Wampanoag-class Frigate

The ''Wampanoag'' class was a series of wooden-hulled screw frigates built for the Union Navy during the American Civil War. The ships were designed to decimate British merchant shipping in the event that the United Kingdom entered the war on the Confederate side. Of the eight ships planned, only five entered service and served brief careers. A combination of engineering, financial, and operational issues limited their practicality and service history even as the class's namesake, , was the world's fastest steamship.

Initially described as "commerce destroyers" and cruisers, the ships featured novel steam engines developed by different engineers, though three failed to reach the intended speed of . Redundant at the end of the Civil War, their construction alarmed Britain during the ''Alabama'' Claims, prompting the Royal Navy to develop an equivalent vessel. Over time, the class's emphasis on speed over armor foreshadowed the evolution of the battlecruiser.

Development

Despite the United Kingdom's official stance of neutrality during the American Civil War, British assets were used to support the rebelling Confederacy, particularly in the development of its navy. Shipyards in Liverpool constructed blockade runners and privateers for the Confederates, exploiting a legal loophole by ensuring the vessels were not armed until they reached Portugal. Among these ships were , , and , which wreaked havoc on Union shipping; ''Alabama'' alone was responsible for destroying 65 merchant vessels.

The Union Navy was alarmed by these developments, as the disruption of American trade routes drove up domestic prices, damaged the economy, and forced the reassignment of ships from blockade duties against the South. By 1863, the Union feared that Britain might intervene to support the Confederates directly - a scenario that would have left the Union Navy hopelessly outmatched by the Royal Navy. Faced with that prospect, the Union Navy began planning for a possible war with the United Kingdom. While the Union fleet could not match the Royal Navy in conventional battles, the plan called for employing commerce raiding. By using cruisers to launch hit-and-run attacks on British ports and merchant shipping, the Union hoped to make a war too costly for Britain to justify, ultimately forcing it back into neutrality.

Design

Benjamin Isherwood, the Union Navy's Engineer-in-Chief, envisioned what he called a "commerce destroyer" for this new role. He proposed a large ship with the range to cross the Atlantic and loiter in British shipping lanes, a heavy armament capable of destroying any merchant vessels encountered, and a top speed of - fast enough to either overtake and attack shipping or evade the Royal Navy. To achieve this, his design incorporated both sails and steam engines. While steam engines of the era provided high speeds, they consumed an immense amount of fuel, making them only practical for combat. Outside of engagements, sails would ensure the necessary range for long voyages without concern for fuel.

Engines

The primary issue with Isherwood's proposal was speed. At 15 knots under steam, the ships would be the fastest in the world. In comparison, most American warships operated at around , while British merchant ships averaged . To achieve this speed, the design featured long, narrow hulls - similar to those of fast clippers - paired with a high-power steam propulsion system created by Isherwood. His design included eight massive boilers, four of which were equipped with superheaters, that supplied steam to four engines with wide pistons. The engines drove an , four-bladed propeller through a novel gearing system designed to prevent excessive vibrations that threatened to rattle the ship apart.

His design was immediately controversial, with objections to its slender hull form, reliance on engines as the primary source of propulsion, and his engine design. One critic was Edward Dickerson, a marine engineer who argued that the design would be highly inefficient based on the later-debunked theory that steam behaved as a perfect gas. After gaining support from elements within the Navy and Congress, Dickerson was granted the opportunity to design the engines for one of the ships, which was named . John Ericsson, the naval architect behind , also opposed the concept. His ship, '' Madawaska'', was built identically to Isherwood's , with the sole difference being its engines. Additionally, the firm Merrick & Sons was permitted to design the engines for another vessel, , while Isherwood's engines were installed in the rest. By diversifying the engine designs, the Navy aimed to have each design compete against one another.

