What Is a Wire Rope Isolator?

A wire rope isolator is a passive shock and vibration control device made from stainless-steel wire rope secured between two mounting bars. One mounting bar connects to the protected equipment, while the other connects to the supporting structure.

When the equipment moves, the rope loops bend, compress and roll. Relative movement between the individual wires creates internal friction, which dissipates part of the mechanical energy.

This structure provides both spring action and damping without relying on rubber as the primary energy-absorbing element. Wire rope isolators are therefore often considered for equipment exposed to repeated shock, wide temperature changes, moisture, dust, oil or corrosive environments.

HOAN’s catalogue includes multiple wire rope isolator families and provides dimensional information, mounting options and performance curves for different loading directions.

When Should You Use a Wire Rope Isolator?

Wire rope isolators are commonly evaluated for:

• Communication and electrical cabinets
• Vehicle-mounted electronic equipment
• Shipboard instruments and control units
• Railway communication equipment
• UAV cameras and compact payloads
• Outdoor monitoring systems
• Industrial control equipment
• Transportation containers
• Precision measuring instruments

They are particularly useful when the equipment experiences both continuous vibration and occasional mechanical shock.

However, they are not automatically the best solution for every project. Rubber mounts may be more economical for light-duty equipment operating in controlled environments. Spring isolators may be more suitable for certain low-frequency rotating machines. A wire rope isolator should therefore be selected according to the complete operating condition.

Seven-Step Wire Rope Isolator Selection Process

Step 1: Confirm the total installed weight

Include the cabinet, internal modules, batteries, brackets, cables and accessories. Do not use the empty enclosure weight.

Step 2: Determine load distribution

Identify the center of gravity and estimate the load carried by each mounting position.

Step 3: Define vibration and shock conditions

Provide frequency, acceleration, displacement, shock peak, pulse duration and excitation direction.

Step 4: Choose the mounting orientation

Confirm whether the isolator will operate in compression, shear or an angled configuration.

Step 5: Check available movement

Make sure the isolator, cables and equipment have enough clearance during shock displacement.

Step 6: Review model-specific data

Compare load-deflection curves, maximum deflection, vibration stiffness and shock stiffness in the actual loading direction.

Step 7: Confirm the selection

For important equipment, the final model should be reviewed by the isolator supplier and verified against the required vibration or shock test.

Calculate the Real Load per Isolator

The basic average load calculation is:

For example, a 100 kg cabinet supported by four isolators produces a theoretical average load of 25 kg per isolator.

This is only an initial estimate.

If batteries or power modules are concentrated at the rear of the cabinet, the rear mounts may carry more than 25 kg. Dynamic loading, shock direction, cable forces and equipment modifications may also change the real load.

The maximum static load shown in a catalogue should not automatically be treated as the preferred continuous working load. A practical selection must retain enough capacity for load imbalance and dynamic movement.

HOAN’s JGX catalogue tables separate maximum static load, maximum deflection, vibration stiffness and shock stiffness. They also provide different values for compression, 45-degree compression/roll and shear/roll operation.

Why Mounting Direction Matters

A wire rope isolator does not have identical stiffness and load capacity in every direction.

Compression

The equipment pushes the two mounting bars toward each other. This arrangement is commonly used beneath cabinets and machine bases.

Shear or roll

The mounting bars move laterally relative to one another. This can occur in wall-mounted, suspended or side-loaded systems.

Angled loading

A 45-degree installation combines compression and roll behavior and may be used where movement is expected in more than one direction.

HOAN’s catalogue presents separate curves for these loading directions. A model chosen from compression data should not be assumed to provide the same performance in shear.

The inquiry drawing should clearly show:

• Equipment side
• Foundation side
• Gravity direction
• Main shock direction
• Mounting-hole arrangement
• Available movement around the rope loops

Define the Vibration Requirement

A statement such as “the equipment vibrates heavily” is not enough for model selection.

Useful vibration data includes:

• Frequency range
• Dominant operating frequency
• Acceleration level
• Displacement amplitude
• Sine sweep profile
• Random vibration PSD
• Test duration
• Excitation direction

The isolator and supported equipment form a dynamic system with their own natural frequency. When the excitation frequency is close to that natural frequency, vibration may be amplified.

This means that a softer isolator is not always better, and a stiffer isolator is not automatically safer. Excessive stiffness may transmit more vibration, while insufficient stiffness may allow excessive motion or instability.

Define Shock Separately from Vibration

Shock selection should include:

• Peak acceleration
• Pulse duration
• Pulse shape
• Number of shocks
• Shock direction
• Equipment fragility limit
• Available stopping distance

For example, “30 g shock” is incomplete without the pulse duration. Two shocks with the same peak acceleration can transfer different energy when their pulse durations differ.

