I think it has been well established that the structure on Mount Douglas was used for VHF frequencies, not HF ("shortwave") frequencies. VHF signals are analogous to "line-of-sight" coverage while on the other hand, HF signals can travel for many thousands of miles and facilitate over-the-horizon communication.When this research on Mt. Douglas started, a a 2005 newsletter from Friends of Mt. Douglas suggested the structure on Mt. Douglas was operated by the RCAF, I started pondering whether that was possible. Did the other services use VHF frequencies during World War II? Certainly the Canadian Army used VHF, the quintessential Canadian military surplus radio known as Wireless Set #19 Mk. III was a high frequency (2.0 - 8.0 MHz) transceiver and a VHF transceiver (229-241 MHz) all in one box. The Royal Canadian Navy also had VHF radio equipment during World War II for ship-to-aircraft communications (TDQ and RCK transmitters) and another VHF set (TBS) for ship-to-ship communications. The RCN also used a VHF homing system (YE/ZB) that enabled aircraft to easily find the carrier over many miles of featureless ocean. Finally, the RCAF also used VHF radio, initially with British equipment and switching to the American built SCR-522 when it became available in quantity beginning in late 1942.
Try as I might, I have been unable to think of a reason why the Canadian Army would need a VHF direction finding station. The Royal Canadian Navy might be a possibility. However, on Atlantic convoy duty, aircraft with radar often worked in close cooperation with surface ships using VHF radio to communicate. Canadian ships operating in the North Sea and Mediterranean also needed to be able to communicate with aircraft. However, on the west coast of BC there was little communication between navy ships and air force planes and no need for the RCN to have a VHF direction finder. However, because the RCN was responsible for defending the sea lanes of British Columbia, the thought occurred to me that perhaps they used a VHF direction finder to listen for and locate Japanese submarines and surface ships. This would not have been for radio signals but rather the emissions sent out by radar. Japanese submarines were equipped with a Type 13 radar that operated in the VHF range at 150 MHz. Radar was a wonderful new tool but it had (and still has) a shortcoming in that as a radar set sends out its pulse and waits for the returning echo. That pulse of radio frequency energy can also be detected by your enemy and it tells him precisely which direction you are coming from. The fact that there may also have been a VHF direction finder at Radar Hill in Tofino which faces the open Pacific does lend some measure of support to this theory. Japanese submarines were active on the west coast in 1942, shelling the Estevan Point lighthouse and sinking freighters. There have been a number of stories suggesting the Estevan attack was perpetrated US or Canadian forces but there is no credible evidence to support that. Likewise the story that the submarine was trying to attack the "powerful radio direction finding station" and radar site at Estevan is also hogwash, since there was no direction finder or radar station at that location.
So, if it wasn't the army or the navy then it had to be the RCAF, right? Why would they want a VHF direction finder? That my friends will take a bit of explaining.
We are fairly certain there was a VHF DF setup on Mt Douglas and probably a similar one at Radar Hill, which I will henceforth refer to as the Tofino radar station. That radar site became operational on 15 February 1943, not in the 1950's as has been cited elsewhere. It was one of eleven radar sites that were established on the BC coast, all becoming operational in late 1942 or early 1943. When these stations were set up, radar was top secret. In fact, it wasn't even called radar, at least in Britain and Canada. It was referred to as "RDF" or radio direction finding. The Tofino radar site was identified as #33 Radio Detachment, later changed to #33 Radio Unit and retained that identification until the end of the war when it was closed. The fact that many historical documents have avoided the term "radar" in favour of "RDF" has, I believe, confused and misled some researchers who have chosen to read such documents without acquiring the technical knowledge necessary to understand it. All eleven radar sites the RCAF had in BC were required to keep a daily diary and it is reading some of those that has ben challenging. They are rife with military acronyms such as WAC, OC, U/S but, thanks to Library and Archives Canada, I was able to sort things out. I took the time to read these diaries in the hope it would give me some insight into how RCAF planes were controlled and if there was a use for VHF direction finding.
