Q. What are the SOLAS requirements in respect of the location of collision bulkhead?
The forward most bulkhead is called the collision bulkhead and is meant to be a second barrier in a collision resulting in bow plate rupture and water ingress to the forepeak area. A collision bulkhead shall be water tight up to the freeboard deck. It is to be located from forward perpendicular to less than 5% of the length or 10m, whichever is the less and except as may be permitted by the Administration, not more than 8% of the length of the ship.
Q. What may be done on ships where a long forward superstructure is fitted?
Where a long forward superstructure is fitted, the collision bulkhead shall be extended weather tight to the deck next above the bulkhead deck. The extension shall be so arranged as to preclude the possibility of the bow door causing damage to it in the case of damage to, or detachment of, a bow door.
The weather tight extension required above need not be fitted directly above the bulkhead below, provided that it lies within the limits provided for the bulkhead. The part of the deck which makes the step is made effectively watertight.
Where a slopping ramp forms part of the extension, the part of the extension of collision bulkhead above the bulkhead deck, shall be weather tight over its complete length. In cargo ships the part of ramp which is more than 2.3m above the bulkhead deck, may extend forward of limits specified for collision bulkhead. Where the ramp does not comply with the above requirement it will not be accepted as an extension to the collision bulkhead.
Q. What are guidelines regarding securing?
The guidelines are applicable to:
- Road vehicles with an authorized total mass of vehicle and cargo between 3.5 to 40t.
- Articulated rod trains with an authorized total mass not more than 45t.
The decks shall be provided with securing points with:
- Longitudinal spacing < 2.5m
- Transverse spacing 2.8 < S < 3.0
- Minimum strength without permanent deformation: 20kN.
Lashing shall consist of chain or any other device made of steel or other material with equivalent strength and elongation characteristics. The strength of lashing without permanent deformation should not be less than 120kN. Lashings should be attached to the securing points with hooks or other devices. Lashings should only be attached to the secure points. The angle between the lashings and the horizontal and vertical planes shall be preferably between 30o and 60o.
Q. What is the recent circular in respect of Ro-Ro by Ministry of Shipping, India?
The circular is from Inland Waterways Authorities’ (MOS) of India. Circular is dated May, 2021. The circular relates to Standard Operating Procedures and Checklists for RoRo, Ropax Vessels Operations on National Waterways.
Q. What details must be provided regarding OMM Ro-Ro?
Operating and Maintenance Manuals should provide the following:
1. Drawings of the door systems
Details are to be described, in order to arrange for the crew a clear understanding of the functionality. Safety features are to be particularly emphasized. Where the shell doors or the inner doors next to the bow doors also serve as ramps for loading and unloading, the content of the OMM needs to be extended accordingly. Design criteria and operating conditions of the shell doors and especially of the ramps are to be provided.
The load limit when using purpose designed preventers or standers must be expressed as for following:
- permissible loads;
- quay limit level relative to ship’s draught or permissible range of inclination of the ramp;
- limiting trim and heeling angles during cargo handling and door operations; and
- limiting range of ambient temperatures.
Detail drawings are to be appended providing information on:
- supporting devices inclusive main hinges, limit wear and tear of individual elements and criterion for rejection;
- locking devices for the opened position of the door – location and adjustment of sensors, e.g. limit switches, proximity switches;
- references for the maintenance procedures;
- check points for gap gauging of the supporting devices such as thrust bearings;
- check points for the measurement of wear and tear of battening bolts, cleats, bearings of hinges etc;
- measurements which are to be performed without dismantling during intermediate surveys; and respective guidances;
- references for the spare parts in case of damages; and
- lubricant recommendation.
The arrangement of the sealings dedicated to maintain the weather or watertightness of the outer and inner doors needs to be described.
2. Documented Operating Procedures for Opening/Closing and Securing of the Doors and Ramps
The documentation must enable the user to operate the shell doors, inner doors and ramps, if applicable, in a safe manner. The closing and securing functions need to be described particularly clear. Besides safety precautions also the maneuvers running automatically must be explained in detail in order to provide a full understanding of the functions. References shall be given for troubleshooting of faults and failures and measures to be taken consequently. Emergency stops and emergency operation e.g. in case of energy supply loss shall be described. The documentation on the operating procedures is to be posted on board at appropriate places.
Q. In respect of maintenance what guidance must be provided in following areas:
a. Mechanical elements and wire rope.
b. Sealing arrangement (rubber gasket for weathertight / watertightness) of the outer and inner doors.
c. Hydraulic system.
