This Endicott battery was named in GO 194, February 14, l902 in honor of Col James Duncan, a West Point graduate, who had a highly distinguished record in the Mexican War, in 1849 he became a Colonel in the Inspector General Dept., but died that same year.
This battery was armed with two 8-inch BL Rifle model 1888, # 8 came from the West Point Foundry and # 24 from Bethlehem Iron Company. Gun weighted 32,489 lbs and cost $16,875.00, there were 93 manufactured.
The following is information on the Model 1888 #8 and #24
Emplacement #1 the reference height of the crest=214.01 and Emplacement #2 the reference height of the crest=214.04.
Gun # 1 Model 1888 Serial 8was mounted and emplaced in April 1900, under the supervision of 1st Lt Harry Clark and was tested for level on May 10/11/12 by Capt. Otto Von Geldru. Reference of base ring /top of ring = M.L.L.W. 212.14 ft. and the number of shots fired was 49, each since its first target practice on Jan. 5, 1904.
Gun # 2 Model 1888 Serial 24was mounted and emplaced in April 1900, under the supervision of 1st Lt Harry Clark and was tested for level on May 10/11/12 By Capt Otto Von Geldru. Reference of the base ring/top of ring M.L.L.W. 212.9 ft, and the number of shots fired was 48, each since its first target practice on Jan 5, 1904.
The following is information on Carriages Model 1892 #2 and #4
Carriage Model 1892 #2was mounted May 10/11/12 under the supervision of 1st Lt Harry Clark and was leveled by Capt. Otto Von Geldru.
Carriage Model 1892 #4was mounted May 10/11/12 under the supervision of 1st Lt Harry Clark, and was leveled by Capt Otto Von Geldru.
The sights on these gun were Model Tels., Mod M 1910, can not find the serial numbers for them.
The means which must be provided for moving ammunition depend, of course, upon the weight and bulk of the piece to be moved. Since this battery was a one story and 1/2 and was level from shell rooms and powder rooms to the loading platforms, and used an overhead trolley to move the shells out of the room into the hall, where they were loaded on a shot truck and taken to the gun for loading, other than a crane to hoist the shell to the breech, in the powder there are no mechanical gear provided, the propellant charges were light enough to carry in a handbarrows.
As with any battery is to be built in any Engineer district, as much information as may be necessary is sent to the district officer. On March 17, 1898 directions were given by telegraph to construct this emplacement for two 8" guns with funds from the appropriation for "National Defense" act of March 9 1898, in the amount of $49,000.00.
Further instructions directed the use of all possible dispatch in carrying this work to a completion. Lt Deakyne was placed in charge, after surveys of the ground had been made and plans prepared work was commenced. This battery was arranged to straddle the ridge and face south, thus giving the most advantageous field of fire. This peculiar situation enabled the magazine, ect to be held at the level of the terrepleins, so that no lifts are required and the service of the guns would be very rapid. There was some time consumed in building roads, arranging pumping plant, and accumulating supplies. The road itself was 2,400 feet long, with a grade of 1 in 15 to connect the battery site. Construction of this battery began in March 29, 1898, with the clearing and grading of the site.
After the site was cleared the excavation was started, there was excavated 17,885 cu yd of dirt and sand. The material encountered was a soft red rock that required blasting and two shifts of men working from 4.00 a.m. till 12.00 p.m. and from 12 p.m. till 8.p.m. were employed in the excavating. Part of the work was done before and after daylight, light being obtained from large oil lamps, known as station lamps. Excavation for magazine was carried down to grade by April 21 and the construction of forms was then begun. On the timber used in making the forms, in all cases dressed lumber will be used, after the forms are started them the iron and steel, in the form of I beams for reinforcing ceilings, and in columns for supporting ceilings, for reinforcing concrete, deformed steel bars were inserted into there places in the forms, a total of over 2,300 lbs of Reinforcing bars was used.
While excavation was in progress the concrete plant was being put up. It consisted, essentially, of a cubic; mixer driven by a steam engine and a large platform above the mixer. The material was hauled up to this platform by teams, and after measurement in the required proportions were delivered a hopper into the mixer. The mixer was given at least 10 turns; the concrete was then discharged into cars running on a track that extended from the mixer to all parts of the work.
The first concrete was laid April 24, but owing to difficulty in operating the original pumping plant concrete work was not fairly started until May4. The rough concrete of the magazine was completed May 12 and cement finishing was immediately begun. In the larger emplacement like Duncan the gun block is very large and complex, and separated from the other portions of the emplacement by "planes" or more "properly, surfaces of weakness", there is one between the parapet and also one between the loading platform, the latter is sometimes it is a few feet farther away from the axis of the gun, also there is the loading platforms, which is space around the gun and the carriage, upon which the members of the detachment stands while loading the ammunition the gun. By the 14th the rough concrete of platforms was in place, and the base rings have been set. There was used over 2,700 yd of concrete and nearly 1,112 yd of finished concrete, which they mixed in a color to help it blend in with top of the hill, was used in this battery.
