HYDRAULIC SAFETY ON CHEMICAL TANKERS- CAPT AJIT VADAKAYIL
On chemical tankers all should be proactive on matters concerning safety.
This means you are on the lookout for coming shadows, not at the wake of events. It must be clearly understood that prevention is better than cure.
A near miss is something which has already happened. An OOW on the bridge does NOT care for fishing boats in the wake of the ship.
When working overside, this means-- crew will wear a safety harness , not safety belt.
RISK ASSESSMENT is a tool for the safety of sailors. This sheet of paper is NOT meant for external auditors. For the matrix to show the reality ( like when crew is going down into the tank for squeegeing ) it must have SEVERITY on X axis and PERIOD OF IMPACT/ CERTAINTY on the Y axis.
A fine spray of hydraulic oil is more explosive that a fine spray of Gasoline. This is due to the auto ignition temp of hydraulic oil being lower. AIT is the temp at which a gas will ignite without an external source of ignition. There is no relationship between FP, volatility and AIT. On the contrary in some cases non-volatile product has a lower AIT.
Never open a pipeline of valve or even a drain cock unless the internal pressure has been de-pressurised in a controlled manner , while wearing proper PPE.
Hydraulic systems are also very dangerous systems due to the extreme pressures involved. 300 bar is not uncommon and if you want a comparison, a bullet leaves the barrel of a gun at much lesser pressures .
Hydraulic oil under pressure can pierce you like an arrow. Pinhole leaks are difficult to locate. A person may notice a damp, oily, dirty place near a hydraulic line. Not seeing the leak, the person runs a hand or finger along the line to find it. When the pinhole is reached, the fluid can be injected into the skin as if from a hypodermic syringe.
Immediately after the injection, the person experiences only a slight stinging sensation and may not think much about it. Several hours later, however, the wound begins to throb and severe pain begins. By the time a doctor is seen, it is often too late, and the individual loses a finger or entire arm.
Unfortunately, this kind of accident is not uncommon. To reduce the chances of this type of injury, run a piece of wood or cardboard along the hose (rather than fingers) to detect the leak Coat cylinder rods with protective lubricants to avoid rusting.
Failure of the system could cause damage to vessel, personnel and cargo.
Personnel using hydraulic equipment should be fully conversant with the proper procedures for its safe operation. Operating instructions should be followed at all times.
Operators should ensure that the pressures shown on a gauge is within the operating parameters set by the manufacturer.
When the equipment is in use, operators should never reach through a linkage of any hydraulically operated mechanism to set, adjust or operate the controls.
Only authorized personnel should undertake repairs to the equipment or adjustment of the pressure settings of safety devices.
The equipment should not be operated if it is in any way faulty without prior permission from the Chief Engineer who must ensure further operations will not compromise safety.
The operator should ensure that all pressures have been released prior to disconnecting any line, plug, etc.
Only use manufacturers' recommended grades of hydraulic fluid.
Keep oil clean. Follow manufacturers' maintenance schedules for changing filters. Efficiency of hydraulic systems is directly related to cleanliness.
Leaks add to danger by causing slippery decks and accidents.
Any spillage of hydraulic fluid should be cleared up immediately. Some fluids are based on mineral oils and any such fluid on the skin should be thoroughly and quickly washed off.
Since vapors from hydraulic fluid may be flammable, naked lights should be kept away from hydraulic equipment being tested or serviced.
Hydraulic leakages to deck can easily run off into the sea and cause pollution. The entire crew should know how to use the emergency stop button. Leaks should be promptly reported to the responsible officer. Every effort shall be made to quickly stem any leaks. Spillages should be quickly cleaned.
Accumulators are designed to store oil under pressure when the hydraulic pump cannot keep up with demand, when the engine is shut down, or when the hydraulic pump malfunctions. Even though the pump may be stopped or an implement disconnected, the system is still under pressure. Always release pressure first. Use the company checklist.
Avoid servicing the hydraulic system while the machine engine is running.
Before disconnecting oil lines, relieve all hydraulic pressure and discharge the accumulator.
Use a non-volatile cleaning solvent to wash parts
Pressure relief valves that are maintained, cleaned and tested regularly help avoid dangerous pressure buildups.
Keep contaminants from hydraulic oil and replace filters regularly.
SAFETY IS THE RESPONSIBILTY OF THE ENTIRE CREW LIST -- NOT JUST 4 STRIPERS OR THE SHORE SUPERINTENDENT.
CAPT AJIT VADAKAYIL
29 years in command.