NCCCO load chart practice: a drill routine that works

It matters because Load Charts are about 27% of the Core written exam and about 35% of each specialty exam. On Core you do the arithmetic without a calculator. This article gives you the routine, and the load chart practice tool gives you invented charts to run it on. When a radius falls between two printed rows, the load chart interpolation drill trains that one step.

The five-step sequence

Say each step out loud or write it down. Skipping to the table is the habit that costs points.

1. Configuration. Which chart applies: outrigger setup, boom arrangement, working area? A correct lookup on the wrong chart is a wrong answer.
2. Radius and boom length. Radius is the horizontal distance from the center of rotation to the load line. Boom length is a separate number. Never swap them.
3. Gross capacity. Read the cell where your row and column meet. If the cell is blank, the chart gives no capacity there.
4. Deductions. Hook block, headache ball, stowed or erected jib, rigging, and anything the chart notes list. Add them first, then subtract once.
5. Compare. Net capacity against the load. Then reread the question: is it asking for net capacity, whether the lift is within it, or the percentage used?

For a walk-through of a full lookup, see how to read a crane load chart.

Worked example 1: a clean lookup (invented numbers)

An invented chart has radius rows at 10, 20, 30 and 40 ft and boom columns at 50, 70 and 90 ft. Its notes say to use the next larger listed radius and boom length when your exact value is not shown. Your setup is a 24 ft radius with a 60 ft boom.

• Next larger radius: 30 ft row.
• Next larger boom: 70 ft column.
• The cell reads 19,800 lb gross.

Deductions are a 520 lb hook block and 300 lb of rigging: 520 + 300 = 820 lb. Net capacity is 19,800 − 820 = 18,980 lb.

By hand, round to make it easy: 19,800 − 800 = 19,000, then take 20 more off to get 18,980. A 17,500 lb load is within that, using 17,500 ÷ 18,980, a bit over 92%, of net capacity.

The rounding rule belongs to this invented chart. A real chart's notes decide how in-between values work, so read them each time.

Worked example 2: a trap (invented numbers)

Same invented chart, but the 90 ft boom column is blank at 40 ft radius. Your setup asks for a 36 ft radius on a 90 ft boom. The next larger radius is 40 ft, and that cell is empty.

The wrong move is borrowing the 30 ft value or guessing. A blank means no listed capacity, so the lift is not supported by this chart at that setup. Questions built on this idea test whether you respect what the chart does not say. Practice spotting blanks and notes before you read any numbers.

Add the other chart parts

Core and specialty outlines list more than the capacity table. Expect to meet notes, specifications, range diagrams, working-area diagrams and, for specialties, boom and jib erection charts. Spend a session on each. The range diagram and working-area charts article shows what each one answers, and parts of line explained covers the line pull check that sits beside capacity.

A two-week drill plan

Keep each session to 15 or 20 minutes. To work a set by hand, press Print this set in the load chart practice tool: you get ten problems, both invented charts and an answer key on a separate page.

Tag misses as wrong chart, wrong row or column, overlooked note, missed deduction or arithmetic slip. After a week you will see which one is yours, and that is the one to drill. The load chart math without a calculator article has the hand-arithmetic shortcuts.

What chart practice does not replace

A practice chart is a teaching model. It is not an equipment rating, and it cannot authorize a lift. On a real crane you follow the manufacturer's chart and operating procedures. For the written exam, the point is the skill: reading carefully, finding every note and getting the arithmetic right under time pressure.

Next step

Take the free 10-question check at /nccco-written to see exactly which topics to fix, including whether chart questions are costing you points. If they are, run the five-step sequence above on the practice tool each day until your misses stop repeating.

FAQ

Do I need to memorize load charts for the NCCCO written exam?

No. You are given a chart and need to read it correctly. Practice the method on many different charts instead of memorizing values from one.

Can I use a calculator on load chart questions?

Not on Core. The specialty exams (LAT, TLL, TSS) allow a calculator. Practice by hand either way, so a calculator only confirms your answer.

What do I do when my radius is between two rows?

Read the chart's notes. Some say to use the next larger listed value, and some allow a straight-line value between rows. Apply only the method the chart gives.

How long until I get faster at chart questions?

Most people feel the steps become automatic after a couple of weeks of short daily sessions, but pace varies. Track your time per item and use it to judge your own progress.