shp, and Falmouth developed 27,900shp and attained 26.8kts. Yarmouth trials showed that on two shafts she had about the same performance as a four-shaft ship. Ships turned out lighter than expected: against the Legend figure of 5,250 tons, Falmouth displaced 5,040 tons, Weymouth 5,044 tons and Dartmouth 5,076 tons, with similar savings at deep load.
The Weymouth class introduced an all-6in main battery. Weymouth is shown. Note her pronounced tumblehome in the waist.
While these designs were being prepared, the British government was negotiating with major colonial governments in hopes that they would help provide naval forces for Imperial defence.8 The British government would much have preferred that the colonies contribute to an Empire Fleet, but the Australian and Canadian governments held out for their own navies. The Admiralty pressed for each major unit in the Empire to create a ‘fleet unit’ which could help protect imperial trade, but which could also be combined with other fleet units to create a fleet for distant areas, i.e. for operations in the Pacific. It argued that the local defence forces the Dominions (particularly Australia) contemplated would provide only a very limited degree of mutual defence, because they could never affect the main threat of commerce raiding (the Australians originally contemplated a cruiser squadron to deal with raiders, backed by local defences). The fleet unit envisaged by the Admiralty comprised a battlecruiser, three Bristol-class cruisers, six destroyers, three submarines, and necessary supporting auxiliaries. At a meeting on 10 August 1909 Admiral Fisher explained the Empire or Pacific Fleet concept, and also argued that the core of any fleet unit had to be the battlecruiser, as without her the lesser units could not be very effective against a commerce raider. Ultimately only Australia bought a fleet unit.
No one explained how the battlecruiser and the cruisers would work together against commerce raiders, perhaps because it was so bound up with Admiral Fisher’s intelligence-based scheme of operations. It is, however, reasonable to imagine that by 1909 he had accepted that a scouting line would be far more likely to find a raider than a single ship, the light cruisers detecting a powerful raider and falling back on the battlecruiser so that she could deal with it. The Australians opted for ‘Improved Bristolswhich meant modified versions of the later Chatham class. Initially they hoped to complete all three by August 1912, which was when the Weymouths were to be completed for the Royal Navy. Then the Australians decided to build two ships in the United Kingdom and the third in Australia, accepting the delay in order to develop their own industry.
HMS Weymouth is shown as built. This drawing omits the two eight-strand radio antennas slung between the upper yards. When coaling, the ship rigged a horizontal cable between the funnels and the masts to support coal-bag handling. When preparing for battle, additional stays could be rigged to support the foremast. Yards are omitted in this drawing to make it possible to indicate the complexity of the standing rigging for the masts. The two cruciform devices carried in cage racks on either side of the mainmast were quick-release lifesaving buoys provided with electric lights. During the First World War the foremast was altered to a tripod to support an enlarged fire-control top (ca. 1917). One 3in anti-aircraft gun was added in 1915 between the second and third funnels, a second being added on the quarterdeck in 1918, at which time the main topmast was struck. A flying-off platform was erected forward of the bridge in 1918 and removed in 1919. During a 1924–5 refit the compass platform (from which the ship was conned) was enlarged and extended forward, and the gun control platform equipped with a ‘gun direction tower’ atop an enlarged fire-control platform. Weymouth and her sisters retained their conning towers throughout their careers. Broader and slightly longer bilge keels were fitted at some point during the First World War. (A D Baker III)
The Canadians considered two alternatives: four improved Bristols, a Boadicea and six destroyers; or three improved Bristols and four destroyers. The Admiralty agreed to provide all possible assistance (April 1910), and the relevant specifications and drawings were provided in February 1911. Then the project died.
Above and below: Weymouth is shown in wartime, before the flying-off platform was fitted, with her mainmast cut down. These photographs were probably taken in 1917, after the tripod had been mounted but before the flying-off platform was added. Weymouth and Dartmouth had an additional 3in anti-aircraft gun on the quarterdeck, but it is not visible here. Weymouth served in the Mediterranean in 1915–16, when her mainmast was cut down, then with the Grand Fleet in 1916–17, then back in the Mediterranean in 1917–18, serving as flagship of the 8th Light Cruiser Squadron.
