French ironclad Marengo
Encyclopedia
Marengo was a wooden-hulled, armored frigate of the , built for the French Navy
in the mid to late 1860s. The ship was running her sea trials in July 1870 when the Franco-Prussian War
began and was immediately placed in reserve until after the war was over. Marengo participated in the French occupation of Tunisia
in 1881 and was flagship
of the Northern Squadron in 1891 when it made port visits in Britain and Russia. She was sold for scrap
in 1896.
as a improved version of the s. The ships were central battery ironclads with the armament concentrated amidships. For the first time in a French ironclad three watertight iron bulkhead
s were fitted in the hull. Like most ironclads of their era they were equipped with a metal-reinforced ram
.
The ship measured 87.73 metre overall, with a beam
of 17.52 metre. Marengo had a maximum draft of 9.09 metre and displaced 7749 tonnes (7,626.6 LT). Her crew numbered between 750 and 778 officers and men. The metacentric height
of the ship was very low, between 1.7–2.2 ft (0.51816–0.67056 m).
. Their engines were powered by eight oval boiler
s. On sea trial
s the engine produced 3600 ihp and Marego reached 13.5 knots (7.3 m/s). She carried 650 metric tons (639.7 LT) of coal which allowed her to steam for approximately 3000 nautical miles (5,556 km) at a speed of 10 knots (5.4 m/s). The Océan-class ships were barque
or barquentine
-rigged with three masts and had a sail area around 2000 sqm.
s on the upper deck, one gun at each corner of the battery, with the remaining guns on the battery deck below the barbettes. Marengos armament was upgraded, before she commissioned, to four 274 millimetres (10.8 in) guns in the barbettes, and on the battery deck, four 240 millimetres (9.4 in) and seven 138 millimetres (5.4 in) guns. By 1885 two more 274-millimeter guns had been added and all of the 138-millimeter guns were replaced by four 120 millimetres (4.7 in) guns.
The 18-caliber
274-millimeter Modéle 1870 gun fired an armor-piercing
, 476.2 pounds (216 kg) shell while the gun itself weighed 22.84 long tons (23.2 t). The gun fired its shell at a muzzle velocity
of 1424 ft/s (434 m/s) and was credited with the ability to penetrate a nominal 14.3 inches (36.3 cm) of wrought iron
armour at the muzzle. The armor-piercing shell of the 19-caliber 240-millmeter Modele 1870 gun weighed 317.5 pounds (144 kg) while the gun itself weighed 15.41 long tons (15.7 t). It had a muzzle velocity
of 1624 ft/s (495 m/s) and was credited with the ability to penetrate a nominal 14.4 inches (366 mm) of wrought iron
armour at the muzzle. The 138-millimeter gun was 21 calibers long and weighed 2.63 long tons (2.7 t). It fired a 61.7 pounds (28 kg) explosive shell
that had a muzzle velocity of 1529 ft/s (466 m/s). The guns could fire both solid shot
and explosive shells.
At some point the ship received a dozen 37 millimetres (1.5 in) Hotchkiss 5-barrel revolving guns
. They fired a shell weighing about 500 g (1.1 lb) at a muzzle velocity of about 610 m/s (2,001.3 ft/s) to a range of about 3200 metres (3,499.6 yd). They had a rate of fire of about 30 rounds per minute. The hull was not recessed to enable any of the guns on the battery deck to fire forward or aft. However, the guns mounted in the barbettes sponson
ed out over the sides of the hull did have some ability to fire fore and aft. Late in the ship's career four above-water 356 millimetres (14 in) torpedo tube
s were added.
waterline belt
. The sides of the battery itself were armored with 160 millimetres (6.3 in) of wrought iron. The barbette armor was 150 millimetres (5.9 in) thick. The unarmored portions of their sides were protected by 15 millimetre (0.590551181102362 in) iron plates. Gardiner says that the barbette armor was later removed to improve their stability, but this is not confirmed by any other source.
in July 1865 and launched on 15 October 1868. The ship began her sea trials on 1 July 1870 and was running them when the Franco-Prussian War
of 1870–71 began. She was immediately put in reserve and not commissioned until 1872 for service with the Mediterranean Squadron. Marengo remained with the squadron until 1876 when she was again placed in reserve. On 2 October 1880 the ship was recommissioned and assigned to the Mediterranean Squadron. Marengo was transferred to the Levant Squadron on 13 February 1881 and bombarded the Tunisian port of Sfax
in July as part of the French occupation of Tunisia. She remained in the Mediterranean until 1886 when she was assigned to the Reserve Squadron. In 1888 Marengo became the flagship
of the Northern Squadron and led the squadron during its port visits to Osborne Bay
and Spithead
in August 1891 and to Kronstadt
in September 1891. She was reduced to reserve the following year and sold on 7 March 1896.
