In the years following the Civil War, Benjamin Franklin Isherwood, Engineer in Chief of the U. S. Navy, found his efforts plagued by a new hindrance—economy. Although the war had determined conclusively that naval power would thereafter be dependent on steam, the need for a large navy for the United States was no longer so apparent. The great cost of the war produced a postwar reactionary desire for retrenchment in naval expenditure; and, by slashing appropriations, Congress soon demonstrated its lack of sympathy for ambitious projects.
While the economizing drive gripped the Department of the Navy ever more firmly in the postwar years, Isherwood stubbornly fought to preserve the strength of the steam Navy. Encouraged to use sail at every opportunity, line officers in command of cruising warships became exasperated with the large amount of space and weight which machinery and coal occupied in their vessels. For a cruise which might last for many months, they insisted on a fair degree of comfort, which meant generous accommodations for officers and plenty of room for provisions. Since they rarely used their ships’ machinery, it became a petty annoyance, and they began to question its worth, especially since the large funnels greatly interfered with the sailing qualities of their ships.
Isherwood soon ran afoul of these officers. Placed on a board to examine alterations that had recently been made to the USS Richmond, he found that his ideas varied greatly from those of the “sea officers” composing a majority of the board. The new Isherwood engines which the vessel had received increased her speed from six to nine knots, but her fuel supply was still grossly inadequate, the Engineer in Chief maintained. She could steam for only seven and one-fourth days, while in the British Navy vessels of comparable speed could steam for ten days. Moreover, Isherwood said, “as we possess neither colonies nor forcing strongholds, it is plainly necessary that our steamers of war should be able to keep the sea longer than those of a power whose drum beat follows the sun around the world.”
Instead of concentrating on more room for officers and crew and for provisions, the Navy Department, he believed, should stress high speed and endurance. The “power of locomotion and command of time” were the prime considerations of warship design, Isherwood said, and “it follows that only a portion of the vessel can be appropriated to armament and crew, as remains after the machinery and fuel are accommodated. This condition is inexorable.” There could be no compromise in peacetime, he added, because a warship, whether in peace or war, must always be ready for battle. Therefore, her equipment and her performance capabilities must always be up to wartime standards.
The experiences of the Civil War and the current precepts and practices of great European naval powers proved beyond doubt that high speed and great endurance were the “controlling necessity”; and no officer, said Isherwood, should be so foolhardy as to disregard these dictates. Instead of turning back the clock to the days of slow speed and limited steaming, the American Navy should develop 18-knot cruisers of great endurance to meet the challenge of European navies and modern merchant fleets. To do less, he warned Navy Secretary Gideon Welles, “would prove a national calamity.”
While Isherwood presented his impassioned argument for a modern Navy, the “sea officers” threw their weight in the opposite direction. Writing to Welles in April 1867, the Admiral of the Navy, David Farragut, objected to the “contest now going on between speed, and, I may say, all the other qualities of a man of war.” Increasing the size of warships, he said, only resulted in benefits to the engineers. Crew’s quarters and spaces for provisions had been sacrificed for speed, and this was senseless when warships were required to use full sail and operate as sailing ships far more than as steamers. Welles, he insisted, must “prevent further encroachments” by Isherwood and his Corps.
Impressed by the arguments of this great naval hero, Welles disregarded Isherwood’s pleas for speedy warships and bluntly informed the Engineer in Chief:
Hereafter, encroachments will not be made upon the space ordinarily allotted to officers and men and the other appointments of a man of war, unless it shall appear after careful examination that ample accommodations will remain. . . .
Writing to his former Assistant Secretary, Gustavus Fox, on 25 April 1867, the Navy Secretary remarked peevishly that the department was being pestered by engineers who “seem to suppose that naval vessels are built for the purpose of carrying engines and engineers.” They had ignored the comfort of the crew, Welles complained, in their “zeal for high speed and powerful motive power.” Welles related that he had often cautioned the Chief of Construction who had “yielded to some extent to Isherwood” on this, forcing the department to interfere and modify the plans of vessels. Welles cited as an example the Pensacola, whose sailing qualities were nearly worthless because the engineers had insisted on locating the funnel so close to the mainmast that it seriously hindered the use of the sails.