The GH and GX product tables in the HOAN catalogue list representative conditions such as resonance magnification, vibration isolation efficiency, working temperature and a stated shock condition. These values apply to the listed series and should not be applied automatically to every model.

HOAN Wire Rope Isolator Series Comparison

The JGX series is the broadest wire rope isolator family presented in the catalogue, while the GR range includes compact configurations for camera and small-payload applications.

Check Maximum Deflection and Installation Clearance

Wire rope isolators absorb energy partly by allowing controlled movement. If surrounding components restrict that movement, the protection performance may be reduced.

Check clearance around:

• Wire rope loops
• Mounting bolts and washers
• Equipment corners
• Adjacent structures
• Electrical cables
• Cooling pipes
• Connectors and harnesses
• Mechanical restraints

Cables and pipes should not create a rigid path that bypasses the isolators. The available installation space must also be compared with the maximum expected deflection, not only the product’s static dimensions.

Materials and Operating Environment

The HOAN catalogue identifies stainless-steel wire rope and lists stainless steel or aluminum alloy as mounting-bar options for several series.

Before ordering, confirm:

• Wire rope material
• Mounting-bar material
• Surface treatment
• Fastener material
• Minimum and maximum temperature
• Salt-spray exposure
• Humidity and condensation
• Oil or solvent contact
• Outdoor exposure
• Maintenance requirements

For marine or coastal applications, review the complete installation rather than the wire rope alone. Mounting bars, fasteners and adjoining metal structures can all affect corrosion performance.

When a Wire Rope Isolator May Not Be the Best Choice

A different isolation method may be more suitable when:

• The project is highly cost-sensitive and operates in a mild environment
• The equipment permits almost no relative displacement
• Only minor high-frequency vibration is present
• The system requires an extremely low natural frequency
• Available space cannot accommodate isolator movement
• A high center of gravity creates unacceptable instability
• The load is too low to place the selected isolator in an effective working range

Objective selection is more reliable than assuming one isolator type is superior in every application.

Common Wire Rope Isolator Buying Mistakes

Common errors include:

• Selecting from equipment weight alone
• Using the empty enclosure weight
• Ignoring the center of gravity
• Treating maximum static load as working load
• Using compression data for a shear installation
• Providing shock acceleration without pulse duration
• Ignoring maximum movement
• Allowing cables to bypass the isolation system
• Assuming a larger or stiffer model is always safer
• Ordering the wrong thread or countersunk-hole configuration

HOAN’s catalogue shows several mounting-interface options, including combinations of through holes, threaded holes and countersunk holes. These details should be confirmed before placing the order.

Wire Rope Isolator Inquiry Checklist

Send the following information for preliminary model selection:

• Equipment name and application
• Total installed weight
• Equipment dimensions
• Center-of-gravity position
• Number and location of isolators
• Installation drawing
• Main loading direction
• Vibration frequency and acceleration
• Shock peak, duration and pulse shape
• Maximum allowable movement
• Operating temperature
• Environmental conditions
• Mounting-hole requirements
• Applicable test standards
• Required quantity and delivery schedule

A photograph can help explain the application, but a dimensioned installation drawing and operating conditions are more useful for engineering selection.

Request a Wire Rope Isolator Recommendation

Selecting the correct isolator requires more than matching equipment weight with a catalogue value.

Send HOAN your equipment weight, dimensions, center of gravity, mounting direction, vibration profile, shock requirements and available installation space. Our team can review the application and recommend a suitable wire rope isolator model for further evaluation.

FAQ

How many wire rope isolators do I need?

Four isolators are common for rectangular equipment, but the correct quantity depends on equipment size, weight distribution, center of gravity, structural stiffness and shock direction. Large cabinets may require six or more mounting points.

Can I select an isolator using equipment weight only?

No. Weight is only the starting point. Mounting direction, vibration frequency, shock pulse, available displacement, center of gravity and operating environment must also be considered.

Is maximum static load the recommended working load?

Not necessarily. Maximum static load is a catalogue limit under specified conditions. The selected working point should leave capacity for load imbalance, dynamic forces and shock movement.

Does mounting direction affect performance?

Yes. Compression, shear and angled loading can produce different load capacities, deflections and stiffness values. Use the performance data for the actual installation direction.

Can wire rope isolators be used outdoors?

They can be suitable for outdoor equipment, but the wire rope, mounting bars, fasteners, surface treatment, temperature range and corrosion exposure must all be reviewed.

Do wire rope isolators require maintenance?

They generally do not require the same maintenance as lubricated mechanical systems, but periodic inspection of the rope, mounting bars, bolts, corrosion condition and surrounding clearance is still recommended.

Can the mounting holes be customized?

Customization may be possible depending on the model, order quantity, material and interface requirements. Provide a detailed mounting drawing when requesting a quotation.

What should I send for model selection?