- Keep loads to a minimum. Heavy loads are caused by the driller attempting to overcome inertia too quickly.
- picking up quickly, leting out the clutch suddenly
- stopping quickly, applying the brake suddenly.
- Reduce winch loads by running a travelling block.
- Reduce friction load by maintaining straight cleanholes and correct machine lubrication.
- Avoid bending loads as they cause high compressive (buckling) stress in the top of the beam.
- Reduce casing weights by using a loat shoe and taking advantage of buoyancy.
- Drill pipe/rod weight is reduced by buoyancy of a hole kept full of liquid.
Use larger sections or beter shaped or placed sections to carry the load. Stresses are increased as cross-sectional area is reduced by wear, so act to prevent or reduce wear and replace worn parts:
- Use larger drill pipe at the top of a long string.
- Use large diameter cable or multiple cables.
- Keep cables lubricated so the load is shared between strands.
- Use beams on edge (rather than lat) to gain improved section.
- Apply loads to ‘strong parts’ (e.g. where members are reinforced or where members meet).
- Drill rig manufacturers should use pipe, square, or rectangular box section members wherever possible, and drillers should request stress-resistant and relieving designs in purchase orders. The main advantage of this is that these members have the same strength in all directions (compared with angle-iron members that can twist and buckle). They have all their strength on the outside where it is needed so they are safe, easy to handle, light, strong, and not easily bent or broken.