16 MARINE REVIEW. [February 20, a AN AMERICAN ELECTRIC GANTRY CRANE IN FRANCE. The methods of dealing with the storing and transportation of stocks of raw material by gantry or other cranes which have attained such vogue in the United States, and particularly in the lake region, is being intro- duced abroad by American companies. The Wellman-Seaver Engineering Co. of Cleveland, O., has recently erected a large gantry crane at the works of the Societe Anonyme de Micheville, France. The crane shown has a total cross-travel of trolley of nearly 200 ft. and the area commanded and whose length is the length of the track. ie structure is made as light as possible, consistent with strength, and t epee principle usual in American bridge building 1s adhered EO y this means all the members are in pure tension or compression, tsk es strength is ob- tained, considering the weight of material used. eign of the central structure is arranged so that the legs transmitting the weight to the track wheels are perpendicular, thus allowing a 60-ft, piece to be raised to a considerable elevation, and carried through as indicated in Fig. 3. The A WELLMAN-SEAVER BLECTRIC GANTRY CRANE IN FRANCE. by the crane can.be increased by prolonging the main tracks. A system of this character' is capable of indefinite expansion. The structure, as shown in Figs. 1 to 3, 1s supported on four vertical legs, each resting on a two-wheeled truck running on one rail. Thus one pair of legs is sup- ported 'by each rail, the distance apart of the legs in the direction of motion being unusually great--viz., 66 ft.--so that 60-ft. bars can be carried across without being turned round. The gauge of the rails is 52 ft., which insures. stability for the structure. The space between the rails can be utilized for. storage purposes, so that the area available is the whole of a rectangle whose breadth is the cross travel of the trolley--viz., 197 ft.-- Fig. 4. re rg B £ Oi 52;6° (16 m) (64 7660) too -- (Traverse cf TroUey 601) 196 10% -------- ELEVATION knee-joints are properly stayed in two directions, giving a thoroughly -- rigid structure, with an absence of redundant parts. On account of the long wheelbase, and in order to prevent the legs separating under the load, the two legs on each side are connected by a tension member, sup- ported by a track wheel in the center. Allowance for expansion and con-. traction of the girders is made as follows: The top side of each truck is fitted with a steel cup having an elongated hemispherical form, the major axis being placed across the direction of the track. A steel ball is placed in each cup, while the under side of the main supporting legs of the crane are fitted with steel hemispherical cups resting in turn on the tops of these ! ee j i | ' oat ele ee aaa ---- ---~ ------------~-- 80'O0 (24 383 m) -------------- PSTN TS TTT ae | | Me OE OOO Bo