Types of Ships in Nelson's Navy
Rated Vessels
Vessels of the Royal Navy were classified according to a system of 'ratings', based upon the number of guns carried. A ship bearing 100 guns or more was classed as a first rate, a ship with 90-98 guns was a second rate, and so on down to 20 guns, which was classed as a sixth rate. Ships known as third rates and above qualified as 'ships of the line', while fifth and sixth rates were known as frigates. All of these vessels had three masts, the principal difference between them, apart from armament, being the number of gundecks. First and second rates had three, while third and fourth rates had two. All others had one deck.
Here's a table below, illustrating the difference.
Three deckers, which carried either 100, 112, or 120 guns, together with second rates, which had between 90 and 98 guns, acted as flagships and carried an admiral and his staff. These large vessels were not only expensive to build, but took years to construct and required very large crews, which accounts for the small number of the heaviest classes of ship.
Third rates carried either 80, 74 or 64 guns. The 74s were the most numerous of this type and were designed to fight an enemy vessel of any size. Ships bearing 80 or 64 guns were not as successful as the 74s and declined in number as the war continued. The 64s were less expensive to build than the others and were designed as line of battleships, but as they carried 24 pdrs, on the lower deck as opposed to the 32pdrs mounted on the large vessels, their fired a considerably weaker weight of broadside: 600lb compared to 800lb. Many such vessels were converted to store ships or harbour ships and seldom served with major fleets.
Ships carrying 50-60 guns were classed as fourth rates. These had two decks while fifth rates, most notably the 44-gun frigates, had one deck, as a consequence of which they did not possess the firepower or structure to be able to hold their place in the line of battle. Nor were fourth rates fast enough to serve as frigates, as a result of which this type of vessel also declined in number as the war progressed.
Single-decked frigates, carrying between 28 and 44 gun, on the other hand, could manoeuvre well, were fast, and sufficiently well-armed to be able to perform operations independently of the fleet, or as part of an all-frigate squadron. If attached to a fleet, frigates performed reconnaissance duties for the commander-in-chief, with their main function being to locate the enemy fleet, notify the admiral of its location and course, and follow it until battle was joined. All navies respected the unwritten convention that a frigate was not to be fired upon by a ship of the line during fleet actions unless the frigate fired first.
The smallest of rated vessel was the sixth rate post-ship, the lighter of the two types of frigate, which carried 20-28 guns, making it slightly larger than a sloop. Beneath this came 'unrated' vessels, such as sloops, which were armed with up to 28 guns. Brigs and schooners fell below these, with gunboats smaller still.
When considering the number of guns associated with a ship, it is important to note that this unrefined statistic reveals less about the strength of a ship than appears obvious on the surface, for numbers of guns say nothing of the actual weight of the shot they fired. Thus, the main armament of a 74 was the 32-pdr cannon (the weight, of course, referring to that of the shot, not the ordnance itself), while those on a 64 were 24-pdrs. Moreover, no ship mounted all the same type of guns. Thus, while a 64 self-evidently carried 64 guns, these were a mixture of 26 24-pdrs, the same number of 18-pdrs, and 12 12-pdrs. Finally, carronades were not counted when calculating armament, which meant that the fighting power of a ship, particularly at close range where carronades could inflict considerable damage, was not uniformly reflected in the tabulation of long guns alone.
Sloops
This category covered a large variety of small vessels. Though less glamorous than the ships of the line that fought the main actions, or even the frigates, many of which fought celebrated ship-to-ship encounters, hundreds of small vessels enabled the Royal Navy to function. Tasks such as inshore patrols and convoy escort duty were vital, if tedious and repetitive, and kept Britain's naval war against France alive. The largest unrated vessel was the ship-sloop (usually abbreviated to 'sloop'), which came in several variations, but in all cases was smaller than a sixth rate frigate and was led by a commander instead of a post captain. Some sloops had both a quarterdeck and a forecastle, others had neither, with the upper deck running continuously the length of the vessel. Most sloops were two masted (thus qualifying them as 'boats' rather than as 'ships'), though they could occasionally appear in a three-masted version.
