How close does the Northern Pass come to where you hike?

[Kimball]

I was curious about how close the Northern Pass Transmission Line comes to where we all like to hike. Running TrailsNH and collecting every hiking trip report in the Northeast puts me in the position of knowing where we hike (and write about) the most. The AMC was kind enough to gave me a copy of the current proposed NP route and I was able to mash that up with the TrailsNH coverage area map.

I'm no expert but it looks to me like the proposed line runs pretty close to some popular summits:

• within 2 miles of the summit of South Kinsman
• about 3.5 from Welch & Dickey
• about 5 from Cannon
• about 6 from Moosilauke
• about 8.5 from Mt Lafayette and Franconia Ridge

Here's my mashup of the proposed route with the popular hiking areas:
http://trailsnh.com/reports/Northern-Pass-Route.php

Sorry the map is zoomed out as far as it is, but this will give you a good overview. Later on I'll generate a more detailed version so we can zoom in for a closer look.

-Kimball

 

[RoySwkr]

I hike a lot in the North Country and dozens of my hikes will have crossed the proposed route, such as Bickford Hill where the new route joins existing lines. You are trading better views down for more ugly ones up.

The A.T. crossing S of Kinsman will be a hot issue with national environmental groups because PSNH doesn't actually own the r-o-w, you can bet NP already know it will be buried but don't want to open that kettle of worms.

 

[JCarter]

The A.T. crossing S of Kinsman will be a hot issue with national environmental groups because PSNH doesn't actually own the r-o-w, you can bet NP already know it will be buried but don't want to open that kettle of worms.

Well, but NP keeps claiming that have a r-o-w through the WMNF, so it must be true.....

As the trail adopter for the Reel Brook Trail, I'm pretty sure many of my outings will be impacted if that alleged r-o-w is allowed to grow some new, horrendous towers rather than being forced underground, or to go west & south of the forest, which would be far more appropriate.

 

[peakbagger]

If you do some searching on VFTT, the subject has come up in the past on the crossing. I personally have wrongly referred to the crossing of the National forest as a "Right of Way" while it is actually covered by a different more restrictive limited permit. I also noticed recently that the NP also appears to cross another WMNF property in the Russel Pond area although this may or may not be covered by the same restrictive permits. No matter what, I think its safe to say that the WMNF supervisor is going to have say in what happens in that location and I would expect there will be public hearings although sadly like many WMNF administrative functions, the hearings are advisory in that the forest service collects input and then explains why they did what they did. Given the congressional backing for increased public visibility on the project, I expect that trying to soft pedal the permitting process through the WMNF will lead to sharp political impact to the supervisor.

I have always been curious why NP did not try to bury the line along the highway through Kinsman Notch as the highway in theory existed long before the WMNF and therefore would be covered by state DOT vs WMNF. Obviously it would impact Woodstock to a much greater extent. Alternatively, replace the existing line with an underground one and install the new line underground to mitigate the current impact. There would still be strip cut but no towers. I guess it comes down to the reported arrogance that NP seems to have with respect to the "locals"

 

[RoySwkr]

I have always been curious why NP did not try to bury the line along the highway through Kinsman Notch as the highway in theory existed long before the WMNF and therefore would be covered by state DOT vs WMNF.

I think NP knows this section will need to be buried eventually but is trying to limit such promises at this point as everyone else will want theirs buried too.

There is also the issue that once they start burying the line the digging will be much easier along old railroad corridors than following the existing power lines over ledges and peaks, so PSNH loses the bundle they were hoping to make on this...

The Bog Pond corridor was considered an alternative to Franconia Notch for I-93 but construction and environmental difficulties ruled it out.

Note also that the notch W of Bog Pond was Kinsman Notch in early guidebooks, and the notch W of Lost River was Lost River Notch.

 

[rocket21]

How wide and deep would the trough have to be if they were to bury the lines? I'm going to venture a guess that it would be a much larger impact than burying fiber optics, for example. In the event NP gets the green light, would it really be less of an impact if they dynamite a canal through Old Kinsman Notch rather than put up towers?

 

[Tom_Murphy]

How wide and deep would the trough have to be if they were to bury the lines? I'm going to venture a guess that it would be a much larger impact than burying fiber optics, for example. In the event NP gets the green light, would it really be less of an impact if they dynamite a canal through Old Kinsman Notch rather than put up towers?

