German Ordnance.

A = Over all.
B = Rifled Bore.
C = Powder Chamber.

Name, Nature, and Classification.		Calibre.	Length.
Name, Nature, and Classification.		Calibre.	A	B	C
		In.	In.	In.	In.
Krupp’s pattern steel Breech-loaders.
30½ cm.	hooped	12	264	172	54.7
28 cm.,	hooped and tubed	11.15	240	171	46.1
28 ”	hooped	10.34	240	171	46.1
26 ”	long hooped	10.24	225	138.5	55.3
26 ”	short ”	10.24	205	128	42.1
24 ”	long ”	9.27	206	136	38.4
24 ”	short ”	9.27	185	115.4	38.4
21 ”	long ”	8.24	185	124.6	33.7
21 ”	short ”	8.24	154	96.8	31.4
17 ”	long ”	6.8	167	107.5	40.8
17 ”	short ”	6.8	134	92.0	24.7
17 ”	short, light hooped	6.8	136	92.7	25.7
15 ”	long hooped	5.87	152	105.8	27
15 ”	short ”	5.87	129	86.8	28.5
15 ”	tubed	5.87	128	86.8	23.5
12 ”	hooped	4.74	115	85.7	14.7
8 ”	heavy	3.19	76	57.6	8.4
8 ”	light	3.19	76	57.6	8.4
8 ”		2.20	62	45.9	7.7
4 ”		1.54	69	54.7	9

D = Number of Grooves.
E = Twist of Rifling.
F = Gun, including Breech-block.
G = Breech-block.

Name, Nature, and Classification.		D	E	Weight.
Name, Nature, and Classification.		D	E	F	G
			Calib.	Lbs.	Lbs.
Krupp’s pattern steel Breech-loaders.
30½ cm.	hooped	72	45	78,980	2,970
28 cm.,	hooped and tubed	36	70	60,500	2,244
28 ”	hooped	36	70	60,500	2,244
26 ”	long hooped	36	50	48,400	1,980
26 ”	short ”	36	50	39,600	1,980
24 ”	long ”	32	70	34,100	1,375
24 ”	short ”	32	65	31,900	1,375
21 ”	long ”	30	68	21,450	858
21 ”	short ”	30	59	19,800	858
17 ”	long ”	30	45	12,320	495
17 ”	short ”	30	59	11,000	484
17 ”	short, light hooped	30	45	7,590	411
15 ”	long hooped	24	45	8,800	319
15 ”	short ”	24	68	7,700	319
15 ”	tubed	24	65	7,040	391
12 ”	hooped	18	60	3,014	178
8 ”	heavy	12	46	714	64
8 ”	light	12	46	650	64
8 ”		12	46	500	55
4 ”		12	70	156	9

A = Preponderance.
B = Carriage.
C = Slide.
D = Height of Axis of Bore above Deck.
E = Chilled.
F = Common.

Name, Nature, and Classification.		A	Carriages.			Projectiles.
			B	C	D	Full Weight.		Bursting Charge.
			B	C	D	E	F	E	F
		Lbs.	Lbs.	Lbs.	In.	Lbs.	Lbs.	Lbs.	Lbs.
Krupp’s pattern steel Breech-loaders.
30½ cm.	hooped		51,040		102	715	609.5	8	22
28 cm.,	hooped and tubed		24,200		102	561	477	7.7	25.3
28 ”	hooped		24,200		102	561	477	7.7	25.3
26 ”	long hooped		16,500	18,075	67	411	367	5.28	17.27
26 ”	short ”		8,849	13,831	48	411	367	5.28	17.27
24 ”	long ”		8,349	13,831	48	308	261	3.19	15.4
24 ”	short ”		5,082	8,756	39	308	261	3.19	15.4
21 ”	long ”		4,290	6,556	40	216	175	2.75	10.45
21 ”	short ”		4,114	6,402	42	216	175	2.75	10.45
17 ”	long ”		2,772	4,576	41	123	112	1.21	9.24
17 ”	short ”		2,321	3,400	33	121	99	1.21	6.6
17 ”	short, light hooped		2,156	2,068	34	117	112	1.32	5.94
15 ”	long hooped	16.5	2,057	3,806	38	78	78	7.7	6.5
15 ”	short ”	48.4	1,947	2,530	34	78	61	7.7	4.4
15 ”	tubed	62.7	1,908	2,640	35	78	61	7.7	4.4
12 ”	hooped	22.2	1,595	2,750	47	38	33		2.48
8 ”	heavy	15.4	1,100		33		9.5		.6
8 ”	light	14.7	880		35		9.5		.6
8 ”		14	246	246	35		6.7		.6
4 ”			Turntable.				125		.28

A = For Steel and Chilled Shot.
B = For Common Shell.
C = Saluting.
D = Penetrating Power.