The first significant operational use of VHF radio frequencies for military communications was during the Battle of Britain, from mid July to late October 1940, without a doubt one of the pivotal battles of World War II. VHF radio was an integral part of the Royal Air Force fighter control system. In this system, information such as radar plots, Observer Corps reports, signals intelligence, etc. was all fed to a central location, a filter centre which analyzed all the information and directed aircraft into the air as necessary in order to conserve aircraft, fuel and pilots. The fighter pilots could sit on the ground and wait for the German bombers to come to them rather than being in the air on endless patrols that wasted fuel and might have little chance of finding the enemy. We can be thankful that Herman Goering and the German Luftwaffe never understood or appreciated this system. The RCAF adopted the elements of this control system for use on the BC coast. Although the coastal radar stations watched for an enemy that thankfully never came, there were of course aircraft that occasionally strayed where they shouldn't be and that would result in fighters scrambling from Pat Bay or Sea Island to intercept. They were directed to their target by a radar station set up for ground controlled intercept or "GCI". There were three GCI radars on the BC Coast:
1. #7 Radio Detachment, Pat Bay - GCI
2. #8 Radio Detachment, Sea Island - GCI
3. #33 Radio Detachment, Tofino - MEW/GCI ("MEW" refers to "microwave early warning")I wonder, is it significant that the two locations that might have had the VHF direction finders were also close to GCI radar sites and RCAF air bases? Is it possible there was also a VHF DF at Sea Island? From what I have learned so far is the that idea seems reasonable for the diaries contain endless entries referring to "calibration flights". That is, sending aircraft out to specific locations to verify the bearing to an aircraft that the radar operator sees on his screen (PPI display) is correct. Having a VHF direction finder could be used to confirm the compass bearing to the aircraft (a double check, if you will) by simply having the pilot key his VHF radio when requested. Also, there were times when many dozens of aircraft might be in the air over a wide area and if a pilot was requesting advice on a course that would enable him to return to base, the VHF direction finder could assist with this when the radar operator might have difficulty determining which blip on his screen represented the aircraft requiring assistance. An aircraft in distress could be similarly assisted. Some of you may be aware of IFF systems (Identification Friend or Foe) but bear in mind that IFF was in its infancy in 1942-43, at least for RCAF use in Canada and not reliable.
To digress for a moment, the shape of these VHF/DF buildings has intrigued me from the beginning and I have been wondering why they were built in an octagon, a design that is far more difficult to construct than a square building. I once built an octagonal gazebo, but with so many angles to cut, never again. The first thought I had was for wind loading, a smaller frontal area would be exposed to a straight-on gust. Then it occurred to me that when you are building a structure so tall on such a small footprint, an octagon is a much stronger structure and in fact many lighthouses are constructed this way, Estevan Point included.
Now to add a bit more to the mystery, there was also an RCAF radar site at Jordan River, identified as "X-1 Detachment". One document I have identifies it as a "CHL" radar site (from the British "Chain Home Low") which was a system designed to detect low flying incoming aircraft. The majority of the RCAF radar sites on the BC coast were configured for this purpose, Another source however lists Jordan River as MEW/GCI, similar to Tofino. If it is similar to Tofino, then could X-1 Jordan River have a VHF direction finder too? Well, going back to the seemingly endless pages of diaries I read through, one entry from the Victoria filter centre diary caught my eye:
"18 August 1944 Inspected X-1 detachment and the proposed site for the VHF fixer station at Glacier Point"
There is the occasional and wonderful Eureka moment when you're digging into history and you come up with a seemingly minor thing that ties everything together and for me seeing the word "fixer" was one of those moments. In navigation terminology "getting a fix" means to obtain a compass bearing on a radio beacon or distant object. If you're using a VHF radio to do that, then you have a VHF direction finder or as the inspecting officer termed it, a "VHF fixer". So where is Glacier Point, I have never heard of it? Well, that took a little digging too and it turns out it is now known as Point No Point (west of Sooke BC.).
Credits and References:1) Tom Brent [navyradiocom(at)gmail.com]
May 1/20