Crane and method of building the same

In building a crane, the electrically actuated winches for raising and lowering the boom for moving a trolley along the boom, and for operating a hoist on the trolley are fixedly mounted in a standard transport container at a construction site remote from the assembly site for the crane. The power supply system for the winches, including a step-down transformer and switch gear, is similarly mounted in a second container remotely from the assembly site. The two containers and their contents are lifted to the top of the erected crane tower and permanently fastened there. The winch motors are connected to the switch gear by a plug-in, multi-conductor cable, and the winches are connected with the boom, the trolley, and the hoist by steel cables or other tension elements. Labor for installing the winches and the associated electrical system is reduced and damage to the relatively sensitive machinery during assembly with other crane elements is avoided.

This invention relates to a crane operated by means of electrically 
actuated winches, and to a method of building such a crane. 
It was common practice heretofore in building a heavyduty crane to erect a 
supporting tower, to pivotally fasten a boom to the tower, to install a 
trolley for movement longitudinally of the boom, individually to install 
the winches needed for operating the boom, the trolley, and a hoist 
depending from the trolley, and sequentially to install the electrical 
power supply system for the winches, typically a step-down transformer and 
switch gear remotely controlled by the crane operator from his cab on the 
trolley. Erection of the principal load-bearing, structural elements of 
the crane had to be completed before the installation of the winches and 
of the electrical equipment could begin, and it was relatively costly and 
time-consuming to install the operating machinery at the top of the crane 
tower. Damage to the machinery during transportation to the top of the 
tower and during installation could not always be prevented. 
It has now been found that the installation of the winches and of the 
associated power supply system can be simplified, and that the risk of 
damage to the machinery can be reduced sharply by permanently mounting the 
winches in one standardized transportion container and the electrical 
equipment in another container at the plants of the respective 
manufacturers, to transport the containers and their contents to the 
assembly site for the crane, to hoist the containers to the top of the 
crane tower, and there to fasten them, thereby installing the winches and 
their electrical power supply system in their respective housings in two 
relatively simple and very short steps. Cables or other tension elements 
may then be arranged between the winches and the boom, trolley, and hoist 
operated by the winches, and a single, multiconductor cable fastened to 
one container at the manufacturing plant may be plugged into an outlet on 
the other container to establish the necessary conductive connection 
between the winch motors and the power supply system. 
It is one of the important advantages of this method that the several 
component parts of the crane may be built at different places 
independently from each other except for final steps as simple as the 
installation of steel cables or the plugging-in of an electrical 
connection. The winch unit and the electrical unit may be transported to 
the assembly site at any convenient time and are protected there against 
accidental damage until the basic crane structure is ready to accept them. 
There is no labor-consuming waiting time, and the effort required for 
installing the several individual machines in their containers in the 
manufacturing plant and for mounting the containers on the crane tower is 
significantly smaller than that required in the conventional building 
method. 
It was customary heretofore to install the winches and associated 
electrical equipment in a common shed high on the crane. By separating the 
mechanical and electrical elements of the drive system, the load of the 
heavy equipment can be distributed more advantageously, and better use can 
be made of the available space. 
If more convenient, not all winches need be mounted in a single container, 
and not the entire electrical equipment need be housed in the second 
container. The step-down transformers employed for reducing the high 
voltage of a power line to the operating voltage of the winch motors may 
be so heavy that it is advantageous further to subdivide the power supply 
system between two containers respectively containing the transformer and 
the remotely controlled switch gear which directs the output current of 
the transformer to the individual winch motors. The winch for the load 
lifting cable of the hoist on the trolley is sometimes installed on the 
trolley itself, and the winch for moving the trolley along the boom may 
also be mounted there. However, two winches are normally needed for 
raising and lowering the boom, and at least some of the advantages of the 
invention are obtained if at least these two winches come to the crane 
assembly site permanently installed in their transportation container 
ready to be mounted on the crane tower together with their container which 
provides a permanent housing for them. 
Doors and windows are preferably provided in the containers before they are 
transported to the crane assembly site so as to permit observation and 
servicing of the machinery in each container after mounting on the crane. 