French Navy
The French Navy, officially the Marine nationale and often called La Royale is the maritime arm of the French military. It includes a full range of fighting vessels, from patrol boats to a nuclear powered aircraft carrier and 10 nuclear-powered submarines, four of which are capable of launching...
in the mid to late 1860s. The ship was running her sea trials in July 1870 when the Franco-Prussian War
Franco-Prussian War
The Franco-Prussian War or Franco-German War, often referred to in France as the 1870 War was a conflict between the Second French Empire and the Kingdom of Prussia. Prussia was aided by the North German Confederation, of which it was a member, and the South German states of Baden, Württemberg and...
began and was immediately placed in reserve until after the war was over. Marengo participated in the French occupation of Tunisia
French occupation of Tunisia
The French conquest of Tunisia occurred in two phases in 1881: the first consisting of the invasion and securing of the country before the signing of a treaty of protection, and the second consisting in the suppression of a rebellion...
in 1881 and was flagship
Flagship
A flagship is a vessel used by the commanding officer of a group of naval ships, reflecting the custom of its commander, characteristically a flag officer, flying a distinguishing flag...
of the Northern Squadron in 1891 when it made port visits in Britain and Russia. She was sold for scrap
Ship breaking
Ship breaking or ship demolition is a type of ship disposal involving the breaking up of ships for scrap recycling. Most ships have a lifespan of a few decades before there is so much wear that refitting and repair becomes uneconomical. Ship breaking allows materials from the ship, especially...
in 1896.
Design and description
The Océan-class ironclads were designed by Henri Dupuy de LômeHenri Dupuy de Lôme
Stanislas Charles Henri Dupuy de Lôme was a French naval architect. He was the son of a naval officer and was born in Ploemeur near Lorient, Brittany, in western France. He was educated at the École Polytechnique...
as a improved version of the s. The ships were central battery ironclads with the armament concentrated amidships. For the first time in a French ironclad three watertight iron bulkhead
Bulkhead (partition)
A bulkhead is an upright wall within the hull of a ship or within the fuselage of an airplane. Other kinds of partition elements within a ship are decks and deckheads.-Etymology:...
s were fitted in the hull. Like most ironclads of their era they were equipped with a metal-reinforced ram
Naval ram
A naval ram was a weapon carried by varied types of ships, dating back to antiquity. The weapon consisted of an underwater prolongation of the bow of the ship to form an armoured beak, usually between six and twelve feet in length...
.
The ship measured 87.73 metre overall, with a beam
Beam (nautical)
The beam of a ship is its width at the widest point. Generally speaking, the wider the beam of a ship , the more initial stability it has, at expense of reserve stability in the event of a capsize, where more energy is required to right the vessel from its inverted position...
of 17.52 metre. Marengo had a maximum draft of 9.09 metre and displaced 7749 tonnes (7,626.6 LT). Her crew numbered between 750 and 778 officers and men. The metacentric height
Metacentric height
The metacentric height is a measurement of the static stability of a floating body. It is calculated as the distance between the centre of gravity of a ship and its metacentre . A larger metacentric height implies greater stability against overturning...
of the ship was very low, between 1.7–2.2 ft (0.51816–0.67056 m).
Propulsion
The Océan-class ships had one horizontal return connecting rod compound steam engine driving a single propellerPropeller
A propeller is a type of fan that transmits power by converting rotational motion into thrust. A pressure difference is produced between the forward and rear surfaces of the airfoil-shaped blade, and a fluid is accelerated behind the blade. Propeller dynamics can be modeled by both Bernoulli's...
