TOPIC:

I have updated my post dealing with 15-pdr shells and their driving bands, in an attempt to clarify the correlation between rifling systems and the various marks of gun used during the ABW. Additional information gleaned from the 1900 handbook for the 15-pdr BL Mk I has led to a re-write of some paragraphs. Please let me know if you spot any errors or have any additional information regarding this rather esoteric topic...

www.angloboerwar.com/forum/21-uniforms-b...tion?start=174#89247

Neville

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“All together boys” – the well-known image of a Naval 12-pdr QF 12-cwt gun on “Scott” improvised carriage, taken by society photographer Horace Nicholls.







The gun is made of steel; it consists of the A tube over which is shrunk the jacket, prolonged to the rear for the reception of the breech screw, and the B tube extending to the muzzle. Over the jacket and the B tube is shrunk the C hoop, which screws into the jacket and is attached to the B tube by a shoulder. The A tube is prevented from moving forward by shoulders between it and the B tube.
At the top and bottom of the jacket are two longitudinal projections, which form guides for the gun in the cradle. The underside of the jacket is provided with a horn to which are attached the piston rod and the running-out rods.
The right side of the jacket has a projection in the form of a bracket, to which is secured, by means of a hinge bolt, the carrier.
The chamber is slightly coned to facilitate extraction of the cartridge after firing.

PARTICULARS OF THE GUN.
.

Nominal Weight	- - - - - - - - - - - -	- - - -	- - - - - - - - - - - - - - - - - - - - - - - -	12 cwts
Length, total	- - - - - - - - - - - - - - - -	- - - -	- - - - - - - - - - - - - - - - - - - - - - - -	123·6 inches
Bore	- - - - - - - - - - - - - - - -	diameter	- - - - - - - - - - - - - - - - - - - - - - - -	3 inches
Bore	- - - - - - - - - - - - - - - -	length	- - - - - - - - - - - - - - - - - - - - - - - -	120 inches
Bore	- - - - - - - - - - - - - - - -	capacity, including chamber and grooves	- - - - - - - - - - - - - - - - - - - - - - - -	878 cubic inches
Chamber	- - - - - - - - - - - - - - - -	diameter (rear end)	- - - - - - - - - - - - - - - - - - - - - - - -	3·6 inches
Chamber	- - - - - - - - - - - - - - - -	diameter (front end)	- - - - - - - - - - - - - - - - - - - - - - - -	3·2 inches
Chamber	- - - - - - - - - - - - - - - -	length	- - - - - - - - - - - - - - - - - - - - - - - -	15·44 inches
Chamber	- - - - - - - - - - - - - - - -	mean capacity of cartridge case	- - - - - - - - - - - - - - - - - - - - - - - -	119 cubic inches

The breech mechanism of the 12-pdr QF, 12-cwt gun (Admiralty handbook, 1906). This diagram shows the breech wired for use with electric primers. During the ABW the electrical components were removed so that the guns could be fired mechanically (with percussion primers).



The mounting is constructed to allow 20 degrees elevation and 10 degrees depression being given to the gun; elevation is limited by the bottom of the spring box taking against a cutaway part of the base plate, depression by the length of the elevating clamping arc.

The gun recoils axially about ·5 inches in a cradle, hydraulic cylinder and spring box combined, similar to that belonging to the Pedestal Mark I. Mounting. The cradle rests in two trunnion boxes of a forged steel carriage, the arms of which have been strengthened as in P. I. Mounting, by means of
screw plugs.

The carriage consists of a forged steel bracket (a1), provided with trunnion bearings for the gun cradle, which is secured by cap-squares (a2) by means of a pin, chain, and eye. The lower portion terminates in a circular base plate with a central boss fitted with an adjustable pivot. The circular base plate has a rim on its outer edge for engaging with the clip ring (a3).

The gun-metal pivot (a5) with hard steel bearing piece is fitted and screwed into the boss in the base of the carriage, and is adjusted so that the weight of the gun and mounting is just supported while the circular flange on the pivot plate is clear both of the corresponding flange on the carriage and the lower part of the clip ring. The pivot is secured in position by a set screw (a6). A bearing of hard steel (a12) supported on a pair of Belleville spring washers (a10) and secured by a nut (a11) and split pin takes the weight of the gun and mounting.

The clip ring is made of manganese bronze in two parts bolted together at the lugs by steel tap bolts. It engages the flanges of the carriage and pivot plate, and prevents the mounting from lifting when the gun is fired. The clip ring is keyed to, and rotates with, the carriage when the gun is trained.

A clamping screw (a7), clamping block, and spiral spring are fitted in the clip ring. These secure the mounting in any position required.

