Welcome, Guest
Username: Password: Remember me

TOPIC:

Artillery and Ammunition 1 year 5 months ago #86275

  • Neville_C
  • Neville_C's Avatar Topic Author
  • Away
  • Senior Member
  • Senior Member
  • Posts: 1337
  • Thank you received: 1900
Gerrit & Rob,

Here are images of the bases of two 75 mm Krupp BL segment shells, the first picked up at Christiana by Lieutenant Hugh Steuart Gladstone, 3rd Bn. King's Own Scottish Borderers (later attached to Field Intelligence Dept.), and the second with silver plaque simply inscribed: "South Africa 1900" .....






Also the base of a 75 mm Krupp BL shrapnel shell, again brought home by Lieutenant Gladstone ....





________________________________________________________




Base of 75 mm Krupp BL segment shell found in the Heilbron district in 2022. Image previously posted by Gerrit.
Note the "AG" (or "MG"?) inspection mark (arrowed), which can also be seen on the base plug of the Chritiana shell pictured above.





...
Attachments:

Please Log in or Create an account to join the conversation.

Artillery and Ammunition 1 year 5 months ago #86297

  • Neville_C
  • Neville_C's Avatar Topic Author
  • Away
  • Senior Member
  • Senior Member
  • Posts: 1337
  • Thank you received: 1900
.
75 mm Krupp BL Segment Shells



Three 75 mm Krupp BL segment shells, which were fired into Kimberley during the siege, photographed with an array of segment fragments in the foreground.


The base plugs seen on 75 mm Krupp BL segment shells show that they were cast in a similar manner to the projectiles manufactured in the De Beers workshops during the Siege of Kimberley.
Molten steel was poured into a mould, which had at its centre a clay core, holding ten segment rings stacked one on top of another. Once cast, the clay core was broken out and the resulting hole in the base of the shell plugged.




The bases of two 75 mm Krupp BL segment shells, showing the central base plugs, each with inspection stamp.






Casting 2.5-inch shells in the De Beers workshops during the Siege of Kimberley. Note the clay cores holding the stacked segment rings. The Krupp shells differed in that the rings were aligned one directly on top of another, rather than being staggered (segment over space over segment), as shown in the image on the left.




Partially exploded shell, showing the segment rings stacked in layers within the cast steel walls of the projectile.



Each Krupp ring had eight segments, joined by 2 to 3 mm wide bridges which broke easily on bursting.
The individual segments were keenly sought by Kimberley jewellers, who fashioned them into all sorts of brooches, pendants and fobs.




A selection of watch chain pendants, sold as curios after the lifting of the Siege of Kimberley.





To make their wares more desirable, some jewellers embellished their pieces with gold or silver plaques, inscribed with exaggerated or false narratives. The above 75 mm Krupp BL segment has an applied gold shield wrongly claiming that the fragment came from a 155 mm Creusot “Long Tom” shell...... And not any old “Long Tom” shell – this piece apparently came from the very first to be fired into Kimberley during the siege!






Reconstruction of a Krupp segment ring, using an engraved pendant as template.





Base of 75 mm Krupp Shell, showing the arrangement of the eight segments, with two remaining in situ. The top and bottom rings differed from the remainder in that the upper (or lower) outer edges were sculpted.





Base with two watch chain danglers, showing how they would have originally been arranged within the steel matrix.





___________________________________________________________________



THE BOER KRUPP GUNS

MC Heunis, O.V.S.A.C. Study No. 11, Jan-Mar 2005.

75mm Krupp BL (Feldkanone L/27)


The Oranje Vrijstaat Artillerie Corps made use of the “export model” of the German horse artillery’s 8-cm leichtes Feldgedchütz Material C/73. Officially it was denoted as: 7.5cm Krupp: Feldkanone L/27, but during the Boer War it became known as the “Free State Krupp”.

In 1890 Captain Albrecht, Prussian CO of Free State Artillery, persuaded the Free State Government to order their first guns from Krupp and by 1893 the Corps had six of these, numbered 1 to 6 and dated 1892. In a report Albrecht noted: “not only can they be handled rapidly and safely by the men, but they are extremely accurate and have a highly desirable effect.” After the Jameson Raid, in 1896, the Free State Volksraad realised that their existing armament was still not sufficient. So, during 1897 a further eight guns, numbered 7 to 14 and dated 1897, as well as nine ammunition wagon/limber combinations were imported from Germany. The only difference between the two batches that are discernible on contemporary photographs is the design of the wooden brake beams of the gun carriages. The first six guns were equipped with curved brake beams, while the second batch had straight beams. The second batch also carried a large Free State coat-of-arms engraved on top of the barrel, just behind the trunnions.