. Their engines were powered by eight oval boiler
Boiler (steam generator)
A boiler or steam generator is a device used to create steam by applying heat energy to water. Although the definitions are somewhat flexible, it can be said that older steam generators were commonly termed boilers and worked at low to medium pressure but, at pressures above this, it is more...
s. On sea trial
Sea trial
A sea trial is the testing phase of a watercraft . It is also referred to as a "shakedown cruise" by many naval personnel. It is usually the last phase of construction and takes place on open water, and can last from a few hours to many days.Sea trials are conducted to measure a vessel’s...
s the engine produced 3600 ihp and Marego reached 13.5 knots (7.3 m/s). She carried 650 metric tons (639.7 LT) of coal which allowed her to steam for approximately 3000 nautical miles (5,556 km) at a speed of 10 knots (5.4 m/s). The Océan-class ships were barque
Barque
A barque, barc, or bark is a type of sailing vessel with three or more masts.- History of the term :The word barque appears to have come from the Greek word baris, a term for an Egyptian boat. This entered Latin as barca, which gave rise to the Italian barca, Spanish barco, and the French barge and...
or barquentine
Barquentine
A barquentine is a sailing vessel with three or more masts; with a square rigged foremast and fore-and-aft rigged main, mizzen and any other masts.-Modern barquentine sailing rig:...
-rigged with three masts and had a sail area around 2000 sqm.
Armament
These ships had their main armament mounted in four barbetteBarbette
A barbette is a protective circular armour feature around a cannon or heavy artillery gun. The name comes from the French phrase en barbette referring to the practice of firing a field gun over a parapet rather than through an opening . The former gives better angles of fire but less protection...
s on the upper deck, one gun at each corner of the battery, with the remaining guns on the battery deck below the barbettes. Marengos armament was upgraded, before she commissioned, to four 274 millimetres (10.8 in) guns in the barbettes, and on the battery deck, four 240 millimetres (9.4 in) and seven 138 millimetres (5.4 in) guns. By 1885 two more 274-millimeter guns had been added and all of the 138-millimeter guns were replaced by four 120 millimetres (4.7 in) guns.
The 18-caliber
Caliber (artillery)
In artillery, caliber or calibredifference in British English and American English spelling is the internal diameter of a gun barrel, or by extension a relative measure of the length....
274-millimeter Modéle 1870 gun fired an armor-piercing
Armor-piercing shot and shell
An armor-piercing shell is a type of ammunition designed to penetrate armor. From the 1860s to 1950s, a major application of armor-piercing projectiles was to defeat the thick armor carried on many warships. From the 1920s onwards, armor-piercing weapons were required for anti-tank missions...
, 476.2 pounds (216 kg) shell while the gun itself weighed 22.84 long tons (23.2 t). The gun fired its shell at a muzzle velocity
Muzzle velocity
Muzzle velocity is the speed a projectile has at the moment it leaves the muzzle of the gun. Muzzle velocities range from approximately to in black powder muskets , to more than in modern rifles with high-performance cartridges such as the .220 Swift and .204 Ruger, all the way to for tank guns...
of 1424 ft/s (434 m/s) and was credited with the ability to penetrate a nominal 14.3 inches (36.3 cm) of wrought iron
Wrought iron
thumb|The [[Eiffel tower]] is constructed from [[puddle iron]], a form of wrought ironWrought iron is an iron alloy with a very low carbon...
armour at the muzzle. The armor-piercing shell of the 19-caliber 240-millmeter Modele 1870 gun weighed 317.5 pounds (144 kg) while the gun itself weighed 15.41 long tons (15.7 t). It had a muzzle velocity
Muzzle velocity
Muzzle velocity is the speed a projectile has at the moment it leaves the muzzle of the gun. Muzzle velocities range from approximately to in black powder muskets , to more than in modern rifles with high-performance cartridges such as the .220 Swift and .204 Ruger, all the way to for tank guns...
of 1624 ft/s (495 m/s) and was credited with the ability to penetrate a nominal 14.4 inches (366 mm) of wrought iron
Wrought iron
thumb|The [[Eiffel tower]] is constructed from [[puddle iron]], a form of wrought ironWrought iron is an iron alloy with a very low carbon...
armour at the muzzle. The 138-millimeter gun was 21 calibers long and weighed 2.63 long tons (2.7 t). It fired a 61.7 pounds (28 kg) explosive shell
Shell (projectile)
A shell is a payload-carrying projectile, which, as opposed to shot, contains an explosive or other filling, though modern usage sometimes includes large solid projectiles properly termed shot . Solid shot may contain a pyrotechnic compound if a tracer or spotting charge is used...
that had a muzzle velocity of 1529 ft/s (466 m/s). The guns could fire both solid shot
Round shot
Round shot is a solid projectile without explosive charge, fired from a cannon. As the name implies, round shot is spherical; its diameter is slightly less than the bore of the gun it is fired from.Round shot was made in early times from dressed stone, but by the 17th century, from iron...
and explosive shells.