The admonitions of the Secretary and the aggrieved protests of the “sea officers” left Isherwood unmoved. Speed and endurance, he maintained, could not be compromised in vessel design if the American Navy wished to retain its power and fulfill its purpose. Instead of acquiescing to the desires of the line officers, Isherwood determined to display to the nation and the world that engineering could no longer be disregarded or depreciated. To achieve this goal, he relied on the vessel which was to be the culmination of his efforts and his hopes, the Wampanoag.
In 1867, the class of Navy Department supercruisers planned four years previously was still in the process of construction, with the Wampanoag furthest advanced toward completion. Only the vessels built to compete with Isherwood’s machinery had been launched and tested. The first of these, the Idaho, built by Paul S. Forbes and Edward N. Dickerson, had been a miserable failure. The second, however, had done considerably better. This vessel was the Chattanooga, whose hull had been built by the reputable firm of Cramp and Sons, in Philadelphia, and whose machinery had been designed and constructed by Merrick and Sons, of the same city. Displacing less weight than the department vessels, the Chattanooga, like the others, had been designed to achieve a 15-knot speed.
On 17 August 1866, she had her speed trial, and over a 24-hour period, she averaged less than 13 and one-half knots in a perfectly smooth sea with little wind. Her machinery developed almost three times the horsepower of Dickerson’s engines, and she burned coal at a slightly more efficient rate. No serious mechanical malfunctions occurred on the trial run, but the board of inspecting engineers noted that there were many minor problems and an excessive amount of abrasion between metal parts. Isherwood told Fox, on 22 December 1866, that the engines were so injured by the 24-hour run that it took weeks to repair them, and it would require extensive alterations and repairs to prepare the vessel for service. After some discussion between the contractors and the Navy Department, the Chattanooga was accepted, despite her failure to come within one knot of the required contract speed.
Several months after the Chattanooga’s trial, John Ericsson’s Madawaska, identical to the Wampanoag except for her engines, had failed to average 13 knots. Thus, the three vessels designed to compete with those of the department had not been able to achieve and maintain a speed which was necessary for an oceangoing commerce destroyer, although in each case their hull design had been tailor-made for extreme speed. The hopes of the Navy now rested entirely on the abilities of its Engineer in Chief.
In the midst of the Civil War when the supercruisers had been proposed, there had been no doubt about their intended function. These vessels were to be commerce destroyers, aimed at the economic heart of European powers that threatened the Union cause by intervention on the side of the South. In 1863, the disparity in naval strength between America and Great Britain, in particular, was so vast that a full-scale naval competition could not be considered. The only recourse was that which America had taken in the past— attempted neutralization of the enemy’s naval predominance by creating havoc among its merchant shipping.
The Wampanoag class of cruisers had to be extremely fast in order to prey successfully on English commerce. In order to catch speedy mail steamers, intercept dispatches, break up ocean communications, and disrupt merchant shipping, these warships had to achieve at least a 15-knot speed. By so doing, they could catch any vessel they wished to fight and run away from any other. To be properly effective in “attacking the enemy’s purse,” they were to fight only when necessary, keep to sea indefinitely, cruise in the lanes of commerce, and destroy each prize they captured, rather than run the risk of taking it into one of the few ports open to them.
Such vessels would have to have enormous engines in order to develop their necessary speed; and yet have full sail power so that they could cruise for weeks, if necessary, without expending fuel except during brief periods of high-speed steaming. As the United States had no coaling facilities abroad, and would be at a particular disadvantage in this respect when at war with Britain, it was, therefore, nearly as important for such vessels to have good sailing qualities as to be able to steam at high speeds.
Restricted by the existing low level of technology and by limited manufacturing capabilities, the designers of these vessels had to use wood, rather than iron, in building their hulls. Thus particularly vulnerable to enemy fire, these vessels had to mount heavy armament so that they could fire at long range and avoid close bombardment, in which situation their great speed would be neutralized and their unarmored hulls most exposed.
With this policy as a guide for construction, both the Navy Department and the competing private builders had started on their ships during 1863. Of the vessels with Isherwood engines, the Ammonoosuc and Pompanoosuc were placed under construction at Boston, the Neshimany at Philadelphia, and the Wampanoag at New York, alongside of her twin, the Madawaska, in which Ericsson was to place his engines.
