Canadian Historic Sites: Occasional Papers in Archaeology and History No. 15

A History of Martello Towers in the Defence of British North America, 1796-1871

by Ivan J. Saunders

Conclusions

Martello towers were a distinctive and characteristic form of light permanent fortification popular in British North America in the half-century between 1796 and 1846. Militarily, they bridged the gap between the ephemeral and scattered colonial defence works of the 18th century and the massive, strategically sited and permanent casemated masonry forts of the 19th century. Politically, the inception of the towers in British North America was closely bound up with the imperial government's desire to regularize the defence of the British American colonies, and their decline coincided with the abandonment of the policy of defending the interior of those colonies against possible American aggression.

Martello towers were of declining value in the altered conditions of British North American warfare after 1846, but they remained in full and active service until rendered obsolete by the adoption of rifled ordnance after 1860. Although this important technical development marked the real end of their direct military use in an effective offensive capacity, all of the towers were retained in service until the British withdrawal in 1870. After that time only three or four of the five in Halifax remained in use, in much diminished roles. Had the British remained, the rifled gun and the need for a much heavier and expanded system of works to combat it would have led to similar treatment of the other towers. Martello towers were very much a product of the late smoothbore era of ordnance development, and, though in eclipse after 1860, they provided 75 years of armed service to the British defenders of British North America.

The Canadian Martello towers were all self-defensible elevated gun platforms erected as battery keeps, light sea batteries or detached land defences. A great variety of structural variation was displayed in the achievement of this essential functional similarity. These variations were products of the personal predilections of their builders and the maturation of the design over time. The Canadian towers can be classified into three separate structural phases: Edward's first three Halifax towers: the seven commenced between 1808 and 1815 at Quebec, Saint John, and Halifax; and the six constructed at Kingston after 1845. Edward's towers were the simplest and least defensible of all those constructed in Canada, while those at Kingston were the most complex and best adapted to resist bombardment by heavy smoothbore guns. The offensive and defensive ordnance of the towers themselves was a free adaptation of the pieces best suited to the requirements and role of each tower. They were generally a mixture of guns and carronades of varying calibres. Such an amalgam combined accurate long-range fire with a high volume of short-range protection. The towers' mixed firepower, resistence to artillery and high escarp walls made them effective and versatile defensive instruments in selected circumstances.

Structurally, the towers displayed certain basic similarities. In addition to their common preparation for a mixed top ordnance of guns and carronades, each was embrasured for several additional pieces lower down the scarp wall, and each was provided with some means of loopholed musketry flank defence. Most of the towers were two storeys in height but in a few cases a third storey was added to provide more barrack accommodation. In every necessary case the lower storey was fitted out as a storage area with a magazine, and the upper storey or storeys were always reserved for barrack use. The towers varied in exterior diameter from 30 to 72 ft. and in height from 26 to 46 ft. The Prince of Wales Tower was at once the lowest and widest of them.

The solid exterior walls of the towers varied greatly in thickness, from 4 ft. at York Redoubt to 15 ft. on the seaward face of the Kingston towers. The Canadian towers were formed from a variety of locally available building materials. In every case they were faced in masonry, either rubble or ashlar. In a few instances their walls were of uniform composition but generally the interior of the towers was lined with brick and the wall filled with rubble masonry to the exterior cut-stone facing.

All but two of the towers were constructed with a circular central brick or masonry pillar to support their wooden terreplein roofs or bombproof arches. These pillars were generally solid columns, but in some of those in the Maritime provinces they were hollow. For the most part the central spaces thus created were small. At the Prince of Wales tower, however, this arrangement was used to create an inner room 16 ft. in diameter.

Most of the Canadian Martello towers were provided with a bombproof brick or ashlar masonry arch during their construction and only two of the Halifax towers remained without that form of defence against high-angled fire. In most cases these were annular arches sprung from the central pillar, although the Branch Ditch towers at Fort Henry were provided with domed arches. Most of the towers contained their own bombproof, brick-lined expense magazine on the lower level, and most were provided with some form of local water supply.

All of the towers, with the exception of some of those at Halifax. were constructed with their main entrances at the second level of the towers. These were reached by means of drawbridges or movable stairs. At Halifax a confusing variety of means of access was provided for the first four towers constructed. The parapet height of most of the towers was 6 ft. as this provided full cover for the defenders and was the level best adapted for the use of traversing guns. A banquette at the base of the parapet was a necessary feature of each. Varying means of musketry flank defence were provided for the towers. They included caponiers, machicoulis, and ranges of loopholes in the tower walls themselves.