Above and below: Weymouth is shown in Malta in 1920, having been refitted in 1919-20 after having been torpedoed by the Austrian submarine U-28 off Durazzo on 2 October 1918. During this refit her mainmast was restored to its previous height, presumably to provide her with increased radio range. The platform below the spotting top was for searchlights.
On 6 August 1909, while bidders’ packages for the 1909/10 cruisers were being prepared, Controller issued instructions for the 1910/11 ships. He wanted them to have a main deck if possible (i.e. to be flush-decked) and to be good seakeepers without adding much size. Improved seakeeping was later explicitly connected with trade protection in distant seas. As in the previous year, horsepower should not be increased (speed should not fall below 23kts). The ships would not be fitted as flagships, and bunker capacity (i.e. range) should not be reduced. Displacement should not exceed 5,500 tons, and cost should not exceed £350,000. DNC pointed out in November that to hold down size he wanted to stay fairly close to the Bristol design. A flush-decked cruiser would come close to the old Challenger, but enlarged to provide 23kts or more. He offered designs for a ship with a forecastle deck extending for two-thirds of her length, carrying all but the after three 6in guns, and serving as the boat deck (to avoid a raised superstructure whose topweight would require increased beam). Armament, bunker capacity and speed would match those of the Bristol and the subsequent class; estimated speed (with the same machinery) was 24.75kts. Alternative sketch designs showed officers’ accommodation forward, as in the previous cruisers, or aft (Commodore (T) was reporting on his experience in HMS Boadicea, which had her officers forward). DNC favoured the Boadicea arrangement. DNC thought he could meet the cost limit.
HMAS Sydney (Chatham class) soon after completion (about 29 August 1912). The obvious change from the previous class was the new bow profile (the below-water profile was the same).
HMAS Melbourne displays standard First World War modifications, including a flying-off platform forward (in Melbourne and Sydney, but not in Brisbane), a tripod foremast topped by a director, and a long-base rangefinder abaft the fourth funnel. This undated photograph must have been taken soon after the war, since the flying-off platform (and conning tower) were removed when the ship returned to Australia. As completed, the ship had two 3pdr guns on quarterdeck level abaft the break of the forecastle, but by this time they had been raised to forecastle deck level. The searchlights amidships and aft were enlarged to 36in diameter.
HMAS Melbourne is shown late in 1921, the flying-off platform and the conning tower beneath it having been removed. The 3in anti-aircraft gun in its bandstand is visible just abaft the long-base rangefinder, and the two 3pdrs are visible near the break of the forecastle. (Photo by Allan C Green via State Library of Victoria)
HMS Chatham is shown as fitted in January 1921 (the scrap elevation view shows her bridge and conning tower before the 1916 modification when she was given a tripod foremast to support an enlarged fire-control top forward). The director tower atop the fire-control top was added in 1920 when she was refitted to serve as flagship of the New Zealand Division of the Royal Navy (11 September 1920 through 1924). The after searchlight tower and the searchlight platform between the second and third funnels were added during a 1916 refit, and in 1917–18 a flying-off platform was erected forward of the bridge (removed 1919, when the ship went into reserve). Also in 1916 the bridge was extended aft to provide an admiral’s sea cabin abaft the pilothouse, and a 24in searchlight was added on the centreline abaft the new cabin. The 3in gun was added in 1915. Four single Hotchkiss 3pdr QF guns were removed during the 1920 refit, when a portion of the after coal stowage was converted to additional oil fuel stowage. Also removed in 1920 were the ship’s mine countermeasures paravanes and their handling gear. The accommodation ladder position amidships for non-rated personnel was moved to the port side aft. (A D Baker III)
The designs submitted in November were labelled ‘New Colonial Cruiser’, suggesting a ship intended to operate on a foreign station. Sketches embodying various modifications were dated 20 December 1909. They included a watch cabin with a sleeping berth on the bridge.