A large amount of excavation was made in front of the battery to cut down the ridge to the necessary grade for the field of fire, at the end of June there was still a months on hand to entirely complete the work.
All walls in contact with earth were coated with paraffin paint. On smooth plastered surfaces 1 gal covered 8 square yards with one coat or 6 square yards with two coats. The magazine was covered with an embankment of earth; in this a lookout was built. The walls and ceiling of the rooms and passages were whitewashed; using 1 barrel of lime, 1 bluing, 1 lb. of potash, and 10 lbs of Russian tallow.
The walls that show in the distance were tinted to correspond with the color of the soil bank surrounding the battery. for this purpose they were coated with a mixture of cement and water to the constituency of whitewash and adding Pecora mortar stain and lampblack in such proportion as to produce as nearly as possible the dull red color of the bank, and the results were satisfactory, both in immediate appearance and durability. The earth covering the magazine and the various slopes was coated with loam and seeded with barley.
A reservoir for permanent water supply of the battery was built on the ridge northwest of the battery. It is cylindrical in shape, 12 feet in diameter and 12 feet high, made of concrete, having its top on a level with the surface of the ground. Its capacity is about 10,000 gals. The water is pumped to the reservoir from a well near Horseshoe Cove with the pumping plant that was used in the construction of the battery.
A latrine was constructed on the west side of the road leading out from the north corner of the battery. It consists of rear and end walls of concrete 1 foot thick, with a frame front and shingle roof. The water for the latrine comes from the reservoir supplying the battery, the outlet is a 4" pipe leading down the hill from the battery and emptying at the bluff near the edge of the bay.
The width across the front of this battery was 165' and the depth was 90', the gun had a range of 16,268 yards, at an elevation of 217 feet; distance between the guns 138 feet. Unlike most heavy-caliber batteries of this period, Duncan was a one story work, with its magazine floor at the same level as the emplacement, and a very high central traverse, it also had a Plotting Room (10' X 28, ) that was equipped with one Lewis Depression Position Finder, one Whistler Hearne Plotting Board: Model 1904, one Pratt Range Board: Model 1905, and Time Intraval Ball, and E and D Room (10' X 10' ) Guard Room ( 10 X 16 ) and a switchboard, which was part of the E and D room with a central gallery ( 75' X 6' ) to take the shells and powder to the guns.
One of the last thing to be done is to the using of sand on the front and flanks of the battery, the sand was filled in front of the concrete then when a shell was fired at the battery it has been found that a projectile entering a mass of sand appears to have a tendency to deflect upward and to leave the sand with out penetrating very far, there was over 3,000 of fill including the back fill. The exception is the blast apron, which is made of concrete, and immediately in front of the gun, they had to be laid very carefully.
When the structure is completed the district Engineer officer prepares the so called "transfer drawing" then the Engineer officer and the local Coast Artillery officer , made an inspection of the structure , and all was in order the keys, were transferred to the Artillery commander. This two 8-inch gun emplacements on Yellow Bluff were completed in March 1899, the Engineers reported it complete and recommended that it be turned over to the care of troops even through the guns and carriages had not arrived. The carriages arrived in July from the east, and R.D. Noble and A. Desonza of Sausalito moved them from the wharf to the site of the battery for the sum of $585.00 and was completed in early 1899. On May 7, 1898, the engineers reported it complete and recommended that it be turned over to the care of the troops even though the gun had not been mounted.
The guns arrived Dec. 1899 and Davis & Sons of San Francisco moved them to the site for a cost of $420.00, the work was completed the same month. The base rings were set in January, the reference of Base Ring-Top LLW 212.14 feet, then the guns where mounted, and the battery was and transferred on May 6 1900, at a cost of $57,536.00.
The Plotting Room at Duncan had the following equipment in a 10' X 28, room that was equipped with one Lewis Depression Position Finder, Type A-Model 1 and the top of the pedestal was 4.35 -- one Whistler Hearne Plotting Board: Type A Model 1904, one Pratt Range Board: Model 1905, and Time Intraval Ball. This battery had a standard B.C. and B station. No horizontal system provided. Standing fire control system installed and was complete in 1909.
It was ventilated by national draft 6" vent from magazine terminating in emplacement wall it was connected to both water and sewer and had a syphon latrine, for data transmission they phone and speaking tubes. Trunnion elevation in the inside of this battery was 215.1, Datum plane M.L.L.W.
It's guns were dismounted in 1917, and shipped to the Watervliet Arsenal, where they were mounted on railway carriages, these weapons were never sent overseas, but rather remained in storage for many years, the original barbette carriages were sold as scrap to the Union Junk CO of San Francisco in May or June of 1918, they also left much of the equipment and machinery place, after the guns in this battery were dismounted, the magazines were use for storage purposes. In July 1, 1932 the latrine and the B. and the B.C. were demolished as per the authority if the 1st IND HQ Ninth Corp. This battery saw service from 1898 to 1917. Battery Duncan offers a vivid contrast to the near by 1870s Battery Cavallo, and the 1900s Battery Yates, to the novice and the expert alike the contrasts in architecture and material among these three batteries can be an exciting experience.