Ship’s General Arrangement Plan — Transcript

Welcome to Marine Gurukul video series. In this video, we shall try and understand one of the most important plans on the ship: the ship's general arrangement plan, or the ship's GA plan. This plan is so important because it is this plan that familiarizes a person with the layout of the spaces on board the ship. Scope of this video includes illustration of general arrangement plan of different ship types, which include general cargo ship, bulk carriers, container ships, passenger ships, tankers including oil, chemical, and gas tankers, combination carriers, and the roll-on roll-off vessels, the RORO ships. Before we start discussing the GA plan of different types of ships, it may add value if we can understand what a GA plan actually is. We know the ships are built for a certain purpose. Accordingly, based on the purpose, the size, dimensions, allocation of spaces within the ship is done, and of course, this allocation has to meet the requirements of applicable rules and regulations. The layout of each vessel will largely depend on its type, the ship type that is, general cargo, tanker, etc., etc., and the owner's specific requirements, if any, like location of machinery space, the size of accommodation, etc., etc. Efficient operation of a ship depends on proper arrangement of each individual space and the efficient interrelationship amongst different spaces. The general arrangement of a vessel can be defined as the allocation of different spaces for different functions or the crucial functions for the operation of the vessel and showing the allocation. Such allocation of spaces for different functions is what is called as the general arrangement or the GA plan. As the GA plan represents the space allocation of the ship, which is a three-dimensional body, and it's being represented on a plane paper or a plane surface, the GA plan uses combination of different views to cover the entire three-dimensional body. It uses the side view of the ship, that means as you look at the ship from port or starboard side, also called as the elevation, also referred to as the profile view. So, side view, elevation, and the profile view are all same. Top view or the plan view or the bird's eye view is another view that is used. And lastly, the midship cross-sectional views, that means along the length of the vessel, if the vessel is cut at point of interest and then you look at that cut section from one of the ends, that is what is called as the cross-sectional view. To facilitate easy familiarization of the ship, a copy of the GA plan is always displayed in a conspicuous location that is accessible and frequently visited by the ship's crew. The GA plan of the ship includes the following: number of cargo compartments and their location, location of tanks and void spaces like cofferdams, location of machinery space, accommodation, location of cargo handling gear, location of emergency steering gear, emergency generator and emergency fire pump, etc., location of bridge, lot room, location of gangway, dimensions of the ship, that is length, breadth, draft, depth, etc., ship stunting both gross and net, and the date keel was laid and the keel plating. Now, depending on ship to ship, all these information may be there as part of GA plan, some may be omitted and contained in other plans, but largely this is the information that is contained in the GA plan of our ship. Let us start with the GA plan of a general cargo ship. Here is the photograph of the ship whose GA plan would be displayed and shared shortly. What we are having is the profile view of the ship viewing it from the starboard side. We can see it's a two-hatch ship with two cranes. You have lifeboats, funnel, accommodation aft, engine room aft, and the mast. Please keep this picture at the back of your mind. Now, if we look at the GA plan of the ship, the GA plan of the ship looks like this. Here you have the profile view or the side elevation, two-hatch ship with two cranes, forward mast, and other things as we discussed in the picture. Then we have the plan view of various decks. This is the main deck plan view at this level. This is the second deck, the plan view at the tween deck level, and the tank top plan view, that is, or at the inner bottom or the tank top, that is the lower part of the hold of the ship. So, we have the three plan views here. We have the plans of each of the decks, fo'c'sle deck and other decks in the accommodation. So, we have all these plans out here and this full thing constitutes the GA plan of this particular vessel, Toyo Hope. Now, in this, some of the images have been enlarged so that we can understand as to how to read these plans because that is the objective of this discussion. Now, this particular profile view has been zoomed in for your benefit and you can see in this case that whatever, if you recall that picture of the ship, I am sure you can map this profile view very easily with that particular picture of the ship which was being seen from the starboard side. Another small plan of captain's deck here has been zoomed in for the benefit of those viewing the video. This plan, when zoomed in, looks like this. You can see each of the cabins out on this deck have been allocated for a certain purpose and once you have access to the GA plan, you can exactly know on this deck which space is allocated for which function. We continue with our efforts of mapping the profile view with the plan view. So, here we have the same profile view of the ship under discussion. Right below this, we now zoom in the plan view of the upper deck. You can see the plan view of the upper deck coming up here. And if you want to now correlate the two, you can very well see that on the upper deck here is the post for the crane. This line represents the crane base. You have the two hatchways here. Now, in this, you can make out that the pond hatch covers are folding type pontoons which get stacked, so pontoon multi-pontoon type which gets stacked at one end. So, for hatch one, you can see the pontoons in the open position will get stacked at the forward end, which are being shown here in this diagram by these earthward ship lines. The pontoons for the hatch number two will get stacked at the after end shown out here. Of course, when the hatch cover is closed, the pontoons are covering the hatchway. In the profile view, you can see machinery space is here, a superstructure or the accommodation is here, and whatever is at the main deck level is being shown in this plan at the upper deck. Now, on the upper deck, we have in the profile view the hatch coaming on which will have the hatch cover, so hatchway protected by hatch coaming and having the provision to close through a hatchway. So, for number two hold, if we see, this represents the hatch coaming and, of course, on top would be the cover. When the covers are opened, they get stacked in this part. If we try to identify the same thing on the upper deck here plan, in the plan view of the upper deck, this represents the hatchway, the opening for number 2 hatch, which will be covered with the hatch cover, and when open, the pontoons will be stacked in the after portion out here like this. Whatever is here at the upper deck level, at this level in this profile view, can all be mapped with the same things shown on the plan view for the upper deck. Now, we do the mapping of the clean deck level, that is the tween deck plan view or the second deck plan view, which is now right below the profile view. That means whatever we are able to see on this plan of the second deck, we are basically talking of this level in the profile view. Now, if you see in this case, below the tween deck, there are some tanks even in the cargo region. Now, tween deck forms the top of these tanks. That means if you see number three ballast tank port and starboard, its top is at the tween deck level. So, this plan view forms the top of these tanks. So, that means these tanks' boundaries can also be shown in this plan view so that the transverse or span of these tanks or compartments can also be appreciated. So, now in this, if you see here, we have a set of tanks, fuel...