The Wampanoag’s measurements were sufficient to remove all doubts that this vessel was built for speed. Her 335-foot length provided nearly an 8-to-l ratio to her 445-foot breadth. Drawing an average I85 feet, she was designed to displace 4,216 tons when loaded. Building a vessel this size out of wood, even if it were live oak, involved serious difficulties in design. To prevent the hull of such a large ship from sagging or hogging, both from the weight of her machinery and her own length, the builder had to reinforce her with longitudinal and diagonal stringers of iron plate.
In an age before experimental model basins, hull design was still very much an individual art, and the Navy Department wisely entrusted the Wampanoag’s design to the famous ship designer B. F. Delano. The skill of this shipwright was all-important, since the process of design was largely a matter of expert guesswork, the accuracy of which would become apparent only after the ship had completed her speed trials. Delano, however, did not have a free hand in this work. Unlike previous vessels in which the machinery had to be designed to fit into a specific hull, the Wampanoag was to have a hull shaped for the machinery already planned by Isherwood. Consequently, the Engineer in Chief took an active part in designing the Wampanoag.
Isherwood originally expected that the Wampanoag would be built of iron, because of the unusually heavy weights and strains imposed by his machinery. When lack of construction facilities made this impossible, he necessarily agreed to a wooden hull, but he insisted on a design which made a radical departure from accepted form. Instead of a barrel-shaped midship section for the cruiser, he substituted a square section, approaching the principle of 20th Century warship design. Working closely with Delano, Isherwood eliminated the overhanging bow of orthodox warships and substituted a straight stem. The forward waterlines of the cruiser showed a decided hollow, giving a general effect, according to a recent writer, quite similar to a modern destroyer.
Delano objected to these radical innovations, by which the ship had been virtually designed around her engine and boiler space. He attempted to modify the lines of the Wampanoag into more orthodox dimensions, but Isherwood prevailed upon their friendship to force him to return to the original plans. “It was rather a tight fit,” Delano admitted, in a letter to Fox dated 12 September 1863, noting that he had to widen the body eight inches and lengthen the ship several feet to get in all the machinery. Nevertheless, he finally concluded that there was nothing objectionable in this unusual practice of shaping the hull to fit the machinery, since it was obvious to him that the Wampanoag would develop great speed from her enormous engines.
Isherwood solved the problem of placing heavy engines in a wooden hull by gearing them to the propeller shaft. In this way, the reciprocations and consequent vibration of the engines would be less, while the propeller could still revolve at high speeds. In a vessel like the Wampanoag, in which the hull was so long and narrow that it did not possess much longitudinal strength, there was a problem with direct-acting engines, whose vibrations would loosen fastenings and possibly pound the hull to pieces. Isherwood planned, instead, to gear his engines to the shaft by the use of huge wooden (lignum vitae) teeth, so that one double stroke of the piston would produce 2.04 revolutions of the propeller. Although wood would seem to be a questionable material with which to build engine gears, it was considered practicable in those days, and builders maintained that it helped to deaden the noise of engine operation.
Eight Martin boilers, with a maximum working pressure of 40 pounds, were used to drive the Wampanoag's two pairs of simple- expansion engines. To produce greater steam pressure and to retard condensation, Isherwood also placed four separately-fired superheating boilers of his own design in the vessel. The boilers were well protected from enemy fire by being set sufficiently low in the hull so that the highest part of the machinery was more than two feet below the waterline. In addition, coal bunkers lined both sides of the hull to provide an additional buffer. To provide sufficient draft for the furnaces, four large funnels protruded from the vessel. Although Isherwood insisted that they did not interfere with the sailing qualities of his ship, he was well aware of the horror his four “chimneys” caused in a day when one such funnel was considered a great nuisance by sailors.
The Wampanoag had to have the ability to cruise for long periods under sail alone, and to meet this demand, Delano and Isherwood placed three ship-rigged masts on the vessel. Isherwood objected to the bowsprit, since it obstructed direct fire ahead; he maintained that there was no need of bowsprit sails, because of the ease of steering a ship of such hull proportions. In addition, the strong, live-oak frame, stiffened by the iron stringers, would make the Wampanoag “the most formidable projectile that could be devised when hurled as a ram at her enormous speed against the side of a slow antagonist,” according to Isherwood. With this purpose in mind, he insisted on the elimination of this projecting spar. Against the advice of most naval constructors, the Wampanoag’s bowsprit was eventually removed after the vessel had been put into service.
