Inside the build of a 7.62 m mine hoist sheave

This project is so exciting, you can't not speak of the scale of it. How proud we are that it's a Canadian customer being manufactured in Canada. A sheave is a wheel, so we're reinventing the wheel here, but there's so much that goes into it and the details are critical. A sheave is used to support the rope as it goes into a mine shaft. So there's a hoist which winds the rope, and then the rope from the hoist goes up to a sheave in a head frame, where it then goes down into the mine shaft and attaches to a conveyance. Its size is the largest that we're aware of in the world, 7.62 metres, which is 25 feet for anyone working in Imperial. The loading is really at the top of the chart for what's been supplied to date. They're going to be used in something called a compensating arrangement. The benefit is that you can usually go deeper. So this mine is 1,800 metres deep. The sheave rotates at 50 rpm, which is equivalent to the rope moving at 72 kilometres an hour. The maximum tension on the rope is 80 metric tonnes. So over 25 years, that adds up to 500 million cycles. And the outcome of the project is dependent on the vendor successfully building it. Ultimately FLS is taking full responsibility. I believe with our design history and financial wherewithal, we're viewed as a top-tier supplier, but a low-risk profile to the project overall. What I really love about doing this when I'm working with these guys is that there is a back and forth. There's actual, real discussion, and it's a meeting of the peers. The big question was, hey, Chris, can you guys do this? With the tools and toys that we have, we came up with a plan and took it on. They've done this for years. And from that experience, they've learned what works well and what doesn't work well. In the construction of a complete sheave, it's all based on smaller components. So we pre-machine a lot of the components, so that way they all fit together like a LEGO set. Then we assemble it, we weld it, and then we finish the machining of the completed sheave at the end of that. What is the risk when you're building a piece of equipment like this? Well, it is a key component in the overall production at a mine. The tolerances and the runouts on the sheaves are really important. So if that sheave is turning and it has a slight wobble to it or movement side to side, just think of that as exaggerating that whip down the cable all the way down, potentially up to thousands of feet into a hole. So you want to try to avoid that. Our FLS team is very proud on the runout for these sheave, which is the "wobble". Today I measured 1/16th of an inch on the axial runout, and we were 1/32nd of an inch on the radial runout, which we're very proud of. It is the heart of the mine, really, the hoisting system in a mine with a vertical shaft. So trust is a big element. Our success is their success and vice versa.