Displacement: 519 tons     Length: 150 feet 6 inches     Beam: 32 feet
General: Wood hull and superstructure; Side paddle wheels'
Built: 1862 (finished)     Builder: (unknown)   Owner: Union Ferry Company     Name: (untitled)
Sold to USN: 1862 (new) at NYC    Decommissioned: 1865 at NYC
Sold to: East River Ferry Company 1865
Operated at: East River running between Pier 11 (Manhattan) and Hunters Point (Long Island City, Queens)
Final Disposition:  Destroyed by fire on February 21, 1868 while in dock at Hunters Point

Step 2 - Facts About the Ship

       The USS Fort Henry was purchased while the ship was being completed or was completed.  While in the service of the USN there appears to be no photos, drawings, or records that indicated what it looked like.  Modifications were made to the ship to convert it to a gunboat which included some sort of protection around the open ends of the main deck.  This could have been sand bags or iron plates that were hinged at the bottom and sloped inward past the vertical position.  Other modifications included enclosing the open ends of the superstructure to make accommodations for the naval crew of approximately 100.
      All NYC ferryboats of the period appear to have only a one level superstructure (main deck) with a pilot house located on each end of the superstructure's overhead.  There were two pass-throughs in the superstructure as the steam machinery and stack were located in the center.  Windows along the side were likely spaced apart and not continuous.
      Pilot houses are also different between the various ferryboats.  Some were round and some square/retangular (as viewed from the top).  Some were mounted on top of the main superstructure's overhead.  Some appear to be sunk down into the overhead giving a squatty appearance.
      Seems that most (if not all) seem to have used a walking beam engine with the big rocking arm above the overhead deck.  This probably drove a crank connected to the side wheels.  The gear and the smokstack location caused the ship to be not symetrical looking as viewed from the side.
      There were a number of different ferry companies operating in NYC during the 1850's through the end of the century until bridges replaced the need for them.  The ends of the deck seem to have different shapes (when looking down), some more elliptical and others somewhat blunt-nosed.  I'm not sure how they fitted into their docks.
      There seems to be a general opinion that despite being double ended and driven by side paddlewheels, that the under-hull had a different shape in respect to the ends (bow, stern).  One end probably had a rudder and the other end a more traditional bow.  The paddle wheels apparently were not individually operated (which would aid in turning) which made them somewhat clumsy.

Step 3 - Drawing Parallels to Other Ferryboats

       With the basic dimensions of the USS Fort Henry known we can look at other ferryboats built in that area, same builder, prior owner, dimensions, dates, etc.  One major problem is the builder.  I have not been able to locate the builder's name.  (See my spreadsheet below for the NYC ferries of the period.)
      The only other ferry that seems to come close is the Somerset.  Also bought "new" from the Same ferry company (Union Ferry Company), the dimensions are quite close.
       Finding the builder for the Somerset seems to also be evasive.  Both ships were finished being built in the same year, but the Somerset appears to have been built in nearby Brooklyn.  If the Somerset is the sister ship to the Fort Henry that adds to the search for the shape.  The Somerset  retained its name after being sold to the East River Ferry Company and was in service until 1914.  (Careful, everything above the main deck seems to have been replaced.)  The Fort Henry became the Huntington after the sale to East River Ferry Company until destruction in 1868.