The experimental firing against HMS Edinburgh demonstrated ‘once again’ the value of thin armour against high-explosive (HE) shell, which were expected to be the main means of attack against unarmoured or lightly-armoured ships. The firing also showed the value of an armoured deck, a somewhat unexpected outcome since there had been no tests against armoured decks for many years. Well after this firing a target was used to compare the value of side and deck armour against 6in shells. This later experiment showed that side armour was much more valuable against HE shells, and that against powder-filled shells side armour gave no great advantage but was no disadvantage. Since almost all foreign navies had adopted HE shells, the HE experiments had priority. Watts therefore proposed developing the 1910/11 design on these lines, the planned ships for colonial navies (Australia and Canada) being of the same type.
It was then pointed out to DNC that by reducing the first and upper decks to 15lbs (⅜in), the ship could be given side armour, extending up from the lower edge of the protective deck to the edge of the upper deck over the length of the machinery, and from the protective deck to 3ft below the upper deck at the ends. On 5,300 tons the ship could have 1¾in side armour, and on 5,400 tons she could have 2¼in, for total thicknesses (including shell plating) of 2¾in and 3in respectively (and 2in and 2½in at the ends). The displacement thus far put forward was 5,400 tons, but 5,300 tons was probably better for structural arrangement. Asked what thickness he could provide if the protective deck was thickened from ⅜in to ¾in, DNC offered 2¾in rather than 3in, and 1¾in at the ends instead of 2in. Yet another possibility (considered in February 1910) was to thicken the lower deck only abaft the forecastle (adding 30 tons); ½in would be removed over the same length on the side. Watts liked the idea, because it would provide more protection where it was needed, further forward. The design finally submitted on 12 April 1910 showed a 3in belt extending to the upper deck over the whole length of the machinery spaces, with a 2½in belt forward to 3ft below the waterline, and a 2in belt aft instead of a thick protective deck. The lower deck would now be ⅛in thick, increased to ¾in abaft the engines, and to 1½in over the steering gear. In a history of recent British cruiser design of October 1918, DNC pointed out that the change to a thin belt had been of considerable wartime value. It led directly to the use of the side armour as part of the hull strength of the later small light cruisers of the Arethusa class.
HMAS Brisbane is shown post-war. The searchlight platform below her fighting top distinguished her from her sisters Melbourne and Sydney. (Photo by Allan C Green via State Library of Victoria)
HMAS Brisbane outside Honolulu Harbor, 8 August 1928, late in her career. (US Navy photo courtesy of Rick E Davis)
HMS Southampton is shown in 1919. Note the concentration dials on the after sides of her spotting top and the after superstructure block, both facing aft so that other ships can see the range at which she is firing. (Perkins)
Length between perpendiculars matched that of the earlier classes (430ft), but these ships had the above-water part of their bow raked rather than ram-form, retaining the below-water bulb (not really a ram). Displacement was 5,400 tons, a growth of about 150 tons compared to the earlier ship. Fuel matched that in the Weymouth class (650/1,500 tons), and rated speed was 24.75kts with power increased to 25,000shp.
The Royal Navy received three of these Chatham class cruisers; three more were built for the Royal Australian Navy (Sydney, Melbourne and Brisbane). Of the British ships, Southampton had Brown-Curtis turbines driving twin screws, the others Parsons driving quadruple screws. Of the three Australian ships, the last was built locally, at Cockatoo Dockyard. Construction was delayed by the late arrival of material from England.
The Birmingham class
Three more ships were included in the 1911/12 programme (Birmingham class). They were very similar to the Chathams, but with nine rather than eight 6in guns (two guns on the forecastle side by side instead of one on the centreline, but a single gun aft on the centreline as in the earlier class). These ships introduced a new shorter, hence more easily manoeuvred, 6in gun (45-calibre Mk XII rather than 50-calibre Mk XI). The gun mounting also offered greater elevation. All had quadruple screws and were rated at 25,000shp. The Australians bought a fourth ship, which they built in Australia as HMAS Adelaide. Her hull and machinery were all made in Australia, the armament being imported from the United Kingdom.
