The Importance of Safety Interlocking in the Waste and Recycling Industry


High resolution photo:
Caption: A Fortress DMSK2 interlock on a gate, with a metal recycling facility in the background

A metal recycling firm was recently fined £35,000 by the HSE after a worker’s hands were severed while cutting metal strips on an industrial baler.

Industrial balers are used to compress recyclable material into stackable, manageable pieces before they are sent for reprocessing. This type of machinery should be extensively guarded and interlocked to ensure operators can only come into contact with the machine when the power has been isolated.

Following an HSE investigation the company in question was served an enforcement notice to cease the inherently unsafe process. The HSE found that the firm was unable to produce evidence that it had carried out a proper assessment of the risks involved in the use of a baler for cutting metal strips.

Although the employee had been taught how to operate the machine by ‘practical demonstration and supervision’, he had not seen or read the operating manual. The immediate cause of the accident was blamed on an inherently unsafe system of work, which was contrary to the manufacturer’s operating instructions and the safety instructions on the machine.

Waste and recycling – an inherently dangerous industry
Human error is always a possibility when operating dangerous machinery and it is the employer’s responsibility to guarantee the safety of its workers by installing adequate safety systems are in place.

Waste and recycling is a particularly high-risk industry. While it accounts for only about 0.5% of the employees in Britain, it accounts for 2.6% of reported injuries to employees, according to the HSE.

Ensuring compliance
In reality there is no reason for many of these injuries to keep occurring – the technology to safeguard workers on all machinery in waste recycling plant already exists. It is also mandatory for Machine manufacturers to comply with the Machinery Directive and other essential health and safety requirements.
One way of demonstrating compliance is by applying the harmonised standards of the. Directive.
In this case, a risk assessment by the metal recycling firm, complying with the requirements of the Provision and Use of Work Equipment Regulations 1998 (PUWER), should have identified safety procedures as being inadequate, with further safety equipment added complying with EN ISO 13849 and EN ISO 14119 standards.

Safety interlocking
One of the most effective ways to ensure worker safety in the waste and recycling sector is machine guarding. However, machine guarding alone isn’t enough to ensure safe working practices, as there is nothing to prevent workers from using designated access points to gain entry into live machinery. It is usually necessary to include safety interlocking into the process

Safety interlocks prevent access to powered machinery and stop inadvertent start-ups while personnel are inside a dangerous area. They do this by forcing operators to isolate the power before anyone gains access. Maximum protection is afforded by incorporating keys into an interlocking system – this forces workers to retain a personal safety key with them while working inside the machine, so power can only be restarted once all the keys have been returned to their original positions. In this way, operators control their own safety.

There is a common misconception that safety interlocking is an unnecessary expense, so some companies implement cheaper alternatives, such as a Lock Out/Tag Out (LO/TO) procedures.

While LO/TO, when properly implemented, provides a minimum level of protection, one of its weakness lies in the inevitable failure of workers to always follow instructions. LO/TO’s greatest weakness is therefore interlocking’s greatest asset: a well-designed safety interlocking system forces operators to follow a pre-determined, undefeatable sequence which they cannot deviate from. This compensates for any possible worker error while successfully safeguarding against potential hazards.

While clearly requiring more investment than LO-TO, safety interlocking offers peace of mind to employers that their workers are safe. Any additional time and cost in the design process is likely to be significantly smaller than the potential financial burden associated with the risk of future litigation.

Added to that, electromechanical safety switches can be a very cost-effective solution that can be wired directly to guard doors, allowing isolation to occur at the point of entry. In addition, these safety gate switches are installed so that they can be easily monitored and not easily defeated.

Until we eliminate the ideology that safety is an unnecessary expense in the waste and recycling industry, easily avoidable industrial accidents will continue to happen.

Comments Off on The Importance of Safety Interlocking in the Waste and Recycling Industry

Fortress and Troax Partner Up for Perimeter Guarding

Fortress safety interlocks pair with Troax mesh doors to form a simple, modular and tough machine guarding system
Erlanger, Ky. (July 15, 2015) –Fortress Interlocks and Troax have combined forces, creating a new perimeter guarding system to prevent access to dangerous machinery. The system utilizes a unique new bracket that fits Fortress interlocks to Troax perimeter guarding panels, enabling the safeguarding of virtually any machinery installation.

A Troax mesh panel fitted with a Fortress safety interlock.

A Troax mesh panel fitted with a Fortress safety interlock.

