The Evolution of Naval Armament by Frederick Leslie Robertson

CHAPTER V

3366 words  |  Chapter 7

THE CARRONADE AT the monthly meeting of the Carron Company, a Scotch iron-founding and shipping firm, which was held in December, 1778, the manager informed the board that, in order to provide armament for some of the Company’s sailing packets, he had constructed a very light species of gun, resembling a cohorn, which was much approved by many people who had come on purpose to inspect it. So favourable, indeed, was the impression given by the inspection of this weapon that, with the company’s permission, he could receive a great many orders for them. Whereon it was resolved to authorize the manufacture of the new species in quantity; and to call all such guns as should be made by them of this nature, Carronades. Such were the circumstances in which the carronade first came into use. And the following advertisement, appearing in Edinburgh shortly afterwards, sufficiently explains the incentive for exploiting the new type of ordnance, and the reason of its popularity among shipowners, passengers and crews. “To sail March 5, 1779, the _Glasgow_, Robert Paterson master, mounting fourteen twelve-pounders, and men answerable.... N.B.--The Carron vessels are fitted out in the most complete manner for defence at a very considerable expense, and are well provided with small arms. All mariners, recruiting parties, soldiers upon furlow, and all other steerage passengers who have been accustomed to the use of fire-arms, and who will engage in defending themselves, will be accommodated with their passage to and from London, upon satisfying the masters for their provisions, which in no instance shall exceed 10s. 6d. sterling. The Carron vessels sail regularly as usual, without waiting for the convoy.” The carronade was a very short, light, carriage gun of relatively large bore, made to take a standard size of long-gun shot and project it, by means of a small charge of powder, against an enemy at close range. Its proprietors soon found a market for the produce of their foundry, not only for merchant ships but for men-of-war. The reputation of the new ordnance quickly spread; carronades found a place almost immediately among the orthodox armament of the greater number of our fighting ships; and kept their place till, after a chequered career of half a century, during which they contributed both to victory and to defeat, they were finally discarded from the sea service. The story of the carronade begins some little time before the meeting of the Carron board in the year 1778. It will be remembered that in 1747 Mr. Benjamin Robins had advocated, in a much-talked-of paper, an increase in the calibre of warships’ guns at the expense of their ranging power, and that in support of his argument he had drawn attention to two features of ship actions--first, that the great majority of duels were fought at close quarters; secondly, that the destructive effect of a cannon-ball against an enemy’s hull depended largely on the external dimensions of the ball, the larger of two balls producing an effect altogether out of proportion to the mere difference in size. However invalid may have been the arguments founded on these assertions--and that there was a serious flaw in them time was to show--there could be no doubt that, so far as considerations of defence were concerned, the conclusions reached were of important value. In the case of a merchant packet defending herself from boarding by a privateer, for example, a light, short-ranging gun throwing a large ball would give far more effective protection than a small-calibre long gun. And if, moreover, the former involved a dead weight less than a quarter, and a personnel less than half, of that involved by the latter, the consideration of its superiority in action was strongly reinforced, in the opinion of shipowners and masters, by less advertised considerations of weight, space, and equipment--very important in their relation to the speed and convenience of the vessel, and hence to all concerned. So the arguments of Robins, though propounded solely with reference to warships, yet applied with special force to the defensive armament of merchant ships. A conception of this fact led a very able artillerist, General Robert Melville, to propose, in 1774, a short eight-inch gun weighing only thirty-one hundredweight yet firing a nicely fitting sixty-eight pound ball with a charge of only five and a half pounds of powder. This piece he induced the Carron company to cast, appropriately naming it a Smasher. Of all the carronades the Smasher was the prototype. It possessed the special attributes of the carronades in the superlative degree; the carronade was a reproduction, to a convenient scale, of the Smasher. That General Melville was the prime inventor of the new type, has been placed beyond doubt by the inscription on a model subsequently presented to him by the Carron Company. The inscription runs: “Gift of the Carron Company to Lieut.