Capstans
The Oxford University Press encyclopedia says that a
capstan is Òa revolving cylinder with a vertical axis used for winding a
rope or cable, powered by motor or pushed around by levers.Ó[1] Sailing ships in the 1800s had one or
more capstans that were used to pull ropes to raise yards and tighten sails. A rope is wound around the barrel of
the capstan and the capstan is rotated by sailors pushing on poles stuck in the
square holes around the top (see figure below). The capstan is prevented from rotating backward by iron
pawls at the base that drop into slots in an iron ring fixed to the deck. See
the Paasch drawing below.
The
Boucher 1916 model in the MFA and most plans that I have seen show the Flying Cloud with 4 capstans. Two on the ship's centerline, one on
the forecastle deck and one just aft of the main mast and two side by side on
the poop deck. The 1926
plans by Magoun[2] say that the
centerline capstans were double acting and the poop deck capstans were singe
acting. Single acting capstans
worked as described above with the poles directly connected to the capstanÕs
barrel. In double-acting capstans
the top ring of holes is connected to a shaft with a gear on it that, in turn,
drives planetary gears that rotate the capstanÕs barrel at a slower, and this a
more powerful, rate. See, for
example, see the discussion of improved capstans in the American Magazine of
Useful and Entertaining Knowledge.[3]
I
have not found any direct information on the design of the Flying Cloud's capstans.
Most of the plans for the ship show the same general from of capstan -
the form that shown in Paasch[4] (and copied by Magoun).
The same form is shown on figure 6 of Duncan McLeanÕs booklet[5] on the McKay ship Great
Republic, so it is clear that McKay used this style of capstan and, thus, it seems safe to
assume that the Flying Cloud had this style of capstan when she was launched.
Paasch Plate 67
Portion of Figure 6 of McLeanÕs booklet on the Great
Republic
Double acting capstans had two rows of holes at the top as described in Crothers[6]
and as can be seen in the following photo, with the top set of holes being the
geared ones for higher power.
Tourists trying out the capstan on the ship Balclutha
(National Park Service)
I
also have found no direct information on the construction of the capstans on
the Flying Cloud when she was
launched but there is some circumstantial evidence that they may have been made
of brass and mahogany. Donald
McKay launched 8 extreme clipper ships between 1850 and 1852. Duncan McLean
wrote stories in the Boston Daily Atlas about the launching of a number of
them. His reports on the Stag Hound and the Flying Fish say that the capstans were of mahogany and either
mounted on or inlayed with brass.
For the Westward Ho and the Bald Eagle he says that they each had two of Perley's patent
capstans. His other stories do not
mention capstans or they just say how many capstans each ship had, without
describing them.
The
Monthly Nautical Magazine of May 1855 says that Allyn's patent power capstans[7]
had been furnished to the Flying Cloud
within Òthe past yearÓ[8], implying
that the original capstans had been replaced. That leaves mahogany and brass,
something McKay was using around the time he built the Flying Cloud, as the likely materials for the Flying CloudÕs
original capstans.
Capstans
are not all that large, as can be seen in the above photograph. The height of the holes for the capstan
bars needs to be between hip and waist high for a sailor and sailors were about
5Õ 5Ó tall in the mid 1850s.[9] Thus the holes in a capstan should be between
30 and 40 inches off the deck (based on the average proportions of adult
males). The capstan depicted in
the McLean booklet on the McKay ship Great Republic was in the
high end of this range, if not slightly taller, but as the photo shows, many capstans
were quite a bit shorter.