All good university-like expose starts with a definition: Naval Technology could be summarized as all ways devised to allow mankind seafaring. It's quite ambitious in its scope and we can only guess the subject would fill such space that the present website, naval-encyclopedia, would be just a part of it. In fact we deal with naval tech in all these pages. There are a few posts specifics about construction or naval warfare innovations.
This section will focus on a particular aspect of naval tech, if related to naval warfare in general, sometimes veering on civilian aspects. Propulsion for example, belongs to both the civilian and military realms, as well as navigational devices, radars, sonars, and any other systems outside armament or protection, proper to military warships. So on the long run, we will see various subjects, posts treated in standalone (like naval artillery) or smaller subjects, like those displayed here, linked to a menu with anchors.
Treated here: The ram is an old idea that resurfaced in the XIXth century.
Carthaginian ram of a ship sunk at the battle of Battle of the Aegates (First Punic War, 241 B.C.), discovered in 2010.
During the antique Mediterranean long naval supremacy contest, it was the spur ram, a separate piece generally in bronze, with various shaped that came to a tactical standard in around the time of Alexander the Great, and stayed that way until the time of the Augustean principate and Roman Empire. Its first use probably went back as far as the 8th Century BC and it was first recorded in use at the battle of Alalia in 535 BC.
It was fitted on all military galleys and used of course to "sink" enemy vessels, using ramming tactics helped by changing the rowing stance. In reality none really sank ever since they were all-wooden built and their floatibility coefficient was such at the worst case, they broke in two, or were just submerged. The idea was to eliminate them from the rest of the action, many were also later captured. The ram's size was also a good way to calculate its carrier galley. The roster monument at Actium (Aktio in Greece) which saw the combined Antony-Cleopatra fleet defeated by Augustus (and Agrippa) aligned a dozen bronze rosters of which only the stone socket shape remained today. By calculating these, archeologists confirmed allegations of ancient writers about the composition of the fleet, notably very large galleys's existence for a long time contested by many historians, such as the "20".
Roster of Alith, the world's best preserved, rear view showing its socket shape, to be integrated into the prolongated spur where the keel and bow piece met.
The Roster of Alith (Israeli coast), a bronze ram buried into marine soil, is today the best preserved original bronze ram ever found. It probably belongs to an ancient Carthaginian "four". The Roman fleet, a beginner in that field, war worried about its capabilities against the long and well trained Punic Navy which had quite a reputation at that time, being trained to battle for centuries against Greek fleets of the time and knew its trade full well. These vessels were fast and had excellent tactics. The pragmatic Romans recoignised this and started to place an armored belt along their trireme, quadrireme and quinqueremes, (as well as catapults and ballistae, and the corvus). They renounced speed and these fancy tactics so much so in imperial times, the ram practically disappeared and mostly became ornemental. But it stayed for centuries a symbol of naval power, as shown by the "roster plaza" close to the Forum where senators often spoke to the people and great decision were made public. Every marine building was also ornemented with rosters.
Survival until the enlightenment:
Ram tip and spur of a Holy League Spanish galley at Lepanto (1571) - Illustration by Tony Bryan, from Renaissance War Galley, 1470–1590, by Angus Konstam (Osprey Publishing, Bloomsbury Press Publishing)
The ram indeed was apparently still used by the Byzantines as shown is some galley depictions, but in some cases, it was no longer at the waterline level but sat well above, used mostly as a boarding passage for marine infantry. Classic medieval to renaissance galleys were always ended forward by a ram, but again, we have no clues of how it was used since artillery was often decisive, for example at Lepanto. In depictions, galleys faced each others, but they were found in melee combat and firepower eventually won the day. Outside of the Mediterranean, sail completely replaced rowing and the classic trade & war vessels such as the Cog, Carrack or Carvel had no ram. Galleons, a marriage of galley and carracks still had a reinterpretation of a basic galley hull but their "ram" mutated into a prolongated piece of the bow, carrying the foremast and symbolic figure, projecting in front of the forecastle. It was no longer offensive but still projected power, symbolic of the Prince's might.
Renaissance in the industrial age:
The ram of HMS Polyphemus (1870)
Indeed, the rule of sails condemd the use of rowing and thus, of independent propulsion. It was now more difficult to "aim" a ship to another. In some rare cases ramming was used only if all conditions were assembled, and as a preamble of a boarding, but the schock was detrimental to both vessels and ofter bordered to desperation. The age of steam completely changed naval tactics. With this new source of power ships were autonomous again from the wind, despite a long transition (1850-1890) seeing sail and steam combined. In 1840, French admiral Nicolas Hippolyte Labrousse proposed building a ram steamship. In 1858, Dupuy de Lôme designed the ironclad "Gloire" with a ram and CSS Virginia's ramming attack on USS Cumberland at the Battle of Hampton Roads in 1862 attracted much attention.