-General Melville, inventor of the Smashers and lesser carronades for solid, ship, shell, and carcass shot, etc. First used against French ships in 1779.”[85] In almost every respect the Smasher was the antithesis of the long gun: the advantages of the one were founded on the shortcomings of the other. For instance, the smallness of the long gun’s ball was a feature which, as ships’ sides came to be made stronger and thicker, rendered the smaller calibres of long guns of a diminishing value as offensive armament. It was becoming increasingly difficult to sink a ship by gunfire. The round hole made near the enemy’s water-line was insufficient in size to have a decisive effect; the fibres of the timber closed round the entering shot and, swelled by sea-water, half closed the hole, leaving the carpenter an easy task to plug the inboard end of it. The large and irregular hole made by a Smasher, on the other hand, the ragged and splintered opening caused by the crashing of the large ball against the frames and timbers, was quite likely to be the cause of a foundering. Again, the high velocity of the long gun’s ball, while giving it range and considerable penetrative power, was actually a disadvantage when at close quarters with an enemy. The maximum effect was gained, as every gunner knew, when the ball had just sufficient momentum to enable it to penetrate an opponent’s timbers. The result of a high velocity was often to make a clean hole through a ship without making a splinter or causing her to heel at all. Hence the practice of double-shotting: a system of two units which, as we have just seen, was less likely to prove effective than a system of a larger single unit. On the other hand the Smasher vaunted its low muzzle velocity. As for the relative powder charges, that of the long gun was wastefully large and inefficient, while that of the Smasher was small and very effective. It was in this respect, perhaps, that the Smasher showed itself to the greatest advantage. And as this feature exerted from the first an important influence on all other types of ordnance, we will examine in some detail the means by which its high efficiency was attained. Apart from the inefficiency inherent in the small-ball-and-big-velocity system the long gun laboured under mechanical disadvantages from which its squat competitor was happily free. In the eighteenth century the state of workshop practice was so primitive as to render impossible any fine measurements of material. Until the time of Whitworth the true plane surface, the true cylinder and the true sphere were unattainable in practice. For this reason a considerable clearance had to be provided between round shot and the bores of the guns for which they were intended; in other words, the inaccuracies which existed in the dimensions of guns and shots necessitated the provision of a certain “windage.” But other considerations had also to be taken into account. The varying temperatures at which shot might require to be used; the fouling of gun-bores by burnt powder; the effect of wear and rust on both shot and bore, and especially the effect of rust on the shot carried in ships of war (at first enlarged by the rust and then, the rust flaking or being beaten off with hammers, reduced in size)--all these factors combined to exact such disproportionate windage that, in the best conditions, from one-quarter to one-third of the force of the powder was altogether lost, while, in the worst conditions, as much as one-half of the propulsive force of the powder escaped unused. Not only was a large charge required, therefore, but the range and aim of the loosely fitting shot was often incorrect and incalculable; the motion of the shot was detrimental to the surface of the bore and the life of the gun; while the recoil was so boisterous as sometimes to dismount and disable the gun, injure the crew, and even endanger the vessel. The inventor of the Smasher, by eliminating this obvious deficiency of the long gun, gave to his weapon not only a direct advantage due to the higher efficiency of the powder-charge, but also several collateral advantages arising from it, such as, economy of powder, ease of recoil, and small stresses upon the mounting and its supporting structure. It had been laid down by Dr. Hutton in 1775, as one of the chief results of the systematic experiments carried out by him at Woolwich in extension of the inquiries originated by Robins, that if only the windage of guns could be reduced very important advantages would accrue; among others, a saving of at least one-third of the standard charges of powder would result. General Melville determined to give the Smasher the very minimum of windage necessary to prevent accident. The shortness of the bore favoured such a reduction. The large diameter, though at first it might appear to render necessary a correspondingly large windage, was actually an advantage from this point of view. For, instead of adhering to the orthodox practice