The information to be provided should be as follows:
Mechanical elements and wire ropes:
- lubricating of sliding-contact bearings, supporting, securing and locking devices;
- appliances for ramps and doors, using recommended lubricants;
- condition check of wire ropes for the lifting appliances;
- visual inspection for detection of broken wires, deteriorated core, external and internal corrosion, deformations such as waviness, strand extrusion, local changes in diameter, flats;
- measurement of diameter mainly with respect to local changes;
- lubrication according to maker’s recommendation; and
- renewal of the wire ropes due to actual condition or maker’s lifespan recommendation.
Sealing arrangement (rubber gasket for weathertight / watertightness) of the outer and inner doors:
- visual inspection of rubber gaskets with respect to wear, aging, hardening, distortion;
- permanent impression to be measured and compared with limit permanent impression;
- cleanliness (surface shall not be painted over);
- greasing of surface especially for operating in cold climate; and
- visual inspection of the packing retaining channels.
- oil level check, maintenance of oil filters according to maker’s recommendation;
- condition check of hydraulic oil: treatment and replacement according to maker’s recommendation;
- condition check and replacement of the hydraulic oil hoses according to maker’s recommendation;
- cleanliness and tightness check of the entire hydraulic system;
- pressures, temperatures and filter indicators to be compared with nominal value range of maker’s recommendation, including operational behaviour of switches, valves, air breathers, electric motors;
- check of hydraulic cylinders for tightness, condition of rods, pins and spherical bearings if applicable;
- check of hydraulic oil hoses for interference and sharp bends and turns, rents, blisters;
- checking procedure of the water leakage detection system; and
- checking procedure of the drainage system in way of shell doors.
Q. What are the regulations in respect of protection of vehicle, special category and Ro-Ro spaces against fire?
Another amendment to regulation 20 of chapter II/2 was on protection of vehicle, special category and Ro-Ro spaces related to fixed fire-extinguishing systems. The amendments apply to ships constructed on or after 1 July 2014. Ships constructed before 1 July 2014 shall comply with the previously applicable requirements. It is to be noted that Part G of this chapter is, ‘Special Requirements’. Its regulation 20 is ‘Protection of Vehicle, Special Category and Ro-Ro Spaces’ (VESCROS). This regulation aims to provide additional safety measures in order to address the fire safety objectives for ships fitted with VESCROS. It wants fire protection systems shall be provided to adequately protect the ship from the fire hazards associated with VESCROS. The VESCROS must be separate from ignition sources, well ventilated. Precaution against ignition of flammable vapours in VESCROS.
In respect of fixed fire detection and fire alarm systems, Fire Safety Systems Code must be complied with. The fixed fire detection system shall be capable of rapidly detecting the onset of fire. The type of detectors and their spacing and location shall be to the satisfaction of the Administration, taking into account the effects of ventilation and other relevant factors.
- Vehicle spaces and Ro-Ro spaces which are not special category spaces and are capable of being sealed from a location outside of the cargo spaces shall be fitted with a fixed gas fire-extinguishing system. If a carbon dioxide fire-extinguishing system is fitted, the quantity of gas available shall be at least sufficient to give a minimum volume of free gas equal to 45% of the gross volume of the largest such cargo space which is capable of being sealed, and the arrangements shall be such as to ensure that at least two thirds of the gas required for the relevant space shall be introduced within 10 min. Any other fixed inert gas fire-extinguishing system or fixed high expansion foam fire-extinguishing system may be fitted provided the Administration is satisfied that an equivalent protection is achieved.
- Ro-Ro and vehicle spaces not capable of being sealed and special category spaces shall be fitted with an approved fixed pressure water-spraying system for manual operation which shall protect all parts of any deck and vehicle platform in such spaces. Such water spray systems shall have clear marking on each manifold valve indicating the spaces served. A sufficient number of drainage valves are to be provided.
- The Administration may permit the use of any other fixed fire-extinguishing system that has been shown, by a full-scale test in conditions simulating a flowing petrol fire in a vehicle space or a Ro-Ro space.
Q. What are the recent amendments in respect of ventilation arrangements on Ro-Ro vessels?
Effective power ventilation system, with up to 10 air changes are to be provided. Monitoring shall be provided on the navigation bridge. Arrangements shall be provided to permit a rapid shutdown and effective closure of the ventilation system from outside of the space in case of fire, taking into account the weather and sea conditions.
