Coal and the Advent of the First World War at Sea

I. Introduction

The changeover from coal to oil propulsion in the world’s navies in the period of the First World War has been treated by many historians largely as a straightforward efficiency exercise in adopting new technology. For the Royal Navy, it has been argued, the most serious complication was the resulting dependence on overseas sources of supply rather than the domestic south Welsh coalfields. ¹ The problems of obtaining, storing, and transporting oil certainly had profound strategic as well as financial and operational implications, but this approach to the subject has tended to leave unexamined some of the key issues involved in the still very extensive naval use of coal before 1914, as well as its effects on the conduct of the naval war in 1914–18.

Many aspects of the coal problem have been dealt with by W.M. Brown ² and Jon Sumida. Together with Sumida’s parallel study of industrial logistics, they have created a much better understanding of the support systems which underlay the working of British naval power. ³ This article assesses the issues of coal through analysis of the problems related to ship operations which were encountered with manpower, ship design, and coal supply. It argues that the demise of coal became likely through the introduction of turbine propulsion, which gave warships for the first time real potential to achieve and maintain high speeds. It then became unavoidable when the limitations inherent in coal firing became obvious in the context of global, long-range operations and a threat environment that included the submarine and which required surface ships to maintain much higher speeds at sea for vastly more extended periods than they had before 1914.

II. The Turbine and High Speed

The relationship between the introduction of the turbine and the adoption of oil in warships was closer than has been generally understood. At the turn of the twentieth century, although significant improvements in engine reliability had been achieved, sustained high-speed steaming remained a significant challenge for large reciprocating engine warships. The essential problem was that the design of a reciprocating plant for an armoured vessel was more constrained than within a merchant ship. In particular, the height of the plant was generally more restricted, which required shorter, faster, and mechanically more demanding piston cycles, while access to machinery and to the furnaces in the boilers was relatively confined. For warships the increase not only in absolute speeds which could be achieved but in the overall reliability of the turbine by comparison was little short of revolutionary. Only a few years after Admiral Sir John Fisher was being praised for having changed the British Mediterranean Fleet from one of 12 knots with breakdowns to one of 15 without, ⁴ the prototype Dreadnought achieved a staggering result with a 7,000 nautical mile return trip to the West Indies at an average of more than 17 knots – with no defects. ⁵ The advantage of turbines was even more clearly demonstrated by the battlecruiser Indomitable, which achieved an average speed of 25.3 knots over three days during her return from Canada in August 1908. ⁶ The best a reciprocating engine cruiser squadron could manage across the Atlantic two years before had been an average speed nearly 7 knots less, ⁷ while all involved had required machinery repairs afterwards.

III. Manpower and Coal

Such an improvement in engine reliability brought into the spotlight the problems of coal firing to a much greater extent than before, particularly for the Royal Navy with its global commitments. The essential problem was coal simply could not be handled mechanically within warships. Despite repeated experiments, which enjoyed greater success in merchant vessels, it proved impracticable to substitute machinery for manual labour. In consequence, engineering personnel constituted approximately half the crew. When the warship was under way, the stokers performed three main functions. The first was placing the coal into the furnaces; the second was the removal of ash and debris (or ‘clinkers’); the third was the shifting of coal between bunkers, a process known as ‘trimming’, from the distant to the ready-use bunkers and thence to the stokeholds. Even if the coal was ideal – and this was not a given – the work was highly demanding, and it became progressively more evident that the requirement for high sustained speeds was incompatible with official schemes of complement. Prior to her record-breaking Atlantic run, Indomitable embarked additional personnel to assist in the stokeholds. ⁸ So did other ships on similar exercises involving sustained high-speed steaming. The device adopted around the turn of the century of having oil spray firing as a supplement to the coal alleviated some of the workload, but by no means all. Fitting and operating the equipment also created its own set of challenges. ⁹