Name, Nature, and Classification.		Powder Charge.			D
Name, Nature, and Classification.		A	B	C	D
		Lbs.	Lbs.	Lbs.	In.
Krupp’s pattern steel Breech-loaders.
30½ cm.	hooped	158.4	158.4		16.4
28 cm.,	hooped and tubed	132	132		14.4
28 ”	hooped	132	132		13.3
26 ”	long hooped	107.8	107.8	17.6	13
26 ”	short ”	107.8	107.8	17.6	11.5
24 ”	long ”	59.4	44	17.6	11.27
24 ”	short ”	59.4	44	17.6	10.05
21 ”	long ”	41.8	30.8	13.2	8.9
21 ”	short ”	35.2	26.4	13.2	8.55
17 ”	long ”	26.4	22	6.6	7.25
17 ”	short ”	17.6	14.3	6.6	7.33
17 ”	short, light hooped	16.5	16.5	6.6	7.88
15 ”	long hooped	18.7	15.4	4.4	6.7
15 ”	short ”	13.2	12.1	4.4	6.58
15 ”	tubed	13.2	12.1	4.4	5.6
12 ”	hooped	7.7	4.62	2.31	5.6
8 ”	heavy		1.1	1.1
8 ”	light		1.1	1.1
8 ”			.98	1.1
4 ”			.41

E = Chilled.
F = Common.

Name, Nature, and Classification.		Initial Velocity.		Working Effect.
Name, Nature, and Classification.		E	F	E	F
		Ft.	Ft.	Foot Tons.	Foot Tons.
Krupp’s pattern steel Breech-loaders.
30½ cm.	hooped	1,591	1,623	12,584	11,176
28 cm.,	hooped and tubed	1,515	1,640	8,960	8,931
28 ”	hooped	1,515	1,640	7,210	8,931
26 ”	long hooped	1,587	1,640	6,802	6,876
26 ”	short ”	1,430	1,387	4,835	6,466
24 ”	long ”	1,502	1,391	4,625	3,511
24 ”	short ”	1,469	1,355	4,625	3,327
21 ”	long ”	1,476	1,394	3,275	2,348
21 ”	short ”	1,312	1,394	2,587	1,970
17 ”	long ”	1,548	1,525	1,944	1,809
17 ”	short ”	1,279	1,279	1,399	1,127
17 ”	short, light hooped	1,325	1,341	1,437	1,411
15 ”	long hooped	1,623	1,615	1,431	1,172
15 ”	short ”	1,477	1,591	1,030	1,072
15 ”	tubed	1,358	1,446	1,001	888
12 ”	hooped	1,476	1,230	584	345
8 ”	heavy		1,118		84
8 ”	light		1,118		84
8 ”			1,135		66.5
4 ”			1,837

GUNS.

Smooth-bore guns are now entirely obsolete. The rifled ordnance is constructed entirely on the Krupp system of steel breech-loaders. Although the Krupp system taken as a whole is represented by three distinct types of guns corresponding to different developments of the breech-closing mechanism, but one, the latest development, appears in the armament of war vessels. There are also two types corresponding to the building of the body of the guns, but these are quite similar, the difference being simply in the use of a number of thin hoops in the later guns to replace a few thick hoops in the earlier construction. All guns except the 9-pdr. bronze breech-loader are built entirely of steel. The broadside-guns of medium calibre are divided into two classes, the long and the short gun, the latter being intended for vessels whose beam or displacement will not permit the use of the longer and heavier gun. The short gun of one calibre is, however, in all cases a more powerful gun than the long one of the next lower calibre.

All naval guns except the converted 15-cm. calibre have a steel body strengthened by hoops. The converted gun has no hoops, it having been strengthened by boring the body up to form a casing, which was shrank over a steel tube. This tube extends from the breech-block to about one calibre beyond the muzzle.

The 30½-cm. gun has three tiers of hoops, the 26-cm. and 24-cm. guns have two tiers, and the remainder one tier. The trunnions in all cases are in one with one of the hoops. The hoops are prolonged forward of the trunnions, diminishing rapidly in thickness.

The bore is rifled on the multigroove plan, the rifling differing slightly according to the projectile which the gun was intended to fire. Formerly all projectiles were provided with a zinc rifling-jacket, and for such, a smooth shot-chamber was necessary, the rifling stopping at its forward end. The French style of copper bands being now used, the rifling is continued through the shot-chamber to the opening of the powder-chamber. With the zinc jackets, the grooves decreased in width from the breech towards the muzzle in order to keep a firm grip on the easily yielding metal throughout the bore. With the copper rotating belt the grooves are of the same width throughout.

The powder-chamber is cylindrical, and about the depth of a groove wider than the diameter of the bore across the grooves. It is connected with the shot-chamber by a short cone which brings up the rear rifling-belt of the projectile in loading. In general the powder-chamber is concentric, but there are two calibres (26 cm. and 15 cm.) in which it is eccentric, its axis being slightly above that of the bore. The powder-chamber ends in a gas-check seat, which is coned and slightly countersunk forward to receive the Broadwell gas-check.

Just behind the gas-check seat is the transverse breech-block seat, three of its sides being flat, and the rear or bearing side being hollowed out to a semicircular wall.

The bore of the gun is continued straight through the breech, forming a loading-hole in rear of the breech-block.

Broadwell Gas-Check, Seat, and Face-Plate.