In 1914 DNC wired the Australian government proposing a new design, the Brisbane design being four years old. Brisbane had eight 6in guns with 3in shields, but the newer Birmingham had nine, and the new light cruisers (Arethusa and Calliope classes) had spray shields rather than heavier protection to their guns.9 Six 36in searchlights should replace the four 24in of the earlier design. Fire control and torpedo air compressor arrangements should be modernised (the earlier design lacked both a fire control platform aft and a gyro adjusting room for torpedoes, and its compressor produced 2,600psi rather than 3,000psi air). The outer thickness of the side armour should be worked longitudinally rather than vertically. The steering gear should be covered by a curved (turtle) deck rather than by a flat deck plus side armour. Parsons reaction turbines (four shafts) should give way to Parsons impulse turbines on two shafts with geared cruising turbines, and twelve boilers all burning coal or oil should give way to six dual-fuel boilers and four oil-burning boilers (in fact the ship had twelve boilers, like earlier ‘Town’ class cruisers).10 There should be two sets rather than one of magazine cooling machinery. Fuel should be changed from 1,240 tons of coal and 260 tons of oil to 750 tons of coal and 600 tons of oil. This would meet Commonwealth requirements, but the change probably reflected both the greater efficiency of oil burning and the greater efficiency of geared cruising turbines. In view of experience, the captain’s accommodation should be moved from right aft on the lower deck to further forward on the upper deck. Wooden lower masts should give way to steel ones which could carry searchlights. Overall, space and weight for machinery and fuel would be traded for equipment and armament. Displacement and form would roughly match those of Brisbane, but internal arrangements would be quite different.11
The ‘Towns’ were the last classic cruisers the Royal Navy built before the end of the First World War, in the sense that they were intended for long-range independent deployment. During the war they served as the Grand Fleet’s scouts, in the ‘A-K Line’ deployed ahead of the battleships. This scouting line became a fixed feature of post-First World War Royal Navy fleet formation. These large cruisers were succeeded by a series of much smaller cruisers best described as super-destroyers (with armour) or destroyer-killers.
HMAS Adelaide in March 1939 after conversion to oil-burning. (Paul Webb)
HMS Lowestoft was unique in the Royal Navy Birmingham class in being completed with a tripod. A similar mast was fitted to HMS Birmingham in 1916–17, but Nottingham was probably lost (19 August 1916) unmodified. All three were given 3in (20 cwt) anti-aircraft guns, abaft the after funnel, in 1915. Neither surviving ship was fitted with a flying-off platform.
Above and below: HMS Nottingham (Birmingham class) is shown soon after completion. Note the paired forecastle 6in guns and the searchlight platform above the bridge.
As the Australians prepared to lay down their fourth cruiser in August 1915, Controller asked for armament alternatives using 9.2in and 7.5in guns. Controller thought, in view of ‘recent trend of opinion’ (presumably in connection with discussions of what became the Hawkins class) that the main alternatives (with the same weight as nine 6in) were three 7.5in and two 9.2in, of which the last could probably be ruled out. Controller asked DNC what four or five 7.5in guns would require, in terms of greater displacement, assuming all guns on the centreline and 300 rounds per gun (rather than 150), as the ships would probably fight at long range, with great waste of ammunition. DNC prepared tracings of both alternatives. A ship mounting four 7.5in guns would probably displace 1,100 tons more and would probably need another 2,500shp (but it seemed that no extra machinery weight would be involved). Adding another 7.5in gun would add another 460 tons, much of it for additional hull (240 tons). The four-gun ship would probably be 450ft long (vs 430ft for Birmingham), and the five-gun ship 465ft long. On 27,500shp both the enlarged ships would make 25.5kts. DNC’s very rough sketches showed single mounts in ‘A’ and ‘B’ and ‘X’ and ‘Y’ positions. A fifth gun would have been worked in at the after end of the forecastle at roughly the same height as ‘X’ gun, which was on a free-standing barbette. Nothing came of this exercise, but in effect this was the first approach to what became the ‘Improved Birmingham or Hawkins class. The most striking difference from the Hawkins was the use of enclosed gunhouses (as in the B designs described below) rather than open shields. The Australian designs also offered considerably lower speed.