There were other cost and management aspects to the manpower problem. The 1914 battlecruiser Tiger (with 39 boilers) had an engineering complement of 600 on coal and oil. By comparison, the post-war Hood, which could develop nearly half as much power again with 24 boilers on oil alone, had one of 300. ¹⁰ Across the entire fleet the potential reduction represented a significant saving at a time when manpower costs were of great concern, and it was identified by John Fisher as a strong argument for oil as early as 1901. ¹¹ This largely involved the junior, lower paid, and less skilled stoker ranks, but reductions in the number of boilers fitted also meant that fewer experienced supervisors were needed. When faced with a ‘Back to Coal’ movement in 1931, the Admiralty estimated that the difference in the personnel requirement between the almost completely oil-fired – and much smaller – fleet of the time and its coal equivalent was some 15,000 men. ¹² These savings were compelling and partly outweighed the greater cost of oil. At the 1912 pay rates, a reduction in one ship of 300 junior stokers constituted an annual saving of more than £11,000 in wages alone ¹³ – the equivalent of well over 2,500 tons in oil fuel, and this without inclusion of the costs of higher rates, pensions (a particular concern), and other elements of personnel support. Given that the pre-war steaming average of capital ships in home waters was close to 10,000 miles, ¹⁴ this equated to something like 20 per cent of the cost of the fuel in peacetime for the British. For the Americans, whose personnel costs were greater and who had more secure access to oil, which was also at a more favourable price in relation to coal, the benefits were even more obvious, and the first American oil-fuelled dreadnought was authorized as early as 1909. ¹⁵

Furthermore, the presence of so large a specialist community which had a culture and an outlook alien in many ways to much of the remainder of the ship’s company was not always a comfortable one. ¹⁶ In the Royal Navy the stokers tended to have been recruited as adults on short-term (five-year) engagements. While a proportion had an army or marine background, many not only lacked the service-oriented outlook created by the deep immersion of the seamen, who joined as boys, but also possessed what was recognized as a militant trade union mentality, with its potential for collective action against authority in the event of grievances. The desirability of reducing the numbers of ‘short service’ stokers was implicit in the 1913 comment by the commodore of the Portsmouth Barracks that ‘Their only qualification is strength and ability to shovel coal into the ships’ furnaces. Some day we may have oil fuel but we haven’t got it yet.’ ¹⁷

In fact, stoking required judgement as well as physical strength, and both coordination of the team and competence of the very junior individuals within it mattered, perhaps even more than was the case for oil. This was most apparent during the surface encounters of the war, but an earlier demonstration of what could be achieved by intelligent stoking had come in the American Great White Fleet’s world cruise in 1908, when the institution of an inter-ship competition to achieve economy in fuel use resulted in a saving of more than 2,000 tons of coal across the fleet – some 2½ per cent. ¹⁸

IV. Ship Design and Coal

Since oil had a calorific value approximately 1.4 times greater than that of coal, ¹⁹ coal inherently took up more internal space than its equivalent in oil, but the storage problem was greater than that. Headroom had to be maintained inside bunkers to allow men working space to manually extract the coal for transfer to the boilers and to ventilate the coal to reduce the chance of spontaneous combustion. This was a significant problem. By comparison, although they required ventilating pipes, oil tanks could be filled to 95 per cent capacity. There were arguments that the coal in wing bunkers provided additional protection against shell and torpedo fire, but after a period at sea there was no guarantee that the bunkers concerned would still contain coal and thus afford any protection. The standard practice was to transfer coal as frequently as possible from the remote bunkers in order to keep those closest to the boilers topped up against the requirements of action and high speed. Oil did require machinery, but it could relatively easily be pumped between tanks. Furthermore, although oil tanks required very close attention to sealing, particularly the rivets, and for safety reasons had to be maintained low inside the hull but away from the heat of the boiler rooms, ²⁰ the assessment was that the corrosion and maintenance issues were much less than those experienced with coal.

There were also challenges in ensuring access for coal transfers inside ships. The battleship Agincourt, originally designed for the Brazilian navy, would be severely criticized in Royal Navy service because her bunker layout was so unbalanced that, despite carrying more than 3,000 tons of coal (comparable with contemporary Royal Navy designs), she would have been unable to keep up with the Grand Fleet for more than a couple of days on coal alone, because her A and B boiler rooms would have run out of supplies. The majority of the bunkers were practicably accessible only from C boiler room. It took the conversion of her double bottom spaces into oil tanks to solve the problem. ²¹ Agincourt is an extreme example, but, as would be demonstrated during the war, many of the ‘reserve’ bunkers in other capital ships were also effectively inaccessible – in that the coal could not be conveyed to the boilers at a rate sufficient to match the requirements of high steaming speed over an extended period. It was later argued that the difficulties in physically extracting the last 25 per cent of the coal carried in most ships were so great that it was unlikely that post-1914 fleet speeds could be maintained from that point, even with personnel reinforcement. ²² A separate but related problem was that bunker access and internal transport for coal also required many more (and much larger) avenues through watertight bulkheads than did oil, which reduced ships’ watertight integrity. Indomitable even had holes ‘cut in the bulkheads’ of the bunkers to ease internal transfer during her Atlantic run. ²³

