＜Upper-Intermediate＞ Lesson No.32
Vibration Analysis Discussion for Propulsion Shaft System Design / 推進軸系設計の振動解析協議
０．Greetings & Ice-break (2min.)｜挨拶と導入
0-1 Greetings
Let’s practice a short small talk that you can use to greet a business partner and start building a good relationship.
講師との挨拶を兼ねて、ビジネスパートナーと信頼関係を築くための短いスモールトークを練習してみましょう。
[Tips / 会話のヒント]
・Can you hear me clearly?
私の声はクリアに聞こえますか？
・How's your day going so far?
今日はどんな一日でしたか？
・Talk about one small topic (Work, Weather, News, Hometown, Sports event, etc.)
軽い話題について話しましょう（仕事、天気、ニュース、地元、スポーツイベントなど）
0-2 Introduction
In today’s lesson, we’ll learn about the following situation. Have you ever experienced something similar?
本日のレッスンでは以下のようなシチュエーションについて学びます。同様のシチュエーションを経験したことがありますか？
- If you have experience, please tell us what it was like, what was difficult, or what you learned.
経験があれば、どんな内容だったか、難しかったことや学んだことなどを教えて下さい。
- If you don’t have experience, try to imagine yourself handling that situation in English.
What do you think would be challenging?
経験がなければ、英語でその状況に対応しているところを想像してみましょう。どんなことが難しそうですか？
Situation / シチュエーション
Conducting design adjustments based on vibration analysis with overseas shaft system specialist manufacturers as avoiding propulsion shaft system vibration problems is a critical issue.
推進軸系振動問題回避が重要課題となり、海外軸系専門メーカーと振動解析に基づく設計調整を行う場面です。
1. Read (2 min)｜型を学ぶ
Let's read the following key sentences aloud!
下記の文章や単語を順番に音読しましょう！
1-1 Basic phrases
１．We acknowledge this is...（これは...であると認識している）
２．Could you elaborate on...（...について詳しく説明していただけますか）
３．We need to assess...（...を評価する必要がある）
４．We are concerned about...（...について懸念している）
５．We will carry out...（...を実施する）
６．We will coordinate with...（...と調整する）
７．Please submit...（...を提出してください）
1-2 Essential words
１．eliminate（解消する）
２．modify（変更する）
３．relocate（移設する）
４．impose（課す）
５．demonstrate（示す）
６．preliminary（予備の）
７．coordinate（調整する）
８．submit（提出する）
９．commit（約束する）
１０．accomplish（達成する）
2. Try (3 min)｜ロールプレイ練習
Let’s practice the role-play.
ロールプレイの練習をしましょう！
Situation / シチュエーション（Reference again）
Conducting design adjustments based on vibration analysis with overseas shaft system specialist manufacturers as avoiding propulsion shaft system vibration problems is a critical issue.
推進軸系振動問題回避が重要課題となり、海外軸系専門メーカーと振動解析に基づく設計調整を行う場面です。
👨💼【Teacher / Shaft System Specialist】:
Thank you for joining this meeting. We completed the vibration analysis for your new vessel, and I need to discuss our findings with you. The propulsion shaft system shows a critical resonance risk at 87 RPM, which could trigger severe vibration during normal operation.
（ミーティングにご参加いただきありがとうございます。新造船の振動解析が完了しましたので、結果についてお話しする必要があります。推進軸系は87 RPMで重大な共振リスクを示しており、通常運転中に深刻な振動を引き起こす可能性があります。）
🧑🎓【Student / Design Engineer】:
Thank you for the detailed analysis. We acknowledge this is a critical issue that must be eliminated before delivery. Could you elaborate on the specific modification options to avoid this resonance condition? We need to assess the impact on our design schedule and manufacturing process.
（詳細な解析をありがとうございます。これは引き渡し前に解消しなければならない重大な問題であると認識しています。この共振状態を回避するための具体的な修正案について詳しく説明していただけますか？設計スケジュールと製造プロセスへの影響を評価する必要があります。）
👨💼【Teacher / Shaft System Specialist】:
We propose 2 solutions. First option is to modify the shaft diameter from 650 millimeters to 680 millimeters, which shifts the natural frequency away from the operating range. Second option is to relocate the intermediate bearing position by 1.2 meters forward.