It is evident that there was no single structural pattern in the development of Canadian Martello towers. Each tower, or small group of towers, in a particular locale was freely adapted and conditioned to the various requirements of its particular military environment. These necessary adaptations were magnified by the whims of their various builders, the press of circumstances and the changing military conditions over the 50-year span of their construction.

This generation of masonry towers originated at the end of the 18th century. Such works had long been a popular form of coastal defence in southern Europe, but their widespread adoption into the British military service at that time was the joint product of an accident of military history and the desperate straits of the British government in the face of a threatened Napoleonic invasion. The impressive resistance of the masonry tower on Cape Mortella in Corsica in 1794 popularized the value of such works. The conditioning of this incident made masonry gun towers an obvious expedient when a decade later, the British government was casting about for a cheap, durable, impressive and easily built means of defending the threatened coastline of the British Isles. There and later in Canada, strictly military considerations were not paramount, and little cognizance was taken of the inherent defects and weaknesses of all such works. The government dwelt instead on their capacity to resist naval gunfire, the difficulty of scaling their high scarp walls and the low level of maintenance and small garrisons that they required. Martello towers were, everywhere and always, a compromise that met the capacities of the British government, even if they did not completely fill the requirements for permanent fixed artillery defences.

The hundred or so Martello towers constructed in Great Britain between 1804 and 1812 were adopted for the single purpose of sea defence. In this capacity their vulnerability to an accurate land-based artillery fire was not a consideration. In British North America their use was not so restricted. Here they were freely adapted to meet a wide variety of local needs. This wider use constitutes the most important single difference between the British and the British American Martello towers. This difference was partly a consequence of the differing defensive requirements of the two areas, but it was chiefly a question of money. Large sums were rarely lavished on colonial defence, and at the end of the 18th century towers generally offered the only means of permanently and cheaply fortifying important colonial centres. Their great durability and low maintenance levels were a great attraction in a climate where hard frosts could destroy equally expensive earthworks in a year. Their thick masonry walls were also infinitely more able to resist artillery fire than the wooden blockhouses that remained their only practical enduring alternative. With these inducements it is not surprising that engineers and other military officers in British North America chose to ignore the disadvantages of the towers in certain circumstances and to employ them in preference to less durable structures or no works at all.

A total of ten Martello towers were completed or commenced in British North America in the first enthusiasm of their acceptance, in the years between 1796 and 1815. The first few were built to combat the menace of French naval attack but all of the later ones were constructed to resist an emergent American enemy. The first three towers, erected at Halifax between 1796 and 1798, owed nothing to the design later accepted in England. They differed from those towers in function and in many significant structural features. They owed their origin to the same pre-1800 causal factors that later produced the English towers. These included the Cape Mortella incident and the pre-1794 British military view of the value of such works in special conditions, primarily as keeps for batteries. All of the other Canadian towers post-dated the commencement of the contemporary English works. In consequence, although they displayed considerable structural dissimilarities in detail, they were basically derived from the English designs, and incorporated all of their more salient features. The first four such towers were constructed at Quebec City between 1810 and 1812. Before 1815, two more were finished and one commenced in the Maritime provinces.

Their unrestricted adaptive use was clearly illustrated in the varied locations of these first towers. The three early Halifax towers were battery keeps, assailable principally from the land. The four Quebec towers and the one built at Saint John, New Brunswick, were employed entirely in land defence roles. Only the ones for Georges Island and Mauger Beach at Halifax fully met the accepted British requisite of being primarily exposed to less effective naval gunfire. The full acceptability of Martello towers in land-bound colonial locales is reinforced by the proposal of a number of others in similar circumstances in this period. These were fully accepted by the local military commanders and by the Board of Ordnance in England. In every instance they appear to have failed of implementation from some combination of labour, time or money rather than from voices raised against their effectiveness. Although eight of the Canadian towers were armed and prepared for combat at the outset of the War of 1812, none of them was subjected to attack.

The military readiness of the Martello towers declined and they were subjected to decades of neglect in the era of peace that followed the War of 1812. No new Martello towers were begun between 1815 and 1845. They continued, however, to be a popular proposed means of meeting a wide variety of local defensive needs. While the towers continued to be an accepted facet of the fortification orthodoxy of the postwar decades, their overall value declined somewhat as a changing imperial policy brought the construction of large permanent masonry works within the grasp of the military in the colonies. This emergent policy, fully articulated by the Smyth Commission of 1825 and accepted and implemented by the engineer committees of 1826-29, produced a concentration of all available financial resources on a few major fortresses collectively designed to resist an American attack until the country could be relieved from abroad. These works were of a new order of magnitude in British America and they severely eclipsed the mere delaying role of even the most advantageously sited of the Martello towers.

