Winch brake holding test onboard oil tanker deck showing hydraulic jack setup on mooring winch brake arm as per MEG4 guidelines | Merchant Navy Life

How to Perform a Winch Brake Holding Test Onboard Ship (Step-by-Step Guide)

/ Adventure place, Asia, Europe, France, Iceland, Japan, maritime, Mexico / By
winch brake holding test

⚙️ How to Perform a Winch Brake Holding Test Onboard Ship (Step-by-Step Guide)

The Winch Brake Holding Test is one of the most important onboard safety verifications carried out on tankers and cargo vessels.
It ensures that each mooring winch brake renders (slips) at the correct designed load. Consequently, it prevents the rope from breaking or fittings from being damaged during mooring operations.

In the past, brakes were tested at 60 % and 80 % of the line’s Minimum Breaking Load (MBL).
However, under OCIMF’s Mooring Equipment Guidelines (MEG4), the mooring system is now designed around the Ship Design Minimum Breaking Load (SDMBL).
The brake rendering test verifies that the winch is correctly set, typically to render around 60 % of the SDMBL, unless otherwise specified by the company’s SMS or OEM.

🎥 Watch: Winch Brake Holding Test (Merchant Navy Life)

👉 Here’s a real onboard video showing the brake test performed at 60 % and 80 % MBL. Under MEG4, SDMBL is now used as the standard design reference.

🎥 Watch the Practical Demonstration

This video shows a real onboard Brake Holding Capacity Test of mooring winches. During filming, tests were conducted at 60% and 80% MBL. Under OCIMF MEG4, the reference term is now Ship Design MBL (SDMBL).

👉 Tip: Follow company SMS and OEM instructions when conducting any onboard winch brake test. Rendering load is typically around 60% of SDMBL.

⚓ Purpose of the Brake Holding Test

The goal of the Brake Holding Capacity (BHC) Test is to confirm that each mooring winch brake will render (slip) safely before the line fails.
This process protects both crew and ship structure.

✅ Confirms the rendering load is within the safe range
✅ Verifies the mechanical condition of brake components
✅ Demonstrates compliance with MEG4, VIQ, and company SMS

🧭 Key Technical Terms

🔹 SDMBL (Ship Design Minimum Breaking Load) – The base design strength used for all mooring components.
🔹 Brake Render Load – The point where the brake slips; typically set around 60 % of SDMBL as per MEG4 guidance.
🔹 LDBF (Line Design Break Force) – The certified breaking strength of a new mooring line (≈ 100–105 % of SDMBL).
🔹 WLL (Working Load Limit) – The safe operational limit; 22 % for synthetic and 55 % for wire ropes.

⚙️ Step-by-Step Winch Brake Test Procedure (Verified Method)

  1. Preparation
    • Inform the Master and duty engineer before testing.
    • Conduct a toolbox meeting and prepare a risk assessment (JSA).
    • Isolate the winch drive; keep the clutch disengaged.
    • Clear all non-essential crew from the mooring area.
  2. Inspection
    • Check the condition of the brake lining, pins, and lever arm.
    • Ensure the drum surface is clean, dry, and free from oil or rust.
  3. Equipment Setup
    • Position the calibrated hydraulic jack and pressure gauge correctly.
    • Place the jack between the brake lever and the fixed point or testing arm.
    • Verify the jack and gauge calibration certificates are valid and recent.
  4. Calculation
    • Determine the required jack force (JF) using: JF=BHC×L1L2JF = \frac{BHC × L_1}{L_2}JF=L2​BHC×L1​​ where:
      • BHC = Brake Holding Capacity (≈ 60 % SDMBL)
      • L₁ = Distance between line pull and lever pin
      • L₂ = Distance between lever pin and jack point
  5. Testing
    • Gradually apply jack pressure until the brake begins to render (slip).
    • Note the pressure reading at that exact point.
    • Then compare it with your calculated target (± 5 % tolerance is acceptable).
  6. Adjustment
    • If the brake slips too early, tighten the spring or nut slightly.
    • Conversely, if it holds too long, ease the setting slightly.
    • Re-test until the brake renders close to the 60 % SDMBL value.
  7. Completion
    • Record all results in the Mooring Line Management Plan (MLMP).
    • Tag or mark the winch with the latest test date if required by SMS.
    • File the calibration and test certificates for vetting inspection.
  8. Safety
    • Never exceed 80 % of SDMBL during testing.
    • Keep all personnel clear of moving parts and pinch zones.
    • Finally, confirm that all tools and jacks are removed before putting the winch back in service.

💡 The purpose of the test is not to “tighten” the brake but to ensure it renders safely at the designed load, preventing catastrophic failure.

📊 Typical Brake Load Reference (Based on MEG4 Guidance)

ParameterDescriptionRecommended Value
Ship Design MBL (SDMBL)Base reference strength100 %
Brake Rendering LoadRecommended render setting≈ 60 % SDMBL
Working Load Limit (Wire)Max operational load≈ 55 % SDMBL
Working Load Limit (Synthetic)Max operational load≈ 22 % SDMBL

📝 Values are indicative per MEG4; always follow your company SMS or OEM specifications.

🔩 Mooring Shackles & Equipment

⚓ Tonsberg Shackle – Connects wire ropes to synthetic tails, providing quick release and proper load alignment.

⚓ Mandel Shackle – A forged high-strength shackle used for permanent mooring connections where reliability is essential.

🧾 Mooring Line Retirement Criteria

Mooring lines and wires must be inspected regularly and replaced if they show:

  • Service life expiry (≈ 5 years)
  • Broken strands, corrosion, or stiffness
  • Glazing, heat marks, or flattening
  • Loss of elasticity or residual strength
  • Any incident where WLL was exceeded

All replacements and inspections should be logged in the MLMP for proper traceability.

⚠️ Safety Reminders

✅ Conduct a toolbox meeting before testing.
✅ Keep clear of snap-back zones.
✅ Use calibrated testing tools only.
✅ Never test with mooring lines under tension.
✅ Always follow company SMS and MEG4 guidance strictly.

📚 Reference Standards

  • OCIMF – Mooring Equipment Guidelines (MEG4)
  • VIQ7 / VIQ9.2 – Mooring System Management Plan (MSMP)
  • ISGOTT – Chapter 23: Mooring & Anchoring Operations
  • OCIMF – Effective Mooring (3rd Edition)

⚓ Final Note

The Brake Holding Capacity Test is more than a routine task; it’s a critical safety barrier protecting lives, ship, and terminal.
Regular testing and accurate recordkeeping build confidence in the mooring system.
Therefore, always perform tests responsibly and maintain a strong safety culture onboard. ⚓

⚠️ Disclaimer

📘 This article is for educational purposes only.
Always follow your company policy, OEM manuals, and SMS procedures when conducting tests.
Merchant Navy Life and the author are not liable for any misuse or deviation from approved practices.

⚓ Promote Safety Culture | All Rights Reserved – Merchant Navy Life

Watch More
Read More