From: http://www.northernpass.us/facilities-equipment.htm
DC Transmission Line, +/-300 kV line, approximately 153 miles long, extending from the Québec/New Hampshire border to the proposed Franklin converter terminal

Couldn't find the federal requlations governing HVDC transmission lines but found this:

From: http://www.concernedcitizensmontana.net/Publish/hvdc_alternative_final.pdf
The burial of HVDC Light cable is similar to that of fiber-optic cables because the equipment used for trenching and the depths at which the cables are laid are comparable (1 to 1.5 m below the surface).

From: http://ceds.org/tl.html#Undergrounding:_Burying_Transmission_Lines
An HVDC circuit is buried in a trench 1.5-feet in width with a separation distance of 15- to 30-feet between circuits. Junction boxes are placed every 1,000- to 2,000-feet to join sections of HVDC cable.

This makes me think it is similar to the power cables run to the Mt Wash summit.

 

[peakbagger]

Based on my observations from the PNGTS project that went through the north country in the past, the actual ditch was about 15 to 20 feet wide at ground level when flat and level for a 16" dia line. As the pipeline was 16" diameter they had to maintain a fairly small deflection in the line so anytime there was a sharp change in elevation like a ledge, they would have to blast deeper to smooth out the curve. Along side the trench they had at least twice the width for the side rigger bull dozers they used to set the line and a haul road adjacent to it. Over all I would estimate 75 to 100 feet width. I used to do water utility work long ago and we could for a considerably less width if need be but it was less productive.

I would expect that NP would probably set the conduits at or slightly below frost line and would set the conduits in bedding to cushion any rough spots left from blasting. Assume 5' deep to frost line and an additional 1 foot of bedding and that is a 6 foot deep trench, then assume a 45 degree fraction plane up to the surface and that is a 12 wide trench plus the wide of the conduits and required spacing. I don't know HVDC enough to know how many separate conductors they need and what sort of spacing. for chuckles lets say 4 conductors and space them 2' apart, that would be 10 foot wide at the base trench plus the fractural plane and it could be a 22 foot wide excavation for each line (the existing and the new NP) so that's 44' plus additional for sharp elevation changes. Add in a haul/maintenance road and it could be 75 wide minimum right of way. I have seen photos of high voltage buried lines in Europe and they let the vegetation grow back in to the point where the actual ROW is no more than 25' wide. Unless HVDC is different, generally if a line fails they don't dig it up and patch it, they have to pull it back to a manhole and replace it. This is far more costly than splicing an overhead line an done of the reasons that NP is fighting the effort, the trade off is if its installed correctly its far less prone to failing in the first place .

One of the options being discussed is to place a buried NP in the old RR line that runs along RT 3 in the north country assuming that is possible, I expect the impact would be similar to RR line.

Generally when a firm gets a right of way they ask for far more space initially in case they want to expand later.

 

[DougPaul]

I don't know HVDC enough to know how many separate conductors they need and what sort of spacing. for chuckles lets say 4 conductors

I would guess two (plus, minus) or three (plus, minus, ground).

Here is a report describing a proposed line between Quebec and NYC that would use two 5-inch cables.
http://www.concernedcitizensmontana.net/Publish/hvdc_alternative_final.pdf. It also states that the ROW would be much narrower than an overhead AC line of the same capacity.

Note: the AC line would most likely be 3-phase: 3 lines plus a ground line above the AC lines.

Doug

 

[RoySwkr]

In the event NP gets the green light, would it really be less of an impact if they dynamite a canal through Old Kinsman Notch rather than put up towers?

One advantage of using existing road/rr corridors is that there would probably be no blasting needed for the depth proposed.

I'm not sure how much bend/kink the conduit is allowed between manholes, but one way to avoid blasting is to fill over the line instead where ledge is near the surface. Very few septic systems are actually buried any more, it's cheaper to just put the material on top of existing ground.

Unless HVDC is different, generally if a line fails they don't dig it up and patch it, they have to pull it back to a manhole and replace it. This is far more costly than splicing an overhead line and one of the reasons that NP is fighting the effort, the trade off is if its installed correctly its far less prone to failing in the first place .

One might think that if the line failed it could be because of trauma to the conduit, perhaps wise to investigate and hard to pull the new cable past a damaged area. (Not applicable in Kinsman Notch, but latest utility bill had a flyer saying you should not call roto-rooter for plugged pipes but instead call DigSafe as line could be plugged because of somebody drilling a gas main through it.)

The city of Concord generally has a fetish for underground utilities, but Unitil is resisting on one upcoming project because that particular line has no redundancy. If something goes kerflooey with a buried line particularly in winter it can take awhile to restore.