A very cool car axle benchmark located at one of the gun emplacements looking out over Mobile Bay on board Fort Gaines is benchmarked twice -- as a tidal (BH1759) and regular (BH2135) benchmark.
You do have to pay an admission fee to get into the Fort to find this benchmark, but since it's a car axle, it's well worth it (in our opinion, being major benchmark geeks).
From the NGS Datasheet for this axle as a tidal benchmark: (
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BH1759 TIDAL BM - This is a Tidal Bench Mark.
BH1759 DESIGNATION - 873 5180 TIDAL STEEL PIPE
BH1759 PID - BH1759
BH1759 STATE/COUNTY- AL/MOBILE
BH1759 USGS QUAD - FORT MORGAN (1982)
BH1759
BH1759 *CURRENT SURVEY CONTROL
BH1759 ___________________________________________________________________
BH1759* NAD 83(1986)- 30 14 52. (N) 088 04 28. (W) SCALED
BH1759* NAVD 88 - 6.316 (meters) 20.72 (feet) ADJUSTED
BH1759 ___________________________________________________________________
BH1759
BH1759_MARKER: Z = SEE DESCRIPTION
BH1759_SETTING: 40 = WALL
BH1759_STABILITY: B = PROBABLY HOLD POSITION/ELEVATION WELL
BH1759
BH1759 HISTORY - Date Condition Recov. By
BH1759 HISTORY - UNK MONUMENTED RBNF
BH1759 HISTORY - 1984 GOOD NGS
BH1759
BH1759 STATION DESCRIPTION
BH1759
BH1759''DESCRIBED BY NATIONAL GEODETIC SURVEY 1984
BH1759''4.0 KM (2.5 MI) EAST FROM DAUPHIN ISLAND.
BH1759''4.0 KM (2.5 MI) EAST ALONG BIENVILLE BLVD FROM THE JUNCTION OF
BH1759''HWY 163 ON DAUPHIN ISLAND TO FORT GAINES ON THE EAST SIDE OF
BH1759''THE ISLAND, THE MARK IS THE TOP OF A 2-INCH DIAMETER STEEL ROD
BH1759''(ACTUALLY A CAR AXLE) WHICH PROJECTS 38.5 CM (15-IN)
BH1759'' ABOVE THE WALL, AT THE EXTREME EAST CORNER OF THE FORT, THE
BH1759''PIPE HAS A TRIANGLE CHISELED IN THE TOP, 1.52 METERS (5.0 FT)
BH1759''WEST-NORTHWEST OF THE EXTREME EAST CORNER OF THE FORT WALL,
BH1759''38.10 METERS (125.0 FT) NORTHEAST OF BENCH MARK NO 4.
The datasheet for this benchmark as a standard benchmark: (
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"BH2135 DESIGNATION - FORT GAINES
BH2135 PID - BH2135
BH2135 STATE/COUNTY- AL/MOBILE
BH2135 USGS QUAD - FORT MORGAN (1982)
BH2135
BH2135 *CURRENT SURVEY CONTROL
BH2135 ___________________________________________________________________
BH2135* NAD 83(1992)- 30 14 53.00700(N) 088 04 29.34910(W) ADJUSTED
BH2135* NAVD 88 - 5.6 (meters) 18 (feet) VERTCON
BH2135 ___________________________________________________________________
BH2135
BH2135_MARKER: DO = NOT SPECIFIED OR SEE DESCRIPTION
BH2135_SETTING: 7 = SET IN TOP OF CONCRETE MONUMENT
BH2135_MAGNETIC: N = NO MAGNETIC MATERIAL
BH2135_STABILITY: C = MAY HOLD, BUT OF TYPE COMMONLY SUBJECT TO
BH2135+STABILITY: SURFACE MOTION
BH2135
BH2135 HISTORY - Date Condition Recov. By
BH2135 HISTORY - 1908 MONUMENTED USE
BH2135 HISTORY - 1941 GOOD CGS
BH2135 HISTORY - 1958 GOOD CGS
BH2135 HISTORY - 1976 GOOD NGS
BH2135 HISTORY - 1978 GOOD USCG
BH2135 HISTORY - 1981 GOOD NOS
BH2135 HISTORY - 1984 GOOD NOS
BH2135 HISTORY - 1986 GOOD USPSQD
BH2135
BH2135 STATION DESCRIPTION
BH2135
BH2135''DESCRIBED BY US ENGINEERS 1908 (JWM)
BH2135''ON TOP OF THE E BASTION OF THE OLD FORT ON A LINE FROM POINT
BH2135''OF THE BASTION TO THE SALLY PORT AND ABOUT 5 FEET BACK FROM THE
BH2135''THE POINT OF THE BASTION. THE STATION IS A 2 1/2-FOOT IRON
BH2135''CAR AXLE CEMENTED INTO THE BRICK, PROTRUDING ABOUT 1
BH2135''FOOT.