Designed for both end users and OEMs, the easy-to-install brackets are 100% compatible with Fortress’ modular amGardpro and tGard ranges of modular interlocks and Troax’s modular mesh panels. Whatever configuration of interlocks or mesh panels is specified first, the brackets will always fit, making the system ideal for both new construction and retrofitting. The amGardpro and tGard interlocks combine solenoid or non-solenoid safety switches with full control functionality in one device, allowing use across a wide range of industrial applications.

The durable system is also impact resistant to 1600 joule. It has been tested in multiple configurations to ensure that the interlocks remain intact after significant force. While the mesh doors deform to absorb the shock, the safety switches remain intact and functional, ready to be installed on a replacement door. See footage of the impact testing at and

For more information about how the Fortress Troax system can be integrated into specific applications, visit, email or call 859-578-2390.

About Fortress:
Fortress Interlocks is a market leader in the design and manufacture of safety access & control systems for an extremely wide range of industries, from power generation to steel production, automotive manufacturing, food and beverage production and product recycling. With an extensive global distribution network, the company supplies industries throughout the world and has been at the forefront of safety interlocking for over forty years. A member of the international Halma Group, Fortress has its US headquarters in Erlanger, Kentucky.

About Troax:
Troax is the world leader in modular mesh panels for machine guarding, materials handling and storage applications. The company has production facilities in Sweden and the UK, offices in 17 countries and a worldwide distribution network.

Both companies are members of the Machine Safety Alliance and meet the requirements of Machinery Directive 2006/42/EC.

Comments (0) »

Fortress Interlocks and Troax Mesh Doors up to the Impact Challenge!

A dramatic impact test on the Fortress Interlocks amGardpro interlock fitted to a Troax St30 mesh door has been captured on video.

(Caption: Impact test with Fortress amGardpro interlock and Troax ST30 mesh door. Watch the video here)

In the test, the mesh door and interlock were subjected to a powerful impact of 1600 joule. The door was slightly deformed by the impact but no parts came loose and it was held firmly in place by the interlock. The interlock was also fully functional after the test.

“This test really demonstrates how robust our interlocks are,” says Fortress’ Managing Director Rob Lewis. Our locks really are ‘fit and forget’ for a huge range of industrial applications in the toughest environments.”

Fortress and Troax recently combined forces to create a new perimeter guarding system to protect workers from dangerous machinery. By utilising a unique new bracket which fits Fortress interlocks to Troax perimeter guarding panels and gates, it enables the safeguarding of virtually any machinery installation.

Very easy to install for both end users and OEMs, the brackets are 100% compatible with Fortress’ modular amGardpro and tGard ranges of modular interlocks and Troax’s modular mesh panels. This means that whatever configuration of interlocks or mesh panels is specified first, the brackets will always fit. Both the amGardpro and tGard interlocks combine solenoid or non-solenoid safety switches with full control functionality in one device, allowing their use across a vast array of industrial applications.

Comments (0) »

Do you need to design safety gate switches?

Then try out Fortress Interlock’s amGard pro product configurator!

amGard pro is Fortress Interlocks’ modular interlock range for safety gate switches for heavy duty applications. Its unique modular construction (made up of actuators, head modules, adaptors, electrical switches/locks and optional push-button pods) allows easy configuration for virtually any safeguarding application up to SIL3 (EN/IEC 60261) Category 4 and PLe (EN/ISO 13849-1).

Fortress Interlocks amGard pro

Fortress Interlocks amGard pro

To assist with amGard pro configuration Fortress now has a Product Configurator on its website. By following the simple steps it allows the user configure a complete unit, with part numbers, an image, a 2D drawing and a 3D model.

The amGard pro offers a range of fully integrated safety interlocks, including solenoid and non-solenoid safety switches with many additional options including key control modules, emergency release, redundant sensors, lock out/tag out and push buttons, e-stops and indication lights for enhanced functionality. Its robust construction also makes it ideal for industrial applications when safety, strength and reliability are of paramount importance.

It replaces all adaptions normally fitted within a guarding system, so additional hardware like door catches, actuators, closing mechanisms, internal release mechanisms, key functions including authorised access and deadlocks are no longer needed. All of these separate functions can be incorporated into amGard pro configurations, resulting in the most flexible safety interlock solution available for today’s industrial environment.

