The Plan of St. Gall a study of the architecture & economy of & life in a paradigmatic Carolingian monastery |
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 | The Plan of St. Gall |  |
A SURVIVING MEDIEVAL HYDRAULIC TRIP-HAMMER
I feel strengthened in this conjecture by the circumstantial
historical evidence surrounding a water-powered
medieval trip-hammer that came to my attention, in the
summer of 1970, while travelling in the mountains of the
province of León in Spain. This mechanism, not only
intact but able to be operated, is housed in a smithy located
in the valley of Compludo, on the grounds of a former
monastery of that name. San Fructuosus, a Visigoth of
royal blood and the founder of Spanish monachism, established
Compludo as the first of a vast web of monasteries.
The trip-hammer owes its anachronistic survival to the
452.B
The processing of grain for domestic use
in China during the centuries just before
and after the birth of Christ in the West
reveals wholly familiar technologies and
associations. The model of the farmyard
(fig. 452. A) contains, in addition to the
trip-hammer, a small mill and what
appears to be a parching kiln built into an
enclosure wall—an association also
reflected in the Plan of St. Gall, some 6
centuries later.
The trip-hammer in the model (figs.
452.A-B) was the simplest of mechanisms;
in it is applied the principle of fulcrum
and lever actuated by direct force.
452.C
WILLIAM ROCKHILL NELSON GALLERY OF ART, ATKINS MUSEUM OF FINE ARTS, KANSAS CITY, MISSOURI
IRRIDESCENT GREEN GLAZED POTTERY, 10¾ × 3½ × 3½ INCHES
is accessible by only a stony mountain road whose narrow
and precipitous course offers to the unexpecting modern
visitors moments of breathtaking suspense.[519] The instrument
is described by Florentino-Augustin Diez Gonzáles,[520]
in a study of the political and social life of the Spain of San
Fructuosus, which also includes a sketch of this unusual
mechanism.[521] It conforms in all respects to the trip-hammer
shown in Spechtshart's woodcut of 1488 (fig. 455)
and the modern specimen discussed by Meringer (fig. 453),
except that it is considerably larger.
The water that sets the Compludo hammer into motion
is channeled from the confluence of two narrow mountain
streams, the Miera and the Miruello, into a collecting
basin (banzao) from where it falls upon the heavy wooden
studs of a waterwheel. This wheel, 8 feet in diameter, is
driven by a shaft (árbol) made of chestnut, 16 feet long
and 2½ feet thick. Rotating horizontally this timber,
hardened by age like stone, activates with its wooden cogs
452.D CHENGTU, SZECHUAN, PROVINCIAL MUSEUM
RUBBING, CLAY TOMB TILE, (46 × 28cm) DETAIL, EASTERN HAN PERIOD, 23-220 A.D.
[after Liu Chih-yuan]
Two men are shown pounding rice with trip-hammers, a scene of daily life of the lower social strata of Chinese society that artists of the
Eastern Han loved to portray.
The tile was excavated in 1956 at T'ai-p'ing-hsiang, P'enghsien, Szechuan Province. It was published in Ssu-ch'uan Han-tai hua-hsiang
pei-t'o p'ien (Portfolio of Han Dynasty Impressed Clay Tiles from Szechuan), Ssu-ch'uan sheng po-wu-kuan (Szechuan Provincial
Museum) by Shang-hai jen-min mei-shu ch'u-pan she (Shanghai People's Art Press), 1961, pl. 3, from which this detail is taken.
453. MODERN TILT-HAMMER (SCHWANZHAMMER)
PLAN AND SIDE ELEVATION
[redrawn after Meringer, 1907, 285, fig. 10]
The cam block driving the hammer can be linked to a drive system
as sophisticated as one powered by steam, or as simple as one driven
by an animal on a treadmill.
smashing hammer (mazo) rises and falls. The rhythm or
beat of the stamp can be controlled from within the forge
by a second mechanism that augments or decreases the flow
of the water turning the wheel, as the varying nature of the
work requires (sketched roughly in Gonzáles's drawing).
The ore is smelted in the furnace by a fire fanned to intense
heat by means of air drafted into it by hydraulic action
(shown in the background of Gonzáles's sketch) and under
the beat of the hammer, converted into malleable iron.[522]
To watch this primordial mechanism in operation was
truly an awe-inspiring experience.
The valley of Compludo lies in the Montes de León some 23 km.
southeast of the city of Ponferrada. It is not shown on the Mapa Oficial
de Carreteras (scale 1:400,000) of Spain. To reach it one must travel from
Pontferrada to the mountain villages of Molinaseca, Riego de Ambroz and
Acebo; and from the latter in precipitous descent (only advisable to
motorists with experience in rough mountain travel) to the completely
isolated valley of Compludo, formed by the confluence of two narrow
mountain streams, the Miera and the Miruello which shed their water
into the Boeza River. The scenery is of outstanding beauty.
Florentino-Augustin Diez González, "Notitias de la vida políticosocial
de la España de San Fructuoso," in San Fructuoso y su tiempo,
1966, 7-57.
The drawing in Gonzáles's article, while portraying operational
details of the smithy of Compludo with great veracity, is not quite
realistic in its perspective. The trip-hammer is not longer, but 3 feet
shorter than the tree by which it is activated and the diameter of the
waterwheel is greater than appears on the drawing (cf. Horn, 1975, 245).
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