As an unarmored commerce destroyer, the Wampanoag had to have heavy armament, both to stop fleeing victims and to hold off attacking warships. Although there were continual modifications and rearrangements of her weapons, as in most 19th Century warships, her normal armament was ten 8-inch, smoothbore guns and two 100 pounders firing in broadside; two 24-pounder howitzers; two 12-pounder howitzers; and one 60-pounder, rifled pivot gun. The vessel was to carry 106,700 pounds of ammunition, with 150 rounds for the pivot gun and 100 for each of the others. The weakness in this distribution of armament, according to some authorities, was that there was an insufficient amount of fore-and-aft fire. For a vessel designed as a commerce destroyer, several heavy bow chasers would seem a necessity, but the extremely fine lines of the Wampanoag prohibited the mounting of a battery of heavy bow guns, and direct fire ahead was restricted to the single pivot gun.
By the end of 1863, construction was well underway on the hull of the Wampanoag as she lay alongside of the Madawaska in the Brooklyn Navy Yard. The $700,000 engines were taking shape at the nearby Novelty Iron Works, while the boilers had been let out to several contractors in New York City and upstate New York. Initially, the Wampanoag, perhaps because she was built in the ship house while the Madawaska was building “in the open air,” led Ericsson’s ship by six weeks, but this advantage of time was not to last. Although the main reason for delaying construction of the Wampanoag was the time needed to manufacture her geared engines, there were also delays in the building of the hull. Undoubtedly, a major factor in the latter was the supervision of the Engineer in Chief, who anxiously hovered over his vessel, making certain that no shoddy material or poor workmanship would go into the Wampanoag.
As the cruiser neared her launching, Isherwood’s enthusiasm mounted. Like Ericsson, he was convinced that the lines of the hull, so carefully sculptured by Delano, would assure great speed. Unlike Ericsson, however, Isherwood had other vessels of this class to supervise, and his interest in them was nearly as great as for the Wampanoag. Writing to Fox on 12 September 1864, the Engineer in Chief declared that the Ammonoosuc, being built in Boston, was the finest steamship he had ever seen and could not fail to be a great success. With the same engines as the Wampanoag, and with nearly an identical hull, the Ammonoosuc had “the power for the speed and the model for the power.”
The first of the department vessels to be started, the Wampanoag was also the first to be launched. On Thursday morning, 15 December 1864, hundreds of privileged spectators clustered in the Brooklyn Navy Yard to watch the daughter of Captain Augustus L. Case, the executive officer of the yard, christen the vessel. In attendance were Admirals Paulding, Gregory, and, above all, Farragut, the latter having arrived with great fanfare in the Hartford the previous day. While “prying visitors” were rigorously excluded from the Navy Yard by the vigilant execution of police regulations, those fortunate enough to observe the launching watched the Wampanoag slide into the East River at 1115. With an accompaniment of cheering and enthusiastic waving of handkerchiefs, the cruiser “entered her destined element in the most graceful and brilliant style.”
Although the Wampanoag was now ready for her machinery, construction on the vessel abruptly halted. Isherwood’s engines were large and expensive, and by necessarily contracting them out to private builders, the Navy Department suffered the consequences. As the months went by, the engines moved toward completion with maddening slowness, and the end of the Civil War only added to the difficulties. Isherwood had demanded expensive materials, such as brass, and he had presented the builders with extremely detailed plans for his complex engine, which they resented, being used to considerable leeway in their work.
The delay in construction was not caused by the Engineer in Chief alone. The officials of the Novelty Iron Works apparently decided that they were going to lose money in building the geared engine, since the contract price would not only fail to provide them with an acceptable margin of profit, but might not even meet construction costs. For this reason, they were reputed to be “unwilling to push work in the completion of which they are sure to be mulcted in quite a large sum,” said the Army and Navy Journal of 24 March 1866. While the private builders competing with the Navy Department had been able to complete their machinery, work on the Wampanoag's engines thus dragged on interminably.