In 1860, the neoclassic style was very popular, and in its wake, the rediscovery of ancient naval warfare. An interest shown by the reconstitution by Napoleon III of a supposed trireme. But the appearance of the first ironclads in 1860 made ramming a potent tactic once again. Bows were reinforced and metallic rams attached to it in early generation ships, and afterwards built-in during construction on all. It was particularly clear at Lissa in 1864 when ramming was used wholesale in melee. It even became the definitive reference signal for all admiralties that the "ram was back". It was from then a prominent feature on all cruisers, gunboats and capital ships, and stayed that way until 1914. In the 1870s it even trigerred a new wave of experiments such as the "torpedo ram". The semi-submerged Polypheums was a good example of this.
The ram in the 20th century:
The reinforced ram of HMS Dreadnought is evident on this cutaway of HMS dreadnought in 1906
But at that time, apart HMS dreadnought ramming and sinking a surface u-boat almost by chance, the ram caused more sinkings by accidents (collisions) than combat. Like the protective nets at anchor, this idea soon diappeared. Tsushima already show QF gunnery and mines were more to fear, and Jutland showed long range naval gunnery ruled the day while both torpedoes and the ram in capital ships were innefficient. HMS Hood, laid down in 1919, had indeed no ram, as all the cruisers built as scouts in the 1910s. Ramming was still used at occasions during WW2, but again, against surfaced U-boats when the chance presented itself, and was often detrimental to the ship doing this manoeuver. Not all had reinforced bows. The small flower class corvettes, designed from northern atlantic whalers, had such 'ice-breaking' bows however. Nowadays, the "bow" is back, but only thanks to mathematics: The bulbous bow is an hydrodynamic feature recoignised for its ability to modify the water flow and increase the ship's penetration, improving its general hydrodynamic qualities. It found its way in many warships as well for the same reasons. It's a second return, but no longer as a weapon.
The bulbous bow of USS Lexington during her reconstruction in 1925, one of the first time that principle was applied.
Wing in ground vehicles
Modern wooden ships
The sail: Types of rigging
The sail: Teamwork & tricks
A familiar sight on 20th century warships, which appeared and disappeared relatively quickly, like protection nets against torpedo attacks between the 1880s and the 1920s. With their appearance of winged torpedoes, suspended on superstructures, they look odd and familiar at the same time, but their role is somewhat a mistery for many: Paravanes has been a fad in naval tech, dedicated to mine and ASW warfare.
Paravanes on the deck of IJN Fuso (wow)
So basically, the Paravane is a towed underwater "glider", a water kite. As a weapon, since it was given a warhead, the Paravane was used in anti-submarine warfare in general, and a British idea, developed from 1914–16 by Commander Usborne and Lieutenant C. Sir Dennistoun Burney. The project was funded by Sir George White, founder of the Bristol Aeroplane Company. It was initially thought of a way to destroy anchored mines, quite a deadly new weapon as shown by the Russo-Japanese war.
The principle was simple:
-The paravane was strung out and streamed alongside the towing ship, either from the bow or stern, but more likely the bow in order not to be perturbed by the propeller's wake.
-The wings were designed to carry the Paravane away from the hull, creating a lateral tension on the towing wire.
-The idea was this cable could snag the cable anchoring a mine*, either severing it by sheer pressure or a cutter**.
-The mine was then bring to the surface where it could be fired upon and destroyed.
-If the mine cable could no be severed, the paravane would met the mine eventually at the end of the cable, detonating it*. *A pull of about 7 cwt. the shears would cut a 1½ in. mooring-wire.
**The mine cable was guided into the jaws of shears or scissors made of special high-grade steel **In that case, the Paravane did not need even to receive a warhead, hoping ot would hurt one of the sensitive Hertz horns.
In the 1920s the normal length of the towing lines was 56 yards and a ship carried several of these. Each one was a three three-strand steel rope made of 37 galvanized wires 0.049 in. in diameter. Their ultimate breaking strength ranged between 100 and 120 tons per sq. inch.
So in short, an anti-mine paravane was a towed underwater cable cutter. But the parralel one developed during WW1 was a proper weapon. There were basically three types of paravanes:
The slow (16 knots), merchant-vessel type called “otters”
The medium, heavy types used by capital ships
The light type "fast" (26-30 kts) type used by cruisers and destroyers.
Destroyer paravanes, well used during both battles of the atlantic used a stern arrangement called a “depressor” to bring the virtual point of tow down to the required depth at the stern.
Paravane minesweeping principle - Seaman's Pocket Book 1943
Anti-mine Paravanes were generally towed from the bow, using the "paravane chains" towed by the same capstans used for moorings cables. A ship towing two paravanes can 'spread its wings' of sweep over 200 feets. However for ASW paravanes, stern cables were used instead. They were maintained as low down as possible, with outboard ends kept about 100 ft away from the ship axis, creating a virtual swept a wedge-shaped track alongside the bow, at the level of the keel or below.