The breech-blocks of all guns traverse the breech transversely, and they are all single blocks. There are two patterns, differing only in the shape of the rear portion, one being cylindrical and the other flat. The latter type is found only in guns where formerly a double wedge (the Kreiner system) was used, so that in changing to the single wedge there was not metal enough left in rear to permit hollowing out that face.

The breech mechanism consists of the breech-block, the covering-plate, the transporting-screw, the locking-screw, the curb-chain, the gas-check, the face-plate, and the vent.

The breech-block is a heavy solid steel block, generally cylindro-prismatic, sometimes square in section. The rear of this block is not parallel to the front, but inclined in wedge shape at an angle of 1° 55´. The prismatic part of the block is slightly wider than the diameter of the cylindrical part, forming at the junction an edge at the top and bottom, which serves as a guide for the block in sliding in and out. The block is much shorter than the width of its seat, so that it is not necessary to entirely withdraw it in order to unmask the bore. Except for special guns, the breech-block always draws out to the left, and its left end has bolted to it a steel plate of the same size, called the covering-plate.

This plate merely serves as a holder for the locking and moving mechanism. With light breech-blocks a shackle-handle bolts to the centre of this plate for withdrawing the block. With the heavier calibre, where the block cannot be moved by hand it is worked in and out by a screw.

This transporting-screw lies along the top of the block from end to end, revolving in journals; one half of the circumference only lies in the block, the other half, projecting, takes in a half-female thread in the upper wall of the gun. The end of the screw projecting beyond the covering-plate is squared so as to permit a crank to be shipped. In this manner, by revolving the screw, the block is worked out or in.

Breech-Block (front).

Breech-Block (rear).

The locking-screw, as its name implies, serves to lock the block. It is on the rear part of the block, placed like the transporting-screw only half in the block, so that its thread will take in the gun-wall. Besides locking the breech, it forces the block close home and releases it, taking the strain from the transporting-screw, which might otherwise be bent by the shock of firing. The threads of the locking-screw, except the first or outer turn, are cut away for one third of the circumference, so that the action of locking and unlocking is similar to that of the French mechanism. The outer thread is left full to cover the joint when the breech is closed. A stop on this thread limits the revolution of this screw by catching on the covering-plate, so that when brought up at one point it shows the breech to be locked, and at the other that it is unlocked. The same crank is used to work the transporting-screw and the locking-screw.

The curb-chain is a short chain which limits the withdrawal of the block and prevents it from being pulled all the way out. One end is fast to the lower end of the covering-plate, and the other to the gun just underneath.

The Broadwell gas-check is a steel ring, fixed in the gun semi-permanently; that is, it does not move with the breech-block, although it may easily be knocked out. This ring is coned around its outer edge, which is turned up cup-shaped. The inner side of this cup-rim is shaped in gutter form, in order to make the best distribution of the gas pressure. The whole middle is cut away, of the same size as the powder-chamber, so that the charge can be passed through it. Three concentric scores are cut around the back of the check, the idea being to break the force of any gas that may escape by making it suddenly expand and contract as it forces its way by them. The rear of the gas-check projects slightly beyond the rear of its seat.

The face-plate is a steel disc attached to the forward face of the block, and forming the bearing surface for the gas-check. This plate has a slightly greater diameter than the height of the block. It fits into a seat cut for it, and is prevented from turning or falling out by a little dowel and a spring-catch on the upper part of the block. As this plate wears, thin washers of brass or copper are fitted behind it. The rear face of this plate is fitted with grooves, which, from the shock of firing, attach and hold fast these washers. Each gun is provided with a spare face-plate and gas-check, and aboard ship a reserve gas-check is supplied in addition for each pair of guns.

Vent-Bush and Vent Gas-Check.

Vent-Piece, showing Hook
for Head of Primer.

The vent is pierced in a steel vent-bush, which traverses the breech-block in the axis of the bore. The forward part of the vent is provided with a simple arrangement for preventing the escape of gas. A small vertical chamber contains a steel ball, which in its normal position covers the vent completely. When the primer is fired, the flame drives the ball up and passes on to the cartridge, but the back-flame also striking the ball drives it down over the mouth of the vent again and seals it. The rear end of the vent-bush is provided with a hook for holding the primer in place for firing. The hook itself completely covers the mouth of the vent, having a slit for the friction-bar of the primer. It is so shaped on the rear side that the back-flame through the vent throws it back. A small knob is fixed to it for convenience in hooking and unhooking. This hook is so screwed on the end of the vent-bush that it may be easily removed, and after removing the vent-bush itself may be easily backed out of the block. Aboard ship each gun is provided with two reserve vent-bushes.

The vent of the 8-cm. boat-gun is a right-angled one, pierced from the face of the block to its centre, and then, turning at right angles, passes up through the block and the wall of the gun. The joint at the top of the block is made tight by copper bearing surfaces. This vent has neither the ball for checking back-fire nor the primer-hook.

All guns except boat-guns are provided with a loading-box. This is a hollow steel cylinder fitting in the loading-hole. When in place, its forward end rests against the back of the gas-check, while the rear end comes to the end of the cascabel, being provided with steadying hooks that hook into the cascabel. The charge being entered in this loading-box is pushed directly home. The boat-guns have no loading-box, but instead the right end of the breech-block is prolonged and a loading-hole is cut through it.

