Precast Concrete Industry – Application Series: 1 of 5

Precast Concrete Industry – Application Series: 1 of 5

Gravel Pits: Conveyor Systems – Trapped Key Interlock Safety Solutions

In 2018, the French Health Insurance reported 144 workplace fatalities and more than 90 000 work accidents into the construction sector

The extraction or storing of aggregate within a gravel pit serves a variety of purposes across many industries including the concrete & cement industries.

Conveyor systems are an important method in the process of transporting materials across the mine surface, into hoppers, over grating for sorting, and into trucks for distribution to plants and manufacturing facilities.

Construction sector injuries account for nearly 20% of all worker's compensation claims

The continuous movement of belts, chains, and diverters place personnel working and operating the system at risk. Regular maintenance on these systems is required to ensure efficiencies. Safety processes must be followed to mitigate human error and save lives. The isolation of power prior to entry into the area is the first step in mitigating risk.

Trapped key interlocking systems are recognized by ISO 19837/2018 as an Alternative LOTO measure

Trapped key interlock safety solutions ensure a pre-determined sequence of operations each & every time. While LOTO provides a visual warning and identifies hazards, a TKI solution physically prevents a specific set of actions from being performed until previous action(s) have been fully completed!

Common trapped key interlock solution interlocking conveyor system with multiple access points and access doors:

Step 1: Power Isolation MS Bolt Lock installed on main breaker for conveyor

Step 2: Multiple Entry Points STI TMEC key exchange box for access to multiple hopper access doors

Step 3: Safe Access XSOL access lock installed on hopper doors

Step 4: Controlled Power STI RTK*E electrical switch installed on control switch for hopper doors