How to Change a Wheel (on a 30 ton crane)??!!?

Today I arrived at work at a cool 6:35 to attend the plant's morning 'Green-Time' meeting. This is a compulsory safety briefing held every morning by the various departments and its compulsory for all employees to attend. Since I'm officially a grease-monkey now (will tell you all about that in a minute), I have to go to these things.

Sigh.  The working world, eh?

There was a very interesting job to be done this morning.One of the wheels on the overhead crane was making weird noises and had to be replaced and investigated for problems. So I got to tag along and check out how this was done. Surprisingly, changing the wheel on a 30-ton capacity crane is almost exactly like changing the tyre on your car! You jack it up, take off the bolts, remove the wheel and change it out. 

Ok, I admit, when you're dealing with loads of this magnitude its slightly more complex than this, and it takes about 3 hours to complete, but the basics are the same.And of course, we're on the 4th floor of the furnace building (about 50m off the ground), in overalls and safety harnesses, with out CO gas monitors buzzing away and smoke, dust and heat billowing all around us...oh yes, and there is grease. Tons of it! But its fun and I love the fact that the guys up there look at me like I'm raving mad! I can just see them saying to themselves, "What the bleeding hell is this little girl doing here? What kind of parent would let their daughter DO this?"

But I love it. I find in fascinating how the mechanical parts all fit together, how the huge, bearings are so accurate and every separate part has a unique function that make this massive machine work under extreme conditions! I think the people that invented and built this are geniuses! Beneath the grease and dust and dirt, this mega-machine is as elegant as any other, and even more so for being able to withstand the heat and particles getting stuck in all its moving parts.

So I'm back in the office, a little dustier than I was before, but I've learnt a lot today:

• How to use on a safety harness and life-line
• How a CO gas monitor works and what is the maximum safe concentration of CO gas in parts per million (this is about 200 by the way, although some say 'when you feel dizzy and throw up, get out quick!')
• How to change a crane wheel
• How a rigging machine and a hydraulic bottle jack works
• How to remove lock-nuts

Okay fine. As an engineer, I probably (definitely) would never need to actually change a crane wheel...ever. But I need to know what the thing looks like and how it get put together/ taken apart so that I can design one. Even if I'm just picking a standard one out of a catalogue, I need to know that I'm choosing the best and safest type for the job as well as the guys who are using it. All in all, it was great fun!