The transporting-screw removes the block by about one and three quarter turns, as it has a very sharp pitch. Below the calibre of seventeen centimetres there is no transporting-screw, the locking-screw serving both purposes.

CARRIAGES

Broadside-Carriage for the Heavy and Light 8-cm. Guns.

This carriage is of the simplest construction. It consists of two plate-iron brackets connected and braced by through-bolts. It is mounted on two trucks forward, and a single broad wooden rear chock. For the light gun, breeching-holes are made in the forward part of the carriage, the ends of the breeching shackling to bolts in the ship’s side; for the heavy gun, the ends of the breeching shackle to the brackets, the bight being shackled under the centre of the port. These carriages are provided with breast-pieces for training, a training handspike, and tackles for running out and in. The light gun is provided with the ordinary elevating-screw, but the heavy one has a rack, pinion, and hand-wheel for rapid and extreme elevating. The pinion is held by a compressing lever. The trucks are of cast-iron with brass journals.

Broadside-Carriage for 8-cm. Boat-Gun.

Broadside-Carriage for 12-cm. and 15-cm. Guns.

This carriage consists of two plate-iron brackets, a forward transom, and two bottom plates. The trunnion-holes, as in all other carriages, are broadened by brass journal-plates. It rests on two cast-iron trucks forward, and in rear on a rear chock. A swivel roller is fixed in the middle of this chock with a forked attachment, by which a trail handspike may be shipped at an angle of about 45°. Heaving down on this handspike lifts the rear of the carriage on the roller, and the lateral movement permitted to the handspike enables the carriage to be steered out. Bolted to the forward transom is a fork which, projecting forwards, forms a pivoting point. In running out it is necessary to run the end of this fork (which has jaws for the purpose) against the bolt provided for it to pivot about. The rear chock is of plate-iron with a brass shoe.

The recoil is governed by what is called the Brookwell apparatus. This consists of a drum with a friction-band controlled by a lever at the left side. Turns of a breeching are wrapped around the drum, the ends being fast to it, and the bight shackling to the pivot-bolt in the centre of the port. In running out, cranks ship on the ends of the axle, and the breeching is in this manner wound on the drum by heaving down the brake, the friction-band is tightened on the periphery of the drum, thus easing the recoil. The power of the cranks is not sufficient to enable the gun to be run out by this arrangement, and side tackles have to be used. A reserve breeching is also kept rove, through breeching-holes in the forward part of the brackets.

Brookwell Broadside-Carriage.

The ordinary elevating-screw is used, working in a screw-box through the rear transom.

Slide-Carriages.

Slide-carriages are used with all guns of seventeen centimetres and upwards. These carriages are classified as either carriages with fixed or with movable slides; and each of these is subdivided into slides for firing from ports or over the rail. As the necessities have arisen for modifications, changes have been made in the details of these carriages and slides, although the general form has remained the same. As a rule, the pivot centre of the slides is either in the middle of the gun-port or close to the spirketing, always forward of the body of the slide.

Slide and Carriage for Short 24-cm. and 21-cm. Guns,
Pattern 1868.

The carriage-brackets are of the double-plate pattern, having a wrought-iron frame, and, connected by a bottom plate, forward and rear transoms secured by angle-irons. The carriage rests on rollers, both front and rear being on eccentric axles. The rear rollers are thrown into action by means of levers, and the act of lifting the rear of the carriage on the axle throws the front rollers into action. The bottoms of the brackets are shod with brass friction-plates for travelling on the slide. The elevating-gear consists of a metal rack and pinion. The front edge of the rack is kept against the pinion by a smooth roller against the rear edge. The pinion is worked by means of a lever and capstan-head outside of the bracket. A screw-brake holds the gear fast, it being worked by a lever. When this lever is thrown up the brake is off, when down it is set fast. The carriage is run out and in by means of tackles, but one tackle being used on each side. The carriage-block for this tackle is a double block working on a hinge midway on the forward end of the bracket. The compressing arrangement is the Elswick pattern ([see English Ordnance]) of iron bars and plates worked by rocking levers, and having a compressing lever outside of one bracket and a regulating lever outside of the other, the former being provided with a trip for automatic compression. The carriage has also front and rear holding-down clips bolted to the bottom plate.

Carriage and Slide for 21-cm. Gun.

Slide Tackle-Block.

Hinged Carriage
Tackle-Block.

Buffer.

The slide consists of two heavy double T-iron rails bent in front. They are connected by three bottom plates, and an angle-iron joining the front ends. Seven compressor-bars are laid in the centre of the slide, and from the middle to the rear bottom plate a wooden platform is laid. Two railway buffers are provided at either end for taking up the shock in violent running in or out. The fighting pivot-flap is a stout bar hinged to the front end of the slide so as to have vertical motion; a single eye in the end enters the jaws of the pivot-shackle in the centre of the port. The slide rests on front and rear rollers, the front ones being permanently in action and the rear ones, on eccentric axles, being thrown into action by levers. The 24-cm.-gun slide is provided with a windlass for running in and out and training. This consists on each side of the slide of a pinion turned by crank and gearing in a spur-wheel which carries the bollard. The out and in tackles are carried directly to the windlass. For training, the fall of the tackle is rove through a leading-block hooked just forward of the windlass to give a fair lead. Housing pivot-flaps are hinged at each end of the slide, which drop and key over bolts projecting from the deck. Bow and stern pivot-slides are provided with transporting rollers, which ship just inside the traversing rollers and work on eccentric axles. There are three traversing circles on the deck: the front and rear are for the front and rear rollers, the centre one holds the slide when it buckles from the position of the gun on it.