While this new strategic departure effectively prevented the completion of any more Martello towers, it did not hamper their continued proposal at all. Each of the new heavy works was inevitably very costly, and in consequence there could be very few of them. Martello towers remained a satisfactory means of filling some of the gaps in a naval and military frontier that extended for over 1,000 miles into the continental interior. The all-important Smyth Commission of 1825 itself recommended their frequent use, and its commendation was repeatedly echoed over the next 20 years by military authorities in England and in British North America.

The last Canadian Martello towers, however, were not constructed as minor adjuncts to the main defensive policy laid down in 1825, but were instead a direct consequence of its recognized failure. As early as 1841 it was realized in some quarters that available financial resources would never allow a number of fortresses adequate to prevent a successful American invasion of the interior of British North America. Rapidly improving land communications and the almost absolute American naval supremacy on the Great Lakes would inevitably open up more avenues of assault for a well-supplied American army than heavy fixed fortifications could ever close. These military factors dictated a further reassessment of the prospects and requisites of British American defence.

This leisurely re-examination was abruptly terminated by a new Anglo-American crisis in 1845. A hurried review of the existing defences in that year prompted the British Colonial Office precipitately to order the commencement of the Martello towers at Kingston. These long mooted works were of no overwhelming military value, but they did meet important political requirements and offer some cursory measure of military defence to the terminus of British interior communications.

After 1846, with the dissipation of the Oregon crisis, the British government was able to resume its interrupted examination of its role in the defence of British North America. In the preceding crisis it had become evident that any successful defence in the interior must rest mainly on the spirit of the local populace. The conclusion that neither fortifications nor British regulars would be of much avail was welcomed in the altered British political atmosphere that prevailed after 1846. This far-reaching decision began to be implemented with the reduction and concentration of the garrisons in the early 1850s. It proceeded, with only one significant interruption, until the final withdrawal of the British army from the North American interior.

This new British political departure guaranteed that no new Martello towers would be built. The Kingston towers were only completed in 1848 because of the previous investment in their construction. They were among the last works to be completed in the interior of British North America. Even without this change in policy, it is doubtful if more would have been erected, as they were clearly approaching obsolescence. The Kingston towers were provided with all possible ancillary defences, but they were never deemed fully defensible against steam war vessels, heavier smoothbore guns and the increased power of the more numerous American armies. These same criticisms applied in even greater measure to the older towers, none of which had been improved since 1815.

The declining value of the 16 Canadian Martello towers was little noted in the peaceful decade of the 1850s. Their defensibility was not improved, and they were not armed or rearmed to meet changing military requirements. Subsidiary military uses were found for some of them, however, and all were maintained as active, unchallenged components of the existing permanent defence system.

This quiet perpetuation of the towers in their original roles was suddenly terminated by the introduction of the powerful and revolutionary rifled gun into the American military service in 1860. This new weapon, with its longer range, greater accuracy and more potent breaching power at once rendered most of the old works of defence, including Martello towers, recognizably obsolete. A display of the power of these new guns in the opening phases of the American Civil War, and the coincident Anglo-American military crisis of 1861-62 with its uneasy aftermath, forced yet another hurried review of British American defences. These examinations, carried out between 1862 and 1865, produced implicit or explicit condemnations of Martello towers in every instance. The successive reports merely voiced a fact that had been inescapable since 1860 and was in process of being recognized even before that. Most of the towers remained armed and some of them continued in their previous uses until 1870, but after 1860 their only possible value was as supporting adjuncts to the new works designed to house and resist the new rifled guns. The simultaneous British military withdrawal prevented the continuation of their services everywhere except at Halifax, where the British remained until 1906. There the Prince of Wales Tower was retained as a magazine, and two of the other towers were incorporated into more modern works. Neither they nor any of the others, however, were of any armed military value after 1870.

Martello towers were erected to meet the nearly static requirements of British North American defence between 1796 and 1846. Their military value declined thereafter and they were made fully obsolete by the rifled gun in 1860. For the most part they ceased to be of any military importance in 1870, when the divergent strands of their technical obsolescence and the imperial policy of withdrawal finally combined to thrust nearly all of them into the hands of an uninterested Canadian nation.