The gun was of a steel construction, strengthened by a steel jacket at the breech end. The breech opening was closed by means of a sliding cylindrical wedge breech block, which opened to the left and was locked by a half turn screw process. It was made gas-tight by means of a steel Broadwell ring in the breech end of the chamber and a steel removable plate on the face of the breechblock, which fitted against the expanding steel ring.
The gun was mounted on a sturdy steel carriage which adapted well to the South African veldt. Maximum elevation was 24 achieved by means of a two-part telescopic screw turned by a horizontal hand wheel. Wheel brakes were used to control recoil, but these were not really adequate. The brakes were applied by turning a hand wheel on the front, centre of the gun, between the axletree mounted seats.

Ignition was by means of friction tube, which fired through a channel constructed transversally through the wedge (or breech block), the housing projecting above the breech. As with the three guns described before this, a bagged black powder charge was used to drive the shell, the shell employing the double copper drive/stabilising band principle. When fired the black powder caused an extremely visible smoke cloud, which made concealment almost impossible. Ring segment, shrapnel and case shot were used with percussion and time fuses, but shrapnel range was short compared to newer guns of the Anglo-Boer War. To lay the gun a right trunnion mounted front sight and tangent rear sight were used.

Although semi-obsolete by the outbreak of the Anglo-Boer War, these guns were the Free State Artillery Corps’ mainstay weapons and they took part in most of the Free State’s battles. The 14 were captured, abandoned or surrendered at:


Qty Captured at Date Serial No.
3Paardeberg27 Feb 19004, 5, 13
1Poplar Grove8 Mar 19006
1Wittebergen – Brandwater Basin24 Jul 19008
1Rensburg Drift27 Oct 190010
3Bothaville6 Nov 19003, 7, 12
1Caledon Road5 Dec 19001
3Tierbank23 Mar 19022, 11, 14
1Heilbron/SodasMay/Jun 19029


...
The following user(s) said Thank You: grapeshot, Moranthorse1, pfireman

Please Log in or Create an account to join the conversation.

Artillery and Ammunition 1 year 5 months ago #86298

  • Rob D
  • Rob D's Avatar
  • Away
  • Senior Member
  • Senior Member
  • Posts: 794
  • Thank you received: 719
Splendid, Neville!
I've sent you a PM...
Rob
The past is not dead. In fact, it's not even past.

Please Log in or Create an account to join the conversation.

Artillery and Ammunition 1 year 5 months ago #86371

  • Neville_C
  • Neville_C's Avatar Topic Author
  • Away
  • Senior Member
  • Senior Member
  • Posts: 1337
  • Thank you received: 1900
.
Dr Jameson’s Armstrong 2.5-in 400 lb RML Jointed Mountain Guns

DRAWINGS







2.5-inch Armstrong Mountain Gun on display at the Royal Artillery "Firepower" Museum (photograph: radio53)





















.Stereoview of the Royal Garrison Artillery 2.5-inch "screw guns" that were used in the Defence of Kimberley.

..
The following user(s) said Thank You: Ians1900

Please Log in or Create an account to join the conversation.

Artillery and Ammunition 1 year 4 months ago #87288

  • Neville_C
  • Neville_C's Avatar Topic Author
  • Away
  • Senior Member
  • Senior Member
  • Posts: 1337
  • Thank you received: 1900
.
ORDNANCE COMMITTEE REPORT

75 mm Creusot QF Gun
&
120 mm Krupp Howitzer


This remarkable confidential report, commissioned by the Ordnance Committee and published in July 1902, has recently come to light amongst Vickers Armstrong’s papers, which are now held by Tyne & Wear Archives. I would like to thank MC Heunis for bringing this invaluable document to my attention.
These reports on the 75 mm Creusot QF Gun and 120 mm Krupp Howitzer and their ammunition are perhaps the only contemporary detailed descriptions of these pieces in the English language.
I have transcribed those sections that deal with the construction and workings of the guns and ammunition.

