Report for Mile Rocks (California) - 1907

General
District: 12th
Inspector: Gottfired T. Olson, Keeper
Location: Situated at S entrance of San Francisco Harbor.
Date of Report: 07/02/1907
Latitude: N 37° 47' 28"
Longitude: W 122° 30' 38"
Premises
Site: Rock projecting out of water size of caisson or foundation of tower.
Date of Reservation:
Date of Deed:
Date of Permission:
Date of Lease:
Area of the Entire Site: 25' x 86'
Area Inclosed:
Character of Soil:
Distance of tower from Nearest High-Water Mark: Base of Caisson at high water mark
Inclosures to Premises / Type of Fence: None
Wharf or Landing on Premises: Landing effected thru hoisting derrick on E side or 40' boom extending over water on W side of structure.
Road to Land or Wharf Chararacter of and Distance:
Means to Reach Light Station: By boat
Distance to Nearest Road: About 5 miles by water to nearest RR & Steam-boat landings
Distance to Post Office: About 6 miles
Distance to Village: About 5 miles to San Francisco
Facilities for Public Conveyance: Launches for hire on San Francisco water front
Facilities for Private Conveyance: By boat.
Means Used for Support of Lantern: Tower
Number of Separate Lights: 1
First Built or Established: Feb,15, 1906
Last Rebuilt, Repaired, or Renovated:
Condition at This Date: Operating efficiency good
Shape of Tower in Plan: Circular
Form of Tower: Cylindrical
Height from Base to Ventilator Ball: 88' 9"
Height of Focal Plane Above Mean High Water: 84' 3"
Background of Lighthouse as Seen from Sea: Hills
Color of Tower: Base for 35' black, balance of tower, white.
Color of Tower/ How Produced: "Biturium" solution for base. Paint for white.
Tower Connection: 2 small bedrooms & kitchen contained in tower.
Object of Navigation: Marking location of Mile Rocks & entrance of harbor.
Building Materials: Structural steel & concrete
General Description: Caisson or foundation
Wall Thickness at Base: Foundation solid concrete covered with 3/8" steel plates
Wall Thickness at Parapet: Covered with 3/8" steel plates
Diameter at Base: Oval base
Diameter at Parapet: Circular 13' 6"
Kind of Stairway and Steps: 1 of concrete, spiral, balance iron, 2.
Number of Landings: 6
Size of Glass: 9 1/4" x 14.5", 9 1/4" x 12", 9 1/4" x 18"; transom, 6" x 29.5" - 9 1/4" x 29.5"
Number of Windows and Size of Sash: 11 - transom 3 - size of sash 2' x 2' 8"; 2' x 2' 6"; 2' x 22"
Number of Doors: 7
Kind of Foundation and Depth Below Surface: Rock
Character of Soil Surrounding the Lighthouse: Rock
Soil Susceptibility: No
Miscellaneous Remarks: Tower consists of an oval steel pier expanding in trumpet shape to form a gallery, surmounted by white, oval, 1 story dwelling; a 2 story, cylindrical tower & watchroom & a black, cylindrical lantern.
Lantern and Fixtures
Order of Lantern: 3rd
Shape of Lantern: Cylindrical
Diameter to Glass: 8' 6.88"
Diameter in the Clear:
Number of Sides: Circular, 9 sides
Type of Bars: Helical
Thickness of Bars:
Height Glazed: 6' 1 1/4"
Number of Plates in Height: 3 & 2 alternately
Number of Plates Each Side: 45
Thickness of Plates: 1/4"
Size of Plates: 2' 10.013", 17.251", 2' 5.148"
Number of Storm Panes: 4
Unglazed Side of Lantern: None
What Bearings:
Construction Material Lantern: Iron & bronze
Construction Material Roof / Cowl: Conical roof of iron castings
Ventilator / Cowl: Iron casting with brass wire ventilating screen
Lightning Spindle: Copper
Description of Lightning Rod: None
Balustrade: Iron standards connected with chain
Lantern Doors: Iron with iron door frames
Floor of Lantern: Cast iron
Watchroom Doors: Cast iron trap door on hinges fitted with circular globe for observing light.
Parapet Diameter: 8' 7.5"
Ventilators
Location / Number: 5 ventilators in lower part of lantern
Ladders / Cleaning Arrangement: Heavy one of iron. also light one of wood.
Curtain Hooks / Hanger: With spring rollers on brackets.


Watchroom
How is Watchroom Fitted: Under lantern with circular glass in trap door for observing light. Has ventilators, serving table, writing desk, chairs, lockers, heating stove, medicine chest & etc.
How is Relief Called: None
Where is Call System Led:
Illuminating Apparatus
Kind of Apparatus:
Intensity in Candles:
Name of Maker: L.S. Sautter et Cie, Paris
Year Made: 1852
Marks and Number: 3rd order fresnel lens
Order of Apparatus: 3rd
Inside Diameter: 3' 3"
Light Characteristic: Ruby fixed
Time of Revolution:
Flash Interval:
Duration of Flash:
Arc of Each Fixed Part: 360 degrees
Number of Panels: 6
Number of Flash Panels:
Arc of Each:
Number of Elements in Central Drum: 1
Number of Prisms Above Center Drum: 6
Number of Prisms Below Center Drum: 6
Does Apparatus Revolve?: False
Is There a Revolving Belt?: False
Revolving Panels:
How Flash is Produced:
Number of Vertical Elements Panel:
Fixed Lens Covered:
Pedestal: Iron
Service Table: Wood
Draft Tube Description: None into ventilator ball. Damper tube runs within 2' 10" of ventilator ball, this made of Russia iron 2" dia.
Revolving Machinery:
Standby and Description:
Chariot Float or Balls:
Chariot Description:
Length of Drop Tube:
Clock Weight:
Length of Winding Time:
Drive During Rewind:
Machinery Protection:
Regulated:
Lens Protection:
How Color is Produced: Ruby or red glass chimney
Red Sectors Description:
Where Color Attached: Illuminating apparatus
Form of Colored Glass:
Lamp Description: Funck 3rd order (old style)
Type of Illuminant:
Number of Spare Lamps: 2
Number of Spare Burners: 3
Candle Power:


