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GERMAN MINE-LAYING CRUISERS.-Among the German warships now in custody at Scapa Flow there are two which invite special attention, representing as they do the sole example of originality in naval design that modern German construction has offered. The vessels in question are the Bremse and Brummer, officially rated as light cruisers, but possessing certain features that put them in a class by themselves. They are, in fact, high-speed mine-layers, and in the opinion of officers who have surveyed them they are uncommonly useful ships for this work. The Bremse (Anglicè Gadfly) was launched from the Vulkan yard, Stettin, at midsummer, 1916, and completed before the end of that year. The Brummer (Growler) was built by the Schichau yard, at Danzig, and completed in December, 1916. Full details of the ships have still to be published, but their dimensions, etc., are approximately the following: Length on waterline, 435 feet; beam, 431⁄2 feet; mean draft, 161⁄2 feet; displacement, 4150 tons. Machinery: Turbines of Parsons type, driving four screws; 14 Schulz-Thornycroft boilers for mixed firing. Maximum fuel supply, including oil, 850 tons. Designed horse-power 32,000 for a speed of 29.5 knots-on trial a mean of 30.2 knots is said to have been maintained for three hours. It appears, however, that on this occasion the ships were in a light condition, and on service their best reliable speed is said not to exceed 29 knots, though they can make 30 for short spurts. The scantlings are flimsy, judged by ordinary standards, and the limited coal supply presupposes a design framed with a special regard to operations in the Narrow Seas. This is borne out by the fact that the living quarters are very cramped, and the general arrangements for accommodating the crew of 370 are somewhat primitive. The same scrupulous regard for economy in

weight is revealed by an inspection of these vessels above water. In general they differ in appearance from other German light cruisers by having pronounced," clipper" stems, cased in funnels, and the minimum of superstructure. On the forecastle there is a 45-caliber 5.9-inch gun, with shield; a second gun of this size is placed between the first and second funnels on the boat deck; a third on the deckhouse abaft the main mast, with a blast screen projecting well over the quarter deck, where the fourth 5.9-inch gun is situated. This disposition of armament gives a broadside of four 5.9-inch guns, fire ahead being limited to one gun, and two guns training astern. On the boat deck between the third funnel and the mainmast are two 3.4-inch guns on high angle mounts. Above the conning-tower is a fire-control station with a rangefinder. The bridge carries a closed-in chart house constructed of splinter-proof steel, and above is a platform for two large searchlights. Each of the three funnels appears to have a steel glacis at the base as protection against splinters. The after bridge is open, with a single searchlight position above it.

The Bremse is reported to have carried 300 mines, but it is not easy to discover where such a large number could have been housed. Two pairs of rails are laid along the quarter deck for transporting the mines to the stern. It is stated, however, that special arrangements exist for releasing mines below water, the object being to deceive hostile scouts or aircraft with regard to the nature of the work on which the vessel was employed when under observation.

At the time of their completion the Bremse and Brummer were probably the fastest cruisers afloat. In addition to laying mines, they seem to have been used occasionally for raiding convoys in the North Sea, and information from enemy sources credits these two vessels with the principal rôle in the action of October 17, 1917, off the Norwegian coast, when the British destroyers Strongbow and Mary Rose were lost, together with a number of merchantmen in their convoy. News of the convoy's position and course having been received by wireless from a scouting Zeppelin, the Bremse and Brummer, with several destroyers, at once left the Baltic and succeeded in intercepting their prey. Steaming at high speed, and using their 5.9-inch guns, the cruisers were able to make short work of the two destroyers and the unarmed merchantmen, after which they withdrew before pursuit could become effective.

It is rather doubtful whether further ships of this type exist. Two other units are said to have been built, viz., Hummel (Bumble-bee) and Wespe (Wasp), but the report cannot be confirmed. The only ships previously built in Germany for the special duty of mine-laying were the Nautilus and Albatross, launched in 1906 and 1907 respectively. They displace 1950 to 2200 tons, and can steam at 20 knots. Another of the few existing vessels of this type is the Swedish mine-layer Claes Fleming, completed in 1915. She is of 1748 tons, and has a speed slightly above 20 knots. In our own navy it has not been deemed necessary to design ships specially for minelaying, which during the war was carried out by vessels of almost every description, from battleships to submarines. Several flotilla leaders and a number of the larger destroyers were temporarily fitted up as mine-layers. The Abdiel, a flotilla leader launched at Birkenhead in 1915, was attached to the Grand Fleet as a "flying mine-layer," and in this capacity made things very unpleasant for the retreating German fleet after the Battle of Jutland. At the other end of the scale is the battle-cruiser Courageous, which is equipped with gear for sowing mines. Of the six old cruisers of the Apollo class, that were reconstructed as mine-layers before the war, several were scuttled as block ships on the Belgian coast, and the remaining vessels are now out of service.-The Engineer, 4/18.

A dispatch from Berlin states that Baron Gemingen, nephew and successor of Count Zeppelin, intends to attempt to cross the Atlantic in the Zeppelin dirigible known as the Z-72. The armistice conditions prevent the completion of the airship, on which about two weeks' work is required.

The cruiser is 715 feet long with a diameter of more than 60 feet. She will have seven motors of 240 horse-power each. Her gas capacity will approximate 2,000,000 cubic feet. Baron Gemingen estimates that the distance from Friedrichshaven to Washington can be covered in 68 hours, depending upon the weather. It is asserted in Zeppelin circles that under favorable conditions the new airship could make the round trip without landing.-Aerial Age Weekly, 5/5.