that familiarizes a person with the layout of the spaces on board the ship scope of this video includes illustration of general arrangement plan of different ship types which include general cargo ship bulk carriers container ships passenger ships tankers including oil chemical and gas

tankers combination carriers and the roll on roll of vessels the roro chips before we start discussing the ga plan of different types of ships it may add value if we can understand what a ga plan actually is we know the ships are built for a

certain purpose accordingly based on the purpose the size dimensions allocation of spaces within the ship is done and of course this allocation has to meet the requirements of applicable rules and regulations the layout of each vessel will largely

depend on its type the ship type that is general cargo tanker etc etc and the owners specific requirements if any like location of machinery space the size of accommodation etc etc efficient operation of a ship depends on proper arrangement of an

of each individual space and the efficient interrelationship amongst different spaces the general arrangement of a vessel can be defined as the allocation of different spaces for different functions or the crucial functions for the operation of the vessel and

showing the allocation such allocation of spaces for different functions is what is called as the general arrangement or the ga plan as the ga plan represents the space allocation of the ship which is a three-dimensional body and it's being represented on a plane

paper or a plane surface the ga plan uses combination of different views to cover the entire three-dimensional body it uses the side view of the ship that means as you look at the ship from port or starboard side

also called as the elevation also referred to as the profile view so side view elevation and the profile view are all same top view or the plan view or the bird's eye view is another view that is used

and lastly the midship cross-sectional views that means along the length of the vessel if the vessel is cut at point of interest and then you look at that cut section from one of the ends that is what is called as the

cross-sectional view to facilitate easy familiarization of the ship a copy of the ga plan is always displayed in a conspicuous location that is accessible and frequently visited by the ship's crew the ga plan of the ship includes the following

number of cargo compartments and their location location of tanks and void spaces like offer dams location of machinery space accommodation location of cargo handling gear location of emergency steering gear emergency generator and emergency fire pump etc location of bridge lot room

location of gangway dimensions of the ship that is length breadth draft depth etc ship stunning both gross and net and the date keel was laid and the keel plating now depending on ship to ship all these information may be there as

