Toothless Clamshell - Loading the Small & Medium Size Stones "version 2.0"

The stone buckets shown in the previous two posts simply couldn't keep up with the shear volume of small and medium size stones being brought in by the dump trucks. The crew needed to be able to move an entire scowl full of this stone out to the Salisbury jetty. The crane was equipped with a clamshell bucket for grabbing the stone. It was a great idea in theory but problematic in practice. The clamshell had a hard time grabbing more than one medium size stone at a time or a decent bucket full of the small stones. The problem seem to be with the shallow design of the bucket and the lack of teeth on it. The short term fix to this problem was to have the excavator load the clamshell. The video captures this process. It put the excavator operator's skills to the test. You will see him adjusting the position of the clamshell and also very carefully loading it. It was good short term solution. However, It was time consuming and took the excavator away from its other duties of moving the stones dumped by the trucks onto the pile where the crane could pick them up.

On my next visit to the construction site (about a week later), I found the toothless clamshell  unceremoniously beached on the sand in the construction staging area. The crew had come up with a new solution ... which I will discuss in the next post.

 

Video of the toothless clamshell and in action.

 

"bye-bye" excavator

 

Toothless clamshell managed to grab a single stone

 

Excavator filling the clamshell

 

A sequence of photos showing the clamshell dumping its load into the scowl.

 

This is what happens when you don't load the scowl evenly .. it tilts to one side.