The pivot plate (a4), which is bolted to the pedestal to reinforce the holding down ring, is a circular steel forging having a recess to receive the gun-metal pivot of the carriage, and a projecting flange for engaging with the clip ring and lugs to suit the service holding-down rings. A gun-metal bush (a9) is secured to the upper part of the recess in pivot place; it is kept in place by two set screws (a8).

The gun and mounting are trained and elevated by means of a should.er piece secured to the left side of the cradle by a key, chain, loop and eye. A forged steel arc is bolted to the left side of the carriage which engages with a clamping screw fitted to the cradle, and secures the mounting at any angle of elevation.

Training stops are bolted on to the holding down ring and a bracket carrying a drop bolt is bolted to left Y bracket.

The main firing battery is suspended in a skeleton iron frame; this frame is bolted to a steel plate prolonged to the rear for the purpose. The steel plate is bolted to the right Y bracket by 4 bolts. This fitting is now employed in all S. II. and P. III. mountings. A pistol grip firing key is secured to the shoulder piece.

To assemble the mounting, the holding clown ring being already in place: – Place on the pivot plate with one of the holes in the pivot in line with the locking bolt. Tighten up pivot plate by screwing to left with the dismounting handspike, then screw up locking bolt, and secure to pedestal by holding down bolts. This secures the pivot plate. (The pivot plate must have its parts assembled before it is lifted into position). Slack up the pivot bolt in the base plate, lift carriage on to pivot plate. Assemble and place on clip ring, then adjust pivot bolt. Lift on gun and cradle complete.

If it is required to remove the gun and mounting complete at the same time, hook the purchase on to lifting bolt of cradle, unscrew locking bolt, place handspike in hole through clip ring and into hole in pivot plate and unlock the latter from holding down ring. Pull up purchase and remove gun and mounting together.

To remount the whole, see locking bolt screwed back, lower mounting into position, screw up with handspike and secure with locking bolt.





The 12-pdr “S II” mounting, as seen in photographs of Naval “Long Twelves” taken during the ABW (Admiralty handbook, 1906).






Men of H.M.S. Powerful's Naval Brigade, posing with their 12-pdr during the siege of Ladysmith






On board H.M.S. Terrible. A “Long Twelve”, mounted on one of Scott’s improvised carriages, ready for land service. Note the use of a lanyard instead of the normal electric firing arrangement employed while at sea.




RIFLING.
.

Rifling	- - - - - - - - - - - - - - - -	number of grooves	- - - - - - - - - - - - - - - - - - - - - - - -	16
Rifling	- - - - - - - - - - - - - - - -	depth of groove	- - - - - - - - - - - - - - - - - - - - - - - -	·04 inch
Rifling	- - - - - - - - - - - - - - - -	width of grooves	- - - - - - - - - - - - - - - - - - - - - - - -	·4 inch
Rifling	- - - - - - - - - - - - - - - -	total length	- - - - - - - - - - - - - - - - - - - - - - - -	103·035 inches
Rifling	- - - - - - - - - - - - - - - -	width of lands	- - - - - - - - - - - - - - - - - - - - - - - -	·189 inch

The rifling is E.O.C. polygroove; the twist is from 1 in 120 at the breech to 1 in 28 at the muzzle, uniformly increasing; but in future guns will be straight for 18 inches and then increasing uniformly to 1 in 30 at the muzzle, and of R.G.F. [Royal Gun Factory] section.


Figure showing the profile of the E.O.C (Elswick Ordnance Company) Polygroove system, as used in the 12-pdr Naval guns. See fragment of shell from Horseshoe Hill below, with intact driving band, clearly showing the grooves left by this type of rifling.






Shell, B.L. or Q.F. Shrapnel, 12 Pr., 12, 8 or 6 cwt, Mark V (top left), together with a horizontal section through a Mark II shell (bottom left). The only major difference between these two types lay in the construction of the cage that held the shrapnel bullets. The Mk II used a system of twelve vertical wires to which was welded a spiral of flat wire, while the Mk V relied on a perforated tin container. On the right is an example from the Ladysmith area, decorated with a painting of the “Handyman at Ladysmith” (photographed by R.E.E. Gell, Newcastle, Natal).






The bases of two 12-pdr Common Pointed Naval shells, each fitted with a Base Fuze (Medium, No. 12, Mk I). Both were overshoots, found in a donga to the north of Horseshoe Hill (west of Hart’s Hill). Note the sixteen grooves in the driving band of the example on the right, displaying the characteristic profile of the E.O.C. polygroove system.






Base Percussion Fuze, Large. The design of this fuze is similar to that of the medium version used with Naval 12-pdr Common Pointed shells (Handbook on Ammunition, 1901, Plate X).






