Naval Warfare in the American Civil War

the first in a three part series

by Peter Hunt 

Introduction

The American Civil War is often cited as the first "modern" war.  In many respects this description is open to argument as many of the innovations such as rifles, breach loaders, telegraphs, railways, etc. had played important roles in other mid 19th Century wars.  Without doubt however the war at sea marked a turning point in naval history marking the end of the "wooden wall" line of battleships which had held sway since the Spanish Armada and laying out the design of the armoured, turreted, steam powered ship which dominated naval strategy until the coming of age of the aircraft carrier in 1941.  Since the A.C.W. also marked the first successful use of the two greatest killers of ships, the submarine and the naval mine it is safe to say that this was the first modern naval war. 

This article will cover the technological changes and the operational aspects that made the war so unique and also, in my opinion, make it a perfect period for wargaming, whether you want to have an accurate recreation of a certain battle or just a straight "set 'em up and go for it" game.  It is also a period where the wargamer's habit of mixing his hobby with alcoholic beverages is not amiss since a fair proportion of the participants in the real thing seem to have done much the same.

Technology

By the start of the ACW steam power as a means of naval propulsion had been around for over 40 years, but it had always been regarded as an auxiliary to sail power, either in the form of a small engine to keep a sailing ship going in a calm or of steam powered tugs to tow sailing ships in harbours and coastal waters.  The reason for this was that early engines were so inefficient that no ship could carry the amount of coal necessary to steam large distances.  Thus navies were still tied to the strategy and tactics of sail power.

For instance, the British fleets that dominated the Baltic and Black Seas in the Crimean War, although consisting in the main of steam-engined ships, were still sailing fleets at heart and would have been familiar to Nelson or Drake.  By the 1860s however engines were rapidly becoming more efficient and it was possible for relatively small ships to carry enough coal to get themselves across large distances with a decent cargo.  Most ships still retained a full sailing rig but now it was the sails that provided the auxiliary power.

Not having to rely on the wind gave admirals much more tactical freedom but there was a strategic price to pay.  In previous wars ships could stay at sea as long as their food, water and ammunition held out.  From now on ships would require refuelling too, either at friendly ports or from supply ships, thus the fleet train of supply vessels to keep the fighting fleet going was born, a naval development to which the USN has always since paid the most attention of' any major power. 

The use of steam power now made it possible to provide armour for ships to keep out shot and shell.  In the war all armour was iron and only the North had the industrial capability to roll armour plate.  The South armoured its warships by using old railroad tracks, but as the war progressed and the Southern railways became more and more dilapidated, even old rails were better than none and railroad iron for warships became like gold.  Although the ACW is remembered as being the first naval war between armoured ships it must be said that most of the ships on both sides were unarmoured and unarmoured ships could, occasionally, take out armoured vessels.  The South also used what I supposed would today be called "organic" armour in that, having no shortage of King Cotton they took to armouring their ships with bales of the stuff.  These "cotton clads" had at least some protection against shot, but of course the cotton was highly inflammable, no small consideration when all ships were still made of wood.  

USS Monitor - watercolour by Oscar Parkes

Improved casting techniques had, throughout the 19th Century, made it possible to cast bigger and bigger guns.  Thus whilst Nelson 's wooden walls would be armed with 6.4" guns firing shot of 32 lb, by the ACW such guns would be regarded as light and most vessels would be armed with 8" - 11" guns firing shot of 150 lb, with some carrying 15" monsters firing 300 lb shot.  Thus, for instance, David Farragut's flagship, a sloop of 21 guns, fired a heavier weight of shot than did Nelson's "Victory" of 100 guns.  As on land many of the naval guns were also rifled.  This gave improvement in accuracy but, more importantly, the higher muzzle velocities gave much better penetration than smoothbores.  It must be stressed that much of this technology was new and untested.  The gunners were working at "the edge of the envelope" and only trial and error could determine the optimum charge for a gun.  The "trials" often took place in the heat of battle as gunners seeing their shot bounce off armoured opponents desperately increased the charge.  An "error" however would mean a burst gun and dead gunners, a not infrequent occurrence.

Finally we turn to the underwater menace.  The term "torpedo" was used in the ACW to describe any naval explosive device and ought not to be confused with the modern, self propelled, explosive "fish" which was not invented then.  There were basically two types of torpedo, firstly there were the sort of things that we would now call mines, containers of explosives moored underwater and set off by contact detonators or, again a first for the ACW, command detonated by electricity.  Since ships of the period had little, if any, internal, water tight sub-dividing, any hole below the waterline could prove fatal and since most of the armoured ships had very little reserve buoyancy anyway, they could sink in seconds as a result of a mine explosion.  At best the torpedoes were unreliable and there are several recorded incidents of ships crews hearing the snapping of detonators as they hit a mine but no explosion resulting.  Even so, such an experience probably did little for the colour of one's underpants.  

USS Housatonic - as portrayed by R.G. Skerrett in 1912

Spar torpedoes were explosive charges placed on a spar clear of the bow of the ship, the idea being to drive your ship at his and detonate the charge against his hull.  Again the effect seems to have been very variable - sometimes devastating, frequently ineffectual.  Theoretically any ship could rig a spar torpedo although both sides had a few vessels that used this weapon as their main armament.   The first successful submarine attack occurred when the CSS Hunley sank the USS Housatonic.  Strictly speaking, the Hunley was a submersible and made the attack on the surface for the very sensible reason that she had already sunk twice with all hands when carrying out diving trials.  As it happened, however, the wash from her bow torpedo explosion swamped the Hunley and she sank again.  After this the Confederates called it a day with submarine development but the way ahead bad been shown.   

Confederate submarine H.L. Hunley - a detail from R.G. Skerrett's painting of 1902

The Theatre of Operations

Simply put, the naval aspects of the ACW took place in three spheres of operations, coastal, riverine and oceanic.  The coastal sphere can also be neatly divided into the East Coast and Gulf of Mexico theatres and the conflicts on the rivers basically took place an the Mississippi and her tributaries in the west and the James in the east.  In the coastal and riverine theatres, a small draught was a considerable advantage although the Mississippi was navigable to ocean going shipping for several hundred miles.  Shallow draught ships were at a considerable disadvantage in normal seas and, if armoured or either badly designed or hastily converted, were often little more than death traps for their crews in open water.

The war on the high seas was basically a matter of commerce raiding and blockade running by the Confederates, and the Union taking countermeasures.  There were several engagements between Confederate raiders and Union warships on the high seas and these, with the substitution of steam for sail power, were akin to the sort of single ship duels that had been a feature of the Anglo-American war of 1812.  Confederate raiders were active in all the great seas of the world except, perhaps, the Mediterranean.

In the next part of this article I shall go on to discuss the way the war was fought and to look into the wargaming possibilities.

back to american civil war    go to part two