The two guns examined were:

120 mm Krupp Howitzer, Serial No. 1 (believed to be the howitzer found buried at Piet Retief during February 1901; current location unknown – probably smelted).

75 mm Creusot QF, Serial No. 420 (possibly the gun found buried at Piet Retief during February 1901, though this has also been claimed of No. 421 , the Creusot now on display at Fort Nelson). Allotted to the Royal Artillery as a trophy; current location unknown.




ORDNANCE COMMITTEE.
16th July, 1902.
Report No. 1,151.

On the 19th August 1901 the Committee were informed that the following guns, ammunition, etc., had been received, viz.: –
(a). One 75 m/m Creusot Q.F. Field gun, complete with breech fittings and sights, carriage and limber.
(b). One 120 m/m Krupp Q.F. Howitzer, complete with breech fittings and sights, carriage and limber.
(c). The ammunition detailed in Appendix I.



APPENDIX IV.
Krupp Field Howitzer with Carriage and Limber.
Howitzer No. 4,441.
[Serial No. 1]
[This is the gun pictured in the well-known photograph of the Staatsartillerie Howitzer at Ladysmith ]





Measurements and weights.

Weight of gun……….. 8 cwt. 2 qr. 21 lb.
Total length of gun……….. 47.25 inches
Bore – length……….. 37.6 inches
Bore – diameter……….. 4.724 inches
Bore – length of rifling……….. 32.4 inches
Rifling – number of grooves……….. 36
Rifling – depth of grooves……….. 0.05 inches
Rifling – width of lands……….. 0.135 inches
Rifling – twist……….. 3 to 8 degrees
Radius of sight……….. 22.35 inches
Weight of carriage……….. 10 cwt. 2 qr. 22 lb.
Weight of limber, empty……….. 9 cwt. 1 qr. 15 lb.
Angle of lock……….. 85 degrees
Track of wheels……….. 5 feet 4 ½ inches
Height of wheels……….. 3 feet 11 ½ inches
Weight at end of trail in firing position……….. 188 lb.
Height of axletree above ground……….. 1 foot 10 inches
Maximum elevation of gun on carriage……….. 35 degs. 15 mins.
Maximum depression of gun on carriage……….. 18 degs. 35 mins.
Height of axis of gun above ground……….. 3 feet 1 ¼ inches
Weight behind team with 16 rounds……….. 34 cwt. 2 qr. 11 lb.


Breech closing mechanism.

This is of the side closing type. It consists of –
(1) Breech block and firing mechanism
(2) Actuating lever and spindle
(3) Extractor
The breech block has slides top and bottom, which run in guides in the breech. The top of the block is hollowed out to receive the revolving spindle of the actuating lever, which is free to revolve in the block, but which is prevented from longitudinal movement by a semi-circular projection on it engaging a groove in the block. The rear face of the block is hollowed out to receive the striker, and a hardened plate with a small hole in it, to allow the point of the striker to pass through, is fastened to the front face. The right face is hollowed out for the reception of the cocking lever and trigger.
The spindle of the actuating lever has three spiral threads cut in it, beginning in a broad groove near the actuating lever which forms part of the spindle. These threads engage in others in the top surface of the opening in the breech in such a manner that when the lever is turned the spindle is forced out to the right, and, as it is allowed no longitudinal movement in the breech block, it carries the latter with it. The broad slot cut at the beginning of the threads allows the spindle to partially turn before the threads actually engage. The object of this is to allow the striker to be cocked before the block commences to move. The cocking is done by means of a lever pivoted at its centre in the block, one arm engaging a projection on the striker, and a stud on the other engaging a cam groove on the spindle. When the striker is sufficiently drawn back another projection on it engages the trigger and it is held in the cocked position. The cocking lever acts as a safety arrangement, as it does not clear the striker until the last movement of closing the breech. The trigger is an “L” shaped lever, the short arm engaging the striker when cocked, and the long arm passing out at the side of the block, and having a loop at its end for the lanyard to hook onto.
The striker is hollow and the main spring is placed inside it. It is placed in the recess in the rear face of the breech block and retained in position by a flat screw which puts the spring into initial compression. The striker can be removed when the breech is closed by taking out this flat screw.
The screw threads in the top surface in the opening in the breech (mentioned before) are made in a piece of steel which slides into position on the right side of the breech, after the breech block and mechanism are put in position, and is secured by 2 screws. It must be removed before the mechanism can be dismounted.

