New C2 locks refitted multiple times without loss of retainer integrity

Background

Location
Queensland, Australia

Commodity
Coal

Digging Conditions
Soft to Medium

Machine
Dragline

Make & Model
8200 &2570

The Challenge

Minesites encountered challenges with the removal of existing C-Locks and maintaining the integrity of Surelock locks during rigging operations. These issues led to extended replacement times for rigging components and, in some cases, contributed to unplanned machine downtime due to premature lock failures. Additionally, current rigging locks were not designed for reinstallation once removed.

The Objective

The objective of this initiative was to evaluate whether rigging locks could be successfully refitted, with the potential to reduce operational delays and deliver measurable cost savings for customers.

The Solution

CR reviewed the problems with the existing C-Lock design and updated the clip mechanism in the nut to enable easier removal without the threat of premature failures. Trial parts of the new design were supplied to 2x Queensland coal sites to trial over a 6-8 month period. Key achievements to observe were:

Locks are easy ot install and remove with existing tools available
Locks could be refitted multiple times without losing retainer integrity
Locks would reach the life of the rigging part is was fitted to.

Figure 1 – CR C2-Lock installation in dragline rigging

The Impact

Both Queensland coal sites were happy with the performance of C2-Locks over existing C-locks and Surelocks. The below table shows a number of locks fitted at both sites and their total BCM’s achieved while also tracking how many times locks were refitted and the BCM’s achieved at each refitment. Locks 1-4 were fitted on site 1 and locks 10-16 were fitted on site 2.

Key Observations

Locks were able to be re-fitted up to 3 times. The third time was a test to see how far the locks could go. CR recommends
a limit of 2 refits to ensure lock integrity is maintained. (Refitments were triggered by rigging part replacements, not because of the lock itself). Lock total BCM’s reached a total of

Site 1 – 6.4M BCM’s
Site 2 – 9.4M BCM’s
Locks were easy to install and remove. Sites reported they were often able to remove the locks with hand tools instead of power tools.
Locks 3, 4, 14, 15 and 16 were not refitted due to maintenance teams throwing out the lock before it could be refitted. (A communication gap between shift changes)
Locks lasted the life of the rigging part they were fitted to