Trapped Key Interlock Case Study: Loading Bay Safety Upgrade

Customer: Leading Consumer Goods Company

BACKGROUND

OVERVIEW

The particular leading consumer goods company was one of Castell’s first Salvo customers using a special version of our ‘through the wall’ key transfer system for manual doors. The KSUPS units used were modified to complement the company’s Lockout/Tagout (LOTO) requirements as operated at 240vac. This included padlock control for the storage and Salvo Control Panel (SCP) enclosure.

After 10 years, the company is undergoing a refurbishment process which includes upgrading the loading bay doors from manual to electric operation. This gave Castell the opportunity to design a bespoke SCP to meet the company’s requirements.

STEP BY STEP

THE NEW PROCESS

Step 1: Driver approaches loading bay with Castell key interlock

Loading bay is in the closed position. External traffic light is green, internal is red.

Step 2: Driver inserts key into Castell interlock to begin loading bay sequence

Driver or shunter reverses the trailer onto the correct loading bay.

Step 3: Loading bay door unlocked via Castell trapped key interlock

The company operator inserts and turns their FK4 key into the SCP unit, which traps the key and opens the panel door. This replaces the current padlock system.

Step 4: Vehicle reverses to loading bay under controlled key interlock process

Operator collects the Salvo Susie or SGL lock and installs it to the emergency airline of the trailer. This releases the trapped Susie/SGL key. Both keys are taken to the SCP unit.

Step 5: Dock leveller engaged as part of Castell 12-step interlock sequence

The Susie/SGL key is inserted into the lock inside the box. The vehicle key is placed inside and the door is closed, enabling the FK4 key to lock the box.

Step 6: Loading bay secured: key trapped, preventing premature vehicle departure

Internal traffic light turns from red to green — the bay is safe and ready to use.

Step 7: Goods loaded or unloaded safely with vehicle immobilised by key interlock

Loading bay door is opened from inside by pressing the open button. External traffic light changes to red — loading in progress.

Step 8: Loading complete: operator initiates key release sequence

Loading and unloading commences.

Step 9: Dock leveller retracted as part of Castell key interlock process

When finished, the loading bay door is closed. External traffic light changes back to green.

Step 10: Loading bay door closed and locked via Castell interlock

Operator returns to the SCP unit and uses their FK4 key to open the door (key is trapped). The key release button is pressed to release the Susie/SGL key. Internal light changes to red.

Step 11: Vehicle key released to driver after bay is secured

Driver or shunter reverses The Susie/SGL is taken to the trailer, inserted, and removed. The airline is refitted. Susie/SGL is returned to the SCP and vehicle keys are retrieved.