（2つの解決策を提案します。第1案は軸径を650ミリメートルから680ミリメートルに変更し、固有振動数を運転範囲から離すことです。第2案は中間軸受位置を1.2メートル前方に移設することです。）
🧑🎓【Student / Design Engineer】:
We appreciate both options. However, we are concerned about the first option because increasing the shaft diameter will impose significant changes on our bearing design and foundation structure. Could you calculate the exact natural frequency shift for the second option? We need to demonstrate to our management that relocating the bearing is the most efficient solution with minimal design impact.
（両案に感謝します。しかし、第1案については、軸径の増加が軸受設計と基礎構造に大きな変更を課すため懸念しています。第2案について正確な固有振動数のシフトを計算していただけますか？軸受の移設が設計への影響を最小限に抑えた最も効率的な解決策であることを経営陣に示す必要があります。）
👨💼【Teacher / Shaft System Specialist】:
Understood. We will carry out the detailed calculation for the bearing relocation option within 3 business days. Based on preliminary assessment, this modification should shift the critical speed from 87 RPM to approximately 102 RPM, which is safely above your maximum continuous rating of 95 RPM.
（承知しました。軸受移設案の詳細計算を3営業日以内に実施します。予備評価に基づくと、この修正により危険速度は87 RPMから約102 RPMにシフトし、最大連続定格の95 RPMを安全に上回ります。）
🧑🎓【Student / Design Engineer】:
That sounds promising. We will coordinate with our structural design team to assess the foundation modification requirements for the bearing relocation. Please submit the calculation report with the updated vibration mode shapes and frequency response curves. We must proceed with the final design approval by the end of this month to maintain our construction schedule.
（それは有望に聞こえます。軸受移設のための基礎修正要件を評価するため、構造設計チームと調整します。更新された振動モード形状と周波数応答曲線を含む計算報告書を提出してください。建造スケジュールを維持するため、今月末までに最終設計承認を進めなければなりません。）
👨💼【Teacher / Shaft System Specialist】:
We commit to that deadline. One additional point — we recommend installing vibration monitoring sensors at the bearing locations to detect any unexpected vibration during sea trials. This will enhance the safety validation process.
（その期限を約束します。1点追加ですが、海上試運転中の予期しない振動を検知するため、軸受位置に振動監視センサーの設置を推奨します。これにより安全検証プロセスが強化されます。）
🧑🎓【Student / Design Engineer】:
We agree with that recommendation. We will incorporate the sensor installation into our instrumentation plan. Please consult with our electrical team regarding the sensor specifications and wiring layout. This collaboration will ensure we accomplish both the vibration mitigation and comprehensive monitoring objectives.
（その推奨に同意します。センサー設置を計装計画に組み込みます。センサー仕様と配線レイアウトについて電気チームと相談してください。この協力により、振動低減と包括的監視の両方の目的を達成できます。）
👨💼【Teacher / Shaft System Specialist】:
Perfect. We will coordinate all technical details with your teams and deliver the complete solution package. I appreciate your quick decision-making on this critical matter. Let's make sure this vessel operates smoothly without any vibration issues.
（完璧です。すべての技術的詳細を貴チームと調整し、完全なソリューションパッケージを提供します。この重要な問題について迅速な意思決定をいただき感謝します。この船が振動問題なくスムーズに運航できるようにしましょう。）
3. Use (4 min)｜ロールプレイ & 実践（空欄補完）
Let's perform the role-play and fill in the blanks by translating the Japanese into English!
空欄の日本語を英語に訳しながら、ロールプレイを実践してみましょう！
Situation / シチュエーション（Reference again）
Conducting design adjustments based on vibration analysis with overseas shaft system specialist manufacturers as avoiding propulsion shaft system vibration problems is a critical issue.
推進軸系振動問題回避が重要課題となり、海外軸系専門メーカーと振動解析に基づく設計調整を行う場面です。
👨💼【Teacher / Shaft System Specialist】:
Thank you for joining this meeting. We completed the vibration analysis for your new vessel, and I need to discuss our findings with you. The propulsion shaft system shows a critical resonance risk at 87 RPM, which could trigger severe vibration during normal operation.