During the months of delay, and especially as the Madawaska came nearer to her trial in early 1867, the Editor of the Army and Navy Journal, William C. Church, launched an assault on Isherwood and the Wampanoag which increased steadily in intensity. On three successive weeks, just before Ericsson’s vessel went out to sea, Church filled his first page with a stinging attack on the Engineer in Chief for committing “an enormous blunder” in building a class of cruisers with geared engines. So needlessly complex was Isherwood’s machinery that the Wampanoag, Church asserted, was virtually stuffed with iron, leaving no room even for the coal in the hull. The four funnels, he complained, were not telescopic. By sticking “bolt upright nearly as high as the maintop,” they required a “forest of wires” to keep them from rolling overboard, and this condition, in turn, made the use of sails almost impossible.
Isherwood’s “vilely-planned machinery” was mere rubbish and “fit only for the scrap heap,” Church maintained. The Engineer in Chief had not placed bedplates in the hull to anchor his engines and boilers, and the crankshaft was excessively long. The twisting and bending of the long, narrow hull in a rough sea would stop these loosely placed engines by mashing their wooden gears, by binding the journals of the propeller shaft, and by creating enormous friction and heat. The Martin boilers, he continued, were inefficient, the separate superheaters were unnecessary, the surface condensers were inadequate, the fixed, four-bladed propeller would be a tremendous drag when sailing, and the whole arrangement was far too expensive.
The shape of the Wampanoag's hull, Church decided, should allow the vessel to go 15 knots using machinery of only half the weight, space, and cost of Isherwood’s. If the Engineer in Chief insisted upon using machinery of the proposed weight, then the cruiser should be able to go at least 16 knots, the editor insisted.
Church concluded, in the Army and Navy Journal of 5 January 1867, by assuring his readers that this criticism had been conducted purely in “the spirit of scientific inquiry, and with no reference to the moral questions therein involved.” He would ignore any “plausible or possible incentive” Isherwood may have had for committing these “costly blunders,” Church declared, leaving little doubt that he would dwell on this aspect at another time. His readers knew he would not disappoint them.
By assuming that the hull of the Wampanoag was so well designed that the achievement of a 15-knot speed would not indicate any special quality in Isherwood’s machinery, Church had placed himself in an awkward position. Since the Madawaska had the same hull, it stood to reason that the machinery designed by John Ericsson should achieve the same speed without any difficulty. When the Madawaska failed by a significant degree to do this, Church had no other recourse than to insist that Isherwood was personally responsible for that cruiser’s failure. Consequently, he accused the Engineer in Chief of being the “tyrannical power” who had made sure that the speed trials of the privately built ships would be failures, not to keep from paying the contractors, but because he had to protect his reputation. Therefore, Church reasoned, there had appeared the “star-chamber severity” which ruthlessly destroyed the hopes of private builders in order to preserve the position of the Engineer in Chief.
In the summer of 1867, the Wampanoag finally received her machinery, and after minor mechanical mishaps (which Church publicized as “radical defects” in the engines, requiring a material change in their design), the cruiser was pronounced ready for trial. On 17 September, she was formally commissioned, and Captain J. W. A. Nicholson took command, bringing with him some of the officers and crew of the Massachusetts, which had been decommissioned on the same day.
As the Wampanoag approached her sea trials, the criticism of her machinery grew more shrill. After suggesting that Isherwood should subject his own engines to the terrible beating he had given to those of his competitors, Church decided that all the machinery which Isherwood had crammed into Delano’s hull should produce a speed of 18 knots or more. However, he cautioned, no matter what results would appear in the trial reports, they could never be trusted, since no naval engineer would be expected to brave the consequences of condemning the work of his Chief. “If the engines don’t absolutely tumble into pieces, we shall of course have a favorable report and a vindication of the genius of Mr. Isherwood,” Church remarked cynically, while establishing an excuse in case the Wampanoag conceivably did develop a 15-knot speed.
Widening his scope to include all of Isherwood’s engineering designs, Church insisted that the “palpable professional incapacity” of the Engineer in Chief was such a “subject of grave national importance” that it gave him carte blanche to abuse Isherwood. At this point, Church was joined by more reputable authorities on steam machinery. The Scientific American, on 26 October 1867, ridiculed Isherwood’s geared engines, asserted that he was using them only because his earlier direct- acting engines “had given such wretched results,” and strongly condemned Isherwood’s “want of engineering skill and common sense” in producing machinery which was “a blunder without parallel of its kind.”