BH2135
BH2135 STATION RECOVERY (1941)
BH2135
BH2135''RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1941 (WMS)
BH2135''STATION RECOVERED IN GOOD CONDITION. DIRECTIONS FOR REACHING
BH2135''STATION NOT GIVEN IN DESCRIPTION AVAILABLE.
BH2135''
BH2135''STATION IS ON W SIDE OF ENTRANCE TO MOBILE BAY, ON E END OF
BH2135''DAUPHIN ISLAND, ON TOP OF SE CORNER OF E BASTION OF AN OLD
BH2135''ABANDONED FORT.
BH2135''
BH2135''MARK IS A 2 1/2-FOOT IRON CAR AXLE CEMENTED INTO THE BRICK,
BH2135''5 FEET FROM THE EDGE OF THE BASTION AND PROJECTS ABOUT 1 FOOT.
BH2135''STATION CAN BE REACHED ONLY BY BOAT.
BH2135
BH2135 STATION RECOVERY (1958)
BH2135
BH2135''RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1958 (RFL)
BH2135''THE STATION IS ON THE W SIDE OF THE ENTRANCE TO MOBILE BAY,
BH2135''ON THE E END OF DAUPHIN ISLE, ON TOP OF THE SE CORNER OF THE E
BH2135''BASTION OF FORT GAINES.
BH2135''
BH2135''MARK IS A 2-1/2 FT IRON CAR AXLE CEMENTED INTO BRICK 5 FT
BH2135''FROM THE EDGE OF THE BASTION AND PROJECTS ABOUT 1 FT.
BH2135''
BH2135''STATION CAN BE REACHED BY TRUCK FROM DAUPHIN ISLAND.
BH2135
BH2135 STATION RECOVERY (1976)
BH2135
BH2135''RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1976 (WOM)
BH2135''STATION MARK, OLD IRON CAR AXLE, RECOVERED AND FOUND IN GOOD
BH2135''CONDITION. STATION RECOVERED AS DESCRIBED.
BH2135''
BH2135''TO REACH FROM THE DAUPHIN ISLAND WATER TANK, GO EASTERLY ON
BH2135''SURFACED ROAD FOR 2.4 MI TO A SIDE ROAD ON THE RIGHT, TURN
BH2135''RIGHT AND GO S FOR 0.05 MI TO A PARKING AREA FOR FORT GAINES,
BH2135''AND STATION AS DESCRIBED IN THE 1958 DESCRIPTION.
BH2135''
BH2135''AIRLINE DISTANCE AND DIRECTION FROM NEAREST TOWN
BH2135''2 MILES E OF DAUPHIN.
BH2135
BH2135 STATION RECOVERY (1978)
BH2135
BH2135''RECOVERY NOTE BY US COAST GUARD 1978 (RM)
BH2135''GOOD, STA IS A CAR AXLE AND CAN BE DRIVEN TO.
BH2135
BH2135 STATION RECOVERY (1981)
BH2135
BH2135''RECOVERY NOTE BY NATIONAL OCEAN SERVICE 1981 (RHH)
BH2135''THE STATION WAS RECOVERED GOOD CONDITION AS DESCRIBED IN 1958.
BH2135''
BH2135''HEIGHT OF LIGHT SHOWN ABOVE THE MARK WAS 1.50 METERS.
BH2135
BH2135 STATION RECOVERY (1984)
BH2135
BH2135''RECOVERY NOTE BY NATIONAL OCEAN SERVICE 1984 (WVH)
BH2135''THE STATION WAS RECOVERED AT THIS DATE.
BH2135''STATION MARK RECOVERED AS DESCRIBED IN 1984, 1986, AND 1987.
BH2135''
BH2135''HEIGHT OF LIGHT SHOWN WAS 1.5 METERS ABOVE THE MARK.
BH2135''
BH2135''RECOVERED BY M. JOHNSON.
BH2135
BH2135 STATION RECOVERY (1986)
BH2135
BH2135''RECOVERY NOTE BY US POWER SQUADRON 1986 (THL)
BH2135''RECOVERED IN GOOD CONDITION."