Large cranes are often assembled in places where equipment for handling 
standardized, large containers is available, as in harbors, railroad and 
truck terminals. It is advantageous to install the winches and the 
associated electrical equipment in containers meeting the dimensional 
standards established by the ISO (International Standardization 
Organization), and equipped with corner fittings meeting such standards so 
that they may be lifted to their installation site on the crane tower by 
means of machinery readily available at the site and equipped with 
engaging fittings matching the corner fittings on the containers.

Referring now to the drawing in detail, and initially to FIG. 1, there is 
seen a transporter crane of the type commonly employed at dockside for 
loading and unloading container ships. The crane has a skeleton tower 10, 
a boom 12 pivotally fastened to the top of the tower 10, and a rear beam 
horizontally aligned with the boom 12 in the illustrated normal position 
of the crane. The boom 12, the beam 14, and a horizontally aligned girder 
16 of the tower 10 carry a continuous track (not shown) for a trolley 18. 
As is better seen in FIG. 2, the tower includes two upright, rectangular 
frames 20 supported on respective undercarriages 22 whose wheels normally 
travel on rails, not shown. The frames 20 are rigidly connected by 
transverse connecting bars 24, 26 and reinforced by diagonal braces 28. 
The top of the tower 10 carries a platform 30 from which a head frame 32 
extends upward. 
The boom 12 and the beam 14 are normally held horizontal by tension rods 
34, 36 attached to the upper chords 38, 40 of the boom and beam and to the 
uppermost part 42 of the head frame 32. The rods 36 are rigid and 
permanently maintain the horizontal position of the beam 14. The rods 34 
each have two longitudinal sections connected by a hinge 46 so that they 
may be folded when the boom 12 is raised to clear the superstructure of 
ships at the dockside. The boom 12 may be raised and lowered on a pivot 44 
by steel cables 48 that are trained from a winch housing 80 over pulleys 
52 at the head frame part 42, pulleys 54 on the boom 12 near the fastened 
ends of the rods 34, and to a fastener, not shown in detail, at the head 
frame part 42. 
The trolley 18 travels on rails, not shown, along the boom 12, the girder 
16, and the beam 14. It may be moved by means of cable 56 whose two ends 
are fastened to the trolley, and are trained in a loop over pulleys 58, 60 
at the free end of the boom 12, pulleys 62 on the crane tower 10, through 
the winch housing 80, and pulleys 66, 68 at the free end of the boom 14. 
The trolley 18 carries the operator's cab 70 and a load carrier bar 72 from 
which a transporting container 74 is suspended as a load. The carrier 72 
may be raised or lowered by means of hoisting cables 76 which are trained 
over pulleys coaxial with the afore-mentioned pulleys 66, 68 at the free 
end of the boom 14 to the winch housing 80. 
As is shown in more detail in FIGS. 3 and 4, the housing 80 is a 
transporting container of normal ISO dimensions and provided with standard 
ISO corner fittings 81. It is mounted on a heavy bracket 82 between the 
frames 20 on the approximate level of the platform 30, and is elongated 
transversely to the direction of trolley travel at the rear of the tower 
10 remote from the boom 12. 
The hoisting winch 78 is longitudinally centered in the container 80. It 
includes a cable drum 84 whose axially terminal parts 86 carry groups of 
windings of the cables 76. The drum 84 is driven by two heavy electric 
motors 88 through speed-reducing gear transmissions 90, the motors and 
transmissions being mounted on pedestals 92 fixedly fastened to a suitably 
reinforced floor of the container 80. The cables 76 pass outward of the 
container 80 toward the free end of the beam 14 through non-illustrated 
openings. 
The winch 64 which moves the trolley 18 in its path is arranged between the 
motors 88 in the transverse plane of symmetry of the container 80 and of 
its contents. It includes a cable drum 94 driven by an electric motor 96 
through a transmission 98. Non-illustrated pedestals attach the motor, 
transmission, and cable drum 94 to the bottom of the container 80. The two 
ends of the cable 56 pass outward of the container 80 toward the ends of 
the boom 12 and of the beam 14 in opposite directions. 