part of ga plan some may be omitted and contained in other plans but largely this is the information that is contained in the ga plan of our ship let us start with the ea plan of a general cargo ship

here is the photograph of the ship whose ga plan would be displayed and shared shortly what we are having is the profile view of the ship viewing it from the starboard side we can see it's a two hat ship with two

cranes you have live boats funnel accommodation aft engine room aft and the mass please keep this picture at the back of your mind now if we look at the ga plan of the ship the ga plan of the ship looks

like this here you have the profile view or the side elevation two hatch ship with two cranes forward mast and other things as we discussed in the picture then we have the plan view of various decks this is the main deck

plan view of at this level this is the second deck the plan viewer at the tween deck level and the tank top plan view that is or at the inner bottom or the tank top that is the lower part of the lower part of the hold

of the ship so we have the three plan views here we have the plans of each of the decks foxel deck and other decks in the accommodation so we have all these plans out here and this full thing constitutes the ga plan

of this particular vessel toyo hope now in this some of the images have been enlarged so that we can understand as to how to read these plans because that is the objective of this discussion now this particular profile view

has been zoomed in for your benefit and you can see in this case that whatever if you recall that picture of the ship i am sure you can map this profile view very easily with that particular picture of the ship which was being seen

from the starboard side another small plan of captain's deck here has been zoomed in for the benefit of those viewing the video this plan when zoomed in looks like this you can see each of the cabins out on

this deck have been allocated for a certain purpose and once you have access to the ga plan you can exactly know on this deck which space is allocated for which function we continue with our efforts of mapping the profile view with the plan view

so here we have the same profile view of the ship under discussion right below this we now zoom in the plan view of the upper deck you can see the plan view of the upper deck coming up here

and if you want to now correlate the two you can very well see that on the upper deck here is the post for the crane this line represents the crane base you have the two hatch ways here now

in this you can make out that the pond hatch covers are folding type pontoons which gets stacked so pontoon multi pontoon type which gets stacked at one end so for hatch one you can see the pontoons in the open position will get

stacked at the forward end which are being shown here in this diagram by these earthward ship lines the pontoons for the hatch number two will get stacked at the after end shown out here of course when the hatch cover is closed

the pontoons are covering the hatchway in the profile view you can see machinery space is here a superstructure or the accommodation is here and whatever is at the main deck level is being shown in this plan at of the upper deck

now on the upper deck we have in the profile view the hatch combing on which will have the hatch cover so hatchway protected by hatch combing and having the provision to close through a hatchway so for number two hold if we see

this represent the hatch coming and of course on top would be the cover when the covers are opened they get stacked in this part if we try to identify the same thing on the upper deck here plan in the plan

view of the upper deck this represents the hatchway the opening for number 2 hatch which will be covered with the hatch cover and when open the pontoons will be stacked in the after portion out here like this whatever is here at the upper

deck level at this level in this profile view can all be mapped with the same things shown on the plan view for the upper deck now we do the mapping of the clean deck level that is the tween deck

plan view or the second deck plan view which is now right below the profile view that means whatever we are able to see on this plan of the second deck we are basically talking of this level in the profile view

now if you see in this case below the tween deck there are some tanks even in the cargo region now twin deck forms the top of these tanks that means if you see number three ballast tank port and starboard

its top is at the twin deck level so this plan view forms the top of these tanks so that means these tanks boundaries can also be shown in this plan view so that the transverse or span of these tanks or compartments can

also be appreciated so now in this if you see here we have a set of tanks fuel oil tank port and starboard that means from with the tween deck forming the top of these tanks and in this plan view

these tanks are here port and starboard of course the tanks are below this plan view level we can map the other tanks port and starboard now you see whereas these fuel oil tanks were covering the full span of the ship

with port and starboard these ballast tanks are only on the sides so here is the number four port side water ballast tank number four starboard side and number three number two number one we can see all these ballast

tanks being here now the this uh profile view shows their longitudinal extent and this would show their longitudinal extent as well as their transverse or warship extent we do the mapping of these tanks and this void space out here

now let's also appreciate the extent of tween deck number two to index in the profile view in the profile view we see this space represents number 2 twin deck or number 2 upper cargo hold whatever you want to call it

