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Cable End Terminal Anchor Bracket

Question
State NE
Description Text

We are drawing up the cable guardrail end treatment from reports TRP-03-155-05 & TRP-03-192-08 & need a little help with the details. Please review the E-mail below & see standard sheet attached.

For A (below) " will you agree to allow the exterior gussets be brought in, to 3/8" from the outside edges? 

This is where we believe the 3/8" weld will work. I assume all gusset plates are welded inside & out, or is a weld on the inside only.


B-Shows the weld from the base plate to the release lever plate. Shown on the Front view, I drew out in blue, the weld that will work (11/16"), and in green the weld that won't work (3/16") according to what they specified. The upper 3 3/8" dimension shows the spacing between the welds, and the bottom 1 ¼" and the 3" dimensions are for the release lever plate. For B (below) - will the welds be allowed for the 1 ¼" across the release lever plate connecting to the base plate?


The bracket plate or cable plate is the only 3/8" plate with the rest being ½". What is the reason for this? Can it be changed to ½" so all plates in this assembly are the same?


Is there a reason for the holes in the triangle release lever plate gussets?

We found a bolt in these holes of report TRP-03-192-08 Figure A-2 Cable Terminal Detail, sheet 2 of 12.


Should there be a light weight tie down cable to keep the cable release lever from flying somewhere it shouldn't go? This was used in the testing on the high tension cable.


What is the length of need for the new cable end treatment system?

Keywords
  • End Treatments & Crash Cushions
Other Keywords none
Date December 10, 2009
Attachment Figure 1.jpg


Response
Response

I have responded to your questions below in red.

 

We are drawing up the cable guardrail end treatment from reports TRP-03-155-05 & TRP-03-192-08 & need a little help with the details. Please review the E-mail below & see standard sheet attached.

For A (below) " will you agree to allow the exterior gussets be brought in, to 3/8" from the outside edges? 

This is where we believe the 3/8" weld will work.

I assume all gusset plates are welded inside & out, or is a weld on the inside only.

 

-          We believe there is no problem with moving the gussets in 1/8" to allow for the 3/8" weld. This is an error in our CAD.

-          Gussets are to be welded inside and out as well as the ends (all the way around)

 

B-Shows the weld from the base plate to the release lever plate. Shown on the Front view, I drew out in blue, the weld that will work (11/16"), and in green the weld that won't work (3/16") according to what they specified. The upper 3 3/8" dimension shows the spacing between the welds, and the bottom 1 ¼" and the 3" dimensions are for the release lever plate. For B (below) - will the welds be allowed for the 1 ¼" across the release lever plate connecting to the base plate?

 

-          This is another error in our CAD. The weld callout should read " 1" @ 4 ¼" C-C". This will center the weld correctly on the release lever plate.

-          I have reviewed the original CAD for the bracket welds and you CAD which appears to be based on it. The weld labeling is confusing and not entirely consistent with what was built. As such, I have drawn a revised detail that should help clear the confusion. Note that some of the dimensions have changed as well. I put in the space for the 3/8" welds that was lacking as well.

 

The bracket plate or cable plate is the only 3/8" plate with the rest being ½". What is the reason for this?

Can it be changed to ½" so all plates in this assembly are the same?

 

-          We have no problem with using ½" plate for the cable plate. It should not adversely affect the design.

 

Is there a reason for the holes in the triangle release lever plate gussets?

We found a bolt in these holes of report TRP-03-192-08 Figure A-2 Cable Terminal Detail, sheet 2 of 12.

 

-          The holes in the plate are for a bolt to connect a retention cable for the release lever. The rationale behind this is detailed in TRP-03-131-08.

-          The design calls for a 5/8" Grade 5 Hex Bolt.

 

Should there be a light weight tie down cable to keep the cable release lever from flying somewhere it shouldn't go? This was used in the testing on the high tension cable.

 

-          Yes, there should be a retention cable. It should be ¼" diameter 7x19 aircraft cable. The cable should be 36" long and formed into a loop  with 1" cable clips.

 

What is the length of need for the new cable end treatment system?

 

-          Test no. CT-1 was conducted on a low-tension, three-cable barrier system according to test designation no. 3-35 of NCHRP Report No. 350. The test was successfully performed as a Length-of-Need (LON) evaluation at the target conditions of 100 kph and 20 deg. The test occurred at post no. 3 or approximately 15 ft from the upstream end of the barrier system. Based on the results obtained from the 2000P test (test no. CT-1), the length of need for the low-tension, three-cable barrier has been determined to be 15 ft.


 

Date December 17, 2009
Attachment 01_LT_Cable_Terminal_Bracket-CT-4 Model (1).pdf
Attachment 00_LT_Cable_Terminal_Bracket-CT-4 Model (1).pdf


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