At four o’clock in the afternoon of Sunday, 29 December 1867, the Wampanoag went to sea on a preliminary trial and returned the following day after 25 hours under way. On the following Thursday, she made another 24-hour trial run; and on the basis of this steaming, Church reported that the vessel had broken down because of the binding and heating of the journals, and that she would take six weeks to repair. He noted that the vessel had failed to make 15 knots at any time on the shakedown cruise, and that at one point the engines had reputedly stopped dead with 40 pounds of pressure in the boilers. Even though Isherwood had used the best steaming coal available, his vessel, Church declared with pleasure, so far had failed to show to the world the vaunted advantages of the geared engines.
Before the Wampanoag departed on her official trial trip, Church determined to fire his parting salvo, and, on 1 February, he devoted a lead editorial to the “foolhardy boldness” and “folly” of the Engineer in Chief. Isherwood, he declared, had initiated a system of steam engineering which caused most of his profession to stand aghast at his endeavors. His great work, the Wampanoag, was obviously a failure, rumored to be laid up with both cylinders split by her “short trial trip in fair weather.” Reviewing the stand of his paper over the previous years toward the Engineer in Chief, Church stated:
We speak, and have spoken, from Vol. 1, No. 1 of the Journal, to this day, very severely of Mr. Isherwood’s practice. But we have done so from mature, profound and complete conviction that he is ruining the Navy by his untenable steam delusions. If we have utterly condemned his theories, we have done so only upon a basis of irrefragable facts.
Pronouncing a conceivably premature sentence of death on Isherwood’s cruiser, which was about to make her decisive speed trial, Church concluded, “We are free to say that there is no such monument of mechanical incapacity as the steam machinery of the Wampanoag class to be found in the annals of marine engineering.”
At 5:00 a.m., on 7 February 1868, after 4½ years under construction, at a cost of $1,575,644, the Wampanoag slowly steamed out of New York Harbor to begin her formal trials while Isherwood waited impatiently in his Bureau office for the results. Temporarily disconnecting her propeller from the shaft, Captain Nicholson first tested the cruiser’s sailing qualities by running the vessel under topgallants, jib, and course, and with no sail on the mizzenmast. In a smooth sea and with the wind fresh on her beam, the Wampanoag made 10½ to 11 knots with no difficulty. She steered well and sailed fast under a fresh breeze, the Captain noted, although she needed to make at least four to five knots so that the propeller would not act as a drag.
Two days later, the Captain began his steam trials, deciding first to run the vessel at a speed of 11 knots to determine economy of fuel consumption. Although forced to end the trial after 25 hours, because of a heavy gale and topping seas, he had run the vessel for 282.5 nautical miles, using slightly less than 47 tons of coal. With her fuel capacity of 750 tons, this meant that the vessel could steam for 17 days at this speed.
After returning to Sandy Hook to repair minor damages caused by the heavy winds, Captain Nicholson once more took his vessel out to sea on the evening of 11 February. This time he determined to achieve maximum speed. For 38 hours the Wampanoag knifed through increasingly rough water, steaming southwest toward Hampton Roads, Virginia, while a fresh breeze shifted between her starboard and port quarter, often blowing from directly astern. Despite the heavy seas which forced the vessel to roll more deeply as the hours went by, the Wampanoag did not reduce speed. The great engines beat on without pause, and soon every man on board knew that Benjamin Isherwood had realized his greatest hopes. The Wampanoag was the fastest steamer in the world.
Within the first six hours the cruiser’s speed had climbed to 17 knots, and then for hour after hour the vessel steadily logged between 16 and 17 knots. For the 38-hour period, the vessel averaged 16.6 knots; and for one hour, made the remarkable speed of 17.75 knots, equivalent to 20.47 miles per hour.
Down in the engine room, Isherwood’s loyal friend Theodore Zeller had been supervising the exertions of the 23 engineers and the 180 firemen and coal heavers who labored to keep the giant fires roaring steadily under the Wampanoag's 12 boilers. With the throttle set wide open, the geared engines worked smoothly and satisfactorily, the only difficulty being with the crank pin of the after engine, which began warming during the 38th hour because a rubber washer had worked loose. Although there was no injury to the engine, Zeller and Nicholson decided to stop the trial at that point in order to replace the defective washer.
