Scientific American Supplement, No. 303, October 22, 1881

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Title: Scientific American Supplement, No. 303

       October 22, 1881

Author: Various

Posting Date: October 10, 2012 [EBook #8296]

Release Date: June, 2005

First Posted: July 4, 2003

Language: English

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SCIENTIFIC AMERICAN SUPPLEMENT NO. 303

NEW YORK, OCTOBER 22, 1881

Scientific American Supplement. Vol. XII, No. 303.

Scientific American established 1845

Scientific American Supplement, $5 a year.

Scientific American and Supplement, $7 a year.

NEW EIGHTY TON STEAM HAMMER AT THE SAINT CHAMOND WORKS

Ever since the improvements that have been introduced into the manufacture of steel, and especially into the erection of works for its production, have made it possible to obtain this metal in very large masses, it has necessarily been preferred to iron for all pieces of large dimensions, inasmuch as it possesses in the highest degree that homogeneousness and resistance which are so difficult to obtain in the latter metal. It has consequently been found necessary to construct engines sufficiently powerful to effect the forging of enormous ingots, as well as special furnaces for heating them and apparatus for manipulating and transporting them.

The greatest efforts in this direction have been made with a view to supplying the wants of heavy artillery and of naval constructions; and to these efforts is metallurgy indebted for the creation of establishments on a scale that no one would have dared a few years ago to think of. The forging mill which we are about to describe is one of those creations which is destined to remain for a long time yet very rare; and one which is fully able to respond, not only to all present exigencies, but also, as far as can be foreseen, to all those that may arise for a long period to come. The mill is constructed as a portion of the vast works that the Compagnie des Forges et Aciéries de la Marine own at Saint Chamond, and which embrace likewise a powerful steel works that furnishes, especially, large ingots exceeding 100 tons in weight.

The mill consists, altogether, of three hammers, located in the same room, and being of unequal powers in order to respond to different requirements. The largest of these hammers is of 80 tons weight, and the other two weigh respectively 35 and 28 tons. Each of them has a corresponding furnace for heating by gas, as well as cranes for maneuvering the ingots and the different engines. The general plan view in Fig. 4 shows the arrangement of the hammers, cranes, and furnaces in the millhouse.

FIG. A.--ELEVATION OF A HAMMER. FIG. B.--PROFILE VIEW

The gas generators which supply the gas-furnaces are located out of doors, as are the steam-generators. The ingots are brought from the steel factory, and the forged pieces are taken away, by special trucks running on a system of rails. We shall now give the most important details in regard to the different parts of the works.

The Mill-House--This consists of a central room, 262 feet long, 98 feet wide, and 68 feet in height, with two lean-to annexes of 16 feet each, making the total width 100 feet. The structure is wholly of metal, and is so arranged as to permit of advantage being taken of every foot of space under cover. For this purpose the system of construction without tie-beams, known as the De Dion type, has been adopted. Fig. 1 gives a general view of one of the trusses, and Fig. 5 shows some further details. The binding-rafters consist of four angle-irons connected by cross-bars of flat iron. The covering of corrugated galvanized iron rests directly upon the binding-rafters, the upper parts of which are covered with wood for the attachment of the corrugated metal. The spacing of these rafters is calculated according to the length of the sheets of corrugated iron, thus dispensing with the use of ordinary rafters, and making a roof which is at once very light and very durable, and consequently very economical. Rain falling on the roof flows into leaden gutters, from whence it is carried by leaders into a subterranean drain. The vertical walls of the structure are likewise of corrugated iron, and the general aspect of the building is very original and very satisfactory.

The 80 Ton Hammer--The three hammers, notwithstanding their difference in power, present similar arrangements, and scarcely vary except in dimensions. We shall confine ourselves here to a description of the 80 ton apparatus. This consists, in addition to the hammer, properly so called, of three cranes of 120 tons each, serving to maneuver the pieces to be forged, and of a fourth of 75 tons for maneuvering the working implements. These four cranes are arranged symmetrically around the hammer, and are supported at their upper extremity by metallic stays. Besides the foregoing there are three gas furnaces for heating the ingots. Figs. 1, 2, and 3 show the general arrangement of the apparatus.