Centre Pivot-Bolt.

Centre-port Pivot-Bolt.

Eccentric Axle and
Handspike Socket.

Windlass for Training
and In Tackles.

Front Housing-Bolt.

Carriage and Slide for the
Long 21-cm. Gun, Pattern 1869.

This pattern only differs from the former in being heavier braced. The fighting pivot-flap is not hinged, but is three-armed and secures to the slide by shackle-bolts. Shifting slides are provided with a third pair of rollers just forward of the centre of the slide, which are thrown in action when pivoting around the rear pivot-bolt; from their position, they lift the forward rollers clear of the deck when in action.

Cabin-Carriage for the Long 21-cm. Gun.

Training-Gear for Cabin-Carriage.

Owing to the cramped space for training bow and stern-guns, and the necessity for rapid training, geared train-wheels are used in this slide in place of the regular training-tackle. A sunken rack in the deck, midway of the slide, forms the track for a heave mitre-wheel, the axle of which cants up to the rear and is held by a journal in the rear transom. On its outer end a large spur-wheel gears in an endless screw which is revolved by cranks. The axle of this endless screw also carries the windlass-drum for aiding the in and out tackle; it is therefore necessary that the screw and spur-wheel can ungear. For this purpose the main axle is in two parts, the rear one carrying a heavy sleeve which is free to revolve, and has a female screw-thread worked in it and handles outside for turning. A male screw-thread is worked on the forward axle, and the end is also slotted to allow a tenon on the after axle to fit it. By revolving the sleeve, then, the rear axle is pushed to the rear through the rear journal, thus releasing the spur-wheel from the screw. In this carriage there is also a slight modification of the arrangement for jamming the elevating-gear. There is also but one compressor-lever working as a ratchet-lever in a ratchet-wheel on the compressor-axle. The slide-rollers of this type are on concentric axles in action permanently.

Slide Rear Roller, showing Manner of
Pinning the Roller in Action.

Slide-Carriage for the Long 21-cm. Gun,
Pattern 1873.

(Plan.)

(Section.)

Stirrup on Carriage for Endless Chain.

Rear of Slide, showing
Training-Gear, Chain-Roller,
Crank, and Recessed Rear
Roller for taking Recoil.

Axle-Grip for Putting Training-Gear in and out of Action.

Training-Axle and Rear Chain-Axle with Gearing.

Front Chain-Roller.

Recoil-Hook and
Countersunk Traverse.

This pattern differs from the 1868 one in having a higher slide and lower carriage, gearing for training the gun, and the Scott endless chain for running out and in. The forward rollers work automatically as in the former pattern. The levers for the rear rollers ship inside the brackets, and heave down instead of up for putting in action. The chain-clamp consists of a stirrup moving vertically, which carries the chain freely when down, but when hove up by a lever jams the links in a toothed rack. A stop on the outside of the brackets holds the stirrup when lifted by the lever. An endless chain travels on each side, but only one is used, the other one being kept as a reserve. The slide-rollers are constantly in action, and are arranged to divide with the pivot-bolt the strain of the recoil. To accomplish this the circle, or racer, is made quite narrow, and the middle part of the roller is hollowed out so as to grip both sides of it. The training-gear is similar to the one for the cabin-carriage, except with regard to connecting the screw and spur-wheel. The screw is worked on a loose sleeve, which at its left end is toothed. A movable toothed gripe revolving with the axle, but free to move along it, is brought to the sleeve or retracted from it, as desired, thus revolving the screw or leaving it free on the axle. The gripe is moved by a lever. The screw-shaft is revolved by means of pinions at each end, which gear in large spur-wheels. The axle of these spur-wheels carries, also, inside the slide, the rear rollers of the endless chain. Outside of the spur-wheels are the cranks. By this arrangement, the same gearing runs the carriage in or out and trains the slide. If the gripe be backed clear of the screw-sleeve, the training-gear is thrown out of action, and by heaving up the stirrup the carriage is clamped to the chain and run in or out. Reversing these processes, the carriage is thrown out of action and the slide is trained to the right or left.

Slide-Carriage for the Short 26-cm. Gun, Pattern 1875.

Gearing for Short 24-cm. Slide.

This pattern is similar in general to the one just described. The forward carriage-rollers are automatic eccentric ones, the rear work by levers, the Scott chain-gear is used for running in and out, and similar training-gear is used. The pivot-bolt does not bear any of the shock of the recoil, it being taken up partially by the slide-rollers and partially by a cramp fixed to the forward end of the slide and travelling in an undercut circle on the deck. The slide inclines to the rear to facilitate running out.

Hydraulic Recoil Cylinder and Piston.

