Vehicular Land Navigation System C1

[Ed Storey]

The Navigational Set, Land Vehicular, C-l, (NAVAID) was developed to provide a self-contained navigational aid, independent of radio assistance, which would give positional and navigational information to commanders of vehicles in armoured and other units under the following conditions:
(1) Closed-down, during mobile operations by day or night, and under nuclear threat conditions.
(2) During conditions of darkness and poor visibility, e.g., fog and smoke.
(3) On featureless or poorly mapped terrain, including the Arctic.

Despite the ease of operation and advantages that were provided by the NAV AID, the art of map reading was still of primary importance and was not to be neglected.

The equipment did not require radio assistance for its operation and by using a gyro-compass it is was affected by variations in the earth's magnetic field or in the magnetic characteristics of the vehicle.

This device was designed to indicate the location of vehicles to within an average accuracy of 1 % of the distance travelled and the heading to within .75 degrees.

This device could be used in unmapped terrain. Under these conditions the· counters on the Indicator Heading and Position were set to an arbitrary reading and an X (representing the present position of the vehicle) marked on the plastic map holder of the Plotter with a china pencil. The vehicle could return to the original start point, after completing a mission, by the commander directing the arrow of light, which corresponds to the movement of the vehicle) toward the X until the arrow returns to the X. The counters were then checked to see that they reflect the arbitrary reading set at the beginning of the mission.

The NAVAID could only be used maps with scales of 1/25,000; 1/50,000; 1/100,000 and 1/250,000. Prior to the first run of the day, the Compass required an initial 30 to 60 minutes warm-up and settling period. The compass had some difficulty maintaining its design accuracy at the higher speeds encountered in road travel. When moving over hilly terrain, the actual distance travelled on the ground is greater than the distance travelled
on the map. Therefore, periodically, the actual heading and position on the ground had to be checked against the heading and position displayed by the NAVAID. If there was a variation appropriate adjustments had to be made.

[Lang]

Ed

As you point out the difference between design accuracy and real life can be quite large. Claiming an accuracy within .75 degrees is a nonsense (about half the width of the needle) - a train driver would be lucky to achieve that!

I defy a 747 captain to hand fly his aircraft just using flight instruments (no GPS or radio aids) over any distance without drifting 2 and probably 5 degrees each side of heading. Driving a vehicle, particularly a skid steered tracked vehicle, over uneven terrain would produce a champagne celebration if they kept inside 10 degrees.

Still it is better than having the enemy watching out of mild curiosity as an entire tank regiment scattered to the four winds during a closed up advance.

Lang

[David Dunlop]

Grant, it is interesting your manuals for the M38 take this system back to it's possible roots in WW2 with the MB/GPW system.

A couple of years ago, while looking for C42 Set information on line, I stumbled into the National Archives site in London, England. They had two sequentially listed documents in their files for a "Vehicle Land Navigation System XC1". One was an initial report, the other the final report, both dated simply 1961, with a very cryptic Canadian reference. These were not online documents but had to be viewed in person or ordered blind. Struck my curiosity but not enough to follow up on, and with the "X" prefix for 'Experimental', my other thought at the time was it probably never saw the light of day.

Now it appears the system did indeed see some level of production volume, with intent for installation in a variety of vehicles. Very intriguing and whets