Question 1

Reversing of engine

Accepted Answer

Reversing swaps ahead to astern through air and oil: solenoids shift the distributor, cams and fuel follow, interlocks guard the sequence. Telegraph to stop, then astern: the ahead-astern solenoid shifts air to the reversing servo through oil and air lines. Air start distributor, manifold valves and fuel-pump timing move to the astern setting together. Interlocks with fuel pumps block a start mid-travel; a stuck solenoid or blocked line holds her in the old direction. Prove by watching the control move to reverse mode on the telegraph ring before admitting starting air. Surveyor follow-up: air pressure good, telegraph astern, still starts ahead — solenoid, distributor or interlock, and where do you look first?

Question 2

Davit limit switch

Accepted Answer

Davit limit switches stop steel meeting steel: hoist and lower motions die at their ends with the winch proved on test weight. Upper hoist switch stops the hook before the sheave; lower switch stages the boat at embarkation and waterline. Proved by slow-hoisting to the automatic stop with test load aboard — creep past the stop fails the davit. Dead-man handle, harbour pin and brake back the switches on power loss and stow. Launch proved at list and trim with falls turned and renewed on schedule. Surveyor follow-up: upper switch passes empty but drifts loaded — brake, switch or falls, and what first?

Question 3

Failsafe brake means

Accepted Answer

Fail-safe means the brake sets when power is lost: the springs hold it, and only current releases it. Brake pads sit applied inside the drum and are pushed in by magnetic springs when idle or on power failure. As the crane or winch is operated, current compresses those springs and the brake releases for the lift. So a power failure or an emergency stop leaves the load held rather than dropped — that is the whole point. It is a safety function, which is why the brake is proved with the crane loaded, not just switched on and off. Surveyor follow-up: fail-safe brake proved open on a power failure — is the coil, the spring or the air gap?

Question 4

Safety on lifeboat davit? Upper limit switch on one arm or two?

Accepted Answer

A gravity davit is lowered by gravity with centrifugal brake control, so the safety is in the brake and the limit switches. The wires which lift and lower the lifeboat are the falls, and gravity lowered boats must be capable of releasing the boat with the falls off. On gravity davits the speed of lowering is controlled by centrifugal brakes, and the falls are released by a pull-release wire from the boat. Hoisting time must not be less than the stated figure and the speed of lowering is not to exceed the limit set for the craft. Each davit arm has its own upper limit switch so a stored energy or hoisting fault on one arm cannot be masked by the other. Surveyor follow-up: one arm with a failed limit switch on a pair davit — can the other arm be trusted to stop?

Question 5

The steering gears used onboard can be a variety of types,clasify the various types with a simple chart. b) describe statutory requirements for i) A main steering gear ii) an auxiliary steering gear , as can be described

Accepted Answer

Two families — electro-hydraulic and all-electric — and the statute splits the duty between a main gear that must work and an auxiliary that must be there. Electro-hydraulic gears are ram type, with two or four rams, or rotary vane; all-electric gears are Ward Leonard or single motor. Control is either non-follow-up, where the gear is set to off once the rudder reaches the ordered angle, or follow-up with hunting gear. Statutorily the main steering gear must be of sufficient power and capable of being operated from the bridge and from the steering gear compartment itself. The auxiliary steering gear must be independent of the main, of separate power supply, and able to put the rudder over at a defined rate for a stated time. Surveyor follow-up: auxiliary gear sharing the main gear’s motor room and power supply — does that satisfy independence?

Question 6

What is proximity switch and limit switch and difference between them

Accepted Answer

A proximity switch senses without contact; a limit switch is tripped by a mechanical stop — one is a presence detector, the other an end stop. A proximity switch detects a target — metal or magnetic — across a gap, with no physical contact and no wear. A limit switch is a mechanical switch operated by a cam or lever at a defined travel position. On a davit, an upper limit switch on each arm stops the hoist before the falls run out or the arm fouls. A proximity switch may be used as an extra presence or approach check, but it does not replace the positive limit. Surveyor follow-up: davit with a proximity switch but no positive upper limit fitted — compliant, and what happens at full hoist?

Question 7

electromagnetic fail safe brake working

Accepted Answer

The brake is held on by springs and released by the solenoid, so power loss means the brake sets — that is the fail-safe direction. Because the braking point is usually remote from the operator, the brake is mechanically applied and electrically released. When no power is applied the springs hold the friction brake and drum securely; energising the solenoid overcomes the spring pressure and releases it. The magnetic field from the solenoid pulls the levers apart against the spiral springs connected to them, opening the brake. So on a power failure the springs win, the brake sets, and a hoisted load is held — which is the whole point of the arrangement. Surveyor follow-up: winch brake that releases when the power fails — what has been wired, and where?

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