now you see in this profile view we can appreciate its longitudinal extent it extends from the forward bulkhead of the number two hold to the after bulkhead of the number two hold in this we can also appreciate its

vertical extent it extends from the tween deck that is the second deck to the upper deck so this defines the longitudinal boundaries of this tween deck and also the vertical boundaries if the same twin deck is to be shown in

the second deck plan view then the clean deck would be shown like this now here we can appreciate its longitudinal view here is its forward bulkhead here is the after bulkhead so the longitudinal extent is from forward bulkhead of the

compartment to the after bulkhead of the compartment but the transverse view which could not have been or the athlonship span which would not have been appreciated in the profile view now becomes absolutely clear the number two upper cargo hold or

number two tween deck extends from ship side to ship side why because these tanks on the sides are not extending above the second deck they are all below the second deck so the twin deck extends from side to

side i hope you are able to understand this mapping which is going to make it very very easy for you to interpret the ga plan of your ship when you get a chance to read it let us now map the profile view of the

ship with the plan at the tank top level or the inner bottom level in this plan the tank top plan has been named as old and bottom plan so the hold and bottom plan is right beneath the profile view for

ease of mapping and let us appreciate the span of number two lower cargo hold in this case now if we look at both the profile view in the plan view at the queen deck level and now at the tank top level

what do we see that unlike the twin deck which extended from the forward bulkhead of number two compartment to the after bulkhead of number two compartment which separated it from the machinery space number two lower hold starts at the

forward bulkhead yes but it does not go right up to the machinery space bulkhead it ends at a bulkhead which separates the cargo space in the number two lower hold with number from number one fuel oil tank why we can say that number two lower

hold ends here because if you see in the plan view of the previous second deck or the plan view at this level what do we see that number one fuel oil tank port and starboard cover the entire earthward ship span of

the ship from ship side to ship side therefore the length of number 2 lower cargo hold gets reduced compared to the length of number 2 twin deck what about the earthwardship spec now in number two twin deck there were

no tanks on the sides the number two twin deck extended from ship side to ship side but we see that in the lower hold region we have these tanks on the side as far as number two old is concerned

in this region we have number three and number four tanks on the sides then yes between then there is nothing so in this part where it is written as number two lower cargo hold in this part the cargo hold extends from

ship side to ship side but in this region the cargo hold width is reduced and it starts from the inner boundaries of these water ballast tanks so if we draw mark out the boundaries of number two lower hold

in this plan view and the boundaries would be like this that means it starts from the forward bulkhead but its width is reduced to allow for these ballast tanks on the sides and then it continues then when the number four water balance

tank ends there the width is span is right friendship side to ship side and then they end at this bulkhead which separates the cargo space from number one fuel oil tank i hope you can appreciate in this that when we read

these two plants in conjunction then only can we appreciate the complete shape of number two lower cargo hold having discussed in reasonable detail the ga plan of a general cargo ship and more importantly having learned to read the plan

and be able to map the profile view with the respective plan view so as to appreciate the shape and size of each space allocated for a certain function now we can quickly run through the ga plan of other types of ships

as far as ga plan of a bulk carrier is concerned not much of a difference except some difference in this cargo space here are the two photographs of the same ship whose ga plan we shall be seeing on the screen shortly

we can see it's a geared bulk carrier that means it has its own gear the cranes for handling the bulk cargo it's a five hedge ship with machinery space and superstructure aft and a stern launched free fall lifeboat

if you can keep this picture at the at the back of your mind then you can easily appreciate as to why this profile of this bulk carrier has been drawn this way i'm sure it should not be a problem now

now in this ga plan this set of small plants here are the different decks in the super structure this one here is the midship section in the way of the cardboard spaces this one is the profile of the bulk area or the side elevation

this one is the plan at the upper deck level then we have these plants at the top of the foxel and different decks in the machinery space and lastly we have plan at the top level we know how to correlate this profile

with the plans at different levels the only difference that the bulk carrier plan would have is always the general cargo plan is the layout of the cargo space which can be appreciated in this midship section here there is no twin deck