The Australian design was updated as she was being designed, so that in effect she reflected ongoing changes in British cruiser design practice. In June 1915 Controller decided that she would have a tripod mast and director control, then being fitted to new British cruisers, and he asked DNO to decide whether her 6in guns should have the 30° elevation then being used. It was clear that if the ship was to be laid down, as desired, in August 1915, she could not embody an entirely new design, but would have to be largely a repeat Birmingham brought up to date. Her hull could be modified to provide more oil fuel, director fire-control and the new way of working in side armour (which would be HT steel instead of the nickel steel used in Birmingham). As completed, Adelaide had the tripod foremast, with spotting top and director, added to British cruisers in wartime. E-in-C thought that the new boilers would provide full power using Australian coal. Machinery repeated that of HMS Lowestoft, except for some auxiliaries, the middle (of three) boiler rooms burning oil only. During design, the two coal-burning boiler rooms were lengthened (total 4ft), adding 20 tons. The ship had to be lengthened slightly, as machinery could not be shifted aft, and any shift forward would cause a trim by the bow. Coal was omitted from the upper bunkers over the after engine room and from the lower bunkers abreast the middle boiler room, stowage being provided for 860 tons (instead of 1,155 tons in Birmingham) and for 500 tons of oil (instead of 236 tons).12 These were not quite the figures initially suggested. A 3in high-angle (HA) gun was added on the deckhouse aft, its magazine displacing the spirit room aft. The after control platform was enlarged to take a rangefinder, a provision made to fit the standard compass on the roof of the control platform.13 Late in November 1915 DNC estimated that the new Australian cruiser Adelaide would displace 5,557 tons, compared to 5,441.8 tons for Lowestoft.
Adelaide was completed in 1922, and in November 1923 the Australian Naval Board decided to modernise her to burn oil fuel only, to have her guns on the centreline, and to have central storekeeping. By this time the Australians planned to build new oil-burning cruisers in the United Kingdom. Converting Adelaide during her planned visit to England would give Australia an all-oil burning squadron by 1931 instead of by 1937, as originally planned. The Australians proposed replacing the existing twelve boilers with four larger ones. She would save considerably on complement during her remaining lifetime of fourteen years. The result would be more compact machinery spaces and reduced number and spacing of funnels. The Australians suggested that her armament could be rearranged on the centreline. The Australians hoped that the Admiralty could arrange favourable terms to justify having the work done away from Australia.
HMAS Adelaide, the modified Birmingham, as completed, with a new-type bridge and a short mainmast. Unlike earlier cruisers, she carried her director below and before her spotting top, rather than atop it. Note the concentration dials on foremast and aft. Nearsisters Birmingham and Lowestoft also had their bridges rebuilt, but they carried their directors atop their spotting tops, with a searchlight platform below the spotting top.
HMAS Adelaide, by then the last remaining British Commonwealth cruiser of pre-1914 design, as modernised in 1938–9 at Cockatoo Island. Her foremast has been rearranged to give her an HA director at its top, the 6in spotting top being brought lower down (the 6in director was not moved). Three 4in anti-aircraft guns were added, one on the centreline to superfire over the after 6in gun, and two at the after end of the forecastle. One of the two forecastle 6in guns was landed. The ship was converted to all-oil fuel, the two forward boilers and the forefunnel being removed. The sheet-anchor was removed, its hawse-pipe plated over. Adelaide recommissioned in this form on 13 March 1939, but the next month was laid up, her crew earmarked for the new cruiser Perth. She recommissioned in September 1939. (Photo by Allan C Green via State Library of Victoria)
Adelaide at sea in wartime, before her 1942–3 Sydney refit, and before she was fitted with radars. She still had her original curved gun shields.
