Silage Clamp Safety: Hazard Identification and Working Safely Around Storage Infrastructure

Silage Clamp Safety: Hazard Identification and Working Safely Around Storage Infrastructure

Executive Summary

Silage clamps present several high-risk hazards that must be carefully managed to protect workers, livestock operations and infrastructure. The most serious risks include structural wall collapse, falls from height, atmospheric hazards beneath clamp covers and machinery operating close to open edges.

Key safety priorities include:

·         Inspecting clamp walls regularly for structural deterioration or effluent damage

·         Preventing over-filling and surcharge loading that increases pressure on walls

·         Installing effective edge protection and safe access systems to reduce fall risk

·         Avoiding lone working and planning rescue procedures for work at height

·         Eliminating high-risk practices such as crawling under silage sheets or lifting personnel in buckets

A systematic approach combining sound engineering design, safe working practices and regular inspection is essential to ensure silage clamps remain safe operating environments.

Silage Clamp Safety: Hazard Identification and Working Safely Around Storage

Silage clamps are critical infrastructure on livestock farms, but they are also among the most hazardous working environments in agriculture. Heavy machinery, high retaining walls, compacted forage and plastic sheeting create conditions where structural failure, falls from height and atmospheric hazards can occur simultaneously.

Falls from height remain one of the leading causes of fatal accidents in agriculture, frequently involving farm structures such as silage clamps. With many clamps exceeding 3–4 metres in height, a fall from the clamp edge can result in severe or fatal injury.

Alongside fall hazards, poorly designed or overloaded clamps may suffer structural failure, while sealed silage covers can trap gases capable of causing asphyxiation.

Safe clamp operation therefore depends on:

·         Preventing wall collapse

·         Managing fall-from-height risks

·         Implementing effective worker protection systems

This article outlines the principal risks associated with silage clamps and the engineering and operational controls required to reduce them.

What is Silage Clamp Safety?

Silage clamp safety refers to the design, management and operational controls used to prevent accidents around silage storage structures.

The primary hazards include structural wall collapse, falls from height, atmospheric hazards beneath silage covers and machinery operating near open clamp edges.

Effective silage clamp safety relies on a combination of:

·         structurally sound clamp walls designed for silage loading pressures

·         safe working practices during filling, sheeting and feed-out operations

·         edge protection and safe access systems to prevent falls

·         procedures that protect workers from gas exposure and machinery hazards

By addressing these risks through proper design, inspection and safe systems of work, farms and anaerobic digestion sites can significantly reduce the likelihood of serious accidents around silage storage areas.

Key Hazards Around Silage Clamps

Several hazards commonly arise during silage clamp construction, filling and operation.

Wall collapse

Over-filling, poor construction, corrosion of reinforcement, effluent attack at the wall base and vehicle impact can weaken the structure and, in severe cases, lead to sudden wall failure.

Falls from height

Open edges, unstable silage shoulders, wet or icy clamp sheeting and improvised access methods can lead to falls from heights exceeding 3 metres, often with life-changing consequences.

Machinery and vehicle risks

Tractors and loading equipment can drop from open edges or roll on steep shoulders, particularly where there is more than 600 mm of vertical drop or poor visibility of the clamp edge.

Entrapment and asphyxiation

Crawling beneath silage sheets exposes workers to low-oxygen atmospheres and potentially lethal fermentation gases trapped beneath clamp covers.

Understanding these hazards is the first step in designing safe working practices around silage clamps.

Structural Failure and Wall Collapse

Concrete silage clamp walls are designed to retain large volumes of compacted forage, often exceeding 600–800 kg per cubic metre depending on crop type and compaction level. The lateral pressure exerted by this material can be considerable.

Structural checks

Before filling and periodically throughout the year, operators should:

·         Inspect wall panels, joints, sealant and foundations for cracks, spalling concrete, corrosion or movement

·         Check external faces and backfilled areas for bulging, settlement or erosion that may indicate overstress or loss of support

·         Look for effluent leaks or damp staining at joints or the wall–floor junction

If significant defects are identified, filling should stop and competent engineering advice should be sought before the clamp is used again.

Load management

Even well-designed walls can be pushed beyond their structural capacity by poor loading practices.

Operators should:

·         Avoid surcharging walls by over-filling the clamp or building shoulders significantly higher than the wall

·         Keep additional materials such as soil or feed at least 3 metres away from the wall base, unless the structure has been designed to support additional loads

·         Maintain a sensible silage profile so material above wall height slopes back rather than pressing directly against the wall

Design choices for safer walls

Good structural design can significantly reduce collapse risk.

Key considerations include:

·         Using appropriate wall thickness, reinforcement and foundations for the expected loading

·         Considering sloping walls or earth banks where practical to reduce vehicle impact and allow better compaction near edges

·         Designing effective effluent drainage to prevent standing liquid at the wall base

Silage effluent is particularly aggressive. It can have a biochemical oxygen demand up to 200 times greater than raw sewage, reflecting the intensity of the fermentation process.

Over time this acidic liquid can attack concrete, causing cracking, reinforcement exposure and structural weakening.

If structural integrity is compromised, collapse may release several tonnes of compacted forage within seconds, creating immediate risk to workers and machinery.

Managing Falls from Height

Falls from height remain the most common cause of serious injury associated with silage clamp operations.

Guardrails and edge protection

Concrete-walled clamps should incorporate safety-sighting rails designed to act as effective edge protection.

Typical systems include:

·         A top rail approximately 1.1 m above the working surface

·         An intermediate rail to prevent people passing beneath

·         A toe board where there is risk of objects slipping from the edge

These systems are designed to prevent people from falling. They are not intended to function as crash barriers for machinery.

