This is called “ Obsessive Compulsive Disorder” planning ahead, and that’s what I like to do. Having these types of drawings allows me to look at the bigger picture before I make a small design gesture because I hate the idea of spending money on a problem only to have to rip it out and re-do it a few years later. Having as-built drawings is really important to people like me because it allows us to figure out long term solutions to current problems. Architects call these drawings “As-Builts” which are exactly what they sound like – drawings that reflect the current condition of a building or space.
Two types of projections are used in engineering drawings. Three-dimensional objects are therefore broken down into two-dimensional drawings that convey their elements with accuracy.
Three-dimensional drawings are included as a qualitative description of what the object should look like when completed, but are inadequate in conveying accurate shape or dimension for the purpose of building. Orthographic projections help engineers and architects draw three-dimensional creations clearly and accurately using the two-dimensional medium of drawing. Orthographic Projections in Civil Engineering Drawings This indicates an accuracy of 50 meters in drawings prepared to a scale of 1:100,000 and 25 millimeters in drawings with a scale of 1:50. It has been estimated that the scaled distances may be read only to an accuracy of 0.5 millimeters in the drawing. For example, a location map may have a scale of 1:100,000, meaning that the dimensions of the actual object or space in reality is 100,000 times larger than that of the drawing. The representative fraction indicates the ratio of the dimensions in the drawing to the dimensions in reality. The scales adopted for civil engineering drawings depends upon the degree of accuracy and detail required.
How to Interpret Scales in Engineering Drawings Reading engineering drawings requires knowledge of the following elements:
Engineering drawings are prepared according to professional codes and technical standards so that they may be read by anyone without misinterpretation or confusion. How to Read Engineering DrawingsĮngineering drawing uses a standard range of conventions and symbols which may seem incomprehensible at first glance. Even the smallest variations are recorded in completion drawings, also known as record or as-built drawings. These variations, additions, and alterations may be due to unforeseen site conditions or budgetary concerns. They are often supplemented by finer design and construction details in the form of notes and additional written instructions.ĭuring any given project, ad hoc changes are likely to have been made that diverge from the working drawings. However, for very large projects or projects with minimalist tender drawings, working drawings need to be much more detailed than previous drawings. These plans inform the actual work and manufacture of a building or other project, and represent the engineer's final decisions regarding various details.įor simple projects, the working drawings may not significantly differ from tender or contract drawings. Working drawings are generally more detailed than tender and contract drawings. If alternate proposals have been accepted, new or additional drawings will need to be prepared according to the accepted tender proposals and alternatives.Ĭontract drawings are printed on good quality paper and given a cloth backing, and are meant to withstand long-term storage. For some projects, if tendering has been straightforward and without any alternate proposals, the contract drawings can be the same as tender drawings.