the cargo hold extends from tank top to the upper deck and because it's a bulk carrier to facilitate the trimming of the cargo when the hold gets filled up the sharp edges are avoided by way of providing these upper hopper tanks you

can see these slanting things creating space for tanks which can be used for carrying ballast these are called as upper hopper tanks upper hopper helps in trimming of the cargo as the compartment gets filled with bulk cargo similar hopper is also made at the lower

or the lower part and we have the lower hopper at the side on the sides why because as you discharge the cargo these lower hopper will reduce the entrapment of the cargo in the sharp corners formed and the cargo will

basically slid down slide down into the hatchway so that it can be easily handled by the cargo discharging gear but for this difference rest everything is like a general cargo ship of course space allocation will vary from ship to ship as said in

the initial introduction to the ga plan va plan of a container ship so let's have a look at the photographs of some container ship of course the ga plan does not belong to the same ship but it will you will be able to correlate

here is the ship container ship seen from the side you can see containers tapped on deck of course they are also stacked under deck and this is the container ship scene from aft so you can appreciate the cross sectional view

where the containers are stacked on deck again here and of course in the cargo region they would be stacked below the deck as well now if you see these two photographs then i am sure you will be able to correlate

the ga plan of a container ship with these two photographs here is the profile view of this ga plan in which in the cargo region you have the container stacked under deck and you have the containers on deck

you have the plants at different levels and here is the midship section in the way of cargo space you have containers under deck and then you have containers above the deck as we saw in the picture i'm sure if those two pictures are at

the back of your mind you will be able to correlate this midship section and this profile view with those two photographs and that's what the ga plan of a container ship looks like now ga plan of a passenger ship again

if you can appreciate the photograph of a passenger ship any passenger ship which looks like this from the side you will be able to appreciate the profile view in the ga plan of a passenger ship here is the ga

plan of the passenger ship you can see you now understand why it is so it has multiple decks above the upper deck also to house the passengers it can have the passengers below the upper deck also depending on the

category of passengers being housed and each deck because it will have multiple decks in this plan we have picked up only two decks deck 8 and 9.

of course in the ga plan you will have the plan view of all the decks on the ship so this is how the ga plan of a passenger ship would look like ga plan of an oil tanker here is the

photograph of an oil tanker where the hose handling gear close to the manifold accommodation and machinery space soft and of course we'll have the other equipment on deck which is appropriate to a tanker now the ga plan would include the profile

view would include the plan view and would include the midship section now we can appreciate in this case it's a double hull tank you can see in the midship section there is a outer side there is an inner side like we have two

bottoms in the double bottom ships in this case we additionally have two sides now the extent of cargo spaces car because that's the primary difference between a general cargo ship and a tanker that the cargo space layout may be slightly different

so let us take any one tank let's take number two tank and if we read this profile view with the midship section we'll be able to appreciate the extent or the boundaries of these tanks let's take any oil tanker

it will be basically if i talk of number two cot cargo oil tank it starts from its forward bulkhead up to the after bulkhead so these two bulkheads define the longitudinal span of number two co2 this one defines the

longitudinal span of number one co2 now the vertical span of all the cargo oil tanks is from tank top to the upper deck so in this profile view we can appreciate the longitudinal span of the cargo tanks and their vertical span to

appreciate their transverse span of warship span we should go either to the plan or to the midship section view in this case it will be easier for us to comprehend in the midship section will come here and see

as far as the athwartship span is concerned the cargo spaces are divided into ports towards and center by two longitudinal bulkheads this is one longitudinal bulkhead this is another longitudinal market which divides the space into port starboard and

port starboard and center now the side tanks side cargo oil tanks they start from this longitudinal bulkhead and extend up to the inner side so their breath is from this longitudinal bulkhead to the inner side the transverse span of this wing tank would

be from this longitudinal bulkhead to this inner side and between these two longitudinal bulkheads would be the center tank the center c cargo oil tank so the cargo oil tanks vertical span from tank top to upper deck longitudinal span from their respective

forward bulkhead to the after bulkhead transfer span for center tank between the two longitudinal bulkheads in this case and the wing tanks from the longitudinal bulkhead to the inner side the water ballast tanks in this case are the water ballast tanks are between the

