The First Fortifications, 1853-1863

A Natural Redoubt: Planning the Works

First Survey

First Lt. William Horace Warner, Corps of Topographical Engineers, surveyed Alcatraz Island in May 1847. Not only was this the first detailed examination of the island, it was one of the very first land surveys carried out on the Pacific Coast by the newly established Tenth Military Department, headquartered at Monterey and still under the command of Brig. Gen. Stephen Watts Kearny. While the army had not yet developed plans for the permanent defenses of San Francisco Bay, Warner's map, with minor corrections, became the basis for future planning over the next 20-odd years. The department's desire to have the island surveyed at this early date indicated the realization that Alcatraz would play an important role in an, as yet, undeveloped scheme of defense.

Joint Board of Engineers and Naval Officers

Two years passed before the U. S. Congress appropriated funds for an examination of the Pacific Coast "in reference to the defense of the same. The resultant Joint Board of Engineers and Naval Officers (Pacific Coast) consisted of three army engineers: Maj. John L. Smith, Maj. Cornelius A. Ogden, and 1st Lt. Danville Leadbetter; and three naval officers: Comdr. Lewis M. Goldsborough, Comdr. G. J. Van Brunt, and Lt. Simon F. Blunt. These officers assembled at San Francisco in early April 1849. Their surveys of the Bay Area, the Columbia River, and San Diego over the next several months were greatly hindered by wholesale desertions of naval seamen who were intent on reaching the gold mines. In desperation, the commission sailed to Hawaii in November to hire an adequate ship's crew from the king. At least, this was a good excuse to visit Honolulu in the winter. They returned to San Francisco in March 1850. At the end of March, the commission prepared its major recommendations concerning lands to be reserved for public use. On the south side of the Golden Gate they proposed one reservation that included all of today's Fort Winfield Scott, the Presidio of San Francisco, and Fort Mason (and the area between the latter two). The recommendation for the north side of the Golden Gate approximated what would later become the Lime Point Military Reservation (Forts Baker and Barry). The commission further proposed a reservation on the eastern side of Mare Island Straits. Finally, they included the three major islands in San Francisco Bay: Yerba Buena, Angel, and Alcatraz. Almost as an afterthought, they provided for a temporary battery at "Racoon" Point, opposite Angel Island, today's Peninsula Point. In its final report, dated November 1, 1850, the commission reiterated the above recommendations, saying:

“The first consideration in connection with defense would be to prevent the passage of hostile vessels through the channel of entrance [Golden Gate]. This would be difficult as the narrowest part of the entrance is about a mile wide and vessels might pass through with the speed of 10 or 12 knots if favored by a strong fair wind, not unusual there, and the flood tide, estimated at 3 knots. The difficulty might be obviated by having, in addition to a strong battery on each shore, at the narrowest part . . . a third battery on Alcatrazos Island which lies within the Bay . . . and which, although about two miles from the other batteries would in cooperation with them and with a temporary battery on Point Jose at the South and another on Angel Island at the North, concentrate the fire of so many guns upon any vessels that might get past the front line of batteries, that they would be destroyed or so disabled as to become harmless.”

The officers urged the building without delay of the fortifications at Fort Point, Lime Point, and Alcatraz. They estimated that the cost of a battery on the island would be $600,000 at Pacific Coast prices. Five days later, before seeing this final report, President Fillmore declared Alcatraz Island reserved for public use, that is, as a military reservation.

Board of Engineers for the Pacific Coast

On June 17, 1851, the defenses of San Francisco Bay took a positive step forward when Chief Engineer Totten established a Board of Engineers for the Pacific Coast. Eventually such a board would consist of engineer officers actually assigned to the West Coast, but for the time being the new board did its planning from Washington. Shortly after appointing the "board, Totten prepared a masterful dissertation on the national defenses of the United States. In it he noted that the new board had barely begun to work and "so far had determined only the locations of the proposed fort at Fort Point. He agreed with the old joint commission that Alcatraz Island belonged to the "First Class" and its battery should be built without delay.

Three of the army engineers who had been on the joint commission became members of the new board: Smith (the senior member), Ogden, and Leadbetter (the recorder). The two new members were Capt. James L. Mason, a veteran of the Mexican War, and Capt. Frederic A. Smith, who was to die within two months after completing the plans. These officers assembled in Washington in October 1851 and proceeded to plan the defenses of San Francisco Bay. In March of 1852 Leadbetter reported that a study had commenced on open (barbette) batteries for Alcatraz, as contrasted to the casemated works planned for Fort Point and Lime Point. On August 4, 1852, the board submitted its plans, estimates, and memoirs to Totten. They included a casemated fort at Fort Point, two redoubts for land defense south of Fort Point, a casemated battery at Lime Point, and open batteries and a defensive barracks on Alcatraz. Yet to come was a proposal for open batteries and a defensive barracks for Angel Island. John Lind Smith did not sign the documents inasmuch as he did not agree with the plans. As the procedures allowed, he was able to file a separate minority report.