A slightly later proposed modernisation would retain six oil-burning boilers, the two end funnels being eliminated and the remaining uptakes trunked into one broad funnel and one narrow one. Armament would be reduced to six 6in guns arranged roughly as on a ‘D’ class cruiser, three guns being landed. To allow for the superfiring gun forward, the bridge would be rebuilt roughly as on a ‘D’ class cruiser, cruiser-type remote control and plotting arrangements being installed. The foremast would not be altered. The foremost 6in gun would have to be moved forward (further forward than in a ‘D’ class cruiser). It had recently been decided to strengthen the anti-aircraft armament of light cruisers, so the single 3in HA gun would be replaced by a pair of 4in HA guns amidships on the forecastle deck, with two 2pdr pompoms (singles) forward (as in the ‘D’ class). The 6in magazines would remain as before. The ship would carry eight torpedoes for her two submerged tubes.
Before this modernisation could be carried out, DNC produced a series of alternative schemes in which an aircraft catapult was placed between the new (fatter) after funnel and the searchlight platform, the former No. 1 and No. 4 funnels being eliminated (as before). The seaplane crane was stepped at the searchlight platform. The fatter after funnel was moved somewhat abaft of the original position of No. 3 funnel. In the simplest version, two 4in HA guns would have been mounted on the centreline, one in place of the forefunnel and one on a platform abaft the two after wing 6in guns. The single 6in guns and the bridge would not have been moved. In a more elaborate alternative scheme, 6in guns would have been mounted where the two 4in were, two forward wing 6in being landed; the two 4in guns would have been on a searchlight platform between the two remaining funnels. That would have given a broadside of six guns, compared to the original five. In a third scheme, a 6in gun was placed in a superfiring position forward (as in the original DNC scheme), and the two 4in HA guns were in the waist to either side of the gap between the funnels. A more elaborate version had a modified bridge and two 6in guns in the waist (total of seven), the 4in HA guns being to either side of the gap between the funnels (or, alternatively, on the searchlight platform). A final version retained the two waist 6in aft, but had the superfiring gun forward and the gun in place of No. 1 funnel. This one was unique in having the catapult aft, at the break of the forecastle deck abaft the two remaining broadside guns. DNC’s sketches were dated 8 July 1926.
The project was evaluated at an Admiralty conference in December 1926. A key point was that the ship, which was slow by current standards, would be used in wartime for trade protection. Conversion to oil fuel made good economic sense. Moving guns to the centreline did not, because it did not add appreciably to the ship’s fighting ability. However, a catapult and aircraft would be very valuable. The best position would be between the after funnel and the after control position (searchlight platform). It would also pay to modernise the ship’s W/T systems, including installation of radio direction-finding. Late in 1927 the Australians decided to limit themselves to a conversion to oil burning, and even to retain the two forward boilers which had been earmarked for removal. Oil would replace coal previously stored in upper bunkers, these spaces becoming peace tanks.
Even this was not done; Adelaide was not modernised until 1938–9, when the two forward coal-burning boilers and the forefunnel were removed. The torpedo tubes were landed, the gun armament modified (the two side-by-side 6in forward replaced by one gun on the centreline and three 4in anti-aircraft [two in sided in the waist, a third superfiring over the after 6in gun] added, plus four 3pdr and eight Lewis guns), and fire controls rearranged. During 1942–3 the two waist 6in guns were replaced by four depth-charge throwers, one 6in replacing the 4in antiaircraft gun superfiring over the after 6in (for a total of seven such guns). All 6in were fitted with new square shields. The two 4in in the waist remained, and the ship had six Oerlikons (she retained the Lewis guns).
