My task is to make a model at the 1:35 military scale of a ferry as would have been used by the Continental Army to cross the Delaware River in the winter of 1776. Three crossings were made by the Army, but the one most remembered is the one made Christmas Day as prelude to the attack on Trenton. A modern painting representing this event is shown above.
There were several ferries near the crossing point, dozens across the region, and hundreds across the country, such as the 19th century image above captures on a mid-western river. Ferries were a generic vessel type, based on a minimalist design, and so mundane that few details of them were ever preserved from the 18th century. They were probably built on site by owner-operators, not in boatyards by professional builders.
They all shared certain basic elements. Essentially a simple rectangular box, with a flat bottom and flat, vertical sides. The functional imperative was simply that it floated, and was easy and cheap to build. The bottom at each end sloped upward, which reduced the water resistence, making it possible to move across the water with minimal effort.
There were no constructed landing docks, such as ferries have today, and loading and and unloading was executed onto a natural riverbank, perhaps modified somewhat to make a sloping ramp as the entry/exit point. Sometimes some minor temporary improvements were made, as seen below in this 19th century photograph.
But since these rivers were normally subject to annual and several erosive flooding, any more significant riverbank construction would probably have been washed away periodically anyway. Plus given the way these ferries were designed, no more substantial landing preparation was really necessary.
A 1:24 scale model of a Colonial Ferry, made by John H. Earl
(see http://modelboatyard.com/ferry.html )
As shown on the above model, a moveable ramp was located at each end of the vessel, pivoting on hinges, and controlled by a long pole mounted along each edge. When crossing the water, both ramps were held in a raised position by locking the inboard ends of the poles under rope loops or metal brackets.
When the boat reached the riverbank, and grounded to a halt, the poles were released, and the ramp dropped down to precisely meet the dirt ramp, permitting people and vehicles to disembark or embark. The timber ramp automatically adjusted for differences in water levels and riverbank conditions.
As can be seen above, for the Hatton Ferry over the James River in Virginia, nothing much has changed in this technology.
The oldest, and probably most dependable, method of propelling a ferry across a river is by poling, as seen below. This is the same method used by most river boats, and the method of choice for the Durham boats used in the military transport acoss the Delaware in 1776.
Poles were of great length, often over 18 feet, but in deeper water, where reaching a firm bottom by poling was impossible, oars could be used, and the ferry rowed across, as seen below.
Except in calm waters where river current was slight, rowing was not a preferable means of propulsion. When under oars, there was no physical contact with the bed of the river, as there was when using poles, and it was only brute strength that kept the boat on course to the opposite side.
A third, and more dependable method of ferrying was the use of the rope, or cable, system, as seen below.
Here a heavy rope, or if possible a spun metal cable, was firmly strung from bank to bank between the landing ramps. To keep the cable from sagging into the water, especially on wide rivers, this had to be held up at each end by a tripod or a gin crane (see far bank above, and crane drawing below).
The advantage of this system was two-fold. First, the boat was prevented from drifing downstream so long as the cable was strong enough to prevent breaking. Second, it eliminated the need for two or more extra hands to pole or row, as one man could operate the mechanism by himself (see below).
The simplist and least complex method of moving a rope/cable ferry has the hand-over-hand method above. But for larger ferries an advantage became desireable, so a mechanical system to wind the boat along the cable, similar to a modern cable car, was created. A more advanced example of this machine is seen below.
Sometimes this tracked along a cable lying in the water, while pulleys overhead guided the boat on its course. This is seen in the image just before the gin crane drawing above, where a smaller wheel is also employed. The overhead guiding pulley system can be seen in several of the images above, including the "Washington Crossing" one at the top of this page.
There are virtually no records of the dimensions of these early ferries. They were too mundane and common to be considered worth recording. The variation of these locally and individually built vessels makes it impossible to generalize, either, even though some constants suggest maximum and minimum dimensions for some components.
The model created by John Earl, based on his own attempts to research the subject of Revolutionary War era ferries and come up with a reasonable result, is perhaps a starting point, as it is a finished and well executed model.
Yet having looked at many images of actual ferries, albeit from many decades after the fact of 1776, one gets an impression that perhaps his plan, being a scale length of 40 feet and a scale width or 12.5 feet (personal communication), is a bit too "square"? Many typically appear to be substantially longer (see below).
I decided to take one example, below, in this case a rope ferry from the Yadkin River in North Carolina, to attempt to calculate actual dimensions. This boat was photographed in 1900, but is clearly typical of much earlier ferries.
The photo is excellent for scaling features as it has several objects shown in near profile of known size.
First, if you look at the wagon and carriage wheels, they appear to be nearly touching the sides of the boat on both sides. This is confirmed by looking at the wheel treads at the rear of the boat.... wide boards nailed down as wearing timbers for wagon wheels to run on. Since the wheel base of 19th century wagons was about five feet, rim to rim, it would appear that there is less than 18 inches free space on either side of the wheels (note standing woman). That would mean the ferry width is just 8 feet. (Note: the width of a Durham boat is also 8 feet, not that this means anything except heavy duty working river boats could do just fine with an 8 foot beam.)
Length can be calcualted from the men on board, assuming and average height of 5.5 feet. If we take the foremost man as the base, this gives us about (adjusting for the oblique angle of the view) six lengths over the hull, excluding the ramps, and another length or a bit more to include the ramps, which are quite narrow. That means the estimated overall length of this boat is 38.5 feet...or rounding up we can say it is 40 x 8 feet.
If only we had a late 18th century eyewitness image of a Delaware River ferry.......
