Crane/Derrick Operator (Crane)

Particles and Waves

In-app purchases

About this app

A Japanese-language study app for the written exam of Japan's Crane/Derrick Operator licence, crane-limited category (クレーン・デリック運転士 クレーン限定).

Please note: the interface, the questions and every explanation are in Japanese. Japanese reading ability is required.

■ What it is
129 original questions written to the published exam scope and format. The 39 questions based on law were machine-checked against the current articles in e-Gov, the Japanese government's official legislation database.

■ Pass or fail is decided by your weakest subject
The exam requires at least 40% in every subject and 60% of the weighted total, so a single subject under 40% fails you. The app scores you by subject against those same thresholds and names the subject you are short on.

■ Weighted scoring, like the real exam
Subjects carry different weights (crane knowledge 30 points, related laws 20, prime movers and electricity 30, mechanics 20). The app applies those weights, not a plain percentage of correct answers, when it checks the 60% overall bar.

■ An explanation for all five choices
Every one of the five choices carries its own explanation, not just the correct one, so you learn why a choice is wrong rather than memorising the answer.

■ Mock exams in the real format
Four subjects: knowledge of cranes and derricks, related laws, prime movers and electricity, and mechanics (the real exam has 10 questions per subject, weighted 30, 20, 30 and 20 points). A half mock of 20 questions and a full mock of 40 questions matching the real exam structure, with a subject-by-subject pass breakdown.

■ About the qualification
The Crane/Derrick Operator licence is a national licence under Japan's Industrial Safety and Health Act; the exam is run by the Japan Exam Association for Safety and Health. It is required to operate cranes with a lifting capacity of 5 tonnes or more, and the crane-limited category covers cranes only. The written exam has four subjects and 40 questions in total; the licence also requires a separate practical exam or completion of a training course. Eligibility, exam dates and application procedures can change; always confirm them on the examining body's official site.

■ Offline and private
Android 8.0 or later. Questions are bundled in the app, so you can study without a connection. The app goes online only to receive question corrections and to process a purchase. There is no account to create, and your study record stays on the device.

■ What is free
10 drill questions in total, one half mock exam (20 questions), and 3 days of the auto-play review mode. The free allowance does not reset daily. A single in-app purchase unlocks the rest. It is not a subscription, and there are no ads. See the In-app purchases line on this page for the current amount.

■ Sources and relationship to government bodies
・Japan Exam Association for Safety and Health (examining body) https://www.exam.or.jp/
・e-Gov law search, Industrial Safety and Health Act https://laws.e-gov.go.jp/law/347AC0000000057
・e-Gov law search, Crane Safety Rules https://laws.e-gov.go.jp/law/347M50002000034
・Ministry of Health, Labour and Welfare https://www.mhlw.go.jp/

This is an unofficial study app made by Particles and Waves. It is not affiliated with, endorsed by, or representative of the Ministry of Health, Labour and Welfare, the Japan Exam Association for Safety and Health, or any other government or examining body, and it does not guarantee a pass. Always confirm application procedures, dates and eligibility on the examining body's official site.

Questions are original work written by Particles and Waves from the Industrial Safety and Health Act, its regulations and the subjects, question counts and pass criteria published by the examining body. They are not reproductions of past exam papers.

English text prepared 2026-09-13 from the Japanese listing, which was verified 2026-09-11 against the shipping app (question counts, free allowance and requirements).

What’s new

First release of the クレーン・デリック運転士（クレーン限定） exam prep app: original questions, per-choice explanations, mock exams, hands-free study, and an exam-day countdown.