Key features of the amGard pro include:

Enhanced machine control functionality

  • Integrated pushbutton control in a single unit
  • Up to three illuminated pushbuttons/lamps/selector switches, plus one e-stop
  • Up to 10 safety/access keys in one configuration

Improved Standards Compliance

  • Complies with all new and forthcoming machine safety standards
  • Integrated redundancy sensor (with coding options)
  • Single motion emergency escape release regardless of solenoid or trapped key locking mechanism

Enhanced strength

  • Stainless steel heads with mounting point, increasing retention force to 10KN
  • Standardisation and enhancement of all anti-vibration features
  • Improved weather resistance


Comments (0) »

Case Study –tGard in Action

tGard is Fortress’ brand new customisable safety system that controls access to hazardous machinery and equipment.

Whatever the application, tGard has the flexibility to be configured to the customer’s needs. Housed in a metal body, tGard accepts elements (components) to create an overall assembled product that is easily mounted onto machine guarding.

You choose which elements are necessary. If you want a standalone emergency stop, you can have it; if the application requires a trapped key interlock to control access, you can have it. If a safety gate switch is needed, (solenoid or non-solenoid), you can have it, and if that gate switch needs machine control buttons integrated, then that too is possible. tGard is built to suit customer needs with almost unlimited configurations.

tGard in Action


tGard is ideally suited to safeguard workers in the packaging industry. Modern automated packaging machines often use robots to handle bigger payloads by picking up complete layers of product for packing. The main danger associated with palletisers is the lack of visibility; a maintenance person can go into the guarded area to undertake work and, if he is underneath the machine, he may not be seen. The door can easily be closed and the machine restarted with him inside, resulting in possible injury or death. EN safety standards recommend the use of safety interlocks to protect workers from the dangers of palletising machines.

Due to its flexibility, tGard can be configured to safeguard the palletiser in a number of ways. tGard can include a solenoid controlled interlock on the guard door. This uses trapped keys to control access, thereby preventing potentially dangerous situations by ensuring actions are undertaken in a pre-determined sequence. Once the solenoid has been energised, the operator uses a unique, coded key in the door lock to shut down the machine and release the door; he then takes the released key with him into the area, preventing the door from being closed and the machine starting up again.  Machine control additions, such as ‘Request to enter’ and ‘restart’ push buttons can also be integrated into the tGard body to create an efficient, integrated system.

EN ISO 14119 standards on machine safety states that if there is a risk of a person becoming trapped behind closed guards, an emergency escape is needed. tGard features an internal release element. If an operator inside the guarded area needs to exit through another door in the cell because his first option is blocked, the operator pushes the tGard Internal Release inside the cell and is granted immediate access out of the area and away from danger.

This is an example of tGard in use; tGard is suitable for several kinds of machines in a wide range of industries from pharmaceuticals to electronics.

Benefits of tGard

Along with its flexibility, tGard offers several benefits. It offers a combination of access and control features, such as gate switches, trapped key interlocks and operator control buttons, all in one unit. It is simple and robust, and future-proof, in that it allows for elements to be added at a later stage.

tGard is easy to install, it only requires two fixings and if the ‘Quick Disconnect’ version is selected then the device comes pre-wired and the installer simply connects the cable, reducing the install time significantly in comparison to other systems on the market. tGard has been designed to be fully compliant with the new machinery safety standards.

For more information about tGard and how it can be used in your application, call Fortress Interlocks on +44 (0)1902 349 000 or email

Comments (0) »

tGard Access Control System from Fortress Interlocks

Customized approach maximizes safety
Erlanger, Ky. (October 17, 2013) – The new tGard Range from Fortress Interlocks is a novel approach to controlling access to hazardous machinery and equipment. The compact, metal-bodied safety system enables the custom configuration of multiple safety products including electrical safety gate switches, mechanical trapped key interlocks and electrical operator controls, for optimum safety.

tGard from Fortress Interlocks

tGard interlocks enable the custom configuration of multiple safety products including electrical safety gate switches, mechanical trapped key interlocks and electrical operator controls.

tGard systems can either be configured as separate devices or integrated into one device and are wholly customized to the needs of the end user. The range of tGard components includes safety switches (solenoid and non-solenoid), personnel keys, emergency release, push buttons, estops, indicator lamps and a choice of operating handles for both hinged and sliding guard doors. The required elements are user selected and then assembled into a robust housing, resulting in an exact configuration specific to the user’s application.

tGard is quick and easy to install and can be mounted directly onto a flat surface, doors or extruded aluminium profiles without the need for mounting plates or brackets. It is IP65 certified as standard and has been designed to be fully compliant with the latest machinery safety standards.