Foundations of the Hammer and Composition of the Anvil-Bed--To obtain a foundation for the hammer an excavation was made to a depth of 26 feet until a bed of solid rock was reached, and upon this there was then spread a thick layer of beton, and upon this again there was placed a bed of dressed stones in the part that was to receive the anvil-stock and hammer.

On this base of dressed stones there was placed a bed formed of logs of heartwood of oak squaring 16 inches by 3 feet in height, standing upright, joined together very perfectly, and kept in close juxtaposition by a double band of iron straps joined by bolts. The object of this wooden bed was to deaden, in a great measure, the effect of the shock transmitted by the anvil-stock.

NEW EIGHTY-TON STEAM HAMMER AT THE ST CHAMOND WORKS.

FIG. 1.--TRANSVERSE SECTION.

FIG. 2.--PLAN.

FIG. 3.--PROFILE VIEW.

FIG. 4.--GENERAL PLAN OF THE FORGING MILL.

FIG. 5.--DETAILS OF THE TRUSSAND SUPPORT FOR THE CRANE.

The Anvil-Stock.--The anvil-stock, which is pyramidal in shape, and the total weight of which amounts to 500 tons, is composed of superposed courses, each formed of one or two blocks of cast iron. Each course and every contact was very carefully planed in order to make sure of a perfect fitting of the parts; and all the different blocks were connected by means of mortises, by hot bandaging, and by joints with key-pieces, in such a way as to effect a perfect solidity of the parts and to make the whole compact and impossible to get out of shape.

The anvil-stock was afterwards surrounded by a filling-in of masonry composed of rag-stones and a mortar made of cement and hydraulic lime. This masonry also forms the foundation for the standards of the hammer, and is capped with dressed stone to receive the bed-plates.

The Power-Hammer (Figs. A and B).--The power-hammer, properly so-called, consists, in addition to the hammer-head, of two standards to whose inner sides are bolted guides upon which slides the moving mass. The bed-plates of cast iron are 28 inches thick, and are independent of the anvil-stock. They are set into the bed of dressed stone capping the foundation, and are connected together by bars of iron and affixed to the masonry by foundation bolts. To these bedplates are affixed the standards by means of bolts and keys. The two standards are connected together by iron plates four inches in thickness, which are set into the metal and bolted to it so as to secure the utmost strength and solidity. The platform which connects the upper extremities of the standards supports the steam cylinder and the apparatus for distributing the steam. The latter consists of a throttle valve, twelve inches in diameter, and an eduction valve eighteen inches in diameter, the maneuvering of which is done by means of rods extending down to a platform upon which the engineman stands. This platform is so situated that all orders can be distinctly heard by the engineman, and so that he shall be protected from the heat radiated by the steel that is being forged. All the maneuvers of the hammers are effected with most wonderful facility and with the greatest precision.

The piston is of cast-steel, and the rod is of iron, 12 inches in diameter. The waste steam is carried out of the mill by a pipe, and, before being allowed to escape into the atmosphere, is directed into an expansion pipe which it penetrates from bottom to top. Here a portion of the water condenses and flows off, and the steam then escapes into the open air with a greatly diminished pressure. The object of this arrangement is to diminish to a considerable extent the shocks and disagreeable noise that would be produced by the direct escape of the steam at quite a high pressure and also to avoid the fall of condensed water.

The following are a few details regarding the construction of the hammer:

  Total height of foundations........... 26    ft.

  From the ground to the platform ...... 28     "

  Platform .............................. 3.25  "

  Height of cylinder.................... 21     "

                                         ________

      Total height...................... 78.25 ft.

  Weight of anvil-stock................ 500 tons.

  Weight of bed-plates................. 122  "

  Weight of standards.................. 270  "

  Weight of platform and cylinder...... 148  "

  Piston, valves, engineman's platform,

    hammer, etc........................ 160  "

                                        __________

      Total weight................... 1,200 tons.

  Weight of the hammer.................. 80 tons.

  Maximum fall.......................... 25.75 ft.

  Distance apart of the standards....... 21.6   "

  Width of hammer.......................  6     "

  Pressure of steam..................... 16 lb.

  Effective pressure to lift 80 tons....  7  "

Description of Figures.--A, the 80-ton hammer; B, B1, B2, cranes; C, C1, C2, supports of cranes; D, D1, D2, gas furnaces;