The main difference between this carriage and the others is the use of a hydraulic recoil cylinder working in a manner quite different from the English style. The cylinder itself is of steel, and is hung on trunnions to the carriage. The piston-rod runs completely through it, and is secured at each end of the slide. Both ends of the cylinder are closed by cast-iron heads with stuffing-glands. The forward head, being the one which receives the violence of the recoil, is secured by a heavy iron brace which fastens to the cylinder trunnions. The cylinder is filled with glycerine, the filling and drip holes being both at the rear end. It rests and slides on a bed fixed along the middle of the slide. The arrangement for checking recoil, and also for governing violent movements of the carriage, is contained in the piston-head. This head is made up of two discs which are bolted together, the interior face of each being hollowed out so as to form a chamber in the piston-head. Four holes are bored through each disc into the chamber, but they are not in line, the hole in one disc coming opposite a blank in the other. Four small valves close the inner ends of the forward holes, and these valves are secured to a plate which is free to move back and forth in the little chamber, and thus open or close the holes. A rod from the back of this plate passes through the hollow rear end of the piston-rod, and seats against a carriage-spring on the rear transom of the slide. This spring holds the valves forward, closing the forward piston-holes. A small hand-lever on the valve-rod enables it to be drawn back, thus opening the valves at will. The action of the compressor is as follows: The recoil of the gun carries the cylinder to the rear and violently contracts the space forward of the piston-head; the oil is forced with violence through the forward holes, pressing back the small valves and escaping by the other holes to the rear of the cylinder. As the recoil ceases, the force of the spring carries the valve-stem and its valves forward again, closing the holes. The gun is held thus in position, as it cannot run out unless the valves permit the oil to pass into the forward end of the cylinder again. The pressure, however, comes against the back of the valves and keeps them closed. A slight turn of the hand-lever opens the valves, and the oil gaining free passage permits the gun to run out. The moment that the gun starts, however, to run out violently, a single movement closes the valves and the gun is held fast.

Piston-Head.

Rear End of Piston-Rod
and Connections.

Slide-Carriage for the Short 24-cm. Gun,
Pattern 1876.

This carriage differs in no important point from the last mentioned, except in the training-gear, which is more compactly arranged. The training-shaft carries on its rear end, instead of a large spur-wheel, a small mitre-wheel. Instead of the endless screw on the shaft, there is a mitre-pinion worked on a loose sleeve and having the same locking apparatus as the one before mentioned. The outer gearing for revolving the train-work is similar to what has been described; the axle carrying the endless-chain rollers, however, is not continued across the slide, but each wheel is independent, its axle seating in a journal inside the slide.

Slide-Carriage for 17-cm., 15-cm.,
and 12-cm. Guns.

These carriages are of the ordinary pattern and simple in detail. The carriage-rollers are like the others, automatic forward and worked by levers in rear. The elevating-gear is rack and pinion style for the 17-cm., and simple screw for the others. In the carriages previous to 1875, breechings are used. Where the gun is not a shifting one, the bight is rove through holes in the forward ends of the brackets; where it is shifting, the ends of the breeching shackle to the brackets. The forward slide-rollers are permanently in action, the rear ones are worked by levers. Where the slide is a shifting one, a third pair of eccentric rollers is midway of the slide and canted for rear-pivoting. The carriage is held on the slide by front and rear clips. Carriages later than 1875, unless they are of the newest type, have Elswick compressors; the latest have the before-mentioned hydraulic recoil cylinder in some instances, and in others the English style. These slides all have rear housing-bolts as above described. Where the fighting pivot-arm is long, a front housing-bolt and lip are used; if it is short, there is none. Tackles are used entirely for running in and out.

Half-Slide Carriage for the 17-cm. Gun,
Pattern 1875.

(Side View.)

(End View.)

Half-Slide Carriage for 17-cm. Gun.

The general plan of slide and carriage is similar to the foregoing. The slide is, however, very low and short, its rollers being permanently in action. The carriage has two front rollers on eccentric axles worked by levers. The rear of the carriage is somewhat longer than ordinary, and under it is hung a single long roller, which, when the gun is run out, does not touch the deck. In recoiling it drops to the deck and supports the rear of the carriage. The recoil is checked by the Elswick compressor, and in addition a breeching is provided, whose bight runs through holes in the front of the bracket. Rack and pinion elevating-gear is used. In slides intended for shifting ports, the rollers can be turned around a vertical axis and be locked so as to move the slide sideways.

Slide-Carriages for Light Guns Firing over the Rail.

The only difference between these and the others is that the slide is much higher and is centre-pivoting. In order to take off the shock of recoil from the pivot-bolt, the slide-rollers overlap the circles on both sides.

Slide-Carriage for the 30½-cm. Gun for Armored Gun-boats.