The extractor is in the form of a flat piece of steel hollowed out to a semi-circle on one side to fit round the cartridge case. On the top and bottom, slides are formed which bend outward at their outer ends. The block moves along these slides till it is very nearly in the open position when it engages the bent ends and so gives the extractor the required movement. The extractor must be removed before the block can be dismounted.


The carriage.

The carriage consists of a square trail with axletree and wheels, and is provided with a brake and spade attachment.
The front of the trail is recessed to receive the Howitzer, and trunnion holes are formed on its top front.
The axletree passes through the trail and is bolted to it on each side. The wheels are of the single spoke pattern and are heavier and smaller than those of the Creusot Field gun. The brake arms are pivoted on each side of the trail about the centre and are supplied with wooden brake blocks. Shafts pass from the outer ends of the brake arms, under the axle, to hand-wheels by means of which the brakes are worked. The brake on each wheel is quite independent and is worked by a different hand-wheel. The body of the trail is hollow and forms a box for the carriage of small stores. The spade is pivoted under the point of the trail and is connected to a spring which tends to run the carriage up into position against the recoil. The traversing handspike is of iron and is pivoted to the end of the trail on the right side. It folds up on top of trail when not in use. The rammer is carried on the left side of the carriage. The breech can be bolted to the carriage for travelling to save wear and tear of the elevating gear.


Elevating gear.

The elevating gear is on the left side of the carriage and consists of a hand-wheel connected to a longitudinal shaft. On the end of the shaft is a worm gearing in a worm wheel on a transverse shaft which passes under the trunnions. On this shaft is a pinion which engages a sector of a toothed wheel bolted under the centre of the Howitzer.
The cap squares are hinged to the rear and secured in front by keep pins.


Sighting arrangements.

The foresight which fits into a socket in the trunnions is missing.
The hindsight is of the reciprocating type and is worked by a thumb-screw.
The metal socket which holds the sight is bolted to the right rear of the breech face. The sight bar consists of a square bar of steel graduated on its rear face. On the top is formed a sliding leaf for deflection worked by a thumb-screw. The sight bar is raised or lowered by hand, being apparently clamped in position by a small screw, which is missing.


The limber.



The limber consists of one steel box supported on an iron frame with axletree and wheels and having pole draught.
The limber box is not fitted for carrying gunners on top.
The box opens at the back and has divisions foe 16 shell. There are divisions to carry 6 leather cartridge boxes, each box fitted to contain 3 cartridges. There are also divisions for a fuze box and for a steel box fitted to contain spare parts of the breech mechanism.
In front of the limber box there are 2 openings, each forming a small box for the carriage of small stores.




APPENDIX IV.
Creusot Field Gun with Carriage and Limber.
No. of gun 3,247.
[Serial No. 420]




Measurements and weights.

Weight of gun6 cwt. 3 qr. 22 lb.
Weight of gun and cradle10 cwt. 0 qr. 8 lb.
Total length of gun97.25 inches
Bore – length93.25 inches
Bore – diameter2.95 inches
Bore – length of rifling80.0 inches
Rifling – number of grooves24
Rifling – depth of grooves0.025 inches
Rifling – width of lands0.135 inches
Rifling – twist3 to 8 degrees
Radius of sight27.85 inches
Weight of carriage10 cwt. 0 qr. 21 lb.
Weight of limber, empty8 cwt. 0 qr. 7 lb.
Angle of lock45 degrees
Track of wheels4 feet 3 inches
Height of wheels4 feet 11 inches
Weight at end of trail in firing position224 lb.
Maximum angle of traverse of gun on carriage R. & L.1 deg. 30 min.
Height of axletree above ground2 feet 5 inches
Maximum elevation of gun on carriage18 degs. 50 mins.
Maximum depression of gun on carriage4 degs. 33 mins.
Height of axis of gun above ground2 feet 5 inches
Weight behind team with 16 rounds32 cwt. 3 qr. 6 ¾ lb.


Breech closing mechanism.

The breech is closed by means of an interrupted screw block and the mechanism is of the single motion type.
It consists of 3 principal parts –

(1) The screw block with firing pin and trigger.
(2) The carrier with hinge bolt and actuating lever.
(3) The extractor.

