The CASCO class Monitors

Built: Various

Commissioned: Various, most never commissioned.

Service: Various

Home Port: Various

Dimensions: 225' Long, 45' Beam, 9' Draft

Armor: 8" iron Turret, 10" iron Pilothouse, 3" iron Hull, 3" iron Deck

Armament: 1x11" Smoothebore, 1x150lb Rifle; most removed the turret and mounted a single, unprotected 11" Smoothebore on a pivot mount, and a retractable spar torpedo.

Engines: Single Screw

Speed: 9 knots

Crew: 69

Fate: Most laid up and broken up without any active service.


The Casco class was designed by John Ericsson as a class of fast, light draft ocean going monitors intended to rectify the seaworthiness issues experienced by USS Monitor, and to incorporate other new ideas learned from experience by monitor crews in combat. Among other things, they incorporated a novel system of ballast tanks designed to raise the ship's profile when travelling on open seas and lower it when engaging enemy vessels and fortifications.

After the failure of the Union Bombardment of Fort Sumter, the Navy decided to redesign the vessels and repurpose them, a task allotted to Naval Chief Engineer Alban C. Stimers, who added significantly more armored protection to the ships. Unfortunately, midway through his modifications, Stimers had a falling out with Ericsson (Ericsson had a notorious ego, and was unwilling to consider any modifications to his designs as a general matter of course), and revamped the rest of the design without input from Ericcson. Because of Stimers' reputation, and because the vessels had originally been designed by Ericsson, the vessels were approved without serious review. Twenty vessels were ordered at a cost of fourteen million dollars (and enormous sum for the time.) It was only after construction began that a serious flaw in the revised Casco class plans were discovered. Stimers had failed to compensate for the extra armor his revisions had envisioned by strengthening the lower hull or adding buoyancy - the result was that the wooden frames of the hulls were exposed to excessive stress, and that the vessels had an amazingly low freeboard of only 3", meaning that they could easily be swamped by a calm wave, let alone rough seas.

Unfortunately, intertia, bureaucracy, and graft in the various ship building contracts meant that the construction of the vessels was not stopped. Instead, John Ericsson was called in to attempt to fix the design. His conclusion was that the only practical solution was to raise designed height of the hull by nearly two feet, and to remove the overloaded turret on most of the vessels to be completed. Instead, a single 11" Smoothebore was placed in an unprotected pivot mount where the turret would otherwise have been located, and a retractable spar torpedo mechanism was installed. Most of the Casco class to be finished during the war were inactive at best; none appear to have used their spar torpedoes against enemy vessels. Only a single ship, the Tunxis, was completed and commissioned with her turret intact before the end of the war, and her service was relatively brief. Very few were actually completed, in any event, before the end of the war, since Ericsson's modifications required significant rebuilding on most hulls.

The majority of the class spent the entire war on the stocks, were laid up thereafter, and only commissioned briefly after the war, or simply broken up as soon as an opportunity presented itself. Some were harvested for components for other post-war vessels.

The Casco Scandal forced the US Navy to reconsider its appropriations practices, and placed all designs acquired from then on under much more serious scrutiny. Unfortunately, this was not the last controversy of its kind, but the reforms it engendered helped to save many lives, and millions of dollars, in the long run.