DIS-TRAN Steel Blog

3 Transmission Structures Broken Down

Posted by Wendy Gintz on Jul 7, 2015 10:45:00 AM

When designing transmission structures...

it’s not as simple as saying “ok, I want self-supporting tangent mono poles with delta configuration for my entire 80 mile stretch.”  While that idea might be more economical than having h-frame or 3-pole structures, it’s just not practical.

Ultimately, the wire configurations determine which type of structure will be used, and typically there will be a mix of these structures in order to follow the right-of-way through small or tight turns. Right-of-ways go alongside or through interstates, highways, fields, woods and even water, so an engineer must keep all these situations in mind when designing.

Three common transmission structures:

  •  Tangent
    • Used when transmission route is straight
    • Generally, no longitudinal loads on the structure
  • Angle
    • Used when transmission route changes direction
    • Used from anywhere less than a 5 degree angle to a 90 degree angle
  • Dead-End
    • As name applies, dead-ends are designed to take the full component of every wire's tension
    • Does not necessarily mean end of transmission line 

                              

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Whether the structures are tangent, angle or dead-end, wire phases can run in multiple configurations.  Horizontal Configurations provide the lowest profile. Vertical Configurations require the minimum width right-of-way. And Delta Configurations is an attempt to use the value of both horizontal and vertical configurations to maintain phase clearances.

Transmission structures can be classified as either self-supporting or guyed.

Self-Supporting Structures do not use guys: meaning they are not tied to the ground or any other structure in a way that offers additional support. They are better for restrictions to right-of-ways and tend to have loads small enough to not warrant guys.

Guying of structures is used to support the structure and allow for a more economical design in both the steel structure and foundation. Guying reduces bending and deflection. However, the downside is that it requires more right-of-way. 

*Here are some main contributing factors to keep in mind when deciding on whether or not to guy a structure:

  • Structural loading
  • Right-of-way requirements
  • Aesthetic design criteria

**Here are some other contributing factors you may want to consider:

  • Line voltage
  • Electric air gap clearance requirements
  • Ground clearance requirequirements
  • Insulation requirements
  • Number of circuits to be supported
  • Electric and magnetic field limits

There is so much to learn about Transmission Structures.  What questions do you have?  We would love to hear from you so please leave a comment below.

Check out our newest resource for Anchored Transmission Structures.  Click below.
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Tags: transmission structures, guyed structures, tangent, dead-end h-frame structures, configurations

DIS-TRAN Take2: How to Calculate the Anchor Bolt Embedment of Transmission Poles

Posted by Wendy Gintz on May 7, 2015 1:30:00 PM

It's been awhile, but we are still at it...  Thats, hopefully createing ueseful tips that make your job easier.

AnchorBolt

We have had a sort of series of Take2s referencing Anchor Bolts.  For this edition we will look at calculating the embedment of steel transmission structures.  Please feel free to go back and view the two previous Take2 Blog posts.

     Anchor Bolt Loads
     Anchor Bolt Design

What you will hear about...

  1. What to consider when calculating the embedment.
  2. What resources to use.
  3. A working example
  4. Additional information to consider

   

Thank you for viewing the DIS-TRAN Take2. We look forward to your feed back.  Please leave any comments or questions you may have about transmission pole or anchor bolt design below.

Until next time...

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Tags: transmission structures, transmission poles, design of steel transmission pole structures, anchor bolts

DIS-TRAN Overhead Solutions: A 50 Year Supplier of Wood Utility Products

Posted by Melissa Hines on Apr 1, 2015 4:52:00 PM

DIS-TRAN Overhead Solutions, LLC has been providing distribution crossarms to utilities for 50 years. Today, we design, manufacture and treat a complete line of Douglas Fir and Southern Yellow Pine distribution crossarms, end plated crossarms, ground wire molding and wood transmission arms and assemblies. We're celebrating 50 years in the business by reflecting on some of our major milestones. 

HistoryTimeline

In July 2006, we began production in our newest location in Vancouver, WA. With two separate facilities located in Pineville, LA and Vancouver, WA, we are available to customers from coast to coast for quick lead times and amazing response to storm restoration. These two locations enables flexibility and allows us more opportunities to effeciently serve the entire country.

Through Columbia Vista Corporation, DIS-TRAN Overhead Solutions, LLC plant facilities in Pineville, LA and Vancouver, WA have both been Forest Stewardship Council (FSC) certified, COC #SW-COC-00244. We have made a commitment to the environment and to promoting the improvement of forest management. We are also the only certified environmentally friendly "green" wood products supplier.

We added transmission products to our scope of work in October 2011. These transmission products include x-braces, vee and knee braces and tension braces along with the necessary hardware.

50 Years in the Making
With the addition of a full time engineer on staff, we can provide you with detailed drawings of structures and assemblies along with accompanying material lists to aid in planning and construction. Our engineer is also available to answer any questions related to our products. 

Is there any additional products you would like to see DIS-TRAN Overhead Solutions, LLC carry? Please let us know. We are always looking to pursue new opportunites especially if it will help fulfill the needs of our customers.

Make sure to follow us on Facebook and LinkedIn to stay up-to-date with the latest happenings.

 
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Tags: wood distribution crossarms, transmission structures, manufacturing, wood transmission structures, Engineering

10 Tips: How to Save Money When Submitting a Bid to a Steel Fabricator

Posted by Brooke Barone on Jun 19, 2014 12:25:00 PM

Every structural steel fabricator is different when it comes down to pricing substation and transmission steel structures. But, there are some commonalities that could help save you money when submitting a Request for Quote (RFQ). How do you do that you might ask?

