In 1960, Kjeld Rasmussen, naval architect of the Danish Greenland
Company, was requested by the author to inspect in the Danish Royal
Archives at Copenhagen a folio of American ship plans, the index of
which had listed some Civil War river monitors. Mr. Rasmussen found the
monitor plans had been withdrawn but discovered that three plans of
Fulton's _Steam Battery_ existed, as well as plans of the first
_Princeton_, a screw sloop-of-war.
Copies of the _Steam Battery's_ plans were obtained at Copenhagen in
September 1960 through the courtesy of the archivist, and were found to
consist of the lines, copied in 1817, an inboard profile and
arrangement, and a sail and rigging plan. From these the reconstruction
for a scale model was drawn and is presented here with reproductions of
the original drawings upon which the reconstruction is based.
It is apparent that Montgéry's description is generally accurate. The
vessel is a catamaran, made of two hulls, double-ended and exactly
alike. The outboard sides are "moulded," with round bilges, the inboard
sides are straight and flat, as though a hull had been split along the
middle line and then planked up flat where split. The hulls are
separated by the race, in which the paddle wheel is placed at
mid-length. The topsides are made elliptical at the ends, and the
midsection shows a marked tumble-home over the thick topside planking
but less on the moulded lines.
[Illustration: Figure 6.]
The lines plan agreed rather closely to Montgéry's description of the
hull. After careful fairing it was found the lines drawing would produce
a vessel 153 feet 2 inches overall outside the stems, or about 151 feet
over the planked rabbets, with a moulded beam of 56 feet and extreme
beam of 58 feet. The moulded depth was 22 feet 9 inches and the width of
the race was 14 feet 10 inches, plank to plank. The room and space of
framing shown was 2 feet. The designed draft appears to be 13 feet and
this would bring the port sills 5 feet 6 inches above the loadline and
the underside of the gun-deck beams about 2 feet 9 inches above the
loadline.
The lines plan is a Danish copy, probably of the building plan by Noah
Brown, and may be based on the plan Montgéry obtained from Brown. The
spar deck has the iron stanchions (Gurley translated these as
"chandeliers") which are set inboard 4 feet from the plank-sheer. This
gives room for cotton bales, outboard the stanchions, to form a
barricade. As will be seen by comparing the original Danish drawing with
the model drawing, the construction indicates that the iron stanchions
should be carried around the ends of the hull in the same manner as
along the sides, since the lower ends of the iron stanchions pass
through the spar deck and are secured to the inside of the inner ceiling
of the gun deck. The rudders are as shown in the Danish drawing, and it
is supposed that they were operated ferryboat fashion, one at each end
of the vessel. Hence, each pair of rudders was toggled together by a
cross-yoke. This was probably operated by a tiller (possibly the
cross-yokes and tillers were of iron) pivoted under the beams of the gun
deck close to the ends of the ship. Tiller ropes led from a tackle under
the gun-deck through trunks to the spar deck, where the wheels were
placed. This allowed proper sweep to the tillers and operation of each
pair of rudders. The paddle wheel was apparently of iron, with wooden
blades, and agrees with Montgéry's description. In the plan for the
model it is shown raised 18 inches above the original design position,
to agree with trial requirements.
[Illustration: Figure 7.--ORIGINAL LINES OF ROBERT FULTON'S _Steam
Battery_, a Danish copy dated September 12, 1817; found in Rigsarkivet,
Copenhagen.]
It should be observed that the close CL-to-CL frame spacing created a
hull having frames touching one another, at least to above the turn of
the bilge, so the vessel was almost solid timber, before being planked
and ceiled, from keel to about the loadline. The sides are not only
heavily planked but, after the frames were ceiled with extraordinarily
heavy, square timbering, a supplementary solid, vertical framing was
introduced inboard and another ceiling added. The sides scale about 5
feet from outside the plank to the inboard face of the inner ceiling at
the level of the gunports.
The hulls were tied together athwartship by the deck beams of the gun
deck and spar deck, except in the wake of the paddle wheel. Knees were
placed along the sides of the race at alternate gun-deck beams. In
addition, the 12 1-foot-square timbers, crossing the race at the rabbets
of the hulls, (mentioned by Montgéry) are shown. These must have created
extraordinary resistance, even at the low speed of this steamer. The
deck details shown are the results of reconstruction of the inboard
works.