MSC.1/Circ. 1515 dated June 2015 is in respect of revised guidelines for the design of suitable ventilation systems for vehicle decks on Ro-Ro ships, car carriers and car ferries.
Ventilation systems for Ro-Ro cargo spaces on board ship generally operate according to the principle of dilution, whereby the supply air flow to the area is sufficient for the exhaust gases to mix thoroughly with the air and be removed. There are two main types of dilution ventilation: exhaust air ventilation and supply air ventilation. Briefly, in exhaust air ventilation, fans remove air from a Ro-Ro cargo space, and this is then replaced by outdoor air entering through open ramps, doors and other openings. Exhaust air ventilation is employed when sub-atmospheric pressure is required in the Ro-Ro cargo space. The sub-atmospheric pressure prevents the pollution from spreading to adjacent areas.
Supply air ventilation works in the opposite way. Fans deliver outdoor air into the Ro-Ro cargo space and the air is then exhausted through ramps and other openings. Supply air ventilation usually creates slight pressurization of the Ro-Ro cargo space.
Q. In respect of various dangerous gases what guidance is given by above circular?
It deals with various exhaust gases and their composition. Thus, exhaust gases from motor vehicles contain hazardous substances. Carbon Monoxide (CO) from petrol engines, and Nitric oxide (NO) and Nitrogen Dioxide (NO2) from diesel engines. Certain substances have a tangible, immediate effect. Others only show injurious effects after a person has been exposed to them for some time. Carbon Monoxide (CO) is a colorless and odourless gas which, to a lesser or greater extent inhibits the ability of the blood to absorb and transport Oxygen. Nitric Oxide (NO) and Nitrogen Dioxide (NO2) are compounds of Nitrogen and Oxygen. NO2 is a brown gas which has a stinging, suffocating odour. It exerts a detrimental effect on the human respiratory system. Asthmatics in particular are susceptible to exposure.
Q. How to estimate the flow of outdoor air required to duly dilute the polluted air in cargo spaces?
The basic particulars necessary for calculating the supply air required are contained in ISO 9785:2002 or national versions of this standard. To assess the number of vehicles which may be in operation at the same time in a cargo space without the occupants being exposed to a hazardous or discomforting level of pollution the guidance contained in ISO 9785:2002 for estimating the flow of outdoor air required to dilute and remove the gases exhausted by a vehicle should be followed.
Q. Is there any resolution in respect of securing of cargo within the cargo units?
In Resolution A.533 (13) it was stated that cargo ‘is stowed on and secured to cargo units and vehicles in most cases at the shipper’s premises and that the cargo on cargo units and vehicles may not always be adequately stowed or secured for safe sea transport’. Also in later Resolution dealt with the required adequacy of lashing such cargo units. Code of Safe Practice for the Safe Stowage and Securing of Cargo, Cargo Units and Vehicles aims towards advising masters of the specific hazards and difficulties associated with the transport of certain cargoes; the stowage and securing of such cargoes; and associated ship handling measures.
Q. Are there any guidelines in respect of safety of passengers and crew from moving vehicles on Ro-Ro vessels?
Marine Guidance Note (MGN) 19 M is regarding Vehicle Decks of Ro-Ro Ships, accidents to Personnel, Passenger Access and the Carriage of Motor Vehicles. This guidance highlights the dangers to passengers and crew from moving vehicles during loading and unloading operations on board Ro-Ro ships. The passengers must be restricted from enclosed vehicle decks. The amount of fuel carried in the tanks of motor vehicles etc must be strictly monitored. Vehicle deck becomes a dangerous place due to congestion and the movement of vehicles, owing to flammable fuel in these vehicles. Ship owner and employers have a general duty to ensure safety of employees. The danger could be due to atmosphere or accident.
Q. How does IMO emphasize on the importance of securing cargo units on Ro-Ro vessels?
In 1981 the Assembly adopted guidelines on the safe stowage and securing of cargo units in ships other than container ships (resolution A.489 (XII)).
Ships should carry a Cargo Securing Manual ‘appropriate to the characteristics of the ship and its intended service, in particular the ship’s main dimensions, its hydrostatic properties, weather and sea conditions which may be expected in the ship’s trading area and relevant to the cargo. In MSC/Circular 385 issued in January 1985 a uniform approach to the preparation of Cargo Securing Manuals, their layout and content was desired. It covered details of fixed cargo securing arrangements and their location, location and stowage of portable cargo securing gear and method of securing. Direction & magnitude of forces likely, to act on cargo units in various positions on board the ship.
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