Historic California Posts, Camps, Stations and Airfields
Fort Winfield Scott: Battery Dynamite
(Harbor Defense and Harbor Entrance Command Posts, Harbor Defenses of San Francisco)
Battery Dynamite
by Justim M. Ruhge
The guns at this battery were a new revolutionary design based on compressed air instead of gunpowder to fire a charge of dynamite. Against Army advice and wishes, the U.S. Congress appropriated $187,500 for the procurement and the mounting of a15-inch caliber, three-gun battery at Fort Scott in 1895. This battery was located off the bluffs and just south of Battery Godfrey. All the construction work and testing was to be conducted by The Pneumatic Dynamite Company. Work began on March 6, 1889. This company soon went bankrupt. The Pneumatic Torpedo and Construction Company finished the contract. The three guns were mounted in December 1895. Test-firings took place from December 4 to December 9, 1895. The guns could fire a 500-pound shell of dynamite 2,500 yards. All test objectives were successfully met.
At the time of the Spanish-American War, army engineers constructed huge earth and concrete traverses around the guns and their powerhouse and compression machinery for their protection. However, the "black powder" army was skeptical of the new technology and had the guns sold and removed in 1904.
During World War II the Dynamite Battery buildings served as the Harbor Defense Command Post (HDCP) and the Harbor Entrance Control Post (HECP) for San Francisco Harbor Defenses.
In early 1944, a two-story structure was built on top of the parapet in front of the gun emplacements. This structure and the original battery powerhouse remain today.
Battery Dynamite
by Chuck Wofford

This battery, unlike most of the batteries in the bay area, was not named for a person, but for the type of gun mounted in it.


This dynamite battery was constructed at Sandy Hook , New Jersey, to the defend the New York Harbor. Battery Dynamite at Fort Scott was the only other dynamite battery constructed in the United States. Note the projectile visible in the upper left that was just fired. There is no smoke since the gun was powered by compressed air.

This battery was armed with three dynamite guns, Model 1890; there were no serial numbers for these guns. They were made on the original contract from the Pneumatic Dynamite Gun Co. which failed March 6 1889 and the contract was taken over by the Pneumatic Torpedo and Construction Company. The distance between the guns was 85 feet, and each being on a level two feet lower than the one on its left. The difference in the level is for the purpose of allowing the air reservoirs of each gun to be conveniently disposed in the under ground vaults that lie between the gun's, and outside the outer gun.

Each gun and carriage cost $60,000.00 as a unit. They were installed by the Pneumatic Dynamite Gun Company, and were emplaced by December 1895.

These guns were mounted on a center-pintle carriages on a concrete ring that was fifty feet in diameter for the carriage wheels to transverse on, and to the outside of the concrete ring, was a small rail track for the shell carts to bring out shells to be loaded.

The following is information on the gun and carriage Reference height of the crest: Emplacement #1=296' and #2=298' and #3=300' above mean low water.

The gun was trained by electricity and the firing and manipulation of the weapon was under the control of just one man, the gunner, the #1 gun could be
traversed right 350° in 54.5 sec #2 in 41 sec and #3 1 min. 23 sec, to the Left #1 traversed Left 1 min.9 sec #2 1 min.4 sec #3 1 min 38 sec Elevation 35° to 0° #1 13 sec #2 11 sec #3 11 1/2 sec, Elevation 0° to 35° #1 9 sec #2 11 Sec #3 11 1/2 sec. These guns had a range of 2,000 yards with 500 lbs dynamite, 3500 yards with 200 lb dynamite, and 5,000 yards with 50 lb dynamite. They were dismounted in December 1904 and sold for scrap.

Ammunition Service

The dynamite side of it came from the explosive gelatin used in the projectiles was manufactured by the Giant Powder Company of San Francisco. Its composition was, 87% nitro-glycerin, 7% gin cotton, 4% camphor, and 2% carbonate of magnesia filling used in the shells, but the propulsion was entirely by compressed air, with two large cylinders alongside the barrel containing 2,000 pounds per square inch of air. The finished shell was loaded into the barrel and then the valves were thrown open to admit the air behind it thus launching the shell with comparatively gentle acceleration. The guns were loaded at 7° and fired at 30° elevation. The tested rate of fire was: #1: 5 rounds in 8 minutes, 23 seconds; #2: 5 rounds in 10 minutes; and #3: 5 rounds in 9 minutes and 20 seconds. Special effort for rapidity was made only in the rounds fired from gun #1. The compressing air up to 2,500 pounds per square inch which was supplied from a steam driven compressor which could produce 20,000 pounds of pressure and weighed 7-1/2 tons. The steam boiler weighed 9 tons and a 20-ton tank was provided to hold the air once it was compressed. The compressed air could be conveyed directly to the firing reservoir of any of the guns or to storage reservoirs, it was practicable to store compressed air for any length of time sufficient for any number of shots. (The one bad thing was its elevating mechanism was cleverly designed compressed air cylinder which raised and lowered the barrel at the turn of a valve handle, but the air cylinders packing quickly wore out under the stress of the 800 pounds of air pressure used to operate the gun).


