Weights and measurements for clockwork mechanisms

This table is a compilation of information culled from the Inspection Reports contained within the National Archives Database. It is intended to accompany the article “Weights and Weightways at American Lighthouses” by John T. Graham which appears in volume 32, number 1 of The Keeper’s Log. The reports included the following categories of information: Lighthouse name; Date of report; Order of the lens; Pounds of weight in use; Lens rotation time; Length of Drop Tube (if any); Time between windings; and whether the lens turned on ball bearings, chariot wheels, or a mercury float system. In one example, the following information was on a 1922 inspection report for the Gay Head, Massachusetts, lighthouse: First Order Lens; 150 pounds of weight in use; Lens rotated once every 4 minutes; Drop Tube was 20-feet long; Weights were wound every 4 hours; a Chariot Wheel system was in use. In many of the reports, data was simply not included for all of the categories, but they nonetheless give a heretofore underappreciated glimpse into this aspect of lighthouse operation.

LIGHTHOUSE YEAR ORDER POUNDS ROT. TIME DROP TUBE FT. WIND TIME HR. BB  CW  MF
Makapuu HI 1916 ,27 0 121   no tube 3.5 BB
Barnegat NJ 1910 1   4 M only part used 2 CW
Cape Cod MA 1927 1 200 20 s   2.25 MF
Cape Fear NC 1918 1 500 4 m   2 CW
Cape Hatteras NC 1927 1 150 2' 24" 130 15 CW
Cape May NJ 1907 1   8 M   8 CW
Cape Meares OR 1910 1   4 M 10 2.5 CW
Cape Mendocino CA 1907 1   8 M   3 CW
Carysfort Reef FL 1912 1   5.33 M 11 3.5 BB
Destruction Island WA 1910 1   4 M no tube 64' drop 5 CW
Gay Head MA 1922 1 150 4 M 20 4 CW
Graves MA 1927 1 250 18 S 45 1.2 MF
Jupiter Inlet FL 1911 1 130 6 M no tube 6 CW
Pensacola FL 1928 1 80 8 M   2.75 CW
Point Arena CA 1908 1   18 S 54 2 MF
Point Conception CA 1907 1   8 M 8 4 CW
Point Reyes CA 1907 1   2 M 22 2.2 CW
Point Sur CA 1907 1   4 M 26 5.5 CW
St. Augustine FL 1911 1 270 9 M 1st landing to pit 2.75 CW
Hillsboro Inlet FL 1911 2 100 20 S none, cntr of strs 2 MF
Isle of Shoals NH 1935 2 160 5 M 40 5 CW
Kilauea Point HI 1913, 16, 27 2 503 20 S 34 3.75 MF
Minots Ledge MA 1922 2 100 30 S no tube 3 MF
Molokai HI 1910 2 272 40 S 33 3 MF
Molokai HI 1927 2 166 20 S 45 2.75 MF
Moose Peak ME 1935 2 100 6 M 40 7 CW
Petit Manan ME 1935 2 250 6 M 22 5.5 CW
Rock of Ages MI 1912 2 235 20 S 94 5 MF
Sankaty Head MA 1927 2 110 8 M   5.5 CW
White Shoal MI 1911 2 225 16 S 44 2.25 MF
Amelia Island FL 1921 3 30   27 4  
Bolivar Point TX 1927 3 40 2 m   12  
Cape Hinchenbrook AK 1935 3 185 20 S 27 3 MF
Cape San Blas FL 1927 3 75 40 S 80 14 BB
Cape San Juan PR 1912 3 254 9 M 27 4 CW
Cape Spencer AK 1927 3 270 15 S 28   MF
Cape St. Elias 1916 3 270 20 S 30 6 MF
Chicago Harbor IL 1927 3 125 80 S 54 3.25 BB
Devils Island WI 1910 3   80 S full len. Of tower 2.75 BB
Galveston Jetty TX 1927 3 138 2 M no tube   8 MF
Little Sable MI 1911 3 90   78 11 CW
Marblehead OH 1909 3   20 S 57 4  
Matagorda TX 1927 3 121   open tower 4 BB
Outer Island WI 1910 3   9 M whole height 8 CW
Point Loma CA 1915 3 130 3 M 47 6.5 CW
Sabine Pass LA 1927 3 150 1.5 M 50 4 BB
Sanibel FL 1912 3 115 6 M 65 12 BB
Thirty Mile Point NY 1909 3   4.5 M 34 4 CW
Brazos River TX 1911 3.5 165 10 s   9.5 MF
Chandeleur LA 1928 3.5 60 20 S 60 4.5 MF
Alcatraz CA 1915 4 80 30 s 20 4  
Alki Point AK 1913 4 110 10 s 26 5  
Baker Island ME 1935 4 70 3 m 27 6  
Barbers Point HI 1927 4 110 5 s  23 5  
Barbers Point HI 1916 4 278 5 s 23 5.75  
Barbers Point HI 1912 4 182 5 s 23 3.5  
Burnt Island ME 1935 4   20 s 16 6  
Cape Poge MA 1929 4 200 30 S 35 5 BB
Chatham MA 1927 4 325 30 S "none" 8  
Cove Point MD 1927 4 50 1 M 40 6.5 BB
Crooked River FL 1927 4 150 12.5 S 80 12  
Cuckolds ME 1935 4 150 12 S 25 4 BB
East Chop MA 1927 4 100 60 S 23 8 BB
Eldred Rock AK 1913 4 135 20 S 31 5 BB
Great Duck Island ME 1935 4 130 40 S 25 7 BB
Gurnet MA 1927 4 150 20 S "none" 8 BB
Hendricks Head ME 1911 4 40 3 M no tube 7  
Honolulu Harbor HI 1916 4 270 24 S no tube 12 BB
Kauhola Point HI 1917 4 246 12 S 23 7 BB
Kauhola Point HI 1927 4 45 12 S 23 7 BB
Lime Kiln WA 1919 4 100   24 4.75 MF
Mount Desert ME 1937 4 30 90 S 30 4.5 BB
Nauset MA 1927 4 200 10 S center of tower 8 MF
New London Ledge CT 1913 4 240 30 S 50 9 BB
North Manitou MI 1910 4   60 S 42 5 BB
Pecks Ledge CT 1928 4 100 30 S 45 6.5 MF
Race Point MA 1927 4 100 3 M 12 4.25 CW
Smith Point VA 1927 4 50 1 M   6 BB
Squaw Island MI 1911 4 50 15 S 28 3.75 BB
Thimble Shoal VA 1915 4 200 6 S Stairwell 10 BB
Two Bush Island ME 1935 4 450 20 S 28 7 BB
Two Harbors MN 1910 4   20 S wood tube 14" 4.5 BB
Whaleback ME 1935 4 350 20 S 6 2 BB
Wolf Trap VA 1927 4 50 45 S 30 7 BB
Wood End MA 1931 4 175 1 M "none" 7.5 BB
Wood Island ME 1935 4 60 1 M   6.5 BB
Butler Flats MA 1931 5 100 30 s 37 6 BB
Hudson City NY 1930 5 180 12 S 29 5 BB
Port Ferro PR 1912 5 200 5 S 27 4.5 MF