Why machines fail quietly — and people get hurt fixing them
Estimated read time: 75–90 minutes
Audience: Cadet → AB → Junior Officer → Chief Mate
Introduction – When machinery problems become human problems
Deck machinery rarely fails without warning. What fails first is usually interpretation. Strange noises, minor leaks, intermittent behaviour — these are often dismissed as quirks of ageing equipment rather than early indicators of failure.
The danger is not the fault itself. It is the moment when crew intervene incorrectly, placing themselves inside a system that is already unstable.
How deck machinery actually fails
Most deck machinery — winches, windlasses, capstans, cranes — fails through progressive degradation, not sudden breakage. Hydraulic systems lose pressure, brakes glaze, seals harden, bearings wear, and controls drift out of calibration.
These faults reduce margins gradually. The machine continues to operate, but with less tolerance for load, heat, or misuse. When the remaining margin is exceeded, failure appears sudden — even though the process began much earlier.
The trap of “it still works”
One of the most dangerous phrases on deck is “it still works”. Machinery that still works is often the most dangerous, because it invites continued operation under degraded conditions.
Crew become accustomed to compensating — applying more brake, slowing operations, manually assisting movement. Each workaround masks the fault while increasing reliance on human presence near moving machinery.
This is how faults turn into injuries.
Hydraulic systems: leaks are load warnings
Small hydraulic leaks are often treated as housekeeping issues. In reality, they indicate pressure loss, contamination risk, and seal degradation. As pressure drops, systems respond more slowly or unpredictably. Operators compensate with increased input, raising stress on components.
Hydraulic failure is rarely explosive. It is erratic — and erratic behaviour is what traps people.
Brakes: the most misunderstood component
Brakes on winches and windlasses are expected to “hold”. In practice, they are friction devices with finite capacity. Heat, contamination, and wear reduce effectiveness silently.
A brake that slips occasionally is not self-correcting. It is failing. Adjusting it tighter may restore holding temporarily while accelerating glazing and eventual loss of control.
🔻 Real-World Failure: Mooring Winch Brake Failure — Fatality at Port of Santos (2016)
In 2016, a fatal accident occurred during mooring operations at the Port of Santos when a mooring winch brake failed under load. The winch had shown signs of degraded braking performance prior to the incident, but operations continued with procedural adjustments.
When the line came under increased tension, the brake could not hold. The line ran out uncontrollably, resulting in a snap-back that fatally injured a crew member.
Investigators identified brake condition and decision-making under known degradation as key contributors. The equipment had not failed without warning; the warning signs had been normalised.
This case illustrates a recurring truth:
Machinery does not injure people.
Continuing to work around degraded machinery does.
Troubleshooting versus intervention
Troubleshooting should reduce exposure. In practice, it often increases it. Crew lean closer, place hands where they shouldn’t, and rely on instinct instead of isolation.
Senior deck officers understand that the safest troubleshooting step is often to stop. If isolation, lock-out, or redundancy cannot be established, the problem is not ready to be fixed.
Knowledge to Carry Forward
Deck machinery failures are slow, quiet, and deceptive. The greatest risk arises not when machines stop, but when they continue operating outside their design margins. Safe troubleshooting prioritises isolation and distance over speed and improvisation.
Competent deck officers treat degraded machinery as already failed, and manage it accordingly.
Tags
On Deck, Deck Machinery, Winches, Windlasses, Hydraulic Systems, Brake Failure, Troubleshooting, Human Factors, Deck Safety, Failure Modes