The projectiles came in the full 15-inch and three sub-caliber, 15-inch projectile, eleven feet long, weight when fully charges-1,150 lbs -- 10-inch
sub-caliber projectile eight feet long, weight when fully charged 570 lbs. --- 8-inch sub-caliber projectile seven feet long, weight when fully charged -- 370 lbs -- 6-inch sub-caliber projectile seven and one half feet long, weight when fully charged -- 300 lbs.


The fuse on the projectile was mechanical in nature and could be set to act on impact or delayed.


The three dynamite guns listed in the 1896 inspection report comprised one of the most unusual seacoast batteries in San Francisco's defenses. In 1888, Congress, over the lack of the army's of enthusiasm, if not objection, and appropriation was made for the purchase from private industry of 'pneumatic dynamite guns, there carriages, ammunition, and machinery necessary to fire them with, in non-technical words these guns that fired charges of dynamite by means of compressed air. Originally proposed by a Mr. Mefford of Chicago, he employed a Lieutenant Zalinski of the U.S. Navy as his Public Relation man to such a good effect that within a short time it became the Zalinski Dynamite Gun. In the Spring of 1889 the ordnance department issued an order for the purchase of three of these weapons (all 15-inch caliber) for the San Francisco Defense area, for the cost of $187,500.00 (the original appropriation was $400,000.00, the money that was not used for the new guns, went to help modernized some of the Endicott batteries, however the company that manufactured the guns were to mount them without any cost to the government. The Congress had Colonel Mendell to find a sight for them, and not knowing too much about them, but the blueprint showed that one 15-inch gun needed and area of about 50 feet, so Mendell picked a site to the Southwest of Battery Godfrey. A 10-ton compressed air firing tank located close to the gun and a pipe ran from it to the air compressor plant. The power plant and the main storage in which there was a huge tangle of plumbing to handle the steam and air, and a complete backup set was provided in case one set failed, and all this machinery was housed in a building 85 feet long by 35 feet wide, and could be placed away from the battery any distance up to one mile, in all there was 200 tons of machinery and plumbing in this battery. The cost of one gun and it carriage was $60,000.00. The construction of the air compressor plant was placed by the contractor (the Pneumatic Torpedo and Construction Company of New York) in the hands of the Fulton Engineering and Shipbuilding Company of San Francisco, whilst the gun and carriages, and projectiles, principally, have been manufactured in the East and shipped to San Francisco for erection. There was also a powerhouse, magazine for projectiles, one for detonators, and one for dynamite, there was also a guard room, commanding officers quarters, telephone room, storage battery room, relocator room, and a chart room, the back retaining was 367 feet, and M.L.W. = (1.1) M.H.W. = (4.8 and the Mean Level of battery at North Point = (2.9), Datum is average of daily lower low water.

The work had been inspected during its progress at Fort Winfield Scott and had progressed so far that it was believed it completed be completed by October 27, 1895, the date of the contract. The complete battery would be tested under the supervision of a board of officers before acceptance by the department. The three guns were mounted in December 1895. They were test fired from December 4-9 1895 and they worked fine, the test was directed by a board of officers headed by Col Babbitt, commanding officer, at the Benicia Arsenal, and a Mr. Bachellor engineer from the company (Pneumatic Torpedo and Construction Co) who operated the gun, there were nine projectile fired at this period of time.

Meanwhile, the Spanish-American War came and at San Francisco the chief engineer worried over the exposed guns of Battery Dynamite, it was in plain view of the ocean, so he had high earthen traverses around the guns, making each gun into a pit, and also around the powerhouse, by adding concrete retaining walls, the earth could be kept as near and high as possible, the magazines and the service could be placed under the traverse around the powerhouse. Covered passageway would lead to the pit between the guns pits from the pits to the ground outside; the magazine would hold 90 projectiles difference sizes, other rooms would store charges and the detonator. These plans were approved and work on the traverses began in August of 1898. When the concrete work was completed in March 1900, the engineers announced the completion of the parapets of the large and complex battery. One year later, in response to a request from the commanding officer of the Presidio, the cost for this work would come to $150,000.00, the plan approved and the work started in Aug 1898 using the standard construction methods and material of the day, the concrete used in the batteries were class A. The reinforcing steel will be measured by the pound in place and ready for pouring concrete and will include allowance for minimum laps, splices and hooks, if any item needs to be embedded in the concrete such as bolts, anchor, pipes or other embedded items are firmly and securely fastened in place indicated on the plans, and they should be clean and free from rust, scale, oil, or other foreign matters. The concrete was completed in November and in March the completion of the parapets of the large and complex battery (the Spanish fleet was destroyed in Manila in May), in 1901. One year later in response to a request from the commanding officer of the Presidio for repairs to the battery powerhouse, but the Board of Ordnance and Fortification declared the pneumatic dynamite batteries to be obsolete, because of the amount of machinery and effort involved was out of proportion to the results. Secretary of War Elihu Root agreed and in 1904 all the guns and the machinery in Battery Dynamite were dismantled, scrapped and sold. By this time the Dynamite Gun was a thing of the past. In the years that followed the battery was used for any number of things, in 1911 the wooden structure was used as a fire control station, in 1919, the engineers were using it corridors and rooms for storage, in 1919 the artillery fire control and the post telephone were installed in one of the room. Two adjoining rooms were converted into sleeping quarters, and still can be seen today. Prior to December of 1904, a few small electrical plants has been installed in some of the batteries at Fort Winfield Scott, but after analyzing the needs of the area, the board concluded that a central power station was needed for each of the Forts, but with the shortage of funds, it was decided to put the first one at Fort Winfield Scott.

