By Patrick McSherry 
Vesuvius in action! ||| Deck plans and section 
The USS VESUVIUS was a one-of-a-kind experimental vessel that saw use in the War. No other vessels of this type were built. The unusual characteristic of the ship were the three 15" "dynamite" guns which constituted the ship's main battery.


The authorization to build a dynamite gun cruiser was obtained on August 3, 1886. The vessel was very unusual and was studied by naval experts from around the world. It obtained a mixed, but generally negative review.

In theory, the Vesuvius could fire thirty projectiles consisting of five hundred pounds of gun cotton, dynamite of other high explosive in thirty minutes. The projectiles were fired from three 15 inch guns using compressed air, hence the name "pneumatic guns". The compressed air would create less of a shock on the projectile than would a normal explosive charge and would therefore have less of a tendency to prematurely explode the projectile, which generally carried nitrocellulose and nitroglycerine.

VESUVIUS joined the fleet on October 1, 1890, operating with the North Atlantic Squadron until decommissioned on April 25, 1895 for major repairs. Relaunched on January 12, 1897, she joined the Cuban Blockade on May 28, 1898. She performed various special duties, and served as a dispatch boat between Cuba and Florida into July. During the War, she conducted eight shore bombardments against Santiago and its defenses. Admiral Sampson claimed that the bombardments had "great effect".

In spite of Admiral Sampson's comments, the VESUVIUS was considered less than effective. She was taken out of service on September 16, 1898 and remained in the Boston Navy Yard until being converted to a torpedo testing vessel in 1904. Her "dynamite" guns were removed and she was outfitted with four torpedo tubes. She was recommissioned on June 21, 1905. VESUVIUS was again decommissioned on November 27, 1907 for repairs. Again recommissioned on February 14, 1910, she served in the vicinity of Newport, Rhode Island. VESUVIUS was decommissioned for the final time on October 21, 1921, and sold for scrap on April 21, 1922.

Congress authorized a second Dynamite cruiser of the VESUVIUS type on March 2, 1889. The authorization was contigent on the Secretary of the Navy being satisfied with the as yet uncommissioned VESUVIUS and her unique armament. This vessel was never built.


The VESUVIUS was an experimental vessel with many problems.

One major problem was that the "dynamite" guns were not located within a movable turret or swivel mounting. For the guns to be brought to bear on a target, the ship had to face the target bow on. Action against moving targets was therefore difficult, and the ship was itself at a disadvantage when operating against a traditionally armed vessel. The ship was virtually defenseless when retreating.

Secondly, the range of the main guns was not as great as many of the vessels it would operate against. Though it had good speed, the speed alone could not ensure itssurvival against at traditionally armed ship with guns of good range. The "dynamite" guns' range was not altered by changing the angle of the guns, but by altering the amount of compressed air used to fire the projectile.

The fuses on the projectiles were initially not armed when the vessel was fired, as the shearing pins were too heavy and not broken at discharge. The fuses themselves may have been defective also.

The ship's guns did have a strong psychological effect. It could fire with almost no warning, since the pneumatic guns were very quiet. If the shells hit, they were devastating. The threat of the untried weapon alone gave it a psychological advantage.

There were other problems, however. The position of the engine starting levers, which actually controlled the speed and direction (forward and reverse) of vessel's engines were placed in a very confined space below decks. The conditions here were so bad that the machinist operating them could make mistakes, causing the vessel to operate out of control and contrary to the orders of the bridge. This did happen on occasion.

When the vessel was operating at speeds of half-ahead (14 knots) or greater, the helm could not be fully used. The steering engine, the engine that actually moved the rudder, was not powerful enough to operate against the stronger current at higher speeds. There was no room for a larger turning engine, so at higher speeds, the vessel only could use about half of the helm's full turning radius. With the vessel travelling at these higher speeds,it would take the VESUSIUS nearly a nautical mile to turn, which was about twice the distance of other vessels.

Because of the narrowness of the beam of the vessel, the twin screws very found to be too close together to be of use in turning the vessel, unless she was making headway. This was a problem for maneuvering in harbor.

The conning tower, where the vessel was directed from in battle, had no door leading to the deck. To enter or leave the connning tower, the crew had to climb through a circuitous route below decks. In battle this could be very dangerous. If the vessel took a hit or was going down, the men in the conning tower would be trapped. This was ventually corrected.

The vessel itself had the disadvantage of having a poorly placed center of gravity. At sea, she pitched terribly. On one occasion in a heavy sea, she recorded rolling 40 degrees on each side of perpendicular twelve times a minute!

The hull structure had a discontinuity about 80 feet back from the bow. The structural deck was interrupted and the strength of the hull became entirely dependent on the steel plating on the sides of the ship. In heavy seas, there were concerns that she would break in two, and there were instances of loud snapping and rivets popping at this point of maximum stress. Speed in heavy seas, therefore, had to be reduced.

Typical projectile from the Vesuvius' guns



Classification: Dynamite Gun Cruiser
Keel Laid: September, 1887
Launched: April 28, 1888
Comissioned: June 7, 1890
Recomissioned: January 12, 1897
Armament: Three 15" pneumatically fired "dynamite" guns mounted
forward, with a range 200 yards to one and a half miles.
Ten shells were carried aboard in the magazine.
Five 3 pounders
One Colt Gatling Gun 
Contractor: Pneumatic Dynamite-Gun Co., New York. Construction
subcontacted to William Cramp & Sons, Philadelphia.
Length: 252 feet 4 inches
Beam: 26 feet 5 inches
Mean draft: 10 feet 7-1/2 inches
Max. draft fully loaded: 11 feet 2-1/2 inches
Displacement: 929 tons
Complement: 6 officers and 63 crewmen,
commanded by Lt. Cmdr. John E. Pillsbury.
Engine type: Four cylinder vertical triple expansion, 4,295 hp. Twin screw.
Boiler type: Two locomotive marine boilers.
Speed: 21.6 knots
Coal bunker capacity: 145 tons
Endurance @ 10 knots: 1800 nautical miles
Armor: 1/2 inch
Cost: $350,000


Clerk of Joint Comittee on Printing, The Abridgement of Message from the President of the United States to the Two Houses of Congress. (Washington: Government Printing Office, 1899. 4 vols). (all are documents relating to the war)

Crabtree, J. B., The Passing of Spain and the Ascendency of America. (Springfield, MA: The King-Richardson Publishing Co., 1898) p. 379

Krausz, John, ed., "U.S.S. Vesuvius", reprinted from Harper's Illustrated, 1891 in How to Buy an Elephant, (New York: Hawthorn Books, 1977) 155-157.

Naval History Department, Navy Department, Dictionary of American Naval Fighting Ships (Washington DC: Government Printing Office, 1959).

Schroeder, Seaton, Rear Admiral, Ret'd., A Half Century of Naval Service. (New York: D. Appleton and Co., 1922).

Wright, General Marcus J., Official History of the Spanish American War. (Washington; War Records Office, 1900). 

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