two sides and the double bottom now in this particular ship the water ballast tanks are divided into port and starboard and each of these ballast tanks is l shaped so this space between the two sides is ballast tank

and this combined up to the center line so over which this cursor is running this entire space represents one water ballast tank and its other counterpart shall be from here this l so these water ballast tanks are divided

by the center line girder in the double bottom tank of course these dbs are also divided longitudinally so we can have number one water balance tank number two water ballast tank but number one we'll have number one port and number one starboard

number two will have number two port two starboard and likewise so if you can read these two plants together you will be able to appreciate the ga plan of a tanker the ga plan of a chemical tanker is

going to be similar to that of a oil tanker primarily both are tankers both are designed to handle liquid the only difference being a in their size because chemical tankers may not be as big as what we may have in

oil tankers number two the chemical tankers are designed to carry certain categories of cargos based on their certification the material of which the tank is made and the coating that the tank may have has to be suitable for the cargo's the

chemical tanker is certified to carry so primary difference would lie in making the cargo spaces suitable for the intended car goes to be carried another difference may be that in a chemical tanker you may have a dedicated pump room

and a certain number of pumps like oil tankers else each of the tanks on a chemical tanker may have its own pump submersible pump called as the framework pump that will give the tanker more flexibility to carry multiple grades at

the same time rest the chemical tankers can have other design differences because not many if not many chemicals may need heating then the owner may not have the heating coils in each of the tanks on the contrary they may mount couple of

heating heat exchangers on deck so any cargo which needs heating would then have to be circulated through the heat exchangers so that they can remain heated to the required temperature so these are the basic differences that a chemical tanker may have with this oil

tanker ga plants would be more or less similar and if we look at the ship here we have the heat exchangers we have the hose handling gear we'll have the manifold here we have a free fall light board which uh

after accommodation after machinery space and a small chemical tanker if we look at the ga plan of the tanker with this photograph again at the back of our mind we will see the plan the profile view would look somewhat like this with the

heat exchangers being there you will have basically the crane to handle the cargo hose you will have the manifold here you can appreciate on the plan view of the main deck and you have this plan view of the tank

top so this is the ga plan of a chemical tanker which i have been repeatedly saying is going to be very very similar to the ga plan of uh oil tanker with whatever small differences that may exist between the two types of tankers

the ga plan of a gas tanker would be more or less like a tanker because it carries the liquefied gases so would have a pumping arrangement pumps to pump it out only thing is since at ambient temperature the cargo

is going to be in the gaseous form so it to keep it in the refrigerator in the liquefied form it has to be either fully refrigerated fully pressurized or partially refrigerated and partially pressurized now here is a picture of a gas tanker

and if we look at its ga plan the elevation of it would look like this where we have these standalone tanks cargo tanks in the cargo spaces each contained by bulkheads and mounted over the double bottom over special

supports to withstand rolling and pitching so that means the tanks are mounted inside the cargo spaces and only the dome comes out of the deck through which all the piping is passed so this is the side elevation or elevation of a

gas tanker other things in the ga plan would be the tank top plants at different deck levels and also may be a midship section so this is the ga plan of a gas tank now let us have a look at the ga plan of

combination carriers the oil bulk core carrier's oboz and the oil ore carrier's os now before we talk about the combination carrier ga plan it may be worth noting that the combination carriers have lived their phase of life and is no

more a very popular option nevertheless since it's there in our syllabus so let's quickly run through the ga plan of such ships uh oboe ship you can see in the photograph it is very much like a bulk area as you can see the vessel is like a

bulk carrier so obviously the ga plan of this ship would also be very much like a bulk carrier which we have already discussed only difference lies in the cargo spaces which can be seen out here in the midship sections

you can see that these ships have double bottom duct keel and then we have the lower hopper and the upper hopper or the upper wing tanks now when the vessel is deployed and carrying oil then the central compartment

is the key or major compartment for holding the liquid cargo besides that even the upper hopper tanks were deployed for carrying liquid cargo so the oil could be carried in the upper hopper tanks as well as this central compartment out here

when it came to carrying bulk if the bulk comprises of high density cargo then only the central compartment was good enough to give vessel enough space to load the required cargo however if the vessel was carrying a lighter cargo in bulk