Adelaide as seen from USS Saratoga on 28 April 1944. Note the new-type squared-off 6in shields. She had a mix of US and British radars: a US SC at the foretop for air search, but a British Type 272 in its flat-sided ‘lantern’ on the lattice tower forward of her forefunnel, and Type 285 atop the HA director. She had six Oerlikons: two in the flat-sided extensions to her bridge structure, two abeam the middle funnel, and two at the after end of the searchlight platform near the stub mainmast. The four depth-charge throwers were mounted, two on either side, behind the bulwark abaft the break of the forecastle. The major modifications were carried out during a 1942-3 refit at Sydney.
When war broke out in 1914, Cammell Laird was building two comparable cruisers for the Greek Navy. They were taken over in 1915 as Birkenhead and Chester. They resembled the Chatham class, but introduced a new 5.5in gun, which figured in some other British warships, including HMS Hood and the aircraft carrier Hermes. It was probably chosen for compatibility with the 5.5in secondary battery planned for the French Bretagne class battleship Greece was then planning to buy. These ships had ten 5.5in guns (two abreast at the bow, two on the centreline in tandem aft) and had a six-gun broadside. Like the ‘Towns,’ they burned coal and oil. Four shaft Parsons direct-drive turbines produced 25,000shp (25kts). Chester was modified while under construction to burn oil fuel only, for 31,000shp (26.5kts).
The Spanish cruiser Reina Victoria Eugenia is generally described as nearly an improved Birmingham. She was almost certainly a Vickers design.14 Vickers also designed the next Spanish cruiser class (Mendez Nunez).15
HMS Birkenhead in 1919, shows wartime modifications: a tripod foremast with a director atop the enlarged spotting top, a flying-off platform (with, unusually, wind protection for the aircraft), concentration dials, and large searchlights. Note the vertical mainmast.
Above and below: HMS Chester was one of two cruisers under construction for Greece in 1914, taken over in 1915 for the Royal Navy. They were built by the Coventry Syndicate, intended to compete with Vickers and Armstrong by linking an armaments firm (Coventry Ordnance Works) with three shipbuilders and steel makers (Cammell Laird, John Brown, and Fairfield). Unlike the very similar Birminghams, she did not have paired guns on her forecastle. These ships also had differently-shaped gun shields. Birkenhead could be distinguished by her vertical mainmast. Note the bandstand (for a light anti-aircraft gun) before the bridge in the later photograph, which shows the 3in anti-aircraft gun aft, just abaft the after two waist guns. The ships were built with platforms, between the after pair of broadside guns and the aftermost 5.5in gun, for two 3in HA guns, but they were not available, and 3pdrs were mounted instead. Chester was unique among the ‘Towns’ in having all-oil-fired boilers; the others had mixed firing. The two ex-Greek ships could easily be distinguished from the other ‘Towns’ by their short mainmasts, only half the height of their foremasts.
In 1912 the new DNC Sir Eustace Tennyson d’Eyncourt drew the Board’s attention to the need to replace the large armoured cruisers then employed on foreign stations. At this time British policy was to match German cruisers on a two-for-one basis. The 1912 German Naval Law called for the construction of ten cruisers specifically for foreign service by 1920. If the Royal Navy built twenty such ships, it could have five each on the China, East Indies and Cape Stations, with five to spare for the West Indies or elsewhere as required.16 Chief of War Plans Captain Ballard also pointed out that the Germans planned to equip ten of their largest and fastest merchant ships as armed merchant cruisers in wartime, probably for distant service (given their large coal capacity).
