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What's inside the Bonner Bridge?

What's inside the Bonner Bridge?




This is an inside view of the pre-cast sections of a post-tensioning tendon bridge. (This picture is from the Lesner Bridge in Norfolk, but it's almost identical to the Bonner)
If you are really bored, and want to read through the FHA manual, here's a link:
Interesting stuff!




https://www.fhwa.dot.gov/bridge/construction/pubs/hif13026.pdf


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RE: What's inside the Bonner Bridge?




All of the tunnels in VA have secondary tunnel over or beside the traffic tunnels, mostly for ventilation, but there are similar 'electrical' and radio system equipment in there.

Do you know where the high voltage, high power cables for the main electric power for HI will be? They wouldn't be putting on the racks above, so maybe the conduits at the bottom? .


RE: What's inside the Bonner Bridge?




All of the tunnels in VA have secondary tunnel over or beside the traffic tunnels, mostly for ventilation, but there are similar 'electrical' and radio system equipment in there.

Do you know where the high voltage, high power cables for the main electric power for HI will be? They wouldn't be putting on the racks above, so maybe the conduits at the bottom? .

Beachmark


I remember in the bid documents there was discussion of the power cable being hung on the side of the bridge, similar to the way the current cables are run. The cost to CHEC is high, which was a factor in the 17 mile bridge proposal, but it's a much shorter run on this bridge alignment.
The power cables to run Ocracoke are subterranean, (You can see where the cables go under at the cable crossing, at the end of the pole road.) But OI may be different. We all remember what happens when the cables get cut....... Confused


RE: What's inside the Bonner Bridge?




This reminds me of the tunnel in the Running Man when then send Arnie out into the badlands! lol


RE: What's inside the Bonner Bridge?




I'm doing the electrical in there. In the middle it's about 8 feet of clearance, and at the bents, it's about 20 feet. Here is a picture taken of the other day of "PT" cables being tensioned where they just joined two segments together. Towards the south end it's completely dark and has an insane echo. I'll take some more pictures when I'm out there next week




RE: What's inside the Bonner Bridge?






I remember in the bid documents there was discussion of the power cable being hung on the side of the bridge, similar to the way the current cables are run. The cost to CHEC is high, which was a factor in the 17 mile bridge proposal, but it's a much shorter run on this bridge alignment.
The power cables to run Ocracoke are subterranean, (You can see where the cables go under at the cable crossing, at the end of the pole road.) But OI may be different. We all remember what happens when the cables get cut....... Confused

Squid Pro Quo


The HV and fiber optic cables in the navigation span are being hung from the ceiling in heavy duty fiberglass conduit. They aren't pictured above as they have only been installed at the south end. On the approaches they look like they will be nestled between the middle girders.



RE: What's inside the Bonner Bridge?




Yup, had our lights fail in the Big Walker Mtn tunnel..... that is DARK. Try walking out of a 100% dark tunnel with rectangular vent holes in the floor every 20' and no light coming up through them... all done by feel.


RE: What's inside the Bonner Bridge?






I remember in the bid documents there was discussion of the power cable being hung on the side of the bridge, similar to the way the current cables are run. The cost to CHEC is high, which was a factor in the 17 mile bridge proposal, but it's a much shorter run on this bridge alignment.
The power cables to run Ocracoke are subterranean, (You can see where the cables go under at the cable crossing, at the end of the pole road.) But OI may be different. We all remember what happens when the cables get cut....... Confused

Squid Pro Quo


The HV and fiber optic cables in the navigation span are being hung from the ceiling in heavy duty fiberglass conduit. They aren't pictured above as they have only been installed at the south end. On the approaches they look like they will be nestled between the middle girders.

jsncrso


Awesome!


RE: What's inside the Bonner Bridge?




The HV and fiber optic cables in the navigation span are being hung from the ceiling in heavy duty fiberglass conduit.

jsncrso
I wonder what would be required to go in there later, with those cables live. Do you kn ow if the voltage is transformed down for that distance and re-transformed backup at the far end?


RE: What's inside the Bonner Bridge?




I wonder what would be required to go in there later, with those cables live. Do you kn ow if the voltage is transformed down for that distance and re-transformed backup at the far end?

Beachmark


It's the 115Kv transmission lines from the Nags Head substation to Buxton. Nothing is stepped down, those are big cables they are pulling through, the conduit for each wire is 5" in diameter. There are no clearance minimums for the wires. There are also lights and receptacles for tools in the "tunnel" but those will be powered by generators brought in by NCDOT when bridge maintenance is required.


RE: What's inside the Bonner Bridge?




I wonder what would be required to go in there later, with those cables live. Do you kn ow if the voltage is transformed down for that distance and re-transformed backup at the far end?

Beachmark


It's the 115Kv transmission lines from the Nags Head substation to Buxton. Nothing is stepped down, those are big cables they are pulling through, the conduit for each wire is 5" in diameter. There are no clearance minimums for the wires. There are also lights and receptacles for tools in the "tunnel" but those will be powered by generators brought in by NCDOT when bridge maintenance is required.

jsncrso


I see they are casting in place the closure panels on the precast sections. How will they access the navigation spans for maintenance and inspection once the bridge is completed?


RE: What's inside the Bonner Bridge?




Yup, had our lights fail in the Big Walker Mtn tunnel..... that is DARK. Try walking out of a 100% dark tunnel with rectangular vent holes in the floor every 20' and no light coming up through them... all done by feel.