Another profound design advantage for oil was the size of the furnaces. This had been a major factor in the multiplication of boilers as both warships and passenger liners grew larger and faster, but warships’ single-ended boilers were effectively restricted in furnace length to a man’s reach with a rake or shovel – approximately 7 feet 6 inches (2.3 metres); in the Lion class battlecruisers the number reached a peak, with 42 boilers being needed to produce sufficient steam for an output of 75,000 shaft horsepower (shp). An oil-fired boiler furnace could be nearly three times longer. The introduction of small tube boilers with their greater efficiency would be another important factor, but oil firing was a major contributor to the fact that the ‘large light cruisers’ of 1917 could achieve 90,000 shp with only 18 boilers. By the time the battleship Nelson was completed in 1927, 8 boilers were all that were needed to provide steam for 40,500 shp. Destroyers provide another example of the efficiencies achieved by the combination of oil and other improvements, the ratio of machinery weight to shp nearly halving between the coal-powered Beagle class of 1908 and the oil fuel M class of 1913. ²⁴

V. The Welsh Coal Advantage

The quality of the coal itself was always key to performance, but it became vital at higher sustained speeds. ²⁵ Boilers needed to have their fires cleared at intervals to prevent the build-up of clinkers and to remove ash. If a boiler had multiple furnaces, this could be conducted furnace by furnace, which allowed the continued use of the remainder. As a rule of thumb the clearing of fires was required at 12-hour intervals, ²⁶ and thus did not materially affect steaming performance if it could be done quickly and easily, but this was highly dependent upon the type of coal. It was here that best Welsh steam coal had overwhelming advantages. Defined as ‘semi-bituminous’, it occupied a place between brown coals and anthracites and had the right combination of volatiles and other materials. In many ways ‘best Cardiff’ or ‘Admiralty’ coal was the ideal at every stage. It tended to come in pieces that were the right size for the furnaces, with little accompanying dust. ²⁷ The coal opened out or ‘cauliflowered’ as it heated up. This allowed combustion so effective that it not only generated great heat, but left only a small residue of clinker on the fire grates, as well as very little ash to fall into the bottom of the furnace or rise to coat the boiler pipes. ²⁸ Furthermore, although there were other sources of coal which allowed nearly the same combustive efficiency within the boilers, they often resulted in much more smoke, an important issue in avoiding early detection by a scouting enemy and in maintaining one’s own ability to see. For this reason, the Royal Navy had avoided ‘north country’ coal from early in the steam era. ²⁹

The best Welsh steaming coal came from one section of the Welsh coalfields, involving approximately 40 collieries, of which 31 were licensed to supply the Admiralty. It was exported worldwide to other navies and merchant fleets, as well as for British flag vessel use – the Royal Navy’s buy represented only 10 per cent of the total ‘steam coal’ region’s production. ³⁰ The advantages were not absolute; the armoured cruiser Drake deliberately used American coal in her high-speed transatlantic run in competition with the other Welsh coal-burning cruisers of her squadron in 1906 and (just) beat them all. ³¹ But it was recognized as world’s best standard. The Japanese fleet in the 1904–5 war with Russia regarded the embarkation of Welsh coal as ‘always the sign of expected action’, ³² and it was with Cardiff coal (albeit carried in German colliers) that the Russian fleet made its slow way from the Baltic to disaster at Tsushima. ³³ The differences in actual performance and in the reduced stress placed on the stokers and boiler tenders were significant, particularly as the Royal Navy’s boilers (and arguably those of all the world’s warships) were designed specifically with Welsh coal’s burning characteristics in mind. Combined oil and coal firing created its own problems, since the residue coalesced as a form of hardened tar on the furnace grates and required considerable strength to remove, ³⁴ while the smoke was often excessive, particularly when changing speed. Bringing together otherwise unsuitable coal types was another technique that could give good results, but this depended upon the ability to combine two types effectively so that the qualities of one complemented the other, and involved obvious complications of supply.