Well, generally, there’s a rule of thumb to consider: the more information you give the Estimating Department, the better price you’ll receive. If very little information is given, it’s harder for the estimating department/engineers to easily go through and pick out requirements, design the structure and then send the RFQ back in adequate time. And sometimes the price might reflect the assumptions that had to be made. 

Different terms used:

  • Request for Quote (RFQ)
  • Request for Proposal (RFP)
  • Purchase Requisition
  • Inquiry
  • Bid Event / BidQuote / Proposal

DTS_Employee

So, if you’ve asked yourself, “what can I do to save money when submitting a bid,” here are five good starting points.

1. Well-Defined Scope of Work- this could include everything from what the fabricator’s responsibility is, to needing the structures galvanized or weathering, delivery process, how hardware should be shipped, etc.  

2. Technical Specifications- this tells the fabricator how you want the structures built, like what kind of steel to use, etc.

3. Commercial Terms- this is more on the legal side, meaning what type of payment or who to invoice, insurance requirements, warranties, damages, etc.

4. Structure/Electrical Layout- this gives the overall dimensions of a structure such as height and width or phase spacing.

5. Enough Time to Bid- it’s important to keep in mind that fabricators typically have a quote backlog already scheduled out. 

Often, in order to send a bid to a fabricator, customers require the fabricator to be on an approved vendor list in order to quote the project.  The approval process usually involves quality assurance / quality control (QA/QC) audit, industry experience, project references, customer references, commercial term agreement, credit approvals, etc. 

Facts That Could Affect Pricing:

6. Weathering steel generally costs less because unlike galvanized steel, it doesn’t get the galvanized coating. (Typically see weathering steel more with transmission structures.)

7. Usually, the more steel ordered at one time could help give you a better price. In this instance, if you had different structures for one substation, instead of ordering separately, try to coordinate to order all the structures together, which could save money on freight and other expenses.

8. Loads with over-length and over-width sections could get costly because you have to get freight permitting depending on the states along the delivery route. Typically, the price for wider structures is greater than longer structures.

9. Expedited lead times can increase price. Since a production backlog is already in place, fabricators would need to expedite engineering, detailing, rearrange product schedule or may have to include some overtime.

10. Special weld inspection requirements and tests that are beyond typical industry standards could raise the price. If the fabricator needs to pull in a third party to inspect, send material off for testing or bring in an expert, it could increase the price.

These are just a few suggestions, and are not meant to be taken as the rule in every situation when dealing with every fabricator. But it is good to know how your project was priced and what affected it so that there are no hidden surprises or confusion.   

So remember: supply ample information, receive accurate price. 

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Tags: transmission structures, substation structures, structural steel fabricators, structural steel price, rfq request for quote, engineering estimating software, structural steel

10 Ways Knowing About Structural Steel Pricing Will Save You Money

Posted by Brooke Barone on Oct 29, 2013 3:52:00 PM

Every structural steel fabricator is different when it comes down to pricing substation and transmission steel structures. But, there are some commonalities that could help save you money when submitting a Request for Quote (RFQ). How do you do that you might ask?

Well, generally, there’s a rule of thumb to consider: the more information you give the Estimating Department, the better price you’ll receive. If very little information is given, it’s harder for the estimating department/engineers to easily go through and pick out requirements, design the structure and then send the RFQ back in adequate time. And sometimes the price might reflect the assumptions that had to be made. 

Different terms used:

  • Request for Quote (RFQ)
  • Request for Proposal (RFP)
  • Purchase Requisition
  • Inquiry
  • Bid Event / BidQuote / Proposal

So, if you’re asking yourself-“well, what exactly do I need to include when submitting a bid,” here are five good starting points.

1. Well-Defined Scope of Work- this could include everything from what the fabricator’s responsibility is, to needing the structures galvanized or weathering, delivery process, how hardware should be shipped, etc.  

2. Technical Specifications- this tells the fabricator how you want the structures built, like what kind of steel to use, etc.

3. Commercial Terms- this is more on the legal side, meaning what type of payment or who to invoice, insurance requirements, warranties, damages, etc.

4. Structure/Electrical Layout- this gives the overall dimensions of a structure such as height and width or phase spacing.

5. Enough Time to Bid- it’s important to keep in mind that fabricators typically have a quote backlog already scheduled out. 

Often, in order to send a bid to a fabricator, customers require the fabricator to be on an approved vendor list in order to quote the project.  The approval process usually involves quality assurance / quality control (QA/QC) audit, industry experience, project references, customer references, commercial term agreement, credit approvals, etc. 

5 Facts That Could Affect Pricing:

1. Weathering steel generally costs less because unlike galvanized steel, it doesn’t get the galvanized coating. (Typically see weathering steel more with transmission structures.)

2. Usually, the more steel ordered at one time could help give you a better price. In this instance, if you had different structures for one substation, instead of ordering separately, try to coordinate to order all the structures together, which could save money on freight and other expenses.

3. Loads with over-length and over-width sections could get costly because you have to get freight permitting depending on the states along the delivery route. Typically, the price for wider structures is greater than longer structures.

4. Expedited lead times can increase price. Since a production backlog is already in place, fabricators would need to expedite engineering, detailing, rearrange product schedule or may have to include some overtime.

5. Special weld inspection requirements and tests that are beyond typical industry standards could raise the price. If the fabricator needs to pull in a third party to inspect, send material off for testing or bring in an expert, it could increase the price.

These are just a few suggestions, and are not meant to be taken as the rule in every situation when dealing with every fabricator. But it is good to know how your project was priced and what affected it so that there are no hidden surprises or confusion.   

So remember: supply ample information, receive accurate price. 

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Tags: transmission structures, substation structures, structural steel fabricators, structural steel price, rfq request for quote, engineering estimating software, structural steel

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