The first anti-submarine Paravane, called by Burney an "high speed sweep" was developed from 1915. Here are its characteristics:
-Horizontal and vertical tail fins to increase stability
-Depth-keeping mechanism in the tail (horizontal rudder actuated by a hydrostatic valve responding to difference in water-pressure)
-80 pounds (36 kg) TNT warhead
-Armoured electric towing cable.
The idea was that when meeting a submarine (creating tension on the cable), the paravane could be remotelly detonated alongside the hull, along three ways:
> By direct contact through a striking-gear on its nose
> When the load on the line exceeded a predetermined value (the circuit closed).
> By manual imput on the other side of the electric line via a hand-switch.
The Paravane was a relatively cheap and simple weapon (much simpler than a torpedo) and could be towed up to 25 knots (46 km/h). Its recovery was reasonably simple also. Paravanes were stored in many ships, mostly battleships and cruisers in both WW1 and WW2. However new ways of dealing with mines and radical improvements in ASW warfare made it obsolete during the cold war. There are indeed very few examples of submarine sunk by paravanes, if any. The Paravane was used for about 30 years and used by all major navies of the world, following the Royal Navy example.
It should be noted the idea resurfaced with the 1940 "Z battery", this time to destroy planes, and using a rocket. It proved too a failure in operation. However it seems the US Department of Defense continues to have some interest in paravanes. The term is also used for fishing "gliders" today. Also the Paravane is distantly related to the Oropesa, a towed sonar fitted inside a submarine glider. The latter is used to vary the sonar's position in depht and spread. The system appeared right at the end of WW2 and became widespread in the 1970s for minesweeping operations and ASW detection.
Paravane deployed by HMS Bentick off Greenock
Smoke screens in the Navy:
Although incendiary weapons were used at sea from the antiquity such as the Roman and Greek stinkpots and salpeter pots, and the early medieval Greek fire and its projector quite popular in the Byzantine Navy. This was times of relatively close warfare.
The earliest recorded use of smoke for the purpose of concealing a ship was the turtle ships in combat, with sailors burning materials creating a very thick smoke on the roof.
USS Lexington testing a smoke screen, 1930
However the use of naval smoke was proposed by Sir Thomas Cochrane in 1812, as much an asphyxiant. Later during the American civil war, R.E. Lee, which commanded a blockade created a thick smoke screen to escape USS Iroquois.
However it would would until the first years of the twentieth century for clear evidence of deliberate use of large scale naval smokescreens.
This became a tactic. As gunnery pushed the ship ten kilometres afar and more, one tactic was to conceal the silhouette to enemy spotters. Its use was regulated, learnt, and practices in exercises. It was already known and well used during World War I, and even more during World War II. Event the introduction of radar did not changed its purpose, at least until better technologies to precisely locate a ship were available.
Smoke screens were created by relatively lighter ships in order to conceal them or others under the same blanket. Cruisers and destroyers were prime candidates for this. They were fast and agile enough to spray their smoke on a large area.
Using smoke screens had one main use: Conceal one of several ships in difficulty, badly hit and escaping for example. This was used most of the time this way, sometimes with the effect of really saving a ship. That was the famous case of HMS Exeter, badly beaten by the Graf Spee and probably on the verge of total destruction when the two light cruisers present at the battle of Rio de la Plata concealed her retreat in a thick smoke. The Graf Spee was herself damaged and this was sufficient to break the chase.
The concealment indeed could hide destroyers, just waiting the best opportunity to launch a volley of torpedoes. Destroyers following in line could create a massive, high curtain of smoke capable of masking the real strength of a fleet, including the smoke plumes.
In was deployed when dealing with coastal fortifications also. Allowing to conceal the ship behind smoke to the coast spotting control, whereas planes, well above it, could provided fire corrections.
It was also (and still is) used to conceal an approaching amphibious fleet. Slow landing crafts were an easy target, therefore smoke could disturb the spotters enough to not be able to hit a single one before the landing was done.
Smoke screens were proficiently used in the Baltic for example, in all sorts of operations and by all participants. They were often laid by motor torpedo boats and patrol boats. The Soviet navy used smokescreens laid perpendicularly to the direction of the attack to cover their MTB approach, in a bent zig-zag. The tactic was to lay it close enough to the target for a massed torpedo attack, without exposing the approaching crafts.
HMS Gloworm against Hipper
Smoke screens were also used with great effects at the Battle of Samar. As Taffy 3 was attacked by the main Japanese fleet, sneaking in the Philippines (part of the battle of Leyte), destroyers not only put an heroic fight to keep the IJN ships at bay, but also generously blanketed the slow and vulnerable CVs, sparing them certain destruction.
Battle of Samar
How it was done ?
In general, the most common way was the same tanks used in the cold war: Injecting injecting oil into the boilers to create black smoke, which exited from the funnel, or chemical canisters disposed at the stern (creating white smoke), which were mostly used by cruisers.
By using planes, and special chemicals (nasty Titanium tetrachloride (FM) here), massive curtains could mask entire fleets, as shown by this interwar USN test: https://youtu.be/0_EdgP57l1Q