October 13, 2013

Mid-Canada Line Test Fence - The McGill Fence - Project Spider Web

Picture Curtosey of Dr. James Rennie Whitehead

"One of the double-doppler sites in the Eastern townships.
(Daughter Valerie got into the picture)"
I made a surprising discovery yesterday regarding the locations of the Mid-Canada Line test sites that were built in the Summer of 1953 to test if the radar doppler principle would be able to be used as an effective tripwire-like air defence mechanism.  The chosen technology from these tests would go on to become the Mid-Canada Line.

Frankly, I hadn't paid a lot of attention to the founders of the technology; I was researching the locations where the technology was used - so I was surprised when McGill's Associate Professor Dr. James Rennie Whitehead's name turned up in a Google Search with a significantly enlightening piece of his memoirs.

...It was obvious that flight trials of a test double Doppler system would be essential. We decided to locate a test line along the Ottawa Valley from Ottawa to North Bay. RCA built enough equipments to enable seven or eight stations to be erected and Ross Warren designed a most ingenious antenna which was not going to be too costly.
I should say a word about the double-Doppler principle at this stage. When you receive broadcast TV and an aircraft flies across the line between the TV transmitter and your receiver, the signal fades in and out in a regular way. This is due to the waves reflected from the moving aircraft having a slightly different frequency from those that go directly, because of the Doppler effect. At the receiver the waves reflected from the aircraft interfere with the direct waves to produce the pulsation that you see.
The McGill fence used a refined version of this phenomenon in which the circuits were designed to enhance this effect rather than the transmitted data. Conventional Doppler radars have the transmitter and receiver in the same location. Ours was called “double” because the transmitter and receiver were at opposite ends of each link. With 50’ towers for the antenna, links as long as 30 miles over normal terrain were possible. We planned to have seven in the Ottawa Valley test line.

It was in the summer of 1953 that we set up the test line along the Ottawa Valley from Ottawa to Mattawa, on behalf of the Defence Research Board. There were stations at Ottawa, Arnprior, Haley Station, Meath (near Pembroke), Deep River, Bisset Creek and Mattawa. Each station consisted of a small wooden hut which enclosed a transmitter-receiver unit. A 50-foot scaffolding tower carried a large rectangular antenna, with the reflecting surface made of wire netting. My headquarters for the test line were in a wooden hut on the site of the old prisoner-of-war camp in Deep River. The project carried the code name “Spider Web”...


...They agreed to have their K-flight ferry me to an airfield in Killaloe – the nearest suitable airstrip to Deep River – whenever we needed flying. I would be met by station wagon at Killaloe and the aircraft would stooge around until I arrived at the HQ to conduct the tests. Then it would fly back and forth across the line at various heights while we took the observations. ...

Copyright © 1995, J. Rennie Whitehead

This provides several revelations, and poses several problems, for my previous research.

This is one of the few mentions of the Cold War-era airstrip at Killaloe that I've found documented, so I'm pleased to see it mentioned.

Dr. Whitehead confirms that there were 7 radar sites in the test fence.  However; the sites don't all match my previous info.

Dr. Whitehead lists
  1. Ottawa
  2. Arnprior
  3. Haley Station
  4. Meath (near Pembroke)
  5. Deep River
  6. Bisset Creek
  7. Mattawa.

In order, I had listed
  1. South Gloucester (Source: Larry Wilson's MCL web site)
  2. Fitzroy Harbour
    (Source: Larry Wilson's MCL web site)
  3. Haley Station
    (Source: Larry Wilson's MCL web site)
  4. Alice
    (Source: Larry Wilson's MCL web site)
  5. Unknown
  6. Unknown
  7. Mattawa
    (Source: Wikipedia)
Let's review point by point

  1. "Ottawa" could have meant "South Gloucester".  The tower still stands in South Gloucester today, so I do have physical proof that it is the right site, and the radar dishes point NW, toward Arnprior or Fitzroy Harbour.
  2. Arnprior and Fitzroy Harbour are close, relatively, to each other... but they aren't close enough that I'd consider Fitzroy Harbour to be a suburb.  Perhaps Dr Whitehead generalized or figured Arnprior was the closest known landmark?  Doubtful, as he mentioned Bisset Creek and Meath, which are pretty obscure. 
    South Gloucester to Fitzroy Harbour; ~32 Miles
    South Gloucester to Arnprior; ~40 Miles.
  3. Haley Station; at least that lines up. 
    Fitzroy Harbour to Haley Station; 30 Miles
    Arnprior to Haley Station; 22 Miles
  4. Meath is right off HWY17, Alice is 9Km West of the highway.  Alice is 28 Miles from Haley Station, while Meath is 15 Miles from Haley Station.  Optimally the radar sites could be 30 Miles apart; why would one be almost half of that?  This was proof of concept stuff; so maybe varying the distance between the locations was the whole point.
  5. Deep River; as the 5th site I had no idea where this would be, so I can't say that Deep River contradicts my expectation.  Also, Dr Whitehead mentioned he was at the old POW Camp in the middle of Deep River - that's a pretty firm memory and positive location identification.  However; Meath to Deep River is ~35 Miles, past the range of the radar.  Unless Meath wasn't exactly Meath, and it was closer to Deep River along HWY17 - or was at Alice.  Alice to Deep River is ~25 Miles.
  6. Bissett Creek; again, I had no idea where this would be.  There is a large ridge immediately West of Bissett Creek, so I would think the site would be up on the top of that.  To the center of Bissett Creek is 28 Miles from Deep River's POW Camp.  A little West on the ridge?  Maybe ~30 Miles.
  7. Mattawa was the last site in the test fence.  Central Bissett Creek to Central Mattawa is ~32 Miles; if Bissett Creek was really on the ridge, it would be closer to 30 Miles away.
I'd like to ask for clarification, but unfortunately Dr. Whitehead passed away last year after a brief illness at the age of 94.  I hope the national archives have some of the information I'm looking for.

In the meantime, I've integrated those points into my MCL Site Map on Google Maps

View Mid-Canada Line (MCL) Sites in a larger map


  1. I think I can help with these sites...

  2. Thanks for writing this. Rennie (Grandpa) would have enjoyed his work being shared.

    1. Thank you Suzanne! I really appreciate your kind words. Your grandfather made a huge contribution to Canadian history, but it seems to be a part of Canadian history that isn't very well known or understood. I hope that will change in time.

      ...of course, if you find a map or additional pictures showing the locations of the aforementioned sites, I'd love to nail down the exact spots for posterity :)

      ( it seems my embedded map isn't showing the right layer... here is the link showing the spots, as best I can figure, your grandfather was racing between along the Ottawa Valley - both with the places he named, and the ones I *thought* were the test sites https://www.google.com/maps/d/edit?mid=zekW-UMq1PR8.kL4p0Ck0pIBo&usp=sharing )

    2. He did indeed :) He would have been thrilled to have someone who wasn't 90 yrs old interested in it all. He was very generous with his time and knowledge. It's difficult to find photos really as he shot in slide film, so without knowing what to look for, it's probably a needle in a haystack.

  3. A shame you and my Dad did not get together. (He would have been 98 today!) He would have been able to pass on everything worth knowing about how they picked the spots, the technology, the process of building the line - and all the politics behind getting them built - and then mothballing them later on. The other fellow that could have helped enormously was Andy Matthews - as he was Dad's pilot for all of this - and as of last year he is gone too :(