INTRODUCTION: THE FRENCH NAVY, 1816-1859
PART 4: DEFINITIONS FOR THE SHIP PAGES
Displacement. The French had no system of tonnage like the British bm tons. Displacements are near full load and generally correspond to the drafts shown in the dimensions. Tonnages are metric.
Dimensions. The dimensions given here differ from those found in early French sources because they have been converted from French to English measurements (1 French foot = 1.06576543 English feet).
Lengths on the waterline are from rabbit to rabbit, or the locations where the stempost and sternpost were notched to receive the hull planking. For screw steamers with a sternpost each side of the screw, the standard procedure was to measure to the after face of the after sternpost (the rudderpost). Some early ships, however, like the frigate Isly, appear to have been measured to the forward sternpost. This makes the recorded length of Isly 8ft 6in shorter than it might have been. Lengths on deck are from rabbit to rabbit at the level of the gun deck. In the mid-1860s the way in which lengths were measured changed slightly--this chapter uses the earlier sailing-era measurements for all ships.
The beam generally recorded for sailing ships was the molded (mld.) beam, a measurement that included the hull frames at the widest part of the hull but not the planking outside of them. Whenever possible, the extreme beam (including planking) is also given here for sailing ships, and it is also given for all steamers. Normally it was measured at the waterline. For paddle steamers, it excludes the paddle boxes.
Maximum and mean drafts are given, with the maximum being aft. Drafts forward can be accurately interpolated from these figures.
Masts. The dimensions of the lower masts are given for sailing ships. These include the length from the main deck to the lower trestle trees and the extreme diameter. Unless indicated, they are calculated from a table of standard dimensions adopted in 1835. A table adopted in 1854 shows only minor changes except for the 80-gun ship of the line, whose rig had been reduced after successful trials in Jupiter.
Machinery. Paddle engines are assumed to be beam (side-lever) engines with flue boilers, unless otherwise stated. In contrast, screw engines unless otherwise noted are direct-acting horizontal engines with tubular boilers.
The horsepower measurement used to compare ships was the nominal horsepower (nhp), derived from the work of Watt. The nominal horsepower of a cylinder was a function of the square of its diameter, its stroke, and the number of cycles completed per minute. Indicated horsepower (ihp) was measured empirically during trials. Advances in steam technology (especially higher steam pressures) tended to make ihp substantially greater than nhp.
The coal capacity given is the normal capacity of the ship ready for sea, usually at the displacement and draft shown. It is not necessarily the ship's maximum bunker capacity.
Armament. The following abbreviations are used:
GD Gundeck: the lowest armed deck, or the only one completely mounted with guns in single-decked ships
MD Middle Gundeck: on 3-deckers only
UD Upper Gundeck: the top gundeck on 2-deckers and 3-deckers.
SD Spardeck (gaillards). The quarterdeck and forecastle, which after 1815 were often joined to form a complete light deck.
Names. Ships are listed with the names which they had in 1816 or when they were launched, whichever was later. Earlier and later renamings are listed in the remarks. In one case these are abbreviated. After the fall of Napoleon, many ships were renamed in 1814 by the restored monarchy. When Napoleon returned for the 100 days, he ordered on 22.3.15 that all these revert to their previous names. After Waterloo, the monarchy restored its names on 15.7.15. These ships are listed as renamed in 1814 and 15.7.15 without mention of the intervening reversion.
Builders. The navy built most of its ships at its five naval ports (Cherbourg, Brest, Lorient, Rochefort, and Toulon) and the steam facility at Indret. In 1816 it still had ships building at yards at Bordeaux, Le Havre, and Dunkirk; and during the 1820s and 1830s it also operated yards at Saint Servan and Bayonne.
For private builders, the names, not locations, of the firms are given in the tables. The locations of those which also built engines can be found in table 4. Exceptions are Cavé, who built his hulls (and his engines after 1850) at Asnières near Paris, and Taylor who built his hulls at La Seyne (the future FCM yard). The locations of the rest are as follows. Arman at Bordeaux (and at Ajaccio for two screw avisos, Adonis and Amphion, launched in 1863), Bataille at La Mailleraye near Rouen, Baudet at Paimboeuf, E. Cardon at Honfleur, Chaigneau & Bichon (later Bichon Bros.) at Bordeaux (Lormont), Courau & Arman at Bordeaux (bankrupt 2.8.47), Guibert at Nantes, Malleux at Rouen, Gaspard Malo at Dunkirk, Moulinié Bros. at Bordeaux, Normand at Le Havre, Pivert at St. Malo, and Emmanuel Thibault at Rouen. All of the ships built by private yards were steamers except for six brig avisos.
Date Laid Down. These, the officially recorded dates, appear to refer to the start of construction, which preceeded the keel laying.
Commissioning Date. The commissioning process took an appreciable amount of time, during which a crew was assembled and the ship was armed and rigged. Official French records record the date on which this process began and the ship's roles were opened. On rare occasions (noted in the tables), this occurred while the ship was still on the ways.
Fate. The notation "steam" for sailing ships indicates that the ship was converted to steam and will also be found in the steam listing. The notation "Stk." (stricken) indicates the date the ship was "rayé," "condamné," or, for the earliest ships, ordered scrapped or hulked. BU generally indicates completion of scrapping by an arsenal or a contractor.
Class remarks. These do not include reassignments between yards, suspensions, and reclassifications made before ships were laid down unless these reflected actual design work. (The French budget and program of works was almost as confused during this period as the English.) All cancelled ships which had names assigned are mentioned, however.
Copyright © Stephen S. Roberts 2004-2015.