The general plan had three principal objectives: (1) to prevent the passage of hostile ships into the harbor; (2) if an enemy vessel did gain entrance, to arrange batteries for the near defense of the town and the navy yard; and (3) to have an interior line of batteries that could fire on the three passages into San Pablo Bay--between Alcatraz and San Francisco, between Alcatraz and Angel Island, and through Raccoon Strait (the board used the original spelling "Racoon").

Plan for Alcatraz

The guns of the day, said the board, could direct an annoying fire on a fleet at a distance of two miles, and at one and a half miles the fire could be quite effective. Should a ship manage to pass through the mile-wide entrance between Fort Point and Lime Point, then Alcatraz Island stood guard:

“Nature seems to have provided a redoubt for this purpose in the shape of Alcatrazes Island--situated abreast the entrance directly in the middle of the inner harbor, it covers with its fire the whole of the interior space lying between Angel Island to the North, San Francisco to the South, and the outer batteries to the West. It is just three miles from each of the Entrance forts and consequently takes up the fire dropped by them at the 1-1/2 mile range. A vessel passing directly to San Francisco must pass within a mile; and the center of the city is about two miles distant. A vessel approaching the city from the north by the Riley channel [east of Angel Island] must pass within two miles of Alcatrazes--thus the main object of preventing an anchorage in the harbor within range of the town may be accomplished from this position and Rincon Point. The Island presents natural advantages for the site of a battery--The walls are already mostly scarped by nature in the solid rock. A slight degree of blasting would complete this part of the work, & the battery may at once be placed at a suitable height upon the top of the Island. It is proposed here to construct only open [barbette] batteries, to be armed with the heaviest pieces--a defensive barrack will be sufficient to complete the defenses.”

In the memoir that accompanied the plan for Alcatraz, the board presented details of the proposed fortifications. Two barbette batteries, one at each end of the island, would cover the various channels. A caponier (a small, strongly built structure with guns mounted internally to provide flanking fire for the protection of the guns of the battery) would be located at each battery. A defensive barrack (capable of resisting shot from enemy guns as well as providing a defense by small arms against an enemy landing party) and a guardhouse would complete the works:

“The island being high & provided with a natural scarp [almost vertical cliffs] in many places, it has been decided to complete this escarpment [by removing the gentler slopes] so as to secure a perpendicular height of 25 feet all round. . . . A battery of 20 guns is proposed to cover the passage to the North in conjunction with Angel Island, and a battery of 23 guns to cover the Southern passage. Three guns of this latter battery are designed to prevent a fleet lying to the east of the island. By blasting a small triangular ditch from the solid rock of which the whole island is composed, for a length of 690 feet [principally in front of the batteries], a height of at least 25 feet is secured [for the natural scarp], flanked for the greater portion of its length.

A ramp [or road] at the wharf [to be built on the east side of the island, out of sight from the Golden Gate] is excavated from reference (10) to reference (30) [that is, from an elevation of ten feet above sea level near the wharf to a point 310 feet distant that was thirty feet above sea level]: --on the upper end of this ramp a wall being constructed on the inside. . . .

A Guard house is placed at the upper end of the ramp enfilading it with 4 mountain howitzers or other small pieces: this guard house also enfilades the ditch on the other side [the "ditch" here became a covered road that led to the northwest battery].

A defensive barrack capable of accommodating comfortably 100 men in bunks, is placed on the Southern end of the island having a good view of the Southern battery, and seeing the northeast slope of the island as far as the Northern caponniere. This barrack is provided with a parapet on the top & the windows of the second story are to be provided with iron bars, thus securing a height of about 33 feet.”

Three sheets of plans signed by the majority (four-fifths) of the board provided further detail. Lt. Fred Smith prepared all three sheets, using Warner's 1847 survey map as a base. The first sheet portrayed a map of the island showing the locations of the batteries, caponiers, guardhouse, and defensive barracks. An inset showed a floor plan (with four embrasures for howitzers) and a profile of the single story, parapeted guardhouse. This sheet today bears the approval signatures of Chief Engineer Totten and Secretary of War Jefferson Davis . The second sheet was somewhat crowded with details of both batteries, profiles of the North and South Caponiers, and a chart showing directrices and arcs of fire for both batteries. The third sheet contained floor plans and profiles of the two-story bastioned defensive barracks. The structure was designed to house enlisted men's barrack rooms, officers' quarters, a guardroom, and cells. An underground cistern capable of supplying water to 200 men for six months was located next to the building. An inset showed plans for a separate powder magazine; but its legend said that the magazine was not necessary and the board had not made an estimate for it. (Powder would be stored in two service magazines, one under each caponier.) The estimated cost of the works came to $300,000:

These plans for Alcatraz, as prepared by the majority of the board, set the general course of action that would be followed during the next decade. Different engineers on the scene would recommend changes and expand the complexity of the works. But the scheme of fortifications for the island was now established.