An extreme of the situation which could be created by different types of coal was shown by the encounter with Australian coal of the new major units of the Royal Australian Navy in 1913–14. It proved totally unsuitable in boilers configured for Welsh coal. An eight-hour full-power trial by the light cruiser HMAS Sydney demonstrated the problem. Although it was possible to maintain nearly full power for six hours with the assistance of oil, the amount of ash created increasing difficulties. Once the trial was finished, every single furnace (and there were 46 in the 12 boilers) needed to be cleaned, which restricted the ship to less than half-power – for nearly six hours. Even after this had been done, the effort to achieve three-fifths power became impossible because of the continual requirement to clean the fires. The need to break up the coal into manageable pieces before placing it in the furnaces added to the workload; that process also damaged the too-thin deck of the stokeholds. While the build-up at the base of the furnaces was one part of the problem, the accumulation of ash on the boiler tubes was another – and the latter could not be cleared away while the boilers were hot. This meant much more frequent shutdowns to allow cleaning. Apart from the fact that the ash began to permeate the entire ship, making it ‘like a continual coaling’, the additional manual labour for even restricted power required the stokers to be supplemented by 30 deck personnel to move coal and ash. If this were to be required during operations, there would be a serious impact on the ship’s fighting efficiency. ³⁵

The battlecruiser HMAS Australia was no better off. At 15 knots Australian coal (heavily supplemented with oil) required all 31 boilers with a consumption rate of 16 tons per hour, plus 2 of oil. By comparison Welsh coal needed 15 boilers with no supplementation by oil and a consumption rate of only 10 tons. Apart from the cut in speed, the battlecruiser’s operational endurance was reduced by more than a third, a very serious matter in the Pacific. The waste and manpower problems were as great as in Sydney. ³⁶ Some modifications could be made to the furnaces to reduce the build-up of clinkers with wider grates, but these inevitably also had the effect of reducing the efficiency of the boilers when they were burning more suitable coal, and they were only applied to a limited number of boiler units. ³⁷ This also did nothing to solve the problem of ash. It will be clear that there were profound implications for both the speed and endurance of the ships concerned. Fortunately, the force had access to New Zealand Westport coal, which was nearly as good as that from Wales and for which the Australian Naval Board hastened to place orders, despite Australian coal industry protests. ³⁸

Most coal did not store well, which was another comparative advantage for oil once the very expensive infrastructure of storage tanks had been developed in ports and bases. It deteriorated, particularly in the open air and at higher temperatures, with a progressive reduction in the volatile component, which meant a significant reduction in steaming performance. Admittedly, Welsh coal was known for its storage qualities, but it had to be carefully monitored for gas if stowed wet. ³⁹ Coal could, even in the Falklands, get too hot to place in the bunkers, as HMS Bristol discovered on 7 December 1914, the day before the action with von Spee’s cruisers. ⁴⁰

VI. Coaling

The issue of replenishment with coal was one that had been a focus of attention for the decade before the war. Probably as a result of a study of the Russo-Japanese War of 1904–5, the then commander-in-chief of the British Mediterranean Fleet, Lord Charles Beresford, embarked upon a campaign to improve the coaling rate of the fleet in recognition of the operational importance of a rapid turnaround. Coaling became a highly competitive evolution and the results were immediate. Before the change, an average hourly coaling rate in a battleship of 162 tons was cited as exceptional. Within two years of Beresford’s initiative the record for the average per hour stood at 289.2 tons for a total loading of 1,180 tons. ⁴¹ It would go higher.

The British move did not pass unnoticed by the Germans, who took similar measures. The early results were widely publicized, perhaps to maintain confidence in the relative professionalism of the young German navy, although the higher speeds achieved were apparently not without their human toll. ⁴² As part of the 1908 naval manoeuvres, the High Seas Fleet conducted a tactical coaling in which the highest maximum hourly rates achieved ranged from 328 tons for the battleship Elsass to 435 for the armoured cruiser Yorck. Compared with those of the Royal Navy, these probably represented the maximum possible, as well as being much higher than the average actually maintained over the complete coaling. The rate of 258 tons claimed for the light cruiser Hamburg with her much smaller crew (and more limited loading points) may have been an exaggeration. ⁴³ Her British contemporary, the cruiser Encounter, was very pleased to achieve an average of 135.2 tons per hour for an 800 ton coaling in 1911. ⁴⁴ The fastest ever sustained Royal Navy speeds seem to have been claimed by the battlecruiser Indomitable, which ‘seldom averaged less than 400 tons per hour and on one occasion … took in 500 tons in just over an hour at an average rate of 474 tons per hour’. ⁴⁵ This was a rate outstanding in the Grand Fleet as a whole ⁴⁶ and reflected not only good organization of the crew, but good design of the ship’s hatches and access routes, something that was not always the case. ⁴⁷