The general principle of the carriage is the same as the ordinary one. Its front and rear rollers are the same, and the elevating-gear is the rack and pinion type, the power being increased in accordance with the greater weight to be moved. The carriage is heavier braced, having three transoms in place of two. There are no out-tackles or chain-gearing, the slope of the slide (6°) being sufficient to run the gun out by its own weight. When it is necessary to run it in, in-tackles are used, the falls being taken over windlass-heads on the rear hurter of the slide. The slide is centre-pivoting, and traverses on four heavy rollers which overlap the edges of the circles to take the force of the recoil. A cramp under the forward end of the slide moving in an undercut circle on deck also takes the recoil shock. The gun is traversed by gearing. Just inside the roller-circles is a circular rack into which a pinion gears; the inner end of the pinion-axle carries a mitre-wheel whose upper and lower cogs gear in mitre-pinions which are worked on loose sleeves on a vertical axle. Between these pinions, revolving with the axle, but free to move vertically, is an iron grip which catches in the upper or lower pinion, according as it is desired to sweep the gun to the right or left. The vertical axle passes down to the lower deck, where is a train-work with crank-handles to be revolved by six men. By means of the single grip arrangement between the mitre-pinions, the gun may be traversed to the right or left or stopped without reversing the motion of the crank-handles below. The hydraulic recoil cylinder above described is used to check the recoil and control the running out of the gun. A sheet-iron musket-proof shelter is raised on the slide for the protection of the gun’s crew. For lifting the projectile to the gun a derrick is fixed at the rear of the slide. The fall of the whip is taken around a windlass-head, and the davit is swung around by means of an endless screw and pinion.

Front Half of Slide for Centre-Pivoting Gun-boat Carriage.

Gear below Deck for Revolving Gun-boat Carriage.

Turret-Carriage for the 21-cm. Gun (Arminius).

Turret-Carriage for Minimum Port.
([See next page].)

The turret-slide is fixed, and forms a part of the turret. The rails incline forward at an angle of 6°, so that out-tackles are unnecessary. The carriage-rollers are of the ordinary type. But one lever is used in throwing the rear trucks in action, as there is not room to work on the inside of the carriage. For running in, two chains shackle to the turret in rear of the gun and pass over a drum in the centre of the carriage. The drum is revolved by gearing. The recoil is controlled by the Elswick compressor. The elevating-gear is the single-screw type.

Turret-Carriage for the 24-cm. Gun, Pattern 1874.

This carriage, intended for a small port, differs in height and shape from the previous ones in order to permit a vertical elevation and depression of the gun-trunnions. It is built on the double-plate plan, with heavy transoms and bottom plates. The four carriage-rollers are arranged in the usual manner, the levers for throwing the rear trucks in action being moved by a tackle. The elevating-gear is fixed to the chase of the gun forward of the trunnions. It is of the ordinary rack and pinion type, but does not connect with the carriage, being hung in a frame which projects from the trunnions. The gun is run in and out by means of the endless-chain gear, the gearing being connected to a long shaft outside of the turret, to which three hand-wheels are attached. These hand-wheels are of course underneath the upper deck, coming out directly under the port. The recoil is governed by a hydraulic recoil piston, the arrangement in this case being identical with the English system. ([See English Ordnance].) The trunnions have three positions, the lower, middle, and upper. They are supported in a saddle whose arms travel in a framework in the brackets, being supported by iron blocks inserted through holes in the sides of the brackets. The saddle is raised by a hydraulic press, which is so fixed in the turret that the piston takes against the bottom of the saddle when the gun is run out. The details of this arrangement are precisely similar to those of the corresponding English turret-carriage. The slide-rails are fixed in the turret with a slope to the front of 5°. In addition to the chain nipping-gear and the hydraulic recoil piston, the gun-carriage is provided with bow-compressors on each side. ([See English Ordnance].)

Boat-Carriages.

The boat-carriage complete consists of a wooden slide bound together in front and rear by iron plates, and a composite carriage made up of a wooden bed surmounted by an iron bed-plate and bracket-frames for the trunnions. Two buffers are put at the rear of the slide to take an over-recoil. The elevating-gear is the simple screw and hand-wheel. The compressor is a brass-faced block whose upper side takes in undercut spaces in the slide. The block is held up and tightened by a screw and hand-clamp. For transporting the boat-carriage and gun together a small block-cart is used, which is nothing more than a heavy, flat, wooden body provided with an axle and two gun-trucks.

Boat-Carriage.

Field-Carriages.

The field-carriage is of the ordinary type, consisting of two straight iron brackets, strengthened along the upper edge by angle-irons, and curved to form a sole at the bottom. To this a trunnion socket-frame is bolted. The brackets are braced by transoms and by two side rods. An iron axle bolts to the under side of the brackets just in rear of the trunnion-holes. The wheels are wooden with brass hub-boxes and iron tires. The elevating-gear is of the plain screw and hand-wheel pattern. A limber is provided with this carriage which carries two ammunition-boxes, each of which holds six rounds of shell and the corresponding cartridges (not fixed to the projectile). The carriage itself also carries two ammunition-boxes of the same size.

Field-Carriage.

GUNPOWDER.

The gunpowder used for the majority of naval guns is of the kind known as prismatic powder. Of this there are two classes. The first, for use with the heaviest calibres, is solid; that for medium calibres is pierced with holes longitudinally—for the high calibres with one central hole, and for the medium with seven. Large-grained cannon-powder is used in shell-guns, whilst the usual classes of small-grained powder is used with small-arms and for shell-charges. Prismatic powder is invariably used for battering-charges in all calibres, the gradation with regard to time of burning being obtained by the holes pierced through the grains: slow powder, solid; medium, one hole; quick, seven holes.