then besides this like the oil cargo even the upper hopper spaces could have been deployed for loading the solid solid cargo therefore in oboz you have a big central compartment which is used both for oil and bulk then you have the upper wing tanks which

can be deployed for carrying liquid cargo or if the volume is required for carrying lighter solid bulk cargo and since on one passage the vessel may be carrying oil in the return passage she may be carrying bulk cargo

solid bulk cargo therefore these ships were called as oil bulk ore carriers or the oboz the general arrangement plan for oil or combination carrier that is oo carrier is very similar to that of an oboe only difference being

that in oboe the vessel may carry even lighter bulk cargoes here it's only designed to carry high density solid cargo that is ore and as the solid cargo required to be carried is high density the volume required for storing such cargo also

reduces so in the midship section of such ships if you see on the sides these two longitudinal bulkheads create these wing tanks which are used for carrying oil and the center tank is also used for carrying oil when the vessel is deployed

in carriage of liquid cargo or the oil cargo now it has a duct keel double bottom and the oil can be carried onto the wing tanks and the center tank but when it is deployed for a solid ore

cargo which is a high density cargo then only the central compartment is utilized for carrying ore the wing compartments are kept empty and being high density cargo this volume provided by the central compartment is good enough to load the vessel down to her marks

now let us have a look at the ga plan of our railroad ship roll on roll off ship like every other case let's have a look at a photograph of such a ship roroship this particular ship has a stern ramp

this ramp opens up bridges the gap between the ship and the jetty and the vehicles can roll on the vessel or roll off the vessel using this link span the ramp which acts as the link span connecting the ship and the jetty

in this ship we can see it has a stern launch free fall live boat accommodation the superstructure is midships and so is the machinery space which is midships before we go to the ga plan let's have another photo of the same ship

with the turn ramp in the open position it's the same ship seen from aft and we can see our vehicle rolling off the ship vessel using the ramp of the ship as the link span now if we have understood these two pictures

then we can make sense as to why the ga plan of this roro ship would be like this on top we have the profile view which you can see matches this picture seen from the side then we have

few plan views of the decks on the ship and right at the bottom we have multiple cross-sectional views of the ship at different locations along the length of the vessel let's just also have the magnified view of the profile

of the roro ship and map it with the picture this is the picture of the rural ship seen from the side here is the profile view from the ga plan having discussed so many of these pictures with their respective profile

views i'm sure correlating these two should not be a difficult task now we can see the superstructure and the machinery space being midships stern launched free fall live boat stern ramp for the vehicles to roll on and roll off

inside the vehicle decks are connected by ramps so that the vehicles which roll on to the ship through the stern ramp can be driven to their designated place for carriage and when they reach their destination they can be driven out through the same

ramps and rolled off through the stern ramp so i am sure you will be able to correlate this profile from the ga plan with this picture of the rural ship if you recall the ga plan of the roro ship

right at the bottom we said there were multiple cross-sectional views at different locations along the length of the vessel now here is the profile of the vessel here you can see the frame numbers here the ship frames are numbered with aft

perpendicular being 0 and then the numbers increasing as we keep going forward the frames if any aft of the off perpendicular would be numbered with negative prefix now these are the cross-sectional areas or views of this ship now this one the first one is at frame

51 so this one is the cross-sectional view at this location the next one is at frame 70 so this view is at this location this one is out here at frame 81 the next one is at frame 126

next one is back frame 171 and last one is at frame 191 so what we can see is as the ship's cross-sectional areas change along the length very significantly in the ga plan multiple cross-sectional views have been included

and they have been taken along the length of the ship at different frames so i'm sure now you can understand what these cross-sectional views mean that means if at frame 70 we cut the vessel like this and have a view from aft

this would be the view of the vessel at frame 70. at frame 191 if the vessel is cut and we have a end on view the vessel would look somewhat like this so that is how we can correlate these

cross sectional areas with their respective frame numbers thank you very much for watching marine gurukul video series hope you find this video useful please share your comments and feedback through the youtube channel or you may write to us at marinegroup gmail.com

thank you very much for your motivation and support do keep watching our videos thank you very much