Overview

With variations in each engine, the dimensions of each ship varied wildly, ranging from in displacement and between in length. Due to the ship's fine hulls, no chaser ( bow-mounted) or aft guns could be mounted, which would have limited the ships' ability to engage fleeing vessels. The exception was a single rifled gun mounted on a pivot, although the Navy viewed it as inadequate and questioned its ability to fire forward. Instead, the rest of the armament was mounted on the broadside; the weapons on ''Wampanoag'' consisted of ten smoothbore and two guns along with two howitzers. The two ships built at private shipyards, ''Chattanooga'' and ''Idaho,'' were armed with 17 and 8 guns of unspecified types, respectively.

While Isherwood wanted the ships to have iron hulls, shortages made him revert to wood. The ships were rigged as barks, had a straight stem as a stern, were fitted with four funnels, and lacked watertight bulkheads inside the hull. In the ships fitted with Isherwood's engines, significant issues arose due to their sheer size. Weighing as much as 30% of the vessel's displacement, the engines occupied an enormous amount of internal space, leaving little room for coal storage, crew accommodations, and provisions.

History

Following the end of the Civil War in 1865, the Navy faced severe funding cuts, which left many projects abandoned. The frigates, which were nearly complete, suffered construction delays as funds dried up. The last ships in the class, '' Neshaminy'', ''Pompanoosus'', and ''Bon Homme Richard'', were all ultimately canceled.

Trials

The first ship launched, ''Idaho'', fitted with Dickerson's engines, was an immediate failure. During her trials, she reached a top speed of just - barely half the intended 15 knots. ''Madawaska'', with John Ericsson's design, briefly hit but could only sustain . The failure was attributed to Ericsson designing machinery better suited for an ironclad. Similarly, ''Chattanooga'' managed but failed to meet the requirement while significantly wearing out her engines. All three ships built against Isherwood's design had failed.

Following further scandals over engine costs and practicality, only ''Wampanoag'' and ''Ammonoosuc'', the two ships fitted with Isherwood's engines, were completed and became serviceable. On her maiden voyage, ''Wampanoag'' reached a top speed of , averaging , making her the fastest steamship in the world and a major vindication of Isherwood's work. Likewise, ''Ammonoosuc'' exceeded the goal by breaking . ''Wampanoag'' held the world speed record for 11 years, and no American warship surpassed her speed until 1899.

Later history

After her initial failure, ''Idaho'' was retained by the Navy and stripped of her engines. She was commissioned and sent to Japan, and was sold off after a typhoon ripped off her sails in 1869. ''Ammonoosuc'' and ''Chattanooga'' were laid up after their trials, and ''Madawaska'' was fitted with new engines and rebuilt.

In 1869, the Secretary of the Navy disapproved of the large number of warships named after Native American tribes and the incoherent naming conventions used across the fleet. As a result, he ordered a systematic renaming of vessels. The five remaining ''Wampanoag''-class frigates were subsequently renamed after American states. That same year, the Navy assembled a board to review war-era vessels as part of budget reduction efforts. The board criticized the class, believing that their high speeds did not justify their costly operation, especially for a role that was no longer needed. By 1870, just years after the class was launched, the entire class had been decommissioned and were gradually disposed of over the next two decades.

Legacy

The original purpose of the frigates was rendered obsolete while they were still under construction. The British government, seeking to enforce neutrality during the Civil War, eventually seized vessels built for the Confederacy and closely monitored Confederate agents to prevent further support. After the war, the United Kingdom perceived the ''Wampanoag''-class frigates as a potential threat, which contributed to its willingness to pay for war damage. During the Alabama Claims, Britain agreed to pay $15.5 million in compensation for the damage caused by the British-built Confederate raiders, which helped to normalize Anglo-American relations. The Royal Navy was interested in the ''Wampanoag''s design, which lead it to build around a similar idea that favored speed over armor and armament: a concept that would later develop into the battlecruiser.

Ships in class

Due to various differences in characteristics, sources vary on what constitutes being a part of the ''Wampanoag'' class. While all eight were built during the same program and to the same general design, some sources only include ''Wampanoag'' and ''Ammonoosuc'', while others exclude ''Chattanooga'' and ''Idaho''.

Footnotes

References

{{Wampanoag class frigate

Ships of the Union Navy
Steam frigates
Steam frigates of the United States Navy
Ship classes of the United States Navy
Frigate classes