with long guns, of making the windage roughly proportional to the diameter of the bore, he gave the Smasher a windage less than that of a much smaller long gun, arguing that though a certain mechanical clearance was necessary, yet the amount of this clearance was in no way dependent on the diameter of the shot or piece. The large size of the Smasher acted therefore to its advantage. The windage space through which the powder gases could escape was very small in relation to the area of the large ball on which they did useful work. But this divergence from the standard practice would appear to necessitate the provision of special ammunition for use with the Smasher: the nicely fitting sixty-eight pound ball would require to be specially made for it? And this would surely militate against the general adoption of the Smasher in the public service? No such difficulty confronted the inventor. For, curiously enough, the principle on which the dimensions of gun-bores and shot were fixed was the reverse of the principle which obtains to-day. Instead of the diameter of the _gun_ being of the nominal dimension and the diameter of the shot being equal to that of the gun minus the windage, the diameter of the _shot_ was the datum from which the amount of the windage and the calibre of the gun were determined. So, the size of the shot being fixed, a reduction of windage was obtainable in a new design of gun by boring it to a smaller than the standard diameter. And this was what the inventor of the Smasher did. The large ball, in combination with the restricted windage and the small charge of powder, gave the Smasher ballistic results far superior, relatively, to those obtained with the long gun. Its lack of ranging power was admitted. But for close action it was claimed that it would prove an invaluable weapon, especially in the defence of merchant ships.[86] Not only would its large ball make such holes in the light hull of an enemy privateer as would break through his beams and frames and perhaps send all hands to the pumps; but, projected with just sufficient velocity to carry it through an opponent’s timbers, it would thereby produce a maximum of splintering effect and put out of action guns, their crews, and perhaps the vessel itself. § On the lines of the Smasher the “lesser carronades,” more convenient in size and more easily worked, were cast, and quickly made a reputation in merchant shipping. The Smasher itself was offered to the admiralty, but was never fitted in a royal ship; though trials were carried out with it later with hollow or cored shot, to ascertain how these lighter balls compared in action with the solid 68-pounders. Meanwhile the Carron Company found a large market for the lighter patterns of carronade; the 24, 18, and 12-pounders were sold in large numbers to private ships and letters-of-marque, and to some of the frigates and smaller ships of the royal navy. The progress of the new ordnance was watched with interest by the board of admiralty. In 1779 we have Sir Charles Douglas writing to Sir Charles Middleton in full accord with his views on the desirability of mounting Carron 12-pounders on the poop of the _Duke_, and suggesting 24-pounders, three a side, upon her quarter-deck. To the same distinguished correspondent Captain Kempenfelt writes, deploring that no trials have yet been made with carronades. Shortly afterwards the navy board discusses the 68-pound Smasher and desires the master-general of ordnance to make experiment with it. A scale is drawn up by the navy board, moreover, and sanctioned by the admiralty, for arming different rates with 18-and 12-pounder carronades. The larger classes of ships, the first, second, and third rates, have their quarter-decks already filled with guns; but accommodation is found for a couple of carronades on the forecastles, and for half a dozen on the poop, which for nearly a century past has served chiefly as a roof for the captain’s cabin. This is now timbered up and given three pairs of ports, making a total of eight ports for the reception of carronades. In the case of smaller ships less difficulty is experienced. Ports are readily cut in their forecastles and quarter-decks, and in some cases their poops are barricaded, to give accommodation for from four to a dozen carronades.