The image above, from the Camden County Historical Society, was done in 1779, just two years after the December 1776 Washington Crossing event, and in the Lower Delaware River, not far downstream from that same event. It shows the ferry being rowed and "arriving from the Philadelphia side of the river".
Using the horse as a scale unit (8'), the hull, excluding the two ramps seen extending from either end, is an estimated length of 48 feet. Adding the ramps, of approximately four feet each, we get a total estimated length of 56 feet. Using the man as a scale unit, we get an estimated hull length of 49.5 feet, plus 8 feet for ramps, and we estimated length at 57.5 feet.
It is not possible to accurately estimate the width of the boat, except that the people and carriage appear to be about as crammed in as in the one above from North Carolina. So let's say 8 feet for width. In both this and the North Carolina boat, the internal height of the sides appears to be less than three feet.
This 18th century Delaware River ferry is estimated at about 57 feet long and 8 feet wide. Nearly the same dimensions as a Durham boat!
The "Flying Machine"?
Another perspective on the size of the Delaware River ferries available to Washington for his several December crossings is revealed in David Hackett Fischer's book "Washington's Crossing". (Below)
This so-called "Flying Machine", as advertised below, was an express coach service that ran between New York and Philadelphia at the time Washington's army was scouring the riverbanks for boats.
A contemporary illustration, below, indicates the size of these vehicles and suggest the need for a large and very stable ferry to make the Delaware crossings.
The ferry at Washington's Crossing imagined in the modern painting, below, appears to be about 10 feet wide, and very long...easily over 50 feet.
Lacking evidence to the contrary, and based on the research detailed above, I anticipate a model that is 55 scale feet long and 10 scale feet wide as reasonably correct, although no doubt individual ferries on the river differed in size.
Cleats and Treads?
One of the questions that needs to be answered to model a Delaware River ferry, c. 1776, is how was the interior finished off, evan as open and seemingly simple as it was? This was a pretty rudimentary commercial vessel; cheap and functional. The interior had to function well for people and horse-drawn wagons and carriages, some heavily loaded.
The bottom of the boat was just flat boards and level, so nothing would seem to be required to facilitate usage. But at each end the floor of the ferry sloped upward, and when released to meet the riverbank, the ramps sloped downward. So installing cleats on these non-level surfaces would provide footing for people and livestock alike, as shown in the model of a "colonial ferry" below.
But when one starts to look at images of actual rural ferries in the 19th century, one sees that something less simple might have served the needs of both the ferry passengers and the ferry operators.
In the photo above we can see treads... boards fastened along the floor on which carriage wheels ride... running at least on the ramps and probably all along the floor. The advantage for the operator is obvious in preventing undue wear to the actual bottom of the boat. Whether there are cleats nailed crosswise on the bottom cannot be seen well in this view.
And one can immediately imagine a difficulty if cleated surfaces had to be traversed by wheeled vehicles. The cleats would inhibit the moving of vehicles, and might damage wheels or suspensions.
A possible innovation is shown above, where cleats are provided down the center of the bottom, clear up to the ramp. This provides traction for horses, livesock and passengers. But there are no cleats along the sides where vehicle wheels would run. There are no treads there, but it works. (Note this is a rope ferry of the slack rope type, where a water-level rope passes through a pulley and is pulled by the operator to move the boat along the fixed rope. Note also the poles that raise and lower the ramp are just held up by a loop of rope, not a more expensive metal bracket. And the pole the operator uses lying on deck to the right appears to be nothing more than a sapling he cut in the woods, rather than a finished boating pole.)
Probably the best set-up for the interior of a large ferry would be cleats down the middle AND treads along the sides for vehicles' wheels to travel on, and modeling this configuration is appealing.
Rope or Nope?
The two best (imagined) views of the ferry crossings used on Christmas, 1776, are the painting done in the 19th century by George Caleb Bingham (below, left) and the one done in the 21st century by Mort Kunstler (below, right).
Both are incorrect as the ferry in each is shown crowded with troops, whereas it is virtually certain the ferries were reserved for artillery and associated baggage. The troops traveled in Durham boats and other craft, until the artillery had passed over.
The two paintings raise an important question. Both are being poled, not rowed, but one is being poled attached to an elevated rope and pulley system (right) and one is being poled as a detached vessel (left). While these paintings are just imaginings, which technology is correct for 18th century Delaware River ferries has implications for how the boat is set up, even if it is modeled as being used as a detached boat?
The 19th century image of a Delaware River ferry (above) reveals the same elevated rope and pulley system portrayed in Bingham's painting, perhaps done around the same time as this photograph. There were numerous ferries operating on the river at the time of the crossing (below).
Did they all have permanent elevated ropes running across the river? Certainly the method was superior to a detached ferry, depending on poles and oars to make it to the landing. But what about all the Durham boats and other craft using the river? Would these overhead ropes be an obstacle? Certainly at the shallows at either end, the rope would be high enough to pass under. But mid-channel, it would sag much closer to the surface and block passage.
The evidence is somewhere. But it is reasonable to see these ferries as some form of rope system, even if not using a rope on Christmas, 1776. Someone needs to do a new ferry painting with just artillery. Then we would have an approximation that matters.
An additonal observation....
We know a collection of artillery was being transported across the river with the army. It would appear, from the configuration of the Durham boat interiors, with several cross bars or thwarts interrupting a narrow and deep cargo hold, that loading artillery, especially remaining on their carriages, would be very problematic.
So given the flat bottoms of the ferries, the low sides, and the easy-on, easy-off ramps, both inside the hold and attached at each end, it would seem that the men went in the Durham boats and the artillery and horses went on the ferries.