Fig.Thrusting Mechanism. Swinging Mechanism.
{Reversible engines, 2 steam cylinders}
[1].{each 6 × 8 ins.}
{Do., do 5 × 6 ins.}Chains attached to circle
} geared
[2].{Rack on dipper handle }to hoisting drum.
{actuated by friction clutch }
[3].{geared to hoisting drum.}
[5]. Reversible engine,}Wire ropes
2 steam cyls. 6 × 8 ins.}attached to circle
[6]. Long st'm cyl.,}and pist'n rods
piston rod at'ch'd to dipper}in long st'm cyl.
[7].{Reversible engine,}Reversible engine, 2 steam
{2 steam cyls. 5 × 6 ins.; }cylinders
[8].{5 × 6 ins.}except A, cylinders 7 × 9 ins.
{Chains on dipper handle actuated by }Chains attached to circle
[9].{friction clutch geared to }geared to
{hoisting drum.} hoisting drum
<————————Crane————————>
<—H'ght ab've—>
gr'nd or track.
Fig.
Post
material.
Material.		Working order,
ft.		Shipping order,
ft.
Radius,
ft.		Swinging
angle,
deg.		Capacity
of dipper,
cu. yds.
W'ht,
tons.
[1].{Wt. iron}Wt. iron261424240240
{A}"2414242401½30
{frame}"201420240120
[2].{Cast iron "2314202002½45
{" "1814182001¾40
{" "1814162001¼30
{" "161412200¾20
[3].{Wt. iron Wood2614202001½37
{" "241420200126
{" "201418200¾16
{" "181418200½12
[5].{Hollow wt. ir. Wt. iron191420200240
[6].{Cast iron "201420200240
[7].{Cast steel Steel2014192002½70
{Cast iron "2014192001¾45
{" "1814172001¼30
[8]. {" "16 Detach'd151851¼20
{" "15"15185¾18
[9].{" Wood20"202002½26
{" "16"182001¼15

Makers: 1 (Osgood): Osgood Dredge Co., Albany, N. Y. 2 (Thompson): Bucyrus Steam Shovel & Dredge Co., Bucyrus, O. 3, 4 (Barnhart): Marion Steam Shovel Ca., Marion, O. 5 (Victor): Toledo Foundry & Machine Co., Toledo, O. 6 (Clement): Industrial Works, Bay City, Mich. 7 (Giant) and 8 (Little Giant): Vulcan Iron Works Co., Toledo, O. 9 (Otis-Chapman): John Souther & Co., Boston, Mass.

Operation of Steam Shovels.—All movements of the steam shovel are controlled by two men, the engineman and the cranesman. The former is stationed near the engine, the latter on a small platform attached to the crane. The engineman directs the movements for raising and lowering the dipper, swinging it into position for unloading, and moving the machine forward or backward. The cranesman regulates the depth of the cut made by the dipper, releases it from the bank when full or near the top of the crane, and pulls the spring latch of the bottom door of the dipper when in position for unloading, thereby dumping its contents.

Fig. 14.—Spade for Cleaning Buckets.

These motions are shown in [Figs. 15] and [16]. Beginning with the dipper in the position shown at A, [Fig. 15], the engineman throws the hoisting drum into gear, and starting the engine pulls the dipper upward, the cranesman at the same time thrusting it forward, regulating the depth of the cut so that it will not stop the engine or tip up the rear end of the machine. When the dipper has reached the position B, near the top of the crane, the engineman throws the hoisting drum out of gear, and holds it in position with a foot brake; at the same time the cranesman by easing his foot brake, allows the dipper to fall back to the position C. The engineman then swings the dipper over the car or wagon, as shown in [Fig. 16], when the cranesman pulls the latch rope, thereby opening the bottom door of the dipper and dropping the contents. The engineman then swings the crane back again to the next cut, at the same time releasing his foot brake on the hoisting drum until the dipper has fallen to a point near the ground, as at D, [Fig. 15], where he holds it for an instant with the foot brake, then drops it by releasing the brake, while the cranesman (during this slight drop) regulates the length of the radius of the dipper handle by releasing his foot brake so as to bring the dipper into the position A again, and adjoining the last cut. While the dipper is being lowered, the bottom door closes and latches itself by its own weight, when all is ready again for another cut.