🧑🎓【Student / Design Engineer】:
Thank you for the detailed analysis. We acknowledge this is a critical issue that must be ［解消する］ before delivery. Could you elaborate on the specific modification options to avoid this resonance condition? We need to assess the impact on our design schedule and manufacturing process.
👨💼【Teacher / Shaft System Specialist】:
We propose 2 solutions. First option is to modify the shaft diameter from 650 millimeters to 680 millimeters, which shifts the natural frequency away from the operating range. Second option is to relocate the intermediate bearing position by 1.2 meters forward.
🧑🎓【Student / Design Engineer】:
We appreciate both options. However, we are concerned about the first option because increasing the shaft diameter will ［課す］ significant changes on our bearing design and foundation structure. Could you calculate the exact natural frequency shift for the second option? We need to ［示す］ to our management that relocating the bearing is the most efficient solution with minimal design impact.
👨💼【Teacher / Shaft System Specialist】:
Understood. We will carry out the detailed calculation for the bearing relocation option within 3 business days. Based on preliminary assessment, this modification should shift the critical speed from 87 RPM to approximately 102 RPM, which is safely above your maximum continuous rating of 95 RPM.
🧑🎓【Student / Design Engineer】:
That sounds promising. We will ［調整する］ with our structural design team to assess the foundation modification requirements for the bearing relocation. Please ［提出する］ the calculation report with the updated vibration mode shapes and frequency response curves. We must proceed with the final design approval by the end of this month to maintain our construction schedule.
👨💼【Teacher / Shaft System Specialist】:
We commit to that deadline. One additional point — we recommend installing vibration monitoring sensors at the bearing locations to detect any unexpected vibration during sea trials. This will enhance the safety validation process.
🧑🎓【Student / Design Engineer】:
We agree with that recommendation. We will incorporate the sensor installation into our instrumentation plan. Please consult with our electrical team regarding the sensor specifications and wiring layout. This collaboration will ensure we ［達成する］ both the vibration mitigation and comprehensive monitoring objectives.
👨💼【Teacher / Shaft System Specialist】:
Perfect. We will coordinate all technical details with your teams and deliver the complete solution package. I appreciate your quick decision-making on this critical matter. Let's make sure this vessel operates smoothly without any vibration issues.
4. Challenge (7 min)｜応用実践
Let's perform the role-play and fill in the blanks by translating the Japanese into English!
空欄の日本語を英語に訳しながら、ロールプレイを実践してみましょう！
*Let's practice this part repeatedly until we can speak it smoothly.
このパートはスムーズにスピーキングできるようになるまで繰り返し練習しましょう。
Situation / シチュエーション（Reference again）
Conducting design adjustments based on vibration analysis with overseas shaft system specialist manufacturers as avoiding propulsion shaft system vibration problems is a critical issue.
推進軸系振動問題回避が重要課題となり、海外軸系専門メーカーと振動解析に基づく設計調整を行う場面です。
👨💼【Teacher / Shaft System Specialist】:
Thank you for joining this meeting. We completed the vibration analysis for your new vessel, and I need to discuss our findings with you. The propulsion shaft system shows a critical resonance risk at 87 RPM, which could trigger severe vibration during normal operation.
🧑🎓【Student / Design Engineer】:
Thank you for the detailed analysis. ［これは引き渡し前に解消しなければならない重大な問題であると認識しています。］ ［この共振状態を回避するための具体的な修正案について詳しく説明していただけますか？］ ［設計スケジュールと製造プロセスへの影響を評価する必要があります。］
👨💼【Teacher / Shaft System Specialist】:
We propose 2 solutions. First option is to modify the shaft diameter from 650 millimeters to 680 millimeters, which shifts the natural frequency away from the operating range. Second option is to relocate the intermediate bearing position by 1.2 meters forward.
🧑🎓【Student / Design Engineer】:
We appreciate both options. However, we are concerned about the first option because increasing the shaft diameter will impose significant changes on our bearing design and foundation structure. Could you calculate the exact natural frequency shift for the second option? We need to demonstrate to our management that relocating the bearing is the most efficient solution with minimal design impact.