The screw block has 2 interruptions; the screw threads being on a slight curve to allow the block to wheel out of the breech. It is hollowed out to receive the firing pin or striker which is attached to it by means of a collar with feather and featherway. The striker has its main spring coiled round it and is meant for percussion firing. The rear end of the striker passes through the carrier and has a loop of steel on it by means of which it can be cocked by hand in case of a misfire without opening the breech. The striker is cocked under the ordinary circumstances by the first motion of the breech screw. A safety pin passes through the back of carrier and through striker. When this pin is put in back to front, the striker cannot reach the cap of the cartridge and so is safe for travelling. When put in the reverse way the gun is ready for firing. The striker can be removed by taking out this pin and giving it a partial turn.









The trigger [purple] is carried on the back of the screw block, and consists of a hollow square of steel through which the striker [green] passes. It is actuated by a spring which forces it to engage a groove in the striker when the latter is pulled back.
The trigger sear [orange] is on the right of the carrier, and consists of a small lever with a loop on its end for the attachment of the lanyard. When the lanyard is pulled to the rear the trigger sear pushes the hollow square to the left till it disengages the striker.
The block is screwed to the carrier by means of 3 screw threads at its back which are quite independent of the interrupted screw threads. The screw block is kept from turning in the open position by a stop pin and spring. This is withdrawn in the closed position by means of a projection on the face of the breech.
On the back of the block there are 4 teeth forming part of a rack pinion. These teeth are engaged by 4 teeth on the sliding bar of the actuating lever, mentioned later. The gun cannot be fired until the breech is completely closed.
The carrier is of gunmetal, and is connected to the gun by the hinge bolt on the left of the breech.
The actuating lever is “L” shaped and is rigidly connected to the top of the hinge bolt, the angle at the elbow being connected to a sliding bar by means of a stud and cam groove.
This sliding bar has 4 teeth on it which engage 4 teeth of a sector of a rack pinion on the back of the breech block, and so turns the block when it is pulled to the left. The hinge bolt has a feather which works in a wide featherway in the carrier and so allows the hinge bolt a slight turning movement before engaging the carrier. This allows the actuating lever to move to the rear so turning the breech block by means of the sliding bar before the feather engages. When the feather engages the featherway in the carrier, the whole swings out of the gun to the left. A small catch on the handle of the actuating lever engages when the breech is shut and prevents the lever flying back when the gun is fired.
The extractor is semi-circular with a projection on it which fits into a slot cut in the bottom of the breech. A pin passes through the under portion of the breech having a squared part which passes through the projection on the extractor. Thus the extractor must turn with the pin. The end of the pin has a bent arm with a stud on it which works in a cam groove fixed by a small screw on the bottom of the hinge bolt. This screw must be removed before the hinge bolt can be taken out or raised, and the hinge bolt must be either taken out or raised before the extractor can be removed.


The cradle.

The gun is trunnionless and is carried in a cradle through which it recoils and to the buffers and spring boxes of which it is connected by projections on the side of the breech.
The cradle, in which are 2 buffers and 2 spring boxes, passes through the axle of the carriage to which it is pivoted by screws top and bottom. This attachment allows of slight traverse being given to gun and cradle on the carriage.


Sighting arrangements.

The sights are attached to the right side of the cradle.
The fore-sight consists of a vertical bar about 10 inches long with a conical top and is secured to a socket in the cradle by means of a feather and featherway, the feather being in the form of a spring which secures it in position.
The hind-sight consists of a metal socket and steel sight bar. The socket of the sight is attached to the socket in the cradle in a similar manner to the foresight, the former carries an adjustable spirit level. There is also a thumb-screw on the socket for raising and lowering the sight bar. The latter consists of a steel bar, square in section and graduated on the rear and side faces.
On the top of this bar is a sliding leaf for deflection worked by an endless screw, having a thumb-screw for manipulation.


The carriage.

The carriage consists of a trail which is forked shaped having a trail eye in rear.
The front of the fork has bearings formed in it through which the axle passes.
The axle is shaped in its centre to allow the gun and cradle to pass through it and has thus to turn in its bearings as the gun is elevated or depressed. The wheels which are light and of the single spoke construction are secured to the axle by keep pin and washer.
On the front of the axle bearings of the fork two brackets are formed through which two rods pass which actuate the brake bar by means of hand-wheels. The brake bar extends across the carriage under the trail and is supplied at each end with brakes. It is pivoted at each side to the trail by short arms.
A spade attachment is pivoted under the trail and is also attached by a bar and spring to the trail further to the rear. On recoil the spring is put in tension and tends to run the carriage up to the firing position when the energy of recoil is absorbed.
The spade can be hooked up to the rear for travelling.


