World Battleships List: US Broadside Ironclads

Revised 6 October 2001
Version 2.01
Compiled and Maintained by: Andrew Toppan
World Battleships Lists Main Page:

New Ironsides masted broadside ironclad
Dunderberg masted broadside ironclad

New Ironsides masted broadside ironclad

Displacement: 4,120 tons full load
Dimensions: 232 x 57.5 x 15 feet/70.7 x 17.5 x 4.6 meters
Propulsion: HDA engines, 4 boilers, 1 shaft, 700 ihp, 7 knots; bark rigged
Crew: 449
Armor: Iron: 3-4.5 inch belt, 4.5 inch battery, 1 inch deck
Armament: 2 8 inch Parrot MLR, 2 5.1 inch Dahlgren MLR, 14 11 inch Dahlgren smoothbore, 1 3.4 inch MLR, 1 12-pound smoothbore

Concept/Program: Was the first US Navy broadside ironclad ship, and the first seagoing US ironclad. In general appearance this ship was similar to the European ironclad frigates of the same era, and was in sharp contrast to the contemporary US monitors. Ships of this type were considered as possible alternative to monitors; although monitors were produced in much greater numbers, each type had unique advantages. Ultimately ships of this type, combined with the turrets introduced in the monitors, developed into the modern battleships.

Design: General arrangement was similar to conventional steam frigates, but with the sides of the ship armored and sloped inwards at 17 degrees. The bow and stern were unarmored. The ship was flat-bottomed and of relatively shallow draft, but was found to be too deep for attacks in shoal coastal waters. The sailing rig was carried only for her initial transit to the combat area, and was removed once she reached that area. Contract speed was 9.5 knots; this was not reached. The 8" and 11" guns were located in conventional broadside batteries, protected by the belt armor; the light guns were in exposed positions on the spar deck. There was a small armored pilothouse. The 5.1 inch Dahlgren MLRs were replaced by 5.3 inch Parrot MLRs in 1864.

New Ironsides
Photos: [New Ironsides as completed], [Stripped for action].

DANFS History

Built by Merrick & Sons, Philadelphia. Contracted 15 October 1861, launched 10 May 1862, commissioned 21 August 1862.

Saw extensive service during attacks on Charleston; extensive shore bombardment duties. Hit by a spar torpedo 5 October 1863, but damage was minimal. Decommissioned for repairs (and probably overhaul) at Philadelphia 30 June 1864; completed and recommissioned 27 August 1864. Participated in shore bombardment support for the assaults on Fort Fisher.

Decommissioned to reserve 6 April 1865. Destroyed by fire at Philadelphia 16 December 1865.

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Dunderberg masted broadside ironclad

Displacement: 7,800 tons full load
Dimensions: 377.5 x 72 x 21.5 feet/115 x 22.2 x 6.5 meters
Propulsion: RCR engines, 6 boilers, 1 shaft, 4,500 ihp, 15 knots design; bark rigged
Crew: ??
Armor: Iron: 2.5-3.5 inch belt, 4.5 inch casemate
Armament: 4 15 inch Dahlgren smoothbore, 12 11 inch Dahlgren smoothbore

Concept/Program: A second, and much larger, broadside ironclad. The design of this ship was considerably different from New Ironsides, and she was far less successful, mainly because she was completed too late to see Civil War service.

Design: A low hull with ironclad sides sloped outwards at 35 degrees; ram bow. There was a large armored casemate, generally similar to that of CSS Virginia, located amidships. She had a iron double bottom and collision bulkheads. Design speed was 15 knots, but on trials only 3,778 ihp was produced, giving 11.7 knots. There were six guns on each broadside: two 15" forward, with 4 11" abaft them. The bow and stern each had five gunports (one axial, two angled to each side) and two 11" guns; each pair of guns was arranged to traverse between the five ports.

Departure from Service/Disposal: Never commissioned in the US Navy.

Photos: [Building, 1865], [Lithograph of Dunderberg on trials], [As French Rochambeau].

DANFS History

Builtby W.H. Webb, New York. Contracted 3 July 1862, launched 22 July 1865, completed for trials 6/1867, never commissioned. Sold back to her builder soon after completion, and was purchased by France later in 1867 as Rochambeau, mainly to prevent Prussia from buying the ship. Was rearmed by the French with 4 10.8" and 10 9.4 inch rifles; commissioned for a few weeks late summer 1870, then decommissioned to reserve. Stricken 1872 and scrapped in 1874.

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