Back on board ship, one of the Long Twelves reverse-mounted, with its barrel over the trail, thus saving space on the gun deck. The gun has been re-wired, ready for use with electric primers, fired via the trigger mechanism visible on the right. During land-service the Naval 12-pdrs were fired mechanically via lanyards. For this the electric primers were removed from the cartridges and replaced with adaptors, into which were inserted percussion tubes.



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Below are three views of a copper gas-check, brought home as a souvenir after the fall of Pretoria. It is engraved: "TAKEN WITH THE BRITISH 12 PDR GUNS AT INGOGO. 1881. / AND RETAKEN AT PRETORIA. 5TH JUNE 1900." 75mm diameter.




The inscription is problematic in many respects.

Firstly, the two British guns engaged at Ingogo were not 12-pdrs; they were 9-pdrs.

Secondly, these guns were not captured, but were safely withdrawn.

Lastly, although some reports state that surplus ammunition was destroyed on the battlefield, which could account for the gas-check finding its way to Pretoria barracks, there is no evidence that the calibre of gun used at Ingogo ever took these devices.

Indeed, although the projections on this 'automatic' gas-check match the grooves of guns rifled on the Woolwich principle (including 9-pdr RML guns), it is clear that all British RML guns of this calibre (7, 9 and 16-pdrs) “fired studded projectiles only, and did not take gas-checks” (Treatise on Ammunition 1897, p. 261).

As the British Army had never employed 9 or 12-pdrs that used gas-checks, this inevitably leads to the conclusion that the “Ingogo” souvenir came from one of the guns in the Staatsartillerie arsenal.

MC Heunis believes there is only one contender: the single 9-pr 6 cwt Experimental RML Armstrong, originally owned by the OVS, but sold to the ZAR in around 1883 (see below). This gun still exists, and is now situated outside the MOTH Hall in Ladysmith.

Comparison of the rifling profile of the 9-pdr "Experimental" with the projections on the gas-check shows a convincing correlation.








9-pr 6 cwt RML of 1864 (Experimental). Courtesy of MC Heunis.







The gun outside the Ladysmith MOTH Shell-hole, before and after restoration. Courtesy of MC Heunis.







The first Boer Republic to import modern rifled artillery from Europe was the Orange Free State. Realising that only artillery would give the Free State forces superiority in a war against the Basotho, Pres. JH Brand in 1864 requested his Consul in Britain, PG Van der Bijl, to enquire about the cost of importing two 6-pr SBML guns. Van der Bijl forwarded his request to agents Messrs. Blyth & Co. who in turn copied it to Sir W.G. Armstrong & Co. On 4 July 1864 Armstrong replied: “…in the English Service the 12-pr rifled Gun has replaced the old 6-pr smooth bore, the rifled Guns being much the lighter…” Armstrong further stated: “Should you prefer a still lighter Gun, we could supply you with a 9 pr of 6 cwt…” Van der Bijl forwarded this reply to Brand with the following note: “I am rather puzzled what to order and think the 9 pr most suitable – certainly better than the old fashioned smoothbore 6 pr.” The price quoted was:

9-pr Complete with sights	……….	……….	……….	……….	……….	£130
1 Carriage & Limber complete with traversing arrangement, ammunition & axletree boxes	……….	……….	……….	……….	……….	£130
1 Elevating screw ball	……….	……….	……….	……….	……….	£7 10s
Fittings of every description, consisting of a great variety of articles required	……….	……….	……….	……….	……….	£32
TOTAL COST	……….	……….	……….	……….	……….	£299 10s

Although the exact order and delivery dates of this gun could not be determined, ample proof exists of its use in Basotholand as early as July 1865, making this specific piece one of the experimental or prototype guns manufactured during the period of the much-debated 1863 to 1865 trials.

In appearance it resembled the 9-pr 6 cwt RBL, but without the early breech closing arrangement. Rifling consisted of an experimental version of the three grooved system and differed in having ‘shunted’ rather than uniform grooves. In this system the grooves were stepped, with a shallow groove towards the driving edge, and a deeper part towards the loading edge. On loading the studs of the shell easily followed the deeper groove until, at the chamber it was shunted across to the stepped-up groove to produce a tighter fit. When fired it followed this shallow groove on the driving edge and thus centred the projectile inside the bore. Although this rifling system produced some good results it was not approved for British field guns.

Like its RBL predecessor the 9-pr RML gun was still mounted on the early double-plate wooden carriages of the smooth bore era. This consisted of a trail and a mounting of two heavy planks or plates held together by the axletree and two or more transoms. Wheels were also reminiscent of those used for earlier carriages complete with ‘Old Pattern’ wooden naves. Elevation was achieved by means of a slow screw process. One end of the screw was attached to the breech, while the second passed through a ball threaded to receive it and working in a socket on the trail. The ball was fitted with four handles, which, when turned, elevated or depressed the gun.