The tasks performed by sloops varied, but included the protection of commerce, inshore defensive patrols conducted all along the coasts of Britain and Ireland to protect against invasion and smuggling, and patrols designed to harass the enemy's coasts. The sloop could not perform the functions of a weakly armed frigate since its armament was insufficient for such duties and because it was quite slow, so that it suffered from double disadvantage of being not only unable to outrun an enemy frigate but was also incapable of defending itself from one. Most sloops carried carronades that were ideal at short range. Sloops with three masts usually carried up to 28 guns on the upper deck as well as swivel guns on the quarterdeck, plus two 6-pdr long guns as chasers. The Navy List in 1805 contained 39 vessels of this type, and 57 ten years later at war's end.
Brigs
Slightly smaller than a sloop and led by a lieutenant rather than a commander, the brig-sloop (or more commonly known as the 'brig') usually carried 14 24-pdr carronades, but might also carry a number of long guns. Such vessels were sometimes converted merchantmen where shortages in the Navy could be made up. Two square-rigged masts propelled a brig.
Bomb vessels
These were shallow-draught vessels used to approach close in shore and fire shot by high trajectory into the interior of a fortification or town. Bomb vessels contained mortars mounted so as to be able to fire at high angle. Seventeen such vessels were in commission in 1805, and were employed in the attack on Copenhagen in 1807, against Walcheren in 1809, and in the attack on Fort McHenry during the Anglo-American War of 1812.
Fireships
Fireships were loaded with combustibles and handled by a skeleton crew who would manoeuvre the vessel into a position from which it could be carried by the wind or current into an anchored enemy fleet. Just prior to releasing a fireship on its somewhat uncertain course, the crew would light the fuses to the explosive charges or inflammable material and make their escape in boats. A few purpose-built fireships existed in the Royal Navy during the wars, but they were generally fitted out only when a particular need arose, such as at Toulon in 1793 and during the attack on the Basque and Aix Roads in 1809. Employing fireships was particularly difficult, for they tended only to achieve success when sent against a large enemy fleet at anchor and amidst favourable wind and tide conditions - these last being particularly fickle.
Schooners
Schooners normally carried two masts, and were fast but weakly armed, with square topsails on the foremast and gaff-rigged courses aft. They were well suited for carrying messages between ships and in the pursuit of other, similarly armed and built enemy craft, such as privateers.
Gunboats
Gunboats were powered by oars or a single sail, and sometimes by both, and armed with one or two heavy guns at either end. Such weapons could only fire straight ahead, for the recoil would capsize the craft if the ordnance were placed in any other position. Gunboats served in harbours and inshore waters, but could not attack a larger vessel except when deployed in great numbers, such as on Lake Borgne in December 1814 during the campaign against New Orleans. Thus, a brig or sloop, stationary owing to becalmed conditions, could occasionally fall prey to a swarm of gunboats, particularly if close to shore.
Ship's boats
While vessels lay in harbour they could carry people and stores between themselves and the shore, or between ships. Ship's boats could also patrol around the ship while it was anchored in a foreign port to prevent an enemy from approaching or to stop sailors from deserting. Boats could also aid in communication between ships at sea and rescue men who had fallen overboard. Most importantly, boats played an essential role in amphibious operations and cutting-out expeditions, which sometimes required lengthy bouts of rowing. Ship's boats could also be used to tow a damaged vessel or one stuck in a calm, or for moving the anchors. Boats were stowed on the parent vessel, but in the battle were often towed astern to protect them - not always with success owing to tray shot - from enemy fire. It left aboard during an action, ship's boats were often riddled with musket balls and shattered by all manner of projectile emerging from the guns, and thus rendered useless. Even if they remained intact, boats were not intended to be used as lifeboats, not least because they were not numerous enough to carry the entire crew.