Elevating gear.

The elevating gear consists of a handle working a worm and worm wheel. The worm wheel is attached to a spindle passing through the right bracket of the carriage by means of a friction cone. On the inner end of the spindle is a pinion which engages a rack which is attached by an arm to the axle of the carriage. Thus, on turning the handle the axle is turned and consequently the cradle and gun elevated or depressed.


Traversing gear.

The traversing gear consists of a long bar fixed to the under screw (which connects the cradle and the axle). At the end of this bar is a worm which gears with a sector of a worm wheel, attached by a longitudinal feather and featherway to the gun.


The limber.



The limber consists of one removable box supplied on a framework of iron, and having pole draught.
The back of the limber box opens and forms a shelf. The inside is prepared to carry 36 cartridges (fixed ammunition apparently), each cartridge having a separate horizontal division. The top of the limber forms a seat for 2 gunners, or in case of emergency 4.







Ordnance Committee plates reproduced courtesy of Tyne and Wear Archives ; remainder from Revue d'Artillerie Vol. 49 (Oct 1896 - Mar 1897) .

..
The following user(s) said Thank You: Ians1900

Please Log in or Create an account to join the conversation.

Artillery and Ammunition 1 year 4 months ago #87290

  • Neville_C
  • Neville_C's Avatar Topic Author
  • Away
  • Senior Member
  • Senior Member
  • Posts: 1337
  • Thank you received: 1900
.
ORDNANCE COMMITTEE REPORT

75 mm Creusot QF Gun
&
120 mm Krupp Howitzer



APPENDIX II
Ammunition



On the 21st November, the Chief Superintendent of Ordnance Factories forwarded the following designs of the ammunition, which are given on Plates 1 to 5, and descriptions in Appendix II: –

R.L. No. 11,257/1Plate 3Case shot, 75 m/m gun.
R.L. No. 11,537/1Plate 3Cartridge case, 75 m/m gun.
R.L. No. 11,790/1Plate 4Fuze, percussion.
R.L. No. 11,760Plate 4Fuze, time and percussion.
R.L. No. 11,742Plate 2Shell, segment and shrapnel, for 75 m/m gun.
R.L. No. 11,741Plate 1Shell, common, segment and shrapnel, and cartridge, for 120 m/m Howitzer.
R.L. No. 11,752Plate 4Percussion primer.
R.L. No. 11,752Plate 5Fuze for 120 m/m shrapnel.





Plate 4.

Fuze, time and percussion, for 75 m/m Gun.

This resembles the fuze supplied with the equipment of Type I gun.
The time portion consists of a matrix of lead and antimony with a special tube of pure tin containing the fuze composition. Holes are left in the brass covering for the purpose of boring through the lead matrix, and these holes are graduated from 0 to 25.
The fuze is ignited by means of a cap over which a pointed hammer is placed, the hammer being separated from the cap by means of a spiral spring. On discharge the hammer compresses the spring and fires the cap, which in turn ignites a ring of pressed powder. The flash from the latter penetrates through the hole bored in the lead and sets fire to the spiral tube of fuze composition. Finally, the composition ignites a channel of loose powder and so fires the fuze.
The percussion portion consists of a pointed hammer fixed to the body of the fuze and a movable plug which contains the cap and igniting charge. The plug fits in a collar, but is prevented from moving forward in it by bow springs. The collar is prevented from moving forward by a spiral spring. Before firing, the latter spring is in compression. On the shock of discharge the collar sets back over the bow springs and forms one body with the plug, the spring between it and the hammer being then extended. On striking, the collar and plug compress the spiral spring thus firing the fuze.
The fuze weighs 12 oz. 13 drs.






Plate 4.

Fuze, percussion, for 75 m/m Gun.

The detonating composition is carried in a metal plug which screws into the body of the fuze. This plug is extended downwards in the form of a hollow cylinder. The hammer is carried on a movable plug which is prevented from moving into the hollow cylinder by bow springs. On the shell striking, the bow springs are compressed and the moveable plug passes up the cylinder, so firing the fuze.






Plate 2.

Cartridge case for the 75 m/m Gun.

