How It Works

I'm going to do my best to explain the detail I went to to make this calculator as accurate as possible starting with the beam and basket. Did you know there is a variable in the depth of the basket based on the angle of the leg relative to the beam? This application calculates the angle of greatest difference and then calculates a percentage of that difference based on the angle, subtracting it from the depth of the basket.

The next thing I did was ensure that the short sides leg is always increased in increment of steel cable with all shackles in the leg included in the length of the leg. dogbones are not included by default but you can allow the application to add dogbones to the primary leg if you want. It will usually result in a shallower bridle which will be more accurate.

The application will then break up the second leg in increments of largest to smallest pieces from the 30 footers down to the inclusion of an extra shackle if necessary. It will not produce a leg that you wouldn't have built yourself. It will never build a leg that is two dogbones and two links (this is a real life example of a leg I've seen a show rigger insist I build).

Another thing this application does better than most is the measurements are taken specifically from the center of the beam. Cause.. you know... that's where every head rigger I've ever met measures from. It's also because that's the pivot point of the basket, which makes the math for the basket easier. However, bridle depth is measured from the top of the beam because that's what you're almost certainly going to use to determine hook height. Even in the case where you're hanging between two different beam sizes but the top of the beams are level, that difference in the height of the center of the beam is accounted for.

When you measure your points you can do it to the far side or the short side and it will produce the same results. No need to make sure you are measuring from a specific side. This is more convenient if you are working in a bay and you are already set up to measure from one side.

If you are working in a bay with a height difference between the beams with multiple points in that bay you can do the same thing. It doesn't matter which side you measure from. HOWEVER, you must measure the height difference relative to the beam you are measuring the point distance from.