Answer Construction Question 5

Question 5: Discuss the need for adequate support of engine room gantry cranes, detailing the following:

(a) Sketch section through the engine room casing showing how the crane is supported by the ship structure;

(b) State what restricts the forward and aft limits of the crane and what is fitted to prevent the crane damaging the forward and aft bulkheads or casing.

(c) State the Second Engineer’s responsibilities for the engine room gantry crane.

Answer: (a) Crane support by ship structure:

A gantry crane is usually fitted in E/R of most of the medium & large size ships to allow tor removal of machinery parts for inspection maintenance & repair.

Typically, an overhead gantry crane of 5 tonne SWL is installed to cover the full width and to travel full length of casing. Crane usually runs on rolled steel joints rails having a rail bar welded on top. Cranes are supported at each end by support brackets tie them to stiffeners at ends of the casting, whilst intermediate brackets extend from casing side to restrict deflection of beams.

(b) Forward and aft limit arrangements of the crane 

The limit of forward and aft travel is restricted by stoppers fitted at the ends of each rail track. To prevent crane colliding with casing ends. At the same time two limit switches are placed at fore and aft end to cut off the power to the motor circuit. The limit of forward and aft travel is the end between the casing. Stops are fitted at the ends of each rail track to prevent crane colliding with the casing ends.

(c) Second Engineers' Responsibility:

Second engineer or a designated engineering officer by him shall carry out the following maintenance work on the engine room crane as per the planned maintenance schedule to ensure the machinery is maintained at good and safe working order.

Maintenance to be done: 

i. Check all cut out, limit switches for hosting lowering check wire condition, slack wire, and broken wire if broken strands then need to be renewed.

ii. Wire compound to be applied regularly,

iii. All greasing points to be regularly greased

iv. Hook should be in a position to swell easily,

v. Tracks to be greased regularly,

vi. Check bearing action and operation,

v. Check brake lining, drum condition too polished and too rough not allowed,

vi. Brake test by lifting a load and switch off power hook should not come down; vii. Emergency switch to be operating properly

viii. Check oil level in gear box;

ix. Check hook condition and it should have non-return flap plate

x. S.W.L marking

xi. Parking locks on track and crane. Together with Electrical officer all alarms and cut outs including audible alarm and siren while crane in operation shall be tried out on weekly basis;

xii. Check electrical overload relay operation;

xiii. Check motor insulation.

(c) The instructions By 2nd engineer:

i. Check the validity and keep the SWL certificates updated;

ii. Proper PPE shall be worn during the crane operation like helmet, hand gloves, reflective jackets etc.

iii. Stay away from the moving objects and maintain a safe distance from the traveling objects swing radius in all directions. Tie a secure rope to the moving and hold it firm to avoid any swing that can hurt the personnel or damage other equipment while swinging.

iv. An audible and visible alarm shall be in operation during its operation. If required assign board shall be placed at either ends to indicate to other personnel who are not involved in lifting operation to be aware that crane is in use.

v. Do not overload the crane more than its Safe working limit.

vi. Follow the safety hand gestures of lifting operation which shall be discussed between those who are involved in the operation prior to starting the operation.

vii. Always bring back the crane to its storing position and the lifting hook shall be either fully hoisted or secured close to the jib or the hook shall be connected to a strong point and hoist the hook until it gets fully stretched and held tight.