Not until 1910 was a central power plant installed in a new concrete building on the same site. It was large and centrally located, and thoroughly protected from enemy fire. Although the board did not think it advisable for this plant to supply electricity to the post at the Presidio, it would certainly be able to light a new artillery post at Fort Winfield Scott. The central power house was built with reinforced concrete walls covered by a corrugated iron roof carried on steel trusses. The building is approximately 40 x 100 feet in ground area and the height from the ground to the cornice line is 21 feet, to the ridge of the roof is 31 feet. The structure is located in the rear of an earthen fill; the crest of the embankment is approximately 10 feet higher than the ridge of the roof of the present powder house. The fill in question affords approximately 9 feet of concrete and 80 feet of earthen horizontal protection against hostile fire at the cornice height of the building more than 200 feet of combined concrete and earth protection at floor level, The power plant was removed from Fort Scott November 16 1946, and the present source of power for the fort is commercial power lines. In the 1911 a fire control station for Fort Scott had been constructed in emplacement #1, but by January 1941, this structure was being used as the Harbor Defense/Harbor Entrance Command Posts (HDCP/HECP) for San Francisco, it stood on concrete bents that rose 18 feet above the emplacement floor, and it measured 37 X 87 feet, but proved to be to small for both the Army and the Navy operations. When in the fall of 1942 nothing had happened regarding the new HDCP, General DeWitt, commanding the Western Defense Command and the Fourth Army, wrote a firm letter to the chief of staff, saying after a year's experience with wartime conditions, "further delay cannot be tolerated" in constructing a new station, but the War Department disapproved, saying to consider constructing a barrier around the existing structure or transferring a part of the combined post to abandoned casemates. In early 1943 two wings, also temporary had been added to the original structure. These additions rested on the old parapets that surrounded the emplacement. But these arrangements were still unsatisfactory. The fire control switchboard was housed in one of the cross corridors of Dynamite Battery, and the power plant was in another corridor, a bomb hit would collapse both corridors, which were too small anyway. There was now $120.000 available for a new operations post, which replaced by a two story structure built to the Left of the old #one and in front of emplacement #2. The second story consisted of two concrete and steel pillboxes type station one for the Army and one for the Navy, and was transferred on January 8 1944, and the cost was $132,000. The pillboxes on the top were nicknamed the "bridge" and had 4 room and a closet Though the structure was built in a deep concrete emplacement like many of the older post, but the roof was only wood and graved tar paper, the Harbor Defenses of San Francisco (HDSF) considered the station only a temporary one, and lobbied the War Dept for a casemated command center, with a Burster Course over the front part of the casemate, there was some testing done on concrete blocks at Battery Townley at Fort Cronkhite, do not know how the test came out, but they were not casemated.

This battery was 360' across, and 440, deep and there was 75' between the guns, the area of connecting passages between the gun pits was 1267 square feet, and the area of connecting passage ways was 4580 square feet, and the total square footage of this battery was 121,413 square feet. This battery is still used for storage, and the powerhouse for class room, the entire battery is fenced off, but you can see the pillboxes from the road, and it is in very good condition. This fascinating old fortification saw service from 1898-1905, the three Dynamite guns and carriages were scrapped in 1905.

Report of Completed Works - Seacoast Fortifications:
Original Diagrams and Records of Completed Works - Seacoast Fortification: Battery Dynamite, Harbor Defense Commnd Post and Harbor Entrance Command Post
Drawings Courtesy of Mark Berhow

Battery Dynamite Today
Two observation posts visible from Lincoln Blvd. are part of the Army and Navy joint defense system for San Francisco during World War II. The Army's Harbor Defense Command Post (HDCP) was independent from the Harbor Entrance Control Post (HECP) of the Navy, but the two operations existed side-by-side so they could closely coordinate. This underground 25 room post was constructed at Battery Dynamite in 1943 to replace a year-old HDCP nearby. (USNPS)
Other Online Histories
National Park Service
Harbor Defenses of San Francisco - A Field Guide 1890 to 1950
Zalinski's Dynamite Gun
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Updated 23 June 2017