At some point the ship received a dozen 37 millimetres (1.5 in) Hotchkiss 5-barrel revolving guns
Hotchkiss gun
The Hotchkiss gun can refer to different products of the Hotchkiss arms company starting in the late 19th century. It usually refers to the 1.65-inch light mountain gun; there was also a 3-inch Hotchkiss gun...
. They fired a shell weighing about 500 g (1.1 lb) at a muzzle velocity of about 610 m/s (2,001.3 ft/s) to a range of about 3200 metres (3,499.6 yd). They had a rate of fire of about 30 rounds per minute. The hull was not recessed to enable any of the guns on the battery deck to fire forward or aft. However, the guns mounted in the barbettes sponson
Sponson
Sponsons are projections from the sides of a watercraft, for protection, stability, or the mounting of equipment such as armaments or lifeboats, etc...
ed out over the sides of the hull did have some ability to fire fore and aft. Late in the ship's career four above-water 356 millimetres (14 in) torpedo tube
Torpedo tube
A torpedo tube is a device for launching torpedoes. There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units installed aboard surface vessels...
s were added.
Armor
The Ocean-class ships had a complete 178–203 mm (7–8 in) wrought ironWrought iron
thumb|The [[Eiffel tower]] is constructed from [[puddle iron]], a form of wrought ironWrought iron is an iron alloy with a very low carbon...
waterline belt
Belt armor
Belt armor is a layer of heavy metal armor plated on to or within outer hulls of warships, typically on battleships, battlecruisers and cruisers, and on aircraft carriers converted from those types of ships....
. The sides of the battery itself were armored with 160 millimetres (6.3 in) of wrought iron. The barbette armor was 150 millimetres (5.9 in) thick. The unarmored portions of their sides were protected by 15 millimetre (0.590551181102362 in) iron plates. Gardiner says that the barbette armor was later removed to improve their stability, but this is not confirmed by any other source.
Service
Marengo was laid down at BrestBrest, France
Brest is a city in the Finistère department in Brittany in northwestern France. Located in a sheltered position not far from the western tip of the Breton peninsula, and the western extremity of metropolitan France, Brest is an important harbour and the second French military port after Toulon...
in July 1865 and launched on 15 October 1868. The ship began her sea trials on 1 July 1870 and was running them when the Franco-Prussian War
Franco-Prussian War
The Franco-Prussian War or Franco-German War, often referred to in France as the 1870 War was a conflict between the Second French Empire and the Kingdom of Prussia. Prussia was aided by the North German Confederation, of which it was a member, and the South German states of Baden, Württemberg and...
of 1870–71 began. She was immediately put in reserve and not commissioned until 1872 for service with the Mediterranean Squadron. Marengo remained with the squadron until 1876 when she was again placed in reserve. On 2 October 1880 the ship was recommissioned and assigned to the Mediterranean Squadron. Marengo was transferred to the Levant Squadron on 13 February 1881 and bombarded the Tunisian port of Sfax
Sfax
Sfax is a city in Tunisia, located southeast of Tunis. The city, founded in AD 849 on the ruins of Taparura and Thaenae, is the capital of the Sfax Governorate , and a Mediterranean port. Sfax has population of 340,000...
in July as part of the French occupation of Tunisia. She remained in the Mediterranean until 1886 when she was assigned to the Reserve Squadron. In 1888 Marengo became the flagship
Flagship
A flagship is a vessel used by the commanding officer of a group of naval ships, reflecting the custom of its commander, characteristically a flag officer, flying a distinguishing flag...
of the Northern Squadron and led the squadron during its port visits to Osborne Bay
Osborne Bay
Osborne Bay is a bay on the north east coast of the Isle of Wight, England, in the eastern arm of the Solent. It lies to the east of East Cowes. Its shoreline is 2km in length and is gently curving. It stretches from Old Castle Point in the west to Barton Point to the east.The seabed is a mixture...
and Spithead
Spithead
Spithead is an area of the Solent and a roadstead off Gilkicker Point in Hampshire, England. It is protected from all winds, except those from the southeast...
in August 1891 and to Kronstadt
Kronstadt
Kronstadt , also spelled Kronshtadt, Cronstadt |crown]]" and Stadt for "city"); is a municipal town in Kronshtadtsky District of the federal city of St. Petersburg, Russia, located on Kotlin Island, west of Saint Petersburg proper near the head of the Gulf of Finland. Population: It is also...
in September 1891. She was reduced to reserve the following year and sold on 7 March 1896.