Comments (0) »

A New Approach to Controlling Access to Hazardous Machinery and Equipment

Fortress Interlocks prepares for the launch of its brand new safety product, tGard.

Made up of elements, tGard options integrate mechanical trapped key interlocking, electrical safety gate switch interlocks and machine controls to create an intelligent control system.

tGard is coming soon!

Comments (0) »

Fortress Interlocks Introduces Compact SR Safety Key Switch to Isolate Power

The new SR unit from Fortress Interlocks is a compact safety key switch that is ideal for isolating power to machinery.

For example, when the key is trapped inside the SR unit the power to machinery is on, and when the key is free, power is off. This allows the person carrying the freed key to enter the machinery or guarded area safely and power is not resumed until the key is returned. This is a typical sequence and other sequences can be specified.


The key switch is heavy duty, housed in a metal enclosure which is IP rated 65/66/67. Its compact design allows the customer plenty of space for wiring, a feature not available in previous switch offerings. The switch current is 20A.

The SR key switch is part of Fortress’ mGard range of safety interlocks. mGard is the premier range of modular trapped key products that are used to safeguard dangerous machines and hazardous processes. Individual modules can simply be added or removed depending on the application which allows flexibility and tailoring. Fortress’ mGard range of products is suitable for use in high risk applications.

For more information about how the SR unit can be used in your application, please call Fortress Interlocks on +44 (0)1902 349 000.

Comments (0) »

Fortress’ mGard Interlock Range receives TÜV SÜD Safety Approval

Fortress’ mGard range of safety interlocks has achieved approval from TÜV SÜD*, the leading international Notified Body for the certification of safety components. Fortress is the only trapped key manufacturer to carry independent third party approval on its trapped key range of interlocks, for use up to SIL3/PLe, reinforcing its position as market leader.

TÜV SÜD has certified that the mGard range meets the interlocking requirements of the latest European safety standards, so customers can install mGard with peace of mind.


Trapped key interlocking is an ideal method of safeguarding machinery or potentially dangerous areas. The mGard range has a fail-safe design, undergoing an extensive FMEA (Failure Modes Effects Analysis) during its design stage, with over 100 different, rigorous safety tests.

Fortress’ mGard range of robust mechanical trapped key products is a completely modular system where individual modules can simply be added or removed depending on the application. The mGard range is ideal for a wide range of industries, such as food and drink manufacturing, for wash-down or explosion proof applications, resulting in an extremely cost-effective and flexible safeguarding solution for a wide industrial audience. Fortress’ mGard range of products is suitable for use in high risk applications.

* Technischer Überwachungs-Verein (Technical Inspection Association). Headquartered in Munich, Germany and founded in 1866, TÜV SÜD is one of the world’s leading technical service organisations. For more information, please visit

Comments (0) »

Fortress Interlocks Unveils New US Facility

Ribbon cutting ceremony celebrates new office
Erlanger, Ky. (February 15, 2013) – Fortress Interlocks dedicated its new Erlanger, Kentucky facility Friday, February 8, in a ribbon cutting ceremony with the Northern Kentucky Chamber of Commerce. The new premises position the UK-based safety products company for continued US growth.

Fortress employees Mark Gilvin, Josie Dewald and Mike Martin.

Fortress employees Mark Gilvin, Josie Dewald and Mike Martin.

When it outgrew its current space, Fortress chose to stay in the same conveniently located Northern Kentucky city of Erlanger, upgrading to new facilities. Now just five minutes from the Cincinnati/Northern Kentucky International Airport, customers can easily visit for on-site training and demonstrations of the company’s safety access and control systems.

State-of-the-art conference facilities enable live conference calls with the Fortress UK manufacturing facility. With additional square footage and warehouse space, some light manufacturing will be possible locally to reduce lead times on common assemblies. 

The office opening was commemorated with a visit from ambassadors of the Northern Kentucky Chamber of Commerce. Chamber members Steve Harrington of ProSource and Tammy Trimble of Zalla Companies joined Fortress employees Josie Dewald, Mark Gilvin and Mike Martin for a tour of the new space and ribbon cutting ceremony.

Existing phone, fax and email contacts remain the same. The new mailing address is 1455 Jamike Ave., Suite 200; Erlanger, KY 41018.

Comments (0) »