Pete Jack wrote:I don't get how such ferry can have no auxiliary power. Seems to me it would oscillate like a pendulum and end up in the middle of the river going nowhere. Or have them fiendish Continentals invented perpetual motion? Is there some kind of adjustable vane arrangement to push the vessel one way or the other? Enquiring minds need to know.
Here is a drawing of the system, https://commons.wikimedia.org/wiki/Cate ... %A4hre.png
The ferry will move from left to right when rigged as shown, to reverse the movement the lengths of the bridle legs (3 in the drawing) will be reversed so that the leading end of the vessel is upstream from the trailing edge. The vessels hull is usually fitted with one or more leeboards which can be adjusted to achieve optimum performance depending on river depth and current.( The same principle is used on trawl nets where the trawl doors or otterboards hold the net mouth open as the trawler hauls the net through the water).
Manual winches are often sufficient to adjust the bridle, but larger ferries will have powered winches.
There are variations on the theme depending on local conditions, but generally no rudder or mechanical power is required.
Instead of an anchor, some ferries use an aerial wire across the river but this has the disadvantage of creating an obstruction for other vessels transiting the river.