Crandall
8 Link Chain Wheels
Crandall
10 Link Chain Wheels
Crandall
Bearings
|
Crandall
hauling machinery for a new or rebuilt railway dry dock generally
consists of the components illustrated in the diagram shown above.
An entire machine package can be custom designed or selected to accommodate
existing conditions such as a particular chain size, number of chains
(single, two, four or six), hauling speed, and space limitations.
We are available to quote on developing and supplying a complete hauling
machine assembly to suit your needs, including foundation details
for its installation. Crandall also supplies individual components
such as chain wheels, bearings, gears, pinions, reduction units, motors
and controls which may be suitable as substitute parts for existing
machines.
Crandall chain wheels are cast from high strength alloyed steel,
heat-treated and ground to template to fit Crandall open-link hauling
chains.
Our wheels have four, five and, in special cases, six teeth (or
sides). They are designated as eight, ten and twelve-link wheels,
since one revolution of a chain wheel results in chain movement
equal to twice the number of teeth on the wheel.
Crandall chain wheels provide a positive hold on the chain at
all times and have excellent wearability due to their hardness.
Crandall can
furnish wheels ground to template; completely machined to accept
existing shaft dimensions, or as rough unfinished castings for in-house
machining.
Capacity Increase
Occasionally, shipyards
ask if it is possible to increase the capacity of their existing railway
dry dock. Quite often, this can be easily accomplished at a minimal
cost by one of the following methods:
- Increase
the chain size and substitute eight-link chain wheels for ten-link
chain wheels.
- Use special
short pitch hauling chain one size larger on the existing chain
wheels.
- Replace existing
iron gears with steel gears having a greater ratio to accommodate
heavier chain wheels and chain.
Electrification
of Old Machines
The reliability
of modern electric motors and their ability to tolerate overload in
many cases makes them most desirable for hauling ships out of the
water. We can supply wound rotor motors, complete with controls, to
suit your needs for new installations or for upgrading of existing
docks. This may involve some gearing change in cases where the motor
speed far exceeds that of the steam or other existing power source.
The size and horsepower of the motor depend on the load, the gradient
and hauling speed desired. Normally, we try to achieve one vertical
foot of lift per minute. Inquiries regarding electrification should
indicate all the characteristics of the power available at the site
(i.e., voltage, KVA, phase and cycle), plus data on the machine gearing
and sprocket size. Generally, motors are provided with automatic brakes
mounted on the motor shaft extension.
|