GREAT BRITAIN

H. M. BATTLE CRUISERS "REPULSE" AND "RENOWN."-In the early months of the war the need for additional battle cruisers of very high speed and armed with big guns, became more and more apparent, both to deal with raids on our coasts by enemy battle cruisers and with possible raids further afield. The value of this type of ship was also most clearly demonstrated at the Battle of the Falkland Isles. The British Admiralty therefore decided on the advice of Lord Fisher in January, 1915, to lay down a new type of cruiser, of great length and limited draft, and of very much increased speed, to meet this need. The battle cruisers Repulse and Renown were therefore ordered, the former from Messrs. John Brown and Co., Ltd., Clydebank, and the latter from the Fairfield Shipbuilding and Engineering Company, Ltd., Glasgow, at the beginning of January, 1915. Both ships are alike in every respect, and were the largest and most noteworthy warships added to the British fleet during the war. The vessel was successfully launched on January 8, 1916.

The Repulse left Clydebank Yard, a commissioned ship, on August 14, 1916, or in 192 months from the date when the requisite information was received by Messrs. John Brown and Co., and the Fairfield Company to proceed with the detailed drawings in conjunction with the Admiralty officials, and to send out orders for material.

On a preliminary run to Ailsa Craig immediately after the vessel reached the Tail-of-the-Bank, the machinery was gradually worked up to 107,000 s. h. p., and on the following day, during the four hours' trial, the mean horse-power developed for the first two hours was 117,000 and for the subsequent two hours 121,000. Further trials were carried out in the Firth of Clyde when the vessel was loaded to about 30,000 tons' displacement, and over a measured course a speed of nearly 32 knots was attained, the machinery developing over 119,000 s. h. p.

The Repulse was the largest and most powerful warship in the world at the time, her length being 790 feet, breadth 90 feet, and depth to upper deck 41 feet, with a normal displacement of about 27,000 tons. The great length in proportion to depth gives the appearance of a large type of light cruiser rather than a battle cruiser, but on closer examination, the two barbettes, each having a pair of 15-inch guns highly mounted for ahead attack, equal in power to those fitted in the super-dreadnoughts, and a similar pair of 15-inch guns mounted in a turret aft, give a strong impression of the great size of the vessel. These guns are each arranged to train through 150 degrees on either side of the middle line, and give a concentrated broadside fire, equal to 75 per cent of that of the latest battleships, thus making the vessel very powerful in attack.

The secondary armament consists of seventeen 4-inch B. L. guns, 15 of these being arranged on triple mountings, two sets on the conning-tower platform level on each side of the forward funnel, and three sets on the

middle line on the flying and the shelter deck level. The single 4-inch B. L. guns are placed on the shelter deck, on each side abreast of the conningtower, with a training sweep of 155 degrees. Two 3-inch high-angle guns are mounted on pedestals on the shelter deck abreast after the funnel, four 3-pdr. Q. F. guns on the same deck abreast the forward funnel, and five machine guns. In conjunction with these guns, there are fitted on platforms attached to the funnels six 36-inch single searchlight projectors, two similar projectors on the compass platform, and two 24-inch single signalling searchlights at the after end of the conning-tower platform. The vessel is fitted with two 21-inch under-water broadside torpedo tubes, placed in a compartment between the platform and the lower deck forward of the forward magazine; stowage is provided for ten torpedoes.

The conning-tower is of oval form, having armour 10 inches thick, with an inner gun control tower with revolving hood and armored rangefinder. An armored torpedo control tower, with revolving hood and rangefinder for controlling the fire of the torpedoes, is placed on the after flying deck. In addition to these towers, which are situated in commanding positions, there are fitted on the foremast high above the navigating platforms a spotting top, a 15-inch gun director platform, and a 4-inch gun director platform; also a director platform and rangefinder for anti-aircraft guns on the main mast; and a signal distributing station in the armored house on the shelter deck under the main conning-tower. The intelligence and de-coding offices are in similarly protected houses placed on the forecastle and shelter decks respectively.

The vessel is minutely sub-divided, having six boiler rooms, four engine rooms, and a cellular double bottom, extending from the middle line around the side and under the main or protective deck. A longitudinal bulkhead forming the boundary of the oil tanks extends alongside the engine rooms, boiler rooms and magazines, with an inner bulkhead forming an air space for the extent of the boiler rooms.

The armor consists of a main belt about 9 feet 6 inches wide extending from abreast the after barbette to forward, and aft of these positions for a further length of 84 feet forward, and 62 feet aft of reduced thickness. The armor belt is finished off by a transverse armor bulkhead forward and aft, and two additional transverse armor bulkheads are fitted to resist end on fire. The maximum thickness of the armor of the barbettes is 7 inches. The forward conning-tower armor is 10 inches thick, and the torpedo control tower 3 inches thick. The main or protective deck is 2 inches thick on the slopes with an additional strake of 2 inches high-tension protective plating in the vicinity of the water-line. The lower deck aft is 31⁄2 inches thick over steering gear.

Structurally, the vessel is very substantially built, the shell plating of the topsides and the forecastle deck consisting of two thicknesses of high tensile steel of a total thickness of 11⁄2 inches, and the bottom plating is generally 1 inch thick, tapered at the ends.

The chart house, admiral's and captain's sea cabins, navigating officer's cabin, are situated on the platform and shelter deck forward. The Repulse was completed as a flagship, the admiral's cabins being in the deck house on the after end of the forecastle deck. The ward room, captain's cabins, and principal officers' accommodation, offices, etc., are on the upper deck aft. The gun room and junior officers' cabins are placed on the main deck aft of midships. The mess decks for the crew are on the upper deck amidships and forward, and on the main deck amidships; the sick bay and operating rooms, and lavatories in connection therewith, are on the upper deck forward; the wash places for crew are on the main deck abreast the boiler rooms and forward.