Vapor Oil Lamp
Number of Wicks or Mantels: 2
Diameter of Outside Wick: 1 3/16"
Diameter of Mantel:
Diameter of Circum Circle:
Closets and Store Rooms
Tower Closet Use: Closets in watchroom, built of wood with shelves (Serviceable) used chimneys, wicks, & other things pertaining to use of light.
Oil House Description: Oil room placed under engine room in concrete foundation of structure.
Oil House Inside Dimension:
Oil House Construction Material:
Oil House Capacity:
Other (Describe): Paint & storeroom in engine room
Suitability: Dry & suitable
Fog Signal General
Fog Signal Kind: 10" air whistle; operated by duplicate 20 hp Hornsby-Akroyd oil engine. Also duplicate air compressors for each.
Time to Start: About 30 min
How Long Will Pressure Last:
Manufacturer: Hornsby Akroyd, De La Vergne Machine Co., NY
Year of Manufacture: 1905
Characteristic: 3 sec blast every 27 sec.
Duplication: Engines, compressors, 1 whistle, Crosby automatic signal in duplicate
Timing Device: Crosby automatic
If whistle, siren, or trumpet, Pressure at Which Blown: 55 lbs (low pressure in tank)
Height Above Water: 50'
Compass Direction:
Location: For marking Mile Rocks. Fog signal for guidance to navigation entering San Francisco Harbor.
Distance and Direction: Connected with lighthouse
Water Supply: Brought from San Francisco by water boat
Reached from Lighthouse:
Description of Fog Signal Building: Fog signal in side of tower 22' x 34'
Pressure And Recording Gauge:
Compressed Air
Compressed Air Machinery:
Kind: Hornsby Akroyd
Manufacturer: De La Vergne Mach. Co, NY
Date Made: 1904
Nominal Size:
Horsepower: 20
Compressor: Bury compressors
Compressor Manufacturer: Berry Compressor Co., Erie Pa
Compressor Bed and Gear: Direct connect with tack gear


Whistle Signal
Whistle Diameter: 10"
Whistle Height: Inside 17 3/4"; outside 18"; overall 2' 7.5"
Whistle Orifice: 2 7/8"
Whistle Tone:
Whistle Chime:
Dwelling
Location: 2 small rooms & kitchens in tower
Coloring:
Construction Materials:
Number of Rooms:
Number of Dwellings:
Heating Plant:
Number of Keepers:
Furnished Quarters:
NOT Furnished Quarters:
Outhouses:
Outhouse Coloring:
Paths and Walks:
Area Inclosed:
Area of Garden:
Area Timber or Shrubbery:
Cultivation Area Available:
Area Cultivated:
Character of Surroundings:
Stove, Maker:
Stove, Size:
Sink, Maker:
Sink, Size:
Pump, Maker:
Pump, Size:
Lamps:
Water
How Procured: By San Francisco water boat; pumped from boat to tank in basement
Quality: Good
Quantity: Ample
Injury Possible: Not liable
Purity Precaution:
Tank Capacity: 7000 gal
Tank Material: Made in concrete foundation of bldg
Distilling Apparatus: False
Distilling Manufacturer:
Well Description:
Well Diameter:
Well Lining:
Pump or Bucket:
What Power Used:
Distance from Dwelling:
Healthfulness
General Opinion: Tower cold, draughty & damp previous to installation of coal stove.
Diseases:
Prevalency:
Local Causes: When cooking in the kitchen, steam condenses into water on the iron walls causing water to run on floor making quarters very damp. This could be remedied by shelling kitchen as rest of tower is done.
Recommended Improvements: An independent inclosed circular stairway, leading from floor of engine room with door at it's foot would stop the draught from soaring upwards, carrying with it gases of combustion, which permeate thru partitions into sleeping quarters & whole tower.
Miscellaneous
Access to Lighthouse: They have a hand hoist & landing at Presidio dock. San Francisco about 5 miles from Rock.
Distance and Direction: About 5 miles in E'ly direction
Miscellaneous Remarks:
Hoisting Engines
Hoisting Engine Kind: Air compressed
Engine RPMs:
Engine Diameter: 4"
Engine Stroke: 5"
Engine Boiler:
Engine Maker and Date:
Serial Number:
Cylinders and Size:
Horsepower:
Fuel:
Hoist Starter:
Hoist Miscellaneous:
Supplemental Reports
Letter; Dept of Commerce
August 10, 1921
Referring to letter of October 22nd, 1919: relative to installation of telephone at light station.
Bureau is informed that the US Coast Guard: completed the installation of telephone at Mile Rock Light Station on August 9. Telephone is connected with US Army Exchange at Fort Miley, San Francisco, CA., which is about 2 miles SW'ly from Fort Point Lighthouse. Fort Miley Exchange is connected with
The Pacific Telephone & Telegraph Company.