The difficulty was that coaling remained time-consuming and exhausting. Replenishment by oil did not require either the intense manual labour of coaling itself (something which occupied practically the entire ship’s company in the Royal Navy) or the dispiriting business of cleaning ship and self which had to follow. With certain limits of safety, oil-powered ships could be re-ammunitioned and re-stored while they were being refuelled. Without slowing the loading rate, this was practically impossible for coal-fired units. With experience and the appropriate infrastructure, the Admiralty estimated that oil could be resupplied at a rate 2.5 to 3 times that of coal. ⁴⁸

This estimate was in fact based on a best case for coal. If the collier’s holds or gear were unsuitable (or, in the case of some coaling hulks, lacked any cranes or lifting equipment at all), the rate could be much slower. Encounter’s coaling statistics for 1911–12 demonstrated the problem. While the crew could achieve more than 130 tons an hour in ideal circumstances, coaling from the hulk Hankow reduced the rate to 86 tons, while an unsuitable collier, with only two accessible holds rather than the usual four, lowered it even further, to 69 tons, little more than half the speed of the best performance. ⁴⁹

VII. The German Experience of War

The events of the war confirmed the problems of coal, as well as the general superiority of the Welsh product. The early German raiders soon experienced the challenges of unsuitable coal. The East Asiatic Squadron initially used Chinese Shantung coal of relatively high steaming quality. The light cruiser Emden was, however, eventually forced to use Indian coal from a captured Greek collier. The results were similar to the Australian experience. Apart from putting out a pall of smoke (with the resulting higher probability of detection) and suffering from reduced endurance and speed, the ship had to undertake boiler cleaning much more frequently. The crew’s prayer became, ‘May we soon surprise an Admiralty ship with Cardiff coal.’ ⁵⁰ They did. The main body of the East Asiatic Squadron did not reach this extreme, but was nevertheless delighted to intercept a French ship carrying ‘First-class Cardiff’ on British consignment, ‘coal which it is a real pleasure to handle’. ⁵¹

The battlecruiser Goeben and the light cruiser Breslau had their own problems in Turkey. As their commander, Rear Admiral Souchon, complained in November 1914, Turkish coal was unsuitable for the ships’ boilers. With the existing stocks of Cardiff coal limited to 25,000 tonnes, the two types of coal could be combined, but the result was still less than satisfactory, and he feared the day when the Cardiff coal ran out. ⁵²

The issues for the High Seas Fleet in German waters were even more complex. Unlike the British case, there were no initial difficulties in getting the coal to the ships, since the fleet was operating from its peacetime bases and anchorages, which were well fitted out with coaling equipment. The problem was rather one of fitness for purpose. Germany was a major producer of coal, although it had imported significant amounts from Britain before the war, including some 215,000 tons of Welsh coal every year, about half of which was probably steam coal. ⁵³ Much of the coal for the fleet came from Westphalia, ⁵⁴ but it was of variable quality, even before the impact of the British blockade and other wartime demands for coal began to be felt in the German navy. The battleships were already experiencing problems with excessive smoke during the Scarborough raid in December 1914, ⁵⁵ while the battlecruiser Von der Tann had difficulty making her speed. ⁵⁶

At the outbreak of war the German battlecruisers’ engineering scheme of complement was found insufficient to manage the transfer of coal from the remote bunkers for extended periods under way, and the upper deck personnel had to be called in to assist. ⁵⁷ This happened again at Jutland. In practice the high-speed encounters in the North Sea were sufficiently brief that there were few immediate tactical implications for the differences in the quality of the coal available to the protagonists, but it was a near-run thing for the German battlecruisers. The Imperial German Navy had in fact not greatly tested this matter before August 1914. The Germans had been later to adopt turbines in capital ships than the British and later to trial them over long distances. Only one sustained high-speed run appears to have been conducted, and this was at the conclusion of the turbine battlecruiser Von der Tann’s deployment in 1911 to South America. On her return she steamed from Tenerife in the Canaries to the vicinity of Heligoland, a distance of more than 1,900 nautical miles at an average speed of 24 knots. ⁵⁸ By comparison, both the deployment of Moltke to the United States in 1912 ⁵⁹ and that of the first turbine battleships Kaiser and Koenig Albert to Africa and South America in 1914 appear to have been considerably more leisurely. While the battleships’ voyage was intended to test their turbine propulsion, they covered no more than 20,000 nautical miles in six months – much more than the usual distance run for capital ships in the same period, but not suggesting substantial periods of high speed, although the German navy appears to have been satisfied with the mechanical reliability of the ships concerned. ⁶⁰