This gun fires case ammunition.
The case is of brass, weighs 3 lb. 10 drs., and is tapered slightly to the front and recessed at the base to receive the percussion cap which is forced into position from the outside, its capacity is 75 cubic inches.
The charge consists of 1 lb. 2 ¼ oz. smokeless nitro-cotton powder which is in the form of flat strips 3.25 inches x 0.7 inch x 0.042 inch, it is made up in three bundles, each tied together in two places with twine. The lowest bundle has a 6 drs. primer of powder in a muslin bag tied to the bottom of the bundle with twine.






Plate 3.

Shrapnel and segment shell, and case shot for the 75 m/m Gun.

The shrapnel when empty weighs 13 lb. 3 oz., and contains 234 bullets (45 to the lb.). The bullets are kept in position by discs top and bottom, and are embedded in sulphur. There are no bullets in the head. The bursting charge, weighing 2 ½ oz., is in the base and is connected by a copper tube with the fuze.
The head is connected to the body by screw threads, and is recessed and screw threaded to receive the fuze. The driving band is of copper 0.4 inch broad, with one cannelure.
There are 2 segment shells for this gun.
One weighs when empty 10 lb. 14 ½ ox., and uses a fuze 4 oz. in weight, bursting charge 3 oz. 11 drs.
The other weighs 11 lb. 3 oz., and uses a fuze 3 ¼ oz. in weight, bursting charge 4 oz. 1 dr. The driving band in each case is 0.4 inch broad with no cannelure.
The case shot contains 156 lead balls, the interstices between the balls being filled up with sulphur. The case is made of zinc, and is connected by 4 rivets to a wooden base which has a brass disc on its base. The total length of the case shot, including the wooden base, is 10.02 inches.






Plate 1. [Note: the base is shown with the primer removed; see below]

Cartridge case for the 120 m/m Howitzer.

This gun fires case ammunition.
The case is 4.125 inches long, and is recessed and screw threaded in the base to receive the primer, its capacity is 75.5 cubic inches. The full charge of 14 oz. 12 drs. is made up in two silk cloth bags, the larger containing 9 oz. 11 drs. and the smaller 5 oz. 1 dr. of the propellant, both primed with powder on their rear ends. They are retained in position in the case by millboard discs and a millboard lid which is a tight fit for the mouth of the case. There is a loop of braid to remove the lid and discs when required.






Plate 4.

Primer, percussion, for cartridge case, 120 m/m Howitzer.

This consists of a brass case, inside of which is fitted a cap kept in position by a screwed plug. The plug has a channel down its centre to allow the flash from the cap to reach the pressed powder which forms the magazine of the primer. The pressed powder is kept in position by a calico disc and a brass washer, the latter being spun in. The calico disc is attached to the brass washer with shellac. The firing pin of the striker of the gun has to indent the metal of the case to fire the cap.






Plate 1.

Common, segment, and shrapnel shells, for the 120 m/m Howitzer.

The common shell is steel, and weighs when empty 34 lbs. 10 oz. It is bushed with metal to receive a direct-action fuze. The bursting charge of six 1 oz. bags of powder, 10 ¾ oz. L.G. powder, and a primer of powder ½ oz.; total 1 lb. 1 ¼ oz.
The driving band is 0.48 inch broad, and has no cannelure.
The shrapnel shell weighs when empty 34 lb. 2 oz., and contains 617 bullets (41 to the lb.). The bullets being embedded in resin.
The burster is in the base, weighs about 5 ½ oz. of powder, and is connected by a tube with the fuze.
The head is fixed to the body by screw threads, and is recessed and screw threaded to receive the fuze.
The segment shell contains iron segments, and has a bursting charge of 14 oz.






Plate 5.

Fuze for shrapnel of 120 m/m.

The lighting arrangement is removable, and is of a well known form consisting of detonator pellets held in place by means of bow springs.
The see-saw spring connecting the two time rings is the most remarkable feature of this fuze. The advantage of this means of setting is that the fuze can be set to much smaller graduations than when only one ring is graduated. The disadvantage is that it requires longer to set.


All images reproduced courtesy of Tyne and Wear Archives

...
The following user(s) said Thank You: Ians1900, grapeshot, pfireman

Please Log in or Create an account to join the conversation.

Moderators: djb
Time to create page: 7.683 seconds
Powered by Kunena Forum