Beachmark


Flashlights?


RE: What's inside the Bonner Bridge?




This is a really cool thread Steve. And thanks to the contributors also. Neat stuff that an old financial guy had no knowledge of!


RE: What's inside the Bonner Bridge?




This is a really cool thread Steve. And thanks to the contributors also. Neat stuff that an old financial guy had no knowledge of!

bobbyg


Thanks Bobby! And how cool is it to hear from somebody that is actually working in there?


RE: What's inside the Bonner Bridge?




This is a really cool thread Steve. And thanks to the contributors also. Neat stuff that an old financial guy had no knowledge of!

bobbyg


Thanks Bobby! And how cool is it to hear from somebody that is actually working in there?

Squid Pro Quo


Awesome pictures...thanks! Does it get hot working in there or does the concrete keep it relatively cool?


RE: What's inside the Bonner Bridge?




Yup, had our lights fail in the Big Walker Mtn tunnel..... that is DARK. Try walking out of a 100% dark tunnel with rectangular vent holes in the floor every 20' and no light coming up through them... all done by feel.

Beachmark


Flashlights?

KHbiker
Those went out too LOL. We were so prepared that day...


RE: What's inside the Bonner Bridge?




I wonder what would be required to go in there later, with those cables live. Do you kn ow if the voltage is transformed down for that distance and re-transformed backup at the far end?

Beachmark


It's the 115Kv transmission lines from the Nags Head substation to Buxton. Nothing is stepped down, those are big cables they are pulling through, the conduit for each wire is 5" in diameter. There are no clearance minimums for the wires. There are also lights and receptacles for tools in the "tunnel" but those will be powered by generators brought in by NCDOT when bridge maintenance is required.

jsncrso
OK, thanks. The insulation on those 115KV cables must be incredibly good, like in the tunnels in NYC. We have done a bit of work in power plants, and they train you stay faaar away from anything above a few kV that is exposed, as that voltage can flashover to you if you get closer than a few inches. The larger the voltage, the larger the safe distance becomes.


RE: What's inside the Bonner Bridge?




I wonder what would be required to go in there later, with those cables live. Do you kn ow if the voltage is transformed down for that distance and re-transformed backup at the far end?

Beachmark


It's the 115Kv transmission lines from the Nags Head substation to Buxton. Nothing is stepped down, those are big cables they are pulling through, the conduit for each wire is 5" in diameter. There are no clearance minimums for the wires. There are also lights and receptacles for tools in the "tunnel" but those will be powered by generators brought in by NCDOT when bridge maintenance is required.

jsncrso
OK, thanks. The insulation on those 115KV cables must be incredibly good, like in the tunnels in NYC. We have done a bit of work in power plants, and they train you stay faaar away from anything above a few kV that is exposed, as that voltage can flashover to you if you get closer than a few inches. The larger the voltage, the larger the safe distance becomes.

Beachmark



Ever seen that big sign at the cable crossing at Hatteras Inlet? "No anchoring"! The cables come off of the last pole on the Pole Road and go right into the ground. That's the main power for Ocracoke Island, so I imagine it's just as juicy! Ouch!


RE: What's inside the Bonner Bridge?




Ever seen that big sign at the cable crossing at Hatteras Inlet? "No anchoring"! The cables come off of the last pole on the Pole Road and go right into the ground. That's the main power for Ocracoke Island, so I imagine it's just as juicy! Ouch!

Squid Pro Quo
Yes, I imagine snagging one of those with an anchor might cause a few 'complications'....


RE: What's inside the Bonner Bridge?




A somewhat related question for this thread about the bridge. As my daughter and I drove over the existing one, she asked what is the plan for it once the new bridge is complete. I told her I assumed they would demolish it, but that seems like it will be quite a job in itself. I also wonder about the impact on the sea life, birds, etc. if they have to use explosives to take it down. Does anyone know of the plan for it?


RE: What's inside the Bonner Bridge?




Same with going to Roanoke Island and didn't one of those cables break a couple years ago?




RE: What's inside the Bonner Bridge?




A somewhat related question for this thread about the bridge. As my daughter and I drove over the existing one, she asked what is the plan for it once the new bridge is complete. I told her I assumed they would demolish it, but that seems like it will be quite a job in itself. I also wonder about the impact on the sea life, birds, etc. if they have to use explosives to take it down. Does anyone know of the plan for it?

lowcountry
Removing the old bridge has been part of the plan all along. I don't know the details but I doubt dynamite is part of it, for the reasons you state.


RE: What's inside the Bonner Bridge?




I was kind of hoping they would keep it for the scare-di-cats like me who, while looking at the height and angle of the new one, might need a family member to Drive Miss Daisy across! I can handle the height of the current Bonner, but the new one? Eeeeek!


RE: What's inside the Bonner Bridge?




Part of the old bridge will remain, to be used as a fishing pier.

John


RE: What's inside the Bonner Bridge?




I was kind of hoping they would keep it for the scare-di-cats like me who, while looking at the height and angle of the new one, might need a family member to Drive Miss Daisy across! I can handle the height of the current Bonner, but the new one? Eeeeek!

lowcountry
The new peak height is not a lot more than the old one....it just lasts longer. Maybe the gentler rise and fall to the new height will make it easier to take!