Safe working platforms

Work at height regulations and industry best practice expect:

·         Secure guarded platforms for sheeting, inspection and maintenance

·         Use of purpose-built man platforms where access is provided by lifting equipment

·         Avoidance of improvised methods such as standing in loader buckets or on machinery

Where fixed guarding cannot be installed, work-restraint systems such as harnesses may be used to prevent workers reaching open edges.

Conditions and planning

Weather and site conditions significantly affect clamp safety.

Operators should:

·         Avoid sheeting or de-sheeting during strong winds, heavy rain or poor visibility

·         Avoid working on icy plastic sheeting

·         Avoid unstable shoulders or freshly tipped silage that has not been consolidated

Harvest schedules should allow adequate time so staff are not pressured into taking shortcuts at height.

Fall Detection and Rescue

Even with strong preventive measures, some residual fall risk may remain.

Avoid lone working

Work at height on silage clamps should never be carried out alone.

At least two competent people should be present during tasks such as sheeting, inspection or working on high shoulders. Reliable communication should be available so emergency services can be contacted quickly.

Fall-arrest systems

Where edge protection cannot be engineered, fall-arrest systems may be required.

These typically include:

·         Full body harnesses

·         Shock-absorbing lanyards

·         Tested anchor points

Equipment should be inspected regularly and users must be trained in correct operation.

Rescue planning

Fall-arrest systems prevent ground impact but introduce the risk of suspension trauma.

For this reason, a rescue plan must be established before such systems are used. The plan should clearly define how a suspended worker will be recovered quickly and safely.

Atmospheric Hazards Beneath Silage Covers

Silage fermentation produces gases including:

·         Carbon dioxide

·         Nitrogen dioxide

·         Carbon monoxide

These gases can accumulate beneath plastic sheeting.

Fermentation also consumes oxygen, meaning the atmosphere beneath a sealed cover may become oxygen-deficient. Workers entering this space may experience rapid unconsciousness or fatal asphyxiation.

For this reason, workers should never crawl beneath silage sheets.

Machinery and Vehicle Risks

Silage clamp operations rely heavily on tractors, loaders and telehandlers for filling and compaction.

Working machinery near elevated clamp edges introduces risks including:

·         Vehicles dropping from clamp edges

·         Rollovers on steep silage slopes

·         Collisions between machinery and pedestrians

·         Impact damage to clamp walls

Drops greater than approximately 600 mm significantly increase the likelihood of vehicle instability, particularly where edge visibility is poor.

During busy silage operations, clear traffic management should separate people and machinery wherever possible.

Safe Systems of Work

Engineering controls must be supported by clear operational procedures.

Risk assessments

Farm operators should carry out documented risk assessments for tasks including:

·         Filling and compaction

·         Sheeting and sealing

·         Removing clamp covers

·         Silage sampling

·         Feed-out operations

Each activity should identify hazards and define safe working methods.

Eliminating high-risk practices

Certain practices repeatedly appear in accident investigations and should be eliminated entirely:

·         Crawling beneath silage sheets

·         Standing on unstable silage faces

·         Using loader buckets to lift personnel

·         Allowing children near clamp areas

Removing these practices significantly reduces the likelihood of serious incidents.

Training and competence

Workers and contractors operating around clamps should be trained in safe access procedures, fall protection and emergency response.

Clear supervision and competence requirements help ensure safe working practices are followed during busy harvest periods.

Personal protective equipment

Appropriate PPE supports safe working conditions around silage clamps.

Recommended equipment includes:

·         High-visibility clothing

·         Safety helmets

·         Protective gloves

·         Slip-resistant safety footwear

High-visibility clothing is particularly important where multiple machines operate in confined areas.

Silage Clamp Safety Checklist

Before silage operations begin, operators should confirm the following:

Structural integrity

·         Clamp walls inspected for cracks, corrosion or movement

·         Effluent drainage functioning correctly

Working at height

·         Edge protection installed and secure

·         Safe access platforms available

Operational controls

·         Traffic management plan in place

·         No lone working on clamps

Worker safety

·         PPE available and worn

·         Staff trained in emergency procedures

Designing and Retrofitting Safer Clamps

Many existing clamps were constructed decades ago and may not meet modern safety expectations.

Retrofitting improvements can significantly reduce risk.

Examples include:

·         Fixed access stairs and guarded work platforms

·         Modular edge protection systems compatible with existing clamp walls

·         Improved vehicle guidance systems

·         Redesigned traffic layouts that separate pedestrians from machinery

Safety-sighting rails should improve edge visibility and protect workers but should not be relied upon to stop vehicles.

Ongoing Review and Upgrade

Silage clamp safety should be reviewed regularly.

Operators should:

·         Review risk assessments annually and after incidents

·         Inspect rails, platforms and access equipment for damage

·         Upgrade older clamps that no longer meet current work-at-height expectations

Regular review ensures safety systems remain effective as infrastructure ages and operational demands change.

How ARK Can Help

Modern clamp design, quality construction and well-engineered safety systems make it easier for farmers and AD operators to operate safely while maintaining efficient silage storage.

ARK supports safer clamp infrastructure through:

·         Designing clamps with appropriate wall strength, drainage and edge protection

·         Advising on retrofitting safety rails, access systems and improved traffic layouts

·         Providing guidance to help customers implement safe systems of work around silage clamps

Whether you are planning a new clamp or reviewing the safety of an existing installation, taking a proactive approach to design and infrastructure can significantly reduce operational risk.

ARK works with farms, contractors and AD operators to design, build and upgrade silage clamps that meet modern safety expectations while supporting efficient silage management.

If you would like to discuss a new project or explore safety improvements to an existing clamp, contact the ARK team for technical advice and guidance.