[87] The new weapon found its way into most of our smaller ships, not always and solely as an addition to the existing long-gun armament, for use in special circumstances, but in many cases in lieu of the long guns of the establishment. The saving in weight and space gained by this substitution made the carronade especially popular in the smaller classes of frigate, the sloops, and brigs; many of which became almost entirely armed with the type. The weak feature of the carronade, which in the end was to prove fatal to it--its feeble range and penetrating power--was generally overlooked, or accepted as being more than compensated for by its many obvious advantages. The carronade, it was said by many, was the weapon specially suited to the favourite tactics of the British navy--a yard-arm action. There were others, however, who were inclined to emphasize the disability under which the carronade would lie if the enemy could contrive to avoid closing and keep just out of range. And on this topic, the relative merits of long gun and carronade as armament for the smaller ships, discussion among naval men was frequent and emphatic. The king’s service was divided into two schools. The advocates of long guns could quote many a case where, especially in chase, the superior range of the long gun had helped to win the day. The advocates of the carronade replied with recent and conclusive examples of victories won by short-gun ships which had been able to get to grips and quickly neutralize the advantages of a superior enemy armed with long guns. When challenged with the argument that, since the advantages of the carronade entirely disappear at long ranges it is essential that ships armed with them should be exceptionally fast sailers, they replied, that the very lightness of a carronade armament would, other things being equal, give ships so armed the property required. As for out-ranging, they were even ready to back their carronades in that respect, if only they were well charged with powder. It was a matter of faith with many that, in spite of Dr. Hutton’s published proof to the contrary, a considerable increase of range could be obtained by the expedient of shortening the gun’s recoil; so that in chase it was a common procedure to lash the breechings of carronades to the ship’s timbers, to prevent recoil and to help the shot upon its way. At first mechanical difficulties occurred in the fitting of the new carronade mountings which, though not due to any defect inherent in the equipments, nevertheless placed them under suspicion in certain quarters. Though the prototype had trunnions like a gun, the carronades afterwards cast were attached by lugs to wooden slides which recoiled on slotted carriages pivoted to the ship’s side timbers, the slide being secured to the carriage by a vertical bolt which passed down through the slot. The recoil was limited by breechings; but as these stretched continuously the bolt eventually brought up with a blow against the end of the slot in the carriage: the bolt broke, and the carronade was disabled. This happened at Praya Bay, where the carronades broke their beds, owing to slack breechings, after a few rounds. Captains complained, too, that the fire of the carronades was a danger to the shrouds and rigging. [Illustration: A CARRONADE] In spite of these views the popularity of the new ordnance increased so rapidly that in January, 1781, there were, according to the historian James, 429 ships in the royal navy which mounted carronades. On the merits of these weapons opinion was still very much divided. The board of ordnance was against their adoption; the navy board gave them a mild approval. In practice considerable discretion appears to have been granted to the commanders of ships in deciding what armament they should actually carry.[88] But the uncertainty of official opinion gave rise to a surprising anomaly: _the carronade, although officially countenanced, was not recognized as part of the orthodox armament of a ship_. What was the cause of this is not now clear. It has been said in explanation, that the carronade formed too fluctuating a basis on which to rate a ship’s force; that a long-gun basis afforded a key to the stores and complement of a ship, whereas carronades had little effect on either complement or stores; or that it may have been merely inertia on the part of the navy board. Whatever the cause, the ignoring of the carronade, in all official quotations of ships’ armaments, led to great uncertainty and confusion in estimating the relative force of our own and other navies, to suggestions of deception on the part of antagonists, to the bickering of historians and the bewilderment of the respective peoples. This extraordinary circumstance, that carronades with all their alleged advantages were not thought worthy to be ranked among the long guns of a ship, is commented on at length by James. “Whether,” he says, “they equalled in calibre the heaviest of these guns, added to their number a full third, or to their power a full half, still they remained as mere a blank in the ship’s nominal, or rated force, as the muskets in the arm-chest. On the other hand, the addition of a single pair of guns of the old construction, to a ship’s armament, removed her at once to a higher class and gave her, how novel or inconvenient soever, a new denomination.” While the products of the Carron firm were gaining unexpected success in the defence of merchant shipping, their value in ships of the line was not to remain long in doubt. Some of the heavier carronades had been mounted in the _Formidable_, _Duke_, and other ships, and their presence had a material effect in Admiral Rodney’s action of April,