Some Basic Facts

This type of vessel certainly best represents the culmination of the work of ship builders of the end of the 18th Century who had previously never reached such a level of perfection in the design of sailing ships.

It is the regulation of 4 August 1762 that defined the dimensions of gunports in all ships of the French Royal Navy and especially the spacing between them; it is from these dimensions that the principal characteristics of a naval vessel can be inferred: length, breadth, depth of hold (height of the hold at the main frame), height of the batteries, type of armament, weight of ballast.

It is then possible to define the main frame and deduce the hull shape from the shape of the 62 other frames, the stem and the stern, limited by the two fashion pieces. The finished vessel displaces 3000 tons when ready for a 6 to 7 months war campaign. Calculating the center of gravity of the bare hull and of the fully armed vessel, it is possible to determine the metacenter to insure its stability. Also, by studying the set of sails and finding the center of wind pressure, the point where the effect of the wind on all the sails is concentrated, the overall quality of a good seagoing ship: stability, handling, speed, ability to beat to windward, windage, gun effectiveness can be determined. The objective of optimizing the overall set of these qualities is to get the greatest possible efficiency in a conflict.

As compared to the enormous 100, 94 or 90-gun 3-deckers, the 74-gun ship represents the best possible combination of fire power and sailing capability, whereas 64 and 50-gun ships are too weak.

In 1780, the state of the French Navy was as follows: 5 110-gun vessels, 1 90, 7 80's, 1 70, 23 64's, 1 60, 1 56 and 3 50's plus a number of frigates, corvettes, cutters, luggers and other small craft whereas the number of 74-gun ships was 36.

The elements of this impressive fleet, capable of standing up to the British fleet, were most often constructed in the three main Navy yards in the six maritime areas of the kingdom: Brest, Rochefort and Toulon. Construction was more infrequent at Dunkirk, Le Havre, Bordeaux. or even St Malo, Lorient and Nantes. Just to take Rochefort as one example, 40 warships were started there between 1742 and 1800, 29 of which were 74's!

The construction of this type of ship represented almost 100,000 man-days at an average of 11 hours per day over a period of one to two years. According to J. Boudriot the cost of such a vessel including construction, fitting out, one campaign and laying off amounted to almost one million pounds of the day, representing the yearly upkeep of about 4000 families.