Both German and British units during the chase phases of Dogger Bank and Jutland seem to have achieved something close to their practical maximum, a tribute to the engineering skills of all concerned, but it is clear that the Germans faced increasingly serious problems within relatively short periods. The chase at Dogger Bank lasted well under five hours, ⁶¹ but Derfflinger had trouble maintaining power without the use of the high-quality ‘torpedo boat coal’, which was available only in limited quantities. ⁶² At Jutland Von der Tann had several furnace grates collapse under the weight of the stone-heavy clinkers and could not maintain fires in all her boilers after 22.00 – following less than seven hours of high-speed steaming (and after less than a day at sea). ⁶³ Seydlitz had the same problem, despite increasing the rate of furnace cleaning. ⁶⁴

The Germans had attempted an alternative solution to the problem of sustained (but not high-speed) steaming in the form of a cruising diesel engine, but the prototype model intended for the battleship Prinzregent Luitpold would not be ready until several years after her completion in 1913. She and her sisters of the Kaiser class were not only the first turbine battleships, but also the first to have supplementary oil firing. It was indicative of the fuel and steaming problems encountered by the High Seas Fleet in the opening months of the war that the modification had to be extended to all other front-line capital ships from early 1915 onwards. ⁶⁵

VIII. The British Experience of War

For the Grand Fleet the immediate demands of the war created equally formidable, albeit different, problems. As an example, the battlecruisers were to be more active in the months between the outbreak of war and the end of 1914 than they would be at any later period in the war – and spent much more time at sea than they had during peace. ⁶⁶ It was the fleet’s higher cruising speeds, largely an anti-submarine measure, which would have put a further nail into the coffin of coal as far as the Royal Navy was concerned, since they created much greater pressure on all aspects of its use than had the more leisurely days of peace and 8 to 10 knot formation speeds – in the form of more stoking, more coaling, and more boiler cleaning. Admittedly, the Royal Navy needed a taste of the new reality to stop the practice of major units heaving to in order to examine merchant ships at sea, as well as to increase customary steaming speeds. Prior to the attack by U-24 on the old battleship Formidable in the English Channel on 1 January 1915, she and the other ships in formation were steaming at 10 knots – never having exceeded 12 on the previous day. ⁶⁷ Nevertheless, as an example, by December 1914 the average speed of units in the battlecruiser squadrons had risen by nearly 4 knots (to 16.8) and would go higher still – in 1915 it was close to 18 knots. ⁶⁸

Australia, one of the few dreadnoughts with an oceanic role, steamed more than 28,000 miles before the end of the year, and her crew felt the strain: ‘All most people think of is the coaling … we are all heartily sick of it … [the coal] is dirty enough to make the keeping of the ship clean, an almost hopeless task.’ ⁶⁹ The battlecruiser New Zealand, which operated only in British waters and the North Sea, steamed 21,108 nautical miles between July and December 1914, more than she did again during any full calendar year during the hostilities. ⁷⁰ This required repeated coaling. Some estimate of the time spent on the task can be made. Assuming an average rate of 200 tons per hour, to replenish the 16,737 tons consumed by New Zealand ⁷¹ would have required nearly 84 hours of effort by the entire ship’s company. In practice, four days at sea at wartime ‘cruising speeds’ would have consumed approximately 1,000 tons of coal and required a five-hour coaling. The smaller ships were in no better a situation. The light cruiser Falmouth spent nearly 79 hours coaling between 11 September and 31 December 1914 for approximately 6,800 tons. ⁷² All this did not include the time required by the crew for rigging and unrigging the coaling gear or cleaning up the ship – and themselves – afterwards, a process estimated to take up to two days in practice. ⁷³