👨💼【Teacher / Shaft System Specialist】:
Understood. We will carry out the detailed calculation for the bearing relocation option within 3 business days. Based on preliminary assessment, this modification should shift the critical speed from 87 RPM to approximately 102 RPM, which is safely above your maximum continuous rating of 95 RPM.
🧑🎓【Student / Design Engineer】:
That sounds promising. ［軸受移設のための基礎修正要件を評価するため、構造設計チームと調整します。］ Please submit the calculation report with the updated vibration mode shapes and frequency response curves. We must proceed with the final design approval by the end of this month to maintain our construction schedule.
👨💼【Teacher / Shaft System Specialist】:
We commit to that deadline. One additional point — we recommend installing vibration monitoring sensors at the bearing locations to detect any unexpected vibration during sea trials. This will enhance the safety validation process.
🧑🎓【Student / Design Engineer】:
We agree with that recommendation. We will incorporate the sensor installation into our instrumentation plan. Please consult with our electrical team regarding the sensor specifications and wiring layout. This collaboration will ensure we accomplish both the vibration mitigation and comprehensive monitoring objectives.
👨💼【Teacher / Shaft System Specialist】:
Perfect. We will coordinate all technical details with your teams and deliver the complete solution package. I appreciate your quick decision-making on this critical matter. Let's make sure this vessel operates smoothly without any vibration issues.
\ If you have some extra capacity, give it a try（余力があればやってみましょう）/
5. Real-world application (5 min)｜実務応用
Let's speak freely with the phrases and flow we learned today. If you can, imagine your real job—it makes practice more effective.
本日学習した単語やフレーズ、会話の流れを思い出しながら、自由に話してみましょう。可能であれば、自身の実務を想像しながら話すと効果的です。
Situation / シチュエーション
A shaft system specialist has completed vibration analysis and identified a critical resonance risk in the propulsion shaft system.
The design engineer must confirm the modification options and coordinate with internal teams to proceed with the optimal solution.
軸系専門家が振動解析を完了し、推進軸系に重大な共振リスクを特定しました。
設計エンジニアは修正案を確認し、最適な解決策を進めるため社内チームと調整しなければなりません。
👨💼【Teacher / Shaft System Specialist】:
We have identified a resonance issue in your shaft system. Could you discuss how your team will proceed with the modification and coordinate the necessary design changes?
（軸系に共振問題を特定しました。貴チームがどのように修正を進め、必要な設計変更を調整するかお話しいただけますか？）
🧑🎓【Student / Your Role】:
(Free Speaking based on today's lesson)
Hints / ヒント
１． Acknowledge the critical vibration issue
２． Assess the impact on design and schedule
３． Coordinate with internal technical teams
４． Demonstrate the optimal solution to management
※This is not a role-play. Please speak until you finish your thoughts.
このパートはロールプレイ形式ではありません。最後まで通して話してみましょう。
6. Wrap-up (2 min) ｜レッスンの振り返り
Let's review today's lesson with your teacher!
今日のレッスンについて講師と振り返ってみましょう！
6-1 Comments from student
・Good points / 良かったところ・上手くできたところ
・Things to work on / 今後強化したいところ
6-2 Feedback from teacher
・Good points / 良かった点
・Things to work on / 今後の強化ポイント
・What to review / 復習ポイント
*6-3 Questions from student (if any)
Japanese translation（日本語訳）
1. Read (2min)（型を学ぶ）｜基本フレーズ
2. Try (4min)（ロールプレイ練習）｜型を使った練習
Let’s practice the role-play.
ロールプレイの練習をしましょう！
3. Use (7min)｜応用
Let’s perform the role-play and filling in the missing English!
英語を補完しながら、ロールプレイを実践してみましょう！
4. Challenge (7min)｜実践
Let’s perform the role-play and filling in the missing English!
英語を補完しながら、ロールプレイを実践してみましょう！
5. Wrap-up (3min) – レッスンの振り返り
"Let’s review today’s lesson with your teacher!”
「今日のレッスンについて講師と振り返ってみましょう！」
5-1. Comments from Student
- Good points / 良かったところ・上手くできたところ
- Things to work on / 今後強化したいところ
5-2. Feedback from Teacher
- Good points / 良かった点
- Things to work on / 今後の強化ポイント
- What to review / 復習ポイント
5-3. Question from Students (If any)