The 2 July 1913 report on the design of a new large cruiser (B3) was labelled (probably by Third Sea Lord) ‘this design was got out as the result of rumours that the new German protected cruisers would be armed with guns of at least 6.9in (sic) calibre (probably larger). The First Lord [Winston Churchill] was anxious to have a design ready in case these rumours were true.’ The ship was described as a Light Cruiser for Atlantic Service. The ship was armed with eight 7.5in guns. DNC pointed out that this was much more powerful than that of any foreign cruiser. He held down cost by limiting displacement to 7,500 tons, on which he was unable to provide more than 4in of belt armour amidships (3in at the ends) with a 3in upper strake amidships. To achieve the desired speed (26kts) on moderate power (as on the new light cruisers, but using heavier machinery for greater reliability), he had to make the ship rather long (500ft); he also gave the ship relatively deep draft (20ft mean) for good seakeeping performance. Unlike existing cruisers, this one would have mounted her heavy guns in turrets: single ones at the ends, and the others in single turrets paired port and starboard. She would have had two underwater torpedo rooms (two tubes each), forward and abaft her machinery spaces.17
Third Lord was impressed by her power and good freeboard – ‘compared with the County class, it is remarkable what a powerful ship she would be for her size’. He also noted that if the existing 6in gun were retained, there would be little scope for improvement over the current Birmingham, although greater length and oil fuel might add another knot and perhaps two more 6in guns or two more torpedo tubes could be mounted.
Churchill was unhappy with the size and cost of the ship; on 4 August he wrote to First Sea Lord that ‘I question whether it does not go beyond anything required by German cruiser construction. I do not like the expression “for Atlantic service.”’ He asked DNC for a second design for comparison: smaller (6,500 tons) but faster (27.5kts on oil fuel), so in August DNC offered B4. It retained the end 7.5in guns but substituted six 6in for the rest: two in ‘B’ and ‘X’ positions, two abreast the bridge, and two on the centreline abaft the funnels. Length was 510ft to achieve the desired speed on the limited power. Alternatively, a 7,000-tonner could burn coal and oil as in the Birmingham class. Given the lower energy content of coal, she was larger (7,000 tons) and slower (26.5kts). As desired, the new design was expected to be considerably less expensive (£550,000 rather than £700,000, in each case exclusive of guns; the mixed-fuel ship would cost £590,000).
Nothing happened for the moment, presumably because the new destroyer-killer (see the next chapter) was more urgently wanted, but design work was approved. In concept, the big cruiser became the basis for the Hawkins class built during the First World War, the justification for which was almost exactly what DNC had written a few years earlier. Despite the German Fleet Law, the two for one policy was applied to produce the small fleet cruisers described in the next chapter.
There was also interest in a new low-performance ‘colonial’ cruiser, in effect the ancestor of the inter-war sloops.18 It died because British finances were badly strained simply to match German cruiser construction as desired. If the colonial cruiser was included in the two-for-one numbers, it detracted from effective British cruiser strength. If it was counted outside those numbers (which might be difficult to explain to Parliament), it stretched the badly extended budget. In 1912 the financial problem was bad enough that First Lord Winston Churchill was interested in an arms control agreement with the Germans, who were also in considerable trouble (but it could not be negotiated).
Design B3. The first sketch design (July 1913) showed a 7,400-tonner (500ft x 52ft x 20ft) with 26ft freeboard forward, armed with eight single 7.5in guns, four HA guns and four submerged torpedo tubes. A 30,000shp powerplant would have driven her at 26kts, and she would have burned only oil. Like later British First World War cruisers, she had only side armour, in this case 4in and 3in amidships. B3 was this size, with the same armament of eight 7.5in in single turrets – not the open mountings of the later Hawkins class, in effect continuations of this theme. The three boiler rooms were separated from two engine rooms by oil fuel stowage. (Norman Friedman)
Design B4 (August 1913). This version of the Atlantic cruiser was somewhat smaller (6,500 tons, 510ft x 53ft x 17ft 6in), armed with two 7.5in guns in turrets (like an armoured cruiser) and six open shielded 6in guns, like a light cruiser. Armour matched that of B3. B4 would make 27.5kts on oil fuel. An alternative version burning coal and oil would be larger (7,000 tons, 510ft x 54ft x 17ft 6in) and slower (26.5kts on 28,000shp). As in B3, each 7.5in gun would have 150 rounds, and each 6in would have 200, plus 300 per HA gun. (Norman Friedman)