Other preparation items on your basic safety checklist should include the following actions and probably a whole lot more. Ask yourself, are the drill lines in good shape, i.e. without snags, broken wires, birdcages, wickers, or other signs of either wear or neglect? Check the cable clamps at the anchor point, especially if your drill line is anchored to the crown. Are the clamps facing the right direction? Remember, the saddle of the clamp goes on the live side of the line, not the dead side. My daddy taught me to remember this with the saying, "Son, never saddle a dead horse."
Also check to see if the block has been raised high enough to run over the clamps on the crown anchor. Sometimes drillers will raise the block a little too high, running over the anchor and sliding the last clamp up the line. When this situation happens, it usually birdcages the line and reduces the anchoring power of the clamps by however many clamps have been moved. If you find this problem, slip the line and re-anchor on undamaged cable. While you're up there, grease the crown sheaves - they are usually the most neglected grease fittings on even a well maintained rig since, after all, they're way up there, out of sight and out of mind. Take a look at the sheaves for signs of bearing failure or sheaves worn too deep. A sheave failure under a heavy load will tear up a drill line right quick and probably cause all sorts of headaches, both literally and figuratively.
And when was the last time you popped the mud pump relief valve? Add this task to your checklist, too. Pull the nail out and gently pressure up against it. With no nail in the valve, it should relieve at well less than 100 psi the first time and practically nothing after that. You did remember to wash that cement out the other day, after pumping all that grout, didn't you? If the valve doesn't open easily, tap on it with a light hammer, using a small amount of pressure against it. Be careful, these valves open fast. Don't beat the tar out of it - just tap it around the seat/stem area, and it should pop.
While you are at it, make sure the valve has a nail of the proper size and not an allen wrench. I've seen this adjustment made in many pumps over the years to increase the pressure rating of the valve, and it will eventually lead to disaster. If you suddenly plug the bit, running wide open, an allen wrench (or any hardened steel pin) will raise the pop-off pressure to the point that you'll probably pull the rods in two, or something else difficult and expensive to fix. The reason nails are used in relief valves is that they are common around the rig, made of fairly soft steel, are predictable, and are probably going to end up there anyway. Each different size has a predictable yield point, and there usually is a set of holes used to gauge the nail, and thus the relief pressure, built into the valve.
It is a good idea to check the chain and belt guards, as well. Sometimes they get removed for service and don't seem to find their way back on. Furthermore, some older rigs didn't come with a guard on the mud pump drive, so this might be a good time to build one.
You should also check the rotary drive u-joints - they take a beating and are usually the first ones to go on a rig. A rotary drive shaft flying out from under the rig can be quite a surprise! (Not to mention, you're going to have to break the pipe out by hand.) If you've got a break-out cylinder, or catheads, check the cables: these cylinders generate tremendous forces and can easily pull the lines in two. It's a short piece of line, so change it often.
These are just a few of the more common preparation items that should be on your safety checklist - there are many more (enough for several more articles). Alongside preparation, one other principle that is very important in field safety is attitude. Just getting by with bailing wire and duct tape may get you through the day, but it won't get you through your career with all your fingers and toes! The attitude should be, we're going to do this right, and we're going to do it safe.
Being in a hurry to get a job done, only to have to do it over, is not saving time. Remember, a rig can't run any faster than its slowest hand. If you've got a new person on the tongs, there's no point in kicking in the rotary before he's got them set. The time you are trying to save is probably going to be spent filling out accident reports.
The safety attitude often is evident when I pull up on a location. Does the crew look professional? Hard hats instead of greasy ball caps? Steel toed shoes instead of blown-out sneakers? Decent uniforms instead of MegaDeath t-shirts? Clean location instead of half of the inventory of Sanford and Son laying around? These are small things, but they add up to attitude. A safe (or unsafe) rig often can be spotted from the road.