Marble Hill Mystery Tunnel

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    • #2008

      There is a 30 foot long brick and stone tunnel under Marble Hill–3 feet wide and 4.5 feet tall–that runs to the curb from the basement of 16 Fort Charles Place.

      The existence of this tunnel came up during our walking tour of Revolutionary Spuyten Duyvil and Kingsbridge on Sunday.  Some believe it was built during the Revolution and was connected to or related to nearby Fort Prince Charles.  I hadn’t realized this but it had been inspected in 2002 by William I. Roberts of Greenhouse consulting.  Prof. Allan Gilbert of Fordham, an expert in bricks, participated in the analysis.  Roberts determined that the tunnel could not have been associated with the fort on Marble Hill for three reasons:

      1) Fort Prince Charles was located on a different part of the hill;

      2) The type of bricks used were “introduced about 1880;” and

      3) The mortar type is “quite hard.  It may well be Portland Cement mortar, which was introduced during 1871.”

      The conclusion was that “the tunnel must date to the period of 1880 through 1911, the approximate date of construction for the house.  It may have been built with the house or up to 30 years earlier.  We have no evidence of its original purpose.”

      To the first point, that the tunnel is in a different part of the hill than was Fort Prince Charles–that is certainly true.  The fort was located on the northern side of Marble Hill and this tunnel is on the east side and further to the south.

      However, Tom Casey suggested the tunnel may not have been part of the fort itself but rather a magazine for storing ammunition.  To back up this idea he points to an original British map from the Revolution indicating that such magazines did exist on that same side of the hill (the eastern side of the hill to the south of the fort):

      What about the other reasons to doubt this tunnel has Revolutionary provenance?  The language used in the report to describe the mortar does not strike me as super-definitive: “The mortar sample is quite hard.  It may well be Portland Cement mortar, which was introduced in 1871.”

      But the strongest indication that the tunnel was built after the revolution is in the analysis of the brick: “The red brick is of standard size.  It has a shallow frog or depression on one side only.  There is no mark or brand.  Standard size red bricks with shallow frogs and no brands were introduced about 1880.”  That seems to blow apart the whole theory of the Revolutionary ammo magazine.  I recently checked in with Allan Gilbert to see if that analysis still holds.  Referring to the bricks he wrote: “If they have a recessed frog, they must be late 19th century. If there is no brand in the frog, chances are good the bricks come from CT and may be early 20th century, associated with the construction of the NYC subway system. That doesn’t mean that the structure they are associated with must be similarly dated since later additions can be made to earlier installations.”  So, he is pretty confident that the bricks are not from the Revolutionary era but does not rule out that they could have been added later.

      So, if this was not a gunpowder magazine, why the heck would someone build a 30 foot tunnel from their basement into the hillside?  Googling the address yielded that the house was occupied by a member of a German singing club in 1885.  In the 1920s it was occupied by the author of a book about “Fairy Mythology.”  In the 60s, a Fordham Professor, Alfeo Marzi, lived there.  He published a book of Bronx-inspired poetry entitled “Bronx Crossing.”  An interesting assortment of people but none of them seem to have been tunnelers!

      What about the years between 1783 and 1885?  Who lived there then?  No one did.  After the revolution, the land was purchased by the Boltons and George Hall, who operated the marble quarry just to the south.  Then it was bought by Isaac Dyckman, who did not have a house on this lot.

      I have to admit, this tunnel has me stumped.

    • #2009

      Any photos? Any slope to the tunnel? Any tracks?  My first guess is a coal chute

    • #2011
      Thomas Casey

      I did get an invite to examine the tunnel from Alfeo Manzi and it is possible the the tunnel was later used to bring in coal.  The surrounding foundation seems to predate the houses in the area and the tunnel drops into a lower basement and out to Broadway.  with a stone platform, perfect for a small cannon.  It was a direct line of fire at the road leading to the Kingsbridge.  The bricks lining the tunnel could have been added in the later years 1880’s.  we did not pull any off  to examine what was underneath.  If this was not used in 1776….Gunpowder may have been stored for the quarry.  See for yourself in some pictures I took.  One has Mr. Manzitunnel 16 ft charles 3

    • #2012
      Thomas Casey

      tunnel 16 ft charles

    • #2013
      Thomas Casey

      tunnel 16 ft charles 2

    • #2014
      Thomas Casey

      Photo of the actual coal chute next to the Tunnel opening..which is about at the curb line.coal shoot

    • #2015
      Thomas Casey

      Note that only the top was lined with brick…the sides are local stone.  I think the brick was added 100 years later.brick ceiling

    • #2016
      Thomas Casey

      The basement foundation of stones, does not match the exactly the floorplan of the house.  It is also a very deep foundation, with a walk out metal door….leading to a flat stone ledge.metal door

    • #2017

      Thomas, this is absolutely fascinating!  Thank you for sharing the photos.

      When I lived in New Orleans, I was trying to unearth an aluminum fence post in my back yard only to have it drop several feet into a hole. It was a brick lined “night soil” pit that was later bricked over with an arch.  The soil was a good couple of feet higher. That the tunnel you saw represents several generations of use, repair, and amendments is easy to imagine.

    • #2018

      Years ago someone in the neighborhood mentioned to me that there were “tunnels” under this section of Marble Hill.  I hadn’t been sure he was telling me the truth, but I had often wondered for years if there really was a tunnel here.  Now I have the proof that there’s at least one tunnel in my neighborhood.  This is most interesting.  Thanks for the find.

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