Current Designation(s) SHAFT NUMBER 11C Plate 23-9, New Croton Aqueduct SHAFT NUMBER 10 Plate 22-15, New Croton Aqueduct Engineers designed Shaft Number 10 to be sunk to a depth of 126 feet. Type Significance(s) Current Designation(s) 34 Interpretation Sign Shaft 11C was constructed with a 14 foot diameter so that pumping apparatus could be lowered down to the New Croton Aqueduct. Type Significance(s) Current Designation(s) Interpretation Sign SHAFT NUMBER 13 Plate 24-8, New Croton Aqueduct The headhouse at Shaft Number 11C was designed to contain appurtenances necessary for the emptying of the Gould’s Swamp Siphon. Shaft Number 13 was designed to be sunk to a depth of 153 feet. Significance(s) Interpretation Significance(s) Interpretation Sign Structure Guide Type Type Sign Current Designation(s) Current Designation(s) SHAFT NUMBER 14 Plate 24-9, New Croton Aqueduct SHAFT NUMBER 12A Plate 23-10, New Croton Aqueduct Shaft Number 12A was engineered at a depth of 43 feet. Engineered to a depth of 28 feet, Shaft Number 14 was paired with the Ardsley Gatehouse. Type Type Significance(s) Interpretation Appendix SHAFT NUMBER 11C HEADHOUSE Plate 23-9, New Croton Aqueduct Significance(s) Interpretation Sign Sign Current Designation(s) Current Designation(s) SHAFT NUMBER 15 Plate 24-12, New Croton Aqueduct SHAFT NUMBER 12B Plate 23-11, New Croton Aqueduct Shaft Number 12B was designed to be sunk to a depth of 40 feet. Type Significance(s) Interpretation Designed to be sunk to a depth of 128 feet. Type Significance(s) Interpretation Sign Sign Current Designation(s) Current Designation(s) 35 SHAFT NUMBER 15 HEADHOUSE Plate 24-13, New Croton Aqueduct SHAFT NUMBER 17 1887 Plate 26-4, New Croton Aqueduct Also referred to as the Mount Hope Headhouse, the structure covered an unpressurized portion of the New Croton Aqueduct. In digging Shaft Number 17 to a projected depth of 60 feet, sand and gravel was encountered. A cave-in occured killing 3 people. Type Significance(s) Interpretation Sign Current Designation(s) Type Significance(s) Interpretation Sign Current Designation(s) SHAFT NUMBER 16 Plate 26-3, New Croton Aqueduct SHAFT NUMBER 18 Plate 28-XX, New Croton Aqueduct Shaft Number 16 was engineered at a depth of 72 feet. Level with the New Croton Aqueduct tunnel, Shaft Number 18 was paired with the South Yonkers Gatehouse . Type Significance(s) Interpretation Sign Type Significance(s) Interpretation Sign Current Designation(s) Current Designation(s) SHAFT NUMBER 16 HEADHOUSE Plate 24-12, New Croton Aqueduct Also referred to as the Nepperhan Headhouse, the structure covered an unpressurized portion of the New Croton Aqueduct. Type Significance(s) Current Designation(s) 36 Interpretation Sign SHAFT NUMBER 19 Plate 28-XX, New Croton Aqueduct Shaft Number 19 was engineered at a depth of 63 feet. Type Significance(s) Current Designation(s) Interpretation Sign SHAFT NUMBER 22 Plate 29, New Croton Aqueduct An headhouse for an unpressurized shaft was placed over Shaft Number 19. Shaft Number 22 was designed at a depth of 82 feet. Type Significance(s) Interpretation Interpretation Sign Sign Structure Guide Type Significance(s) Current Designation(s) Current Designation(s) SHAFT NUMBER 23 Plate 29, New Croton Aqueduct SHAFT NUMBER 20 Plate 28-XX, New Croton Aqueduct Shaft Number 20, engineered at a depth of 115 feet, marked the beginning of the pressurized portion of the New Croton Aqueduct. Type Significance(s) Interpretation Appendix SHAFT NUMBER 19 HEADHOUSE (Status Unknown) Plate 28-XX, New Croton Aqueduct Engineers designed the shaft to be sunk to a depth of 65 feet. Type Significance(s) Interpretation Sign Sign Current Designation(s) Current Designation(s) SHAFT NUMBER 24 Plate 29, New Croton Aqueduct SHAFT NUMBER 21 Plate 29, New Croton Aqueduct Shaft Number 21 was engineered at a depth of 103 feet. Marking the eastern end of the Harlem River Siphon, numerous difficulties were encountered in its construction. Type Type Significance(s) Interpretation Significance(s) Interpretation Sign Sign Current Designation(s) Current Designation(s) 37 SHAFT 24 HEADHOUSE Plate 29, New Croton Aqueduct Type A diminutive stone structure was placed over Shaft Number 24 on the eastern side of the Harlem River. Type Significance(s) Interpretation Sign SHAFT NUMBER 25 1886-1890 Plate 29, New Croton Aqueduct For more information, see fiche on page XXX. Interpretation Sign Current Designation(s) SHAFT NUMBER 25 HEADHOUSE (Demolished) Plate 29, New Croton Aqueduct Built to house a powerful steam-engine used to power the pump shaft in Shaft Number 25, an expressive Romanesque Revival style was employed. The headhouse overlooked the Harlem River Speedway. 38 Sign Current Designation(s) SHAFT NUMBER 25 STEPS AND RETAINING WALL c 1892 Plate 29, New Croton Aqueduct Type Marking the point where the New Croton Aqueduct entered Manhattan Island, Shaft Number 25 employed revolutionary engineering in its design. Significance(s) Interpretation An elaborate stairway was built into the side of Shaft Number 25 with access to the Harlem River Speedway through a glorious arch. Current Designation(s) Type Significance(s) Significance(s) Interpretation Sign Current Designation(s) SHAFT NUMBER 26 Plate 29, New Croton Aqueduct Engineered at a depth of 120 feet, Shaft Number 26 was also designed to protect Manhattan from any undue pressure resulting from