Whether you’re a seasoned Engineer or still working on your P.E., there are a few ASCE must-haves when it comes to designing substations and transmission structures.
The first reference, Substation Structure Design Guide, also referred to as ASCE Manual 113, was first published in 2008 and is the first of its kind for substation design. The second must-have is the Design of Steel Transmission Pole Structures, also known as ASCE Standard 48-11.
Now let’s see how good you are…
Do you know the main difference in the two? (Besides the obvious that one is intended for substation design and the other for transmission pole.)
Well, if you said one is a guide and the other is a standard then you are correct! It should be addressed that while guides, standards and codes are all used, there is a difference between them.
There is a level of importance that falls with these, meaning that if a guide contradicts a standard, the standard typically wins, and if a standard contradicts a code, the code typically wins.
The substation design guide is currently being updated along with a handful of other design guides, standards and codes. Jennifer Gemar, Vice President of the Engineering Department at DIS-TRAN Steel, is on the ASCE 113 Design Committee which is responsible for revising the guide, and has a few updates from the latest meeting that was held in the Houston area last month.
The plan is to have the revision ready for submittal to ASCE by late 2015. Since this is the guide’s first time going through a revision, it will remain a design guide with the thoughts that it will eventually become a design standard through enough revisions and time. Overall, it seems the guide has been well received throughout the industry, especially being the first time published. It has quickly become a “go-to” book, and a great reference and training tool for newer engineers. It’s pretty much straight forward, and has general definitions of equipment and types of structures found inside a substation. The fundamentals are basic, and while it points in the right direction when designing, it doesn’t actually give the formulas to design the steel structures.
The second book, ASCE Standard 48-11, was published in 2012 as a revision to the ASCE Standard 48-05, that was first published in 2005. This standard replaced the ASCE Manual 72, which at the time, was the main design reference for transmission pole structures. The standard outlines the minimum criteria that must be considered in the structural design, fabrication, testing, assembly and erection of these type structures. Unlike the substation guide, ASCE 48-11 explains how to design steel poles and their corresponding connections. There is a committee currently updating this standard as well.
It’s important that these references stay updated as knowledge and experience permits. It’s also beneficial to be active on one of the committees responsible for these updates. Though it can be hard work, it can also be a very educational with opportunities to contribute and shed light on problems or issues that need addressing.