ISO 3827-1:1977 pdf download.Shipbuilding - Co-ordination of dimensions in ships' accommodation
1 SCOPE AND FIELD OF APPLICATION
This International Standard sets out the basic principles of dimensional co-ordination, with particular reference to the co-ordination of dimensions in ships' accommodation.
3.2 Modular components
The size of components should be co-ordinated in accordance with the preferences given in tables 1 and 2. A component having a co-ordinating size derived from these preferences is a modular component.
3.1 Dimensional framework
In order to ensure that dimensionally co ordinated com-ponents or assemblies of components fit the spaces ailocated to them a dimensional framework, or reference system, is employed which is common to both.
3.1.1 Modular grids
The dimensional framework is represented by a grid, in which the grid lines are spaced in multiples of the standard modules, or increments of size, and the grid lines indicate the boundaries for the component and the space allocated to it.
The use of a grid on drawings is an aid in locating components and in reading the drawings; as such it is a tool for communication.
3.2 Modular components
The size of components should be co-ordinated in accordance with the preferences given in tables 1 and 2. A component having a co-ordinating size derived from these preferences is a modular component.
The co-ordinating size of a component is equivalent to the size of the co-ordinating space allocated to it. Both include the work size of the component plus an allowance for its joints and tolerances.
4 THE CONTROLLING REFERENCE SYSTEM
In establishing a dimensional framework, or reference system, which can he related to both dimensionally coordinated components and the structure incorporating them it is essential to establish certain controls over the principal dimensions of the reference stystem.
The initial control is based on the use of the standard modules given in table 1 but, in order to reduce the considerable number of permutations possible with these modules, further controls are necessary.
Certain known datum lines, which are related to user requirements, can be identified within the structure and the structure can be divided by these datum lines into a number of spaces. Some of these spaces ate teinied “usable spaces”, for example cabin interiors, and others termed “zoncs” arc the spaces surrounding the usable space and are allocated to the structure or services. These terms are described later in this clause. The principal dimensions of these zones and spaces can be standardized to give a limited range of sizes, which are multiples of the standard modules, but achieve a considerable degree ot variety reduction, in relation to particular components. These dimetisioris are theefore termed “controlling dimensions”. The identified datum lines which define the zones and usable spaces are termed “controlling lines” and in three-dimensional considerations the planes which these lines represeiti. on plans, sections and elevations are termed “key reference planes”. The entire framework of planes, zones and dimensions is described as the “controlling reference system”.ISO 3827-1 pdf download.