Two winches 50 are arranged in the two longitudinal ends of the container 
80. Each has a cable drum 102, an electric motor 104, a gear transmission 
106, and necessary pedestals 108. The two cables 48 respectively wound on 
the drums 102 converge toward the center of the head frame part 42, and 
the axes of the drums 102 are inclined relative to each other to ensure a 
tangential relationship between the drum surfaces and the cables 46. 
The electric motors, speed-reducing transmissions, and cable drums are 
permanently mounted in the container 80 in their illustrated respective 
positions by means of pedestals at the plant of the winch manufacturer, 
and may actually carry the associated steel cables when transported in the 
container to the assembly site for the crane. Because they are fixedly 
fastened to the container, they cannot damage each other during any mishap 
in transit that cannot destroy the container. The container and its 
content may be stored at the assembly site until the tower 10 is ready to 
receive the winches and their housing. When the container is fastened to 
the bracket 82, only the cables need be attached to the respective 
operating elements of the crane, and power supplied to the motors of the 
winches. Only an insignificant portion of the total construction time for 
the crane is spent at the assembly site for mounting the winches in their 
operating positions. 
A door 110 in one of the longitudinal walls of the container 80 is secured 
in the closed position during transportation and hoisting of the 
container, and gives access to its interior for inspection and maintenance 
of the winch units. As is seen in FIG. 4, a rail 112 along the top wall of 
the container 80 supports a traveling hoist 114 and is installed 
simultaneously with the winch units. A roof 116 sloping toward one side of 
the container may be installed last to deflect rain water. If so desired, 
the top wall of the container may be raised on one side for the same 
purpose, and the resulting gaps between the top and side walls sealed by 
prepared wedges and strips. During transportation, the container 80 has 
the shape of a rectangular prism which facilitates handling. 
The power supply system for the winches is installed in another container 
118 as a permanent housing. The contents of the container 118 are 
assembled and installed at the electrical manufacturer's plant and 
protected by the container 118 during shipment and installation. The 
container 118 is mounted on a bracket 120 on the approximate level of the 
platform 30 and elongated transversely to the direction of trolley travel. 
The brackets 82, 120 are connected by a bridge 100. The container 118 is 
offset relative to the container 80 in an upward direction to clear the 
trolley driving cable 56. Both containers are installed on the tower 10 as 
far from the boom 12 as possible to serve as counterweights. 
The container 118 has two compartments 122, 124 separated by a narrow aisle 
126. A door 128 in the outer container wall leads into the aisle 126 from 
which the compartments may be entered through doors 130, 132. 
The compartment 122 houses high-voltage equipment in a cabinet 134 and a 
step-down transformer 136. The compartment 124 encloses a switchboard 138 
carrying switches for the winch motors which are remotely controlled from 
the cab 70 by the crane operator. The connections between the cabinet 134 
and an external high-voltage line have not been shown and are 
conventional. All winch energizing circuits in the container 80 terminate 
in a socket 140 on an outer wall of the container 80, and the 
corresponding circuit parts in the container 118 terminate in a socket 142 
on the wall of the container 118 opposite the socket 140 in the installed 
condition of the containers. The sockets are installed and wired in the 
respective manufacturers' plants. After installation of the containers, 
plugs at the ends of a short, multi-conductor cable 144 are inserted into 
the sockets 140, 142 to complete installation of the winches and of their 
electrical power supply system. The individual conductors linking the 
sockets 140, 142 to the winch motors and to respective relays on the 
switchboard 138 have not been illustrated, but will be obvious. 
As is evident from joint consideration of FIGS. 3 and 4, the containers 80, 
118 are equal in height, in width and differ in length only. A similar 
relationship between more than two containers can be maintained if the 
electrical equipment or the winches are not all installed in a common 
housing. 
It should be understood, of course, that the foregoing disclosure relates 
only to a preferred embodiment of the invention, and that it is intended 
to cover all changes and modifications of the example of the invention 
chosen for the purpose of the disclosure which do not constitute 
departures from the spirit and scope of the invention set forth in the 
appended claims.