Random Shots August 1998

Monitor vs. Warrior.

When she was launched in 1859, HMS Warrior was only the second ocean-going ironclad warship in the world, after the French, Gloire, launched one month earlier.By the time of the first clash of ironclads, between the USS Monitor and CSS Virginia (neither of which could be classed as ocean-going) in March 1862, the Royal Navy had an additional ironclad, Defence in service. Black Prince and Resistance, were nearing completion with 3 more ironclads launched. The French Navy had 4 ironclads at sea and two more nearing completion. The US Navy had just completed work on USS Galena, a small lightly armoured schooner and the much more serious New Ironsides was nearing completion.

In the recently published 'Stars and Stripes for ever', Harry Harrison postulates British intervention in the American Civil War, leading to an engagement between Monitor and Warrior. In the book, Monitor steams to within 'a few scant feet' before firing into Warrior's armoured battery… 'punching the cannon balls through the armour plate to wreak havoc and destruction in the gun deck'. Monitor then sails on to position herself on Warrior's stern to destroy her means of propulsion. Well, before we consider the inherent likelihood of this outcome, perhaps we should examine the ships themselves.

HMS Warrior:

Launched December 1860 Completed October 1861.
Displacement 9137 tons, Overall length, 420ft.
Max. Speed 14 knots (17.5 knots under steam & sail)
Armour
Citadel: 4.5 inch wrought iron plate, backed by 18 inches of teak
Bow & stern, none
Armament
10 110lb rifled breech loaders
26 68lb muzzle loaded smoothbores
4 40lb rifled breech loaders

HMS. Warrior, photographed in 1867

USS Monitor:

Launched January 1862 Completed February 1862 (!)
Displacement 917 tons Overall Length 172ft.
Max. Speed 5.5 knots
Armour
Hull: 2-4 x 1 inch plates
Turret 8 x 1 inch plates
Armament
2 11 inch muzzle loaded smoothbores

 

Monitor's crew photographed after their engagement with Virginia

Manoeuvre

Warrior was considered unmanoeuverable by the Royal Navy, having a turning circle of 760 yards at 12 knots and having a sluggish reaction to the helm. However she was one of the fastest ships afloat at the time. Monitor by contrast was fairly manoeuvrable. However, her best speed was between 5 and 6 knots, and that, only on a dead calm sea. She could not make headway in even rolling seas, almost being lost as she was towed towards Hampton Roads, and actually sinking in a force seven being towed back.

Armour.

Warrior's armour was 4.5 inch rolled iron in 15ft by 3ft plates, tongued and grooved together, backed by 18 inches of teak. Monitor's armour, in the main was composed of 1 inch rolled iron plated bolted together to a thickness of 8 inches in the turret and 2 to 4 inches along her sides.

Guns.

Warriors main armament was of 30 8 inch smoothbores (15 per broadside), throwing a 68lb ball with a rate of fire of a round every 55 seconds. Additionally she carried 10 110lb Armstrong breechloading rifles, 6 of which could bear on a single broadside. These fired a bolt or shell every 50 seconds. Apart from being faster to re-load, the rifles were far more accurate, especially at long range. Monitor carried 2 11 inch, turret mounted Dahlgren smooth bores. These had a theoretical rate of fire of a 150lb solid shot every 2-3 minutes, but in action against the Virginia,
managed only a round every 6-8 minutes.

In Combat.

We know from actual events that the Monitor's chosen tactic was to get as close to her enemy as possible and then pound away with her 11 inch Dahlgrens. We also know something of Warrior's intended tactics from notes made by her commander, Captain Cochrane about his plans for a possible encounter with Gloire. He intended to use his superior speed to bring about an action, but then remain at long range until French fire had been suppressed or at least reduced. Similar tactics would probably have been used in the event of an engagement with Monitor.
One of Warrior's 110lb Guns
If Warrior opened fire at 1,500 yards, then even if she had remained stationary, it would have taken Monitor at least 12 minutes to close. And if Warrior had used her superior speed, that time could have been extended indefinitely. During a 12 minute exchange of fire, Monitor could have fired at most 8 150lb solid shot. Warrior could have fired 156 68lb solid shot and 72 110lb solid bolts. During the Civil war, USN ironclads achieved a hit rate of 33% against fort Sumter at ranges of upwards of 500 yards. At 100 yards, Monitor had hit Virginia with 20 of 55 shots fired. So with luck, Monitor may have hit warrior 3 times during the 12 minutes. Warrior's task was far more difficult, as Monitor made a very small target, so 10% for the 68lbers and 15% for the rifles, rather than 30 might be a fair guess. This would mean, during the same time period, Monitor being hit by 16 68lb and 10 110lb shot.
 
During the engagement between Monitor and Virginia, Monitor's 20 hits on Virginia's armour had caused dents to 6 of her 2 inch plates, but failed to penetrate. However, her guns had been served with only half charges, since they were not proofed. We may assume the use of full charges against the Warrior. Monitor in return had been hit by 24 shots from Virginia. Hits on Monitor's pilot house and turret caused considerable plate damage and some crew casualties, but failed to actually penetrate the armour. However, Virginia had been outfitted to combat wooden ships and had very quickly run out of solid shot; leaving her only shells, which were not expected to penetrate armour. In later engagements against largely against forts, vessels similarly armoured to Monitor, suffered little penetrative damage. However damage and crew casualties due to partial penetration, causing plates to spring and shatter and rivets to pop was widespread. Warrior carried 33 solid armour piercing rounds for each rifle and 90 rounds of solid shot for each 68lber.
USS Monitor & CSS Virginia in Hampton Roads March 1862

 

Penetration trials carried out by the Admiralty during the 1860s showed that British 68lb shot would penetrate upto 8 inches of composite plate armour similar to the Monitor's at upto 100yds and 6 inches at upto 500yds. Performance of the 110lber is difficult to gauge, as, although it had an aerodynamic shot, it generated a lower muzzle velocity than the 68lber due to defects in its breech mechanism. Monitor's 11 inch guns, even fully charged and firing wrought iron shot could not penetrate Warrior's armour at any range. Although later 15 inch Dahlgrens would penetrate with wrought iron shot at 100yds and steel shot at upto 500yds.

Conclusion.

We must conclude that in the unlikely event of Monitor going up against Warrior, she would have been overwhelmed by Warrior's fire, long before she closed, even were the Warrior's captain to have allowed her to close. The cumulative damage of shot striking the composite plate of her turret, and associated crew casualties, must have quickly rendered her unserviceable. A single shot penetrating the lesser plate of her hull, would have caused even more catastrophic results. Warrior on the other hand, could withstand any number of hits to her armoured citadel, with minimal casualties. As for hits on the unarmoured bow or stern, only a extremely lucky shot striking the rudder would have affected her. Her buoyancy being unimpaired by damage outside the citadel and the steering gear being accessible from inside.
 
Mr. Harrison's estimation of the possible encounter between Monitor and Warrior, is, I'm afraid indicative of the entire book. However, the possibilities offered by the general scenario are intriguing. Did you know for instance that the Czar was a close ally of the Union, and that the Imperial Russian Navy undertook the US Navy's Pacific duties during the war.
 
Anyone interested in Alternative histories of the American Civil War might do better to look at the writings of Harry Turtledove, particularly, How few Remain.
 
Dave Millward, August 1998.

Back to Wargames Forum Back to Previous Shots Return to the Library