Zeller and his crew of engineers recorded that the boilers were developing 31.97 pounds of pressure, which was sufficient to run the engines at 31.06 revolutions per minute and turn the screw propeller at 63.37 revolutions. For 24 consecutive hours, their vessel had made 16.97 knots, and the maximum speed of 17.75 knots had been obtained over four separate half-hour periods. With a trained crew of firemen and coal heavers, they maintained, the Wampanoag would be able to steam easily across the Atlantic at this top speed.
Bad weather forced the discontinuation of the speed trial, as Zeller decided that the machinery had proved its ability to develop 17 knots consistently. The Wampanoag proudly steamed into Hampton Roads, on the afternoon of 17 February, to begin her duties as flagship of the North Atlantic Squadron.
The achievements of the Wampanoag included more than her extraordinary speed. By using geared engines, the cruiser had been able to run at a very economical rate. Developing a maximum 4,049 indicated horsepower, the vessel burned 12,671 pounds of mixed semibituminous and anthracite coal per hour, producing a rate of consumption of only 3.129 pounds of coal per horsepower hour at top speed. This amount compared to 5.170 for the Madawaska, 6.160 for the Chattanooga, and 7.600 for the ill-fated Idaho. When steaming on only half-boiler power, the Wampanoag still made 11 to 12 knots, although burning only one and 7/8 tons of coal per hour, compared to five and 3/4 tons at top speed. At one-quarter boiler power, and burning one and 3/8 tons of coal per hour, the vessel could still steam at nine knots.
At top speed, the Wampanoag was able to steam for five and a half consecutive days, covering 2,200 miles. While cruising at 11½ knots, she could cover 4,700 miles. This was more than sufficient steaming endurance for a warship which was to operate primarily under sail, relying of steam mainly when chasing or escaping from vessels.
Even the cruising speed of the Wampanoag was unusual for steamers of the 1860s. The top speed of American naval vessels built before the war had rarely exceeded 11 knots, while they cruised at no more than nine knots. The fastest British transatlantic merchant steamers averaged less than 12 knots for the crossing, and the rate for ordinary vessels was closer to ten knots. Without the influence of weather, a medium-sized, well-designed screw steamer could usually attain, at best, a 10½-knot average for an Atlantic crossing, and this achievement was without economizing on fuel, while using sail power whenever practicable. Occasionally, world-famous steamers could do better. The Collins Line’s Adriatic made a top speed of 15.91 knots, but over a measured mile using the best Welsh coal, a performance which could not be compared to any extended steaming under normal conditions.
The Wampanoag’s speed so far exceeded that of contemporary steamers that it was not until September 1889, when another American naval vessel, the cruiser Charleston, would equal her speed, and no ocean steamer in the world was able to match the 17.75 knots until the Arizona achieved it in 1879, over 11 years later.
When he received Zeller’s telegram from Norfolk, informing him of the Wampanoag’s achievements, Isherwood was jubilant. Immediately writing to Fox, the Engineer in Chief stressed the fact that the vessel had been fully loaded with coal, provisions, and armament; and yet, in a very rough sea, she had attained “the most wonderful success.” No other steamer in the world, fully loaded and at sea, could average 12½ knots for 48 consecutive hours, he declared. In addition, the performance of his vessel in relation to those of her competitors should be judged on the ratio of the cubes of their speeds, so that in comparison with the “miraculous” speed of the Wampanoag, boasted Isherwood, “the Chattanoogas, Madawaskas & Idahos are simply insignificant.” For the Engineer in Chief, the trial of the Wampanoag had been nothing less than “the most wonderful performance ever made in Steam Engineering.”
Much of the credit for the Wampanoag’s success, Isherwood insisted, should go to Fox. “I am both glad & proud,” he stated in a letter to Fox, 18 February 1868, “to be thus able to vindicate myself & your confidence in me, which notwithstanding the unprecedented abuse and calumny that interest & envy has heaped on me & are still heaping, never faltered, but with wonderful magnanimity and judgement sustained me throughout.” Sincerely as he intended his praise, it must not have escaped the Engineer in Chief that such generous sharing of the credit might provide him with a powerful ally in his disagreements with the “sea officers” who had already raised such objection to his work.