A tangent sight graduated in yards was used which fitted into a socket on the right side of the breech. The gun was also equipped with open centre sights, probably for boat use. Shells were fired by means of a copper friction tube igniting a black powder filled serge bag.

During the Second Basotho War this specific 9-pr saw action as early as 25 July 1865 during the first bombardment of Thaba Bosiu and it was reported to have scored a direct hit on Chief Mosjesh’s house. In August 1865 it was used to cover both large frontal attacks on Thaba Bosiu, while in September it accompanied Capt. Goodman’s party that was sent to punish Molapo and to clear Witsieshoek. The Third Basotho War saw it taking part in the attacks on Beestneus (17 April 1867) and Thaba Culo (2 May 1867), but a commando report after the Thaba Culo fight stated: “…the Armstrong missed the entire mountain…” In August and September it was again employed, at Mount Koranna and possibly also at the closing battles of Makwai, Tandjesberg and Kiemeberg. Being the largest rifled gun in Free State use at that stage, it was one of the main causes why the last Basotho War was often referred to as the “War of the Cannon’s Boom”.

After the Basotho Wars the gun remained in Free State service and by December 1880 was reported by Capt. FWR Albrecht to be the best of the Free State’s field guns. In November 1882 the Transvaal requested the Free State’s assistance to quell an uprising by the Ndebele tribe of Chief Njabel. According to a Free State newspaper of the time, The Friend of 23 November 1882, the Transvaal at first asked for three guns and the services of Albrecht, but in the end only Adjutant JAJ van Rensburg and the 9-pr were dispatched; the gun arriving by wagon at the main Transvaal laager somewhere between 16 and 24 January 1883. It is not clear how or when the gun and its ammunition were sold to the Transvaal.

It is not known whether the gun saw service in any of the other Transvaal tribal campaigns of the 1880s and early 1890s. By this time it was completely obsolete and since it would not have been of much use against better-equipped Western enemies, it was stationed at Pietersburg for use against possible tribal uprisings in the north. In his reminiscences SPE Trichard, last CO of the Staatsartillerie, recalled that during the Malaboch campaign of 1894 a steel fort was erected at Cooksley’s shop near Louis Trichardt in the Northern Transvaal. Later known as Fort Hendrina, its armament consisted of “various whitworth and armstrong cannon”.

It is not certain whether this gun saw any service during the Boer War or exactly where and when it was captured, but one war-time photograph of it is captioned: “Boer gun captured by force under General French”. The most likely listing in British Public Records Office (PRO) documents on captured Boer guns is a 9-pr RML captured at the occupation of Pretoria on 5 June 1900.




9-pr 6-cwt RML (Experimental), photographed at Pretoria Ordnance Depot, after the gun’s capture.


In Free State use mention could only be found of segment shells with bursting charges and percussion fuzes, but Transvaal ammunition inventories of 1886 and 1896 contain “double walled”, shrapnel, star and incendiary shells as well as “Pettman BL plain fuzes”. A defence report of 1892 also makes mention of case shot and “long shells” in stock at Pietersburg and Fort Hendrina.

Fortunately this remarkable gun survived. PRO WO32/7028 states that a 9-pr RML, serial number 1225, was allocated to the Mayor of Ladysmith in 1904. Today it rests outside the Ladysmith MOTH Shellhole. It was originally thought to be a gun used by a Royal Navy landing party during the 1879 Zulu War, but the gun’s serial number confirms the WO32/7028 listing. The left trunnion is engraved: Sir WG Armstrong & Co. / No. 1225 / 1864 and the right: Weight 648 lb / 9 pr / Prep 45 lb. After the gun’s history was researched and revealed, the author volunteered to restore it to its original Boer War condition.




Left trunnion of the gun, engraved: "Sir WG Armstrong & Co. / No. 1225 / 1864" (after restoration). Courtesy of MC Heunis.




Muzzle of the 9-pdr, showing the rifling grooves and how these match the projections on the “Ingogo” gas-check.




Photograph of the ZAR 9-pdr captioned “Boer gun captured by force under General French”.


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Thank you for yet another truly brilliant post Neville. I found this very interesting indeed. You know, you really should write a book.

Boer Artillerymen with Maxims

The artillery of the Boers has naturally been made the subject of a great deal of discussion. They were exceptionally well provided with Nordenfelt Maxims, the terrible 'Pom Pom' (to use the now familiar name); and there term Long Tom, as applied to their bid guns, considering their length of range as well as length of barrel, was certainly appropriate.

Source: www.angloboerwar.com/forum/19-ephemera/3...-w-h-gill-1900#89968

A truly fascinating article, with wonderful sleuthing. Thank you.

Owen