How to Achieve Cost-Effective Risk Reduction with Mechanical Trapped Key Interlocks

Enhancing Safety Doesn’t Always Require Expensive Modifications

From assembly lines to food processing facilities, and construction sites to warehouse operations, worker safety is always a top priority. Companies are constantly working to protect employees from hazards, but when equipment is outdated or modifications are needed, safety improvements can appear to come at a high price.

However, in some cases it is possible to make practical, budget-conscious improvements – especially when working with legacy machines – while still achieving a high level of protection for personnel and meet machinery safety standards and regulatory requirements.

Mechanical Trapped Key Interlocks and Legacy Equipment

Fortress Safety helped a company with upgrading a 50-year-old concrete mixer. A facility needed to install a second set of blades to make cleaning easier. However, after a risk assessment it became clear that there was a high potential for severe injury. These new blades would be within easy reach, potentially exposing personnel to a hazard if the machine were to run while the guards were open.

The replacement of the control system to automate and monitor guard safety would cost in the excess of $300,000 – an unrealistic option for such an old machine. Fortunately, there are cases where risk reduction can be accomplished without changing the machine control system.

A mechanical trapped key system offered a simple, low-cost solution. This type of risk reduction measure is particularly effective for older machines where upgrading the control system is impractical.

Benefits of mechanical trapped key interlocks include:

• Physically preventing the machine from operating until all safety conditions are met
• Ensuring access doors can only be opened once power to the system is turned off
• Enforcing a key sequence to manage access to areas with hazards
• Preventing accidental re-energizing of the machine while the guards are open

Not only did this solution reduce the risk of unexpected start-up of the mixer and eliminated the need for a full control system overhaul, but it also provided considerable monetary savings. The final cost for the entire upgrade, including the new blades and interlocks, was under $1,000, which is a fraction of the cost of a full retrofit, and it brought the equipment into compliance while significantly enhancing worker safety.

mGard interlocks on a legacy concrete mixer 

Enhanced Safety Through Simple Solutions

As the concrete mixer example shows, mechanical solutions, thoughtful planning, and proper use of safety standards can deliver major safety gains, even on old machines. Fortress Safety brings extensive expertise in designing and supplying trapped key interlock systems that can meet each application’s requirements.

The mGard range of mechanical trapped key interlocks, made from durable metal alloy (with stainless steel options available), is built to perform even in the most demanding environments. mGard interlocks can be seamlessly integrated into both new installations and legacy equipment, providing a robust, cost-effective safety solutions. 

How do Trapped Key Systems Work?

For those that want to understand more about how trapped key systems work and how they can be used to provide controlled access to areas containing hazards, more information can be found at the following link.