Spring Operated vs Motorised Cable Reeling Drums
— Which Suits Your Application?

The spring operated cable reeling drum is the simplest, most compact and most cost-effective type in the range. It uses a pre-tensioned clock-type spring — similar in principle to a clockwork spring mechanism — wound inside the drum hub. The spring stores energy as the cable is paid out and releases that energy to retract the cable automatically when the machine returns.

Mitool spring drums are built on sealed-for-life bearings, require no motor, no control panel and no electrical power supply to the drum drive itself. The standard slip ring assembly accommodates composite cables combining up to 200 Amps of power and control signals.

Ideal Applications

• Light-duty cranes and hoists with shorter travel runs
• Small transfer cars and material handling trolleys
• Workshop and maintenance area cable management
• Space-constrained installations where a motor drive is impractical
• Horizontal, catenary, vertical and DC magnet cable lay configurations

Limitations

• Spring tension is fixed — not adjustable to varying loads
• Suitable only for shorter travel distances; spring force diminishes with cable length
• Not suited for very heavy cables or high-speed machine travel

The slipringless variant operates on the same spring-driven retraction principle as the standard spring drum, but eliminates the slip ring assembly entirely. Instead of passing the electrical connection through a rotating central slip ring, the drum uses a specific geometric cable lay design that allows the cable to pay out and retract over a limited travel range without requiring rotating electrical contact at the drum centre.

This eliminates the most maintenance-intensive component in a standard cable drum — the carbon brush contacts on the slip ring — making this type particularly attractive in environments where reducing service frequency is a priority.

Ideal Applications

• Applications where slip ring brush maintenance is a pain point
• Clean-room, food processing or pharmaceutical environments sensitive to carbon brush dust
• Facilities where service access to the drum is difficult
• Shorter travel distances where slipringless geometry is geometrically viable

Limitations

• Restricted to a defined maximum travel distance determined by drum geometry
• Not suitable for long cable runs where slip ring contact is necessary

The sprocket or gear driven cable reeling drum takes a fundamentally different approach to cable management. Rather than using spring tension or motor torque to maintain constant cable tension, this type uses a chain-and-sprocket or gear drive mechanism connected either to the travelling machine's own drive system or to a dedicated synchronised motor.

The result is that the cable drum pays out and retracts at a speed that is precisely matched to the machine's travel speed — eliminating cable slack and cable over-tension simultaneously. The cable is wound and unwound in direct mechanical proportion to machine movement. This is the highest-precision cable management method available.

Ideal Applications

• High-speed EOT cranes where spring or torque-controlled tension cannot react fast enough
• Cranes with frequent acceleration and deceleration cycles
• Applications requiring zero cable slack at any travel speed
• Long-span gantry cranes where cable management precision is critical
• High-torque, heavy-duty drives where mechanical synchronisation is preferred over electronic control

Limitations

• Requires mechanical connection to the machine's drive system — more complex installation
• Chain and sprocket elements require periodic lubrication and inspection
• Less suitable for applications where the machine travel speed is highly variable or unpredictable

The torque controller motorised drum uses an electric motor paired with an electronic torque controller — a device that continuously monitors and adjusts the motor's output torque to maintain consistent, user-defined cable tension regardless of machine speed fluctuations or cable load changes.

As the machine accelerates, the torque controller increases motor output to prevent cable slack. As the machine decelerates or reverses, it modulates the torque to prevent over-tension and cable damage. The result is smooth, controlled cable management across the full speed range of the machine — without mechanical synchronisation hardware.

Ideal Applications

• Cranes and conveyors with variable travel speeds
• Transfer cars operating over medium-to-long distances
• Applications where electronic tension adjustment is preferred over mechanical sync
• Automated systems requiring feedback-controlled cable management
• Machines with frequent speed changes or complex duty cycles

Limitations

• Requires electrical power to the drum motor and control panel
• Electronic controller adds a component that may need calibration or replacement over time
• Higher cost than spring-driven alternatives

The stall torque motor operated drum is the workhorse of the range — the standard choice for heavy-duty continuous industrial operation on EOT cranes, gantry cranes and transfer cars in steel plants, ports and mines. It uses a specially designed motor that is intended to operate continuously at or near stall condition, delivering a constant, high torque output that keeps the cable permanently under controlled tension.

Unlike standard induction motors which would overheat if stalled, the stall torque motor is thermally rated for this operating condition. Mitool supplies this type in two motor variants:

• Squirrel Cage Motor Type — simpler construction, lower cost, direct-on-line starting, suitable for most standard heavy-duty crane applications.
• Slipring Motor Type — provides higher starting torque with external resistance control, smoother speed control, and is preferred for very long cable runs, high-inertia loads and applications requiring precise torque adjustment.

Ideal Applications

• EOT cranes — the primary cable drum choice for most crane installations
• Goliath and gantry cranes with long traversal distances
• Transfer cars in steel plants — reliable continuous-duty operation
• Ship-to-shore (STS) cranes and quay cranes — high current, long cable runs
• Mining equipment — coal cutters, shuttle cars, continuous miners

Squirrel Cage vs Slipring — When to Choose Each

• Choose Squirrel Cage for standard crane applications, shorter cable runs and where direct-on-line starting is acceptable
• Choose Slipring Motor for very long cable runs (100m+), heavy cables, high-inertia loads and applications requiring smooth torque ramp-up