Some, albeit tardy, ⁷⁴ preparation had been made before August 1914 for the supply of coal to the Royal Navy in northern anchorages, including by rail. ⁷⁵ On the issue of the warning telegram, the Admiralty planned for nearly a quarter of a million tons of coal to be shipped by sea to Scapa Flow, Invergordon, Rosyth, and the Humber, with another 150,000 tons to be assembled by rail and maintained as a reserve on sidings at Rosyth and the Humber. There were also no illusions about the expected scale of use, which was estimated at 648,900 tons for the first month of hostilities. ⁷⁶ This compared with a pre-war annual buy by the navy (which included purchase for activities as diverse as the Egyptian Railways) of only 1.5 million tons. In fact, long-term consumption would be much less than predicted. ⁷⁷

The Admiralty rapidly chartered or requisitioned the hulls it needed. By October 1914, 163 colliers were supporting the Grand Fleet and dispersed units in home waters, while 18 more were allocated to the dockyards and a further 122 to other stations. ⁷⁸ Their employment was not uniform. In the northern anchorages, large numbers of colliers had to be kept available for the resupply of the fleet on its return, while much of the effort for foreign stations was carriage of coal to overseas bases. The design and suitability of many of the colliers also proved of real concern. Compatibility between a collier and the ship to be supplied remained a problem. Holds and gear in the wrong place and inexperienced collier personnel slowed the rate of coaling and sometimes contributed to serious accidents. The evolution could be and was conducted much faster if the ship and its collier were used to each other, and the big ships were soon allocated a collier each. ⁷⁹ Given that the colliers carried on average some 2,000 tons of coal and that the usual requirement per capital ship coaling was only half of this, there were potential inefficiencies in the use of the tonnage involved which would cause concern later in the war, ⁸⁰ but the 1 : 1 ratio was never waived.

The policy of collier allocation stemmed from the problems of operational availability which refuelling coal created. Jellicoe, as C.-in-C. of the Grand Fleet, was insistent that one collier be maintained at the home anchorage for every major unit in order to allow a rapid turnaround. ⁸¹ He had been desperately concerned about the numbers of colliers available in the early months of the war, and for good reason, since it would have been almost impossible to resupply the entire fleet in reasonable time. ⁸² The Admiralty’s massive take-up from trade solved the numbers problem within a few months, but, even so, the C.-in-C. was well aware that the refuelling cycle for the fleet as a whole was in the order of ‘one and a half days to coal (cruisers longer if in two batches)’. ⁸³ In retrospect, although the Germans identified the possibility during their pre-war gaming, ⁸⁴ it is surprising that the High Seas Fleet never attempted to play upon this weakness in the Grand Fleet’s ability to deploy its maximum strength. Convincing feints might have kept the British at sea long enough to force the return of at least some of their ships to harbour to refuel.

IX. Conclusion

Careful examination of the issues with coal which arose during the period of the First World War confirms the long-term importance – and the validity – of the British decision to move to all-oil firing. The British were best positioned to realize the benefits that could be gained from the change, which were even greater than official statements suggested at the time. Although Fisher spoke eloquently of factors such as the greater endurance provided by oil, the reduced manpower involved, and the potential to refuel at sea, ⁸⁵ it was becoming clear that coal could not provide the energy required to propel large warships for long periods at high speeds – a point implied by Churchill in his later commentary on the manpower issue. ⁸⁶ With ‘best Cardiff’ the strain on ships’ companies was great; without it, over time (a matter of a few days, if not hours) the problem could become unmanageable, not only in manpower, but in the progressive degradation of boiler performance and its effects on both speed and endurance.

What had been acceptable in war-fighting terms even a few years earlier was no longer good enough. Before 1914, high speed was very much a temporary tactical requirement when in or near contact with an enemy fleet. From 1914 onwards, the increasingly pervasive submarine threat created the need to operate at much higher cruising speeds than had ever been the case before. It is arguable that the very short distances of the North Sea and the Baltic, as well as the restricted sea time, concealed the extent of the problem that this represented for the Germans, who did not enjoy the same access to high-quality coal as the British. It is notable, however, that the German shift to oil accelerated during hostilities – the capital ships and cruisers under construction were all fitted with an increasing proportion of oil-fired boilers, while new torpedo boats were wholly oil-fired. ⁸⁷

In almost any other operational environment than the North Sea, the limitations of coal would have been much more obvious than they were in 1914–18. Nevertheless, they were clear enough that for the Royal Navy there would be no return, whatever the industrial and economic problems that might result – and that every other navy would follow suit.