PROJECTILES.

The projectiles used in the German Navy are shot, shell, case-shot, and shrapnel. Shot are either solid or hollow for the lighter calibres, and hollow for the heavy ones. They are of ordinary cast-iron, chilled cast-iron, and steel, the solid shot being invariably made of ordinary cast-iron. They are of two different types, according to the style of rifling arrangement. In the earlier patterns, all projectiles were provided with a lead belt extending from the shoulder to within about two inches of the base. To receive and hold this jacket, broad shallow grooves were cut around the circumference of the projectile, the ridges left having slots cut through them at intervals to resist the tendency of the jacket to slew around. The jacket was moulded around the projectile and zinc-soldered. Corresponding with the grooves in the projectile, there were grooves in the jacket to receive the overflow of metal forced back when the projectile took the rifling.

Chilled Shot.

Common Shell.

27-cm. Gun.

Chilled Shot.

Common Shell.

Long Shell.

15-cm. Gun.

Segment Shell.
17-cm. Gun.

Common Shell.
8-cm. Gun.

In the late patterns, instead of a jacket, two rings are used; the forward one being for centring or holding steady the head of the projectile, and the rear and larger one for rifling. This rear one is provided with grooves to receive the overflow of metal. Both rings are copper. The steel and chilled shot are very similar in appearance.

Shell are similar in exterior shape and appointment to shot, and are all made of ordinary cast-iron. Double shell ([see English Ordnance]) are used with the 17-cm. and 15-cm. calibres.

Case-shot are of the ordinary pattern.

Shrapnel are only used with boat-guns, and are similar in construction to the English. ([See English Ordnance].)

Solid shot are used only with the 17-cm. and 15-cm. guns.

Case-shot are not used with boat-guns.

Hollow-shot, shell, and case-shot are used with all the higher calibres.

Fuses are not used with hollow-shot, the bases of which are closed by a gun-metal screw-plug.

FUSES.

German Percussion Fuse.

Both percussion and time fuses are used in the shells of all calibres. The percussion fuse consists of a plunger having a fire-hole through the centre and surmounted by a pointed anvil. This is dropped into the fuse-hole of the shell, and hangs on a shoulder in the wall of the fuse-hole. Even with the point of the anvil a hole is bored through the wall of the shell horizontally, into which a pin is inserted whose inner end covers the anvil and keeps it from going forward. A gun-metal case screws into the end of the fuze-hole, and into this screws a small cap carrying the fulminating composition. When the gun is fired the centrifugal force throws the pin out, and when the projectile strikes the plunger rides forward against the fulminate and explodes it. The fulminate-cap and the pin are not inserted until the projectile is brought to the gun, the mouth of the fuse-hole being kept sealed by a wafer. The Krupp time-fuse consists of a gun-metal body which screws into the fuse-hole and has two chambers. The lower one, containing the blowing-charge, opens into the shell. It is solid to the rear, except a diagonal channel on one side which is pierced up and opens on a small table which carries the fuse-composition disc. The latter is circular and on the principle of the Bormann fuse, its exterior wall being marked for seconds and fractions. The upper chamber of the fuse is open at its upper extremity and closed at the lower, except several side channels leading to the composition disc. In the bottom of this chamber is a pointed anvil. The fuse-cap is ogival and screws over the tipper chamber, fitting tightly down on the composition disc. In this cap is a plunger loaded with fulminating composition at its lower end, and suspended by five small tenons. The composition is ignited by the percussion part of the fuse on firing. A safety-pin passes through the fuse-cap and plunger, and is withdrawn when the shell is brought to the gun.

German Time-Fuse.

PRIMERS.

Friction primers are used altogether. These are of the same type as those used with English guns. ([See English Ordnance].)

SIGHTS.

Sight-Bush and Clamp.

Rear-Sight.

Front-Sight.

Rear-Sight for Light Guns.

The sights used with naval guns are all of the tangent pattern, and all except the boat-guns are provided with sights on both sides. The socket for the tangent-sight is bored through the breech-piece, the upper part having steel or bronze bushing and a clamp-screw passing through at right angles. The sight is cylindrical, with a flat rear surface on which is marked elevations to sixteenths of degrees. On the left cylindrical side, elevations for every 100 metres are marked for common shell, and on the right for chilled or steel shot. The head of the sight consists of a rectangular cross-head fastened to the top of the bar, in whose upper surface a swallow-tailed groove is cut in which travels the sight-notch. On the face of the cross-head, gradations of sixteenths of a degree corresponding to elevations are marked, and the sight-notch carries a small pointer. The gradations are marked each way so as to account for drift and deviation to the right or left. The forward sight is cylindrical, with a conical point, and screws into the trunnion-hoop. Sights for boat-guns differ in having gradations only on the rear face, and the sliding leaf works by an endless screw. These sights are all vertical. With some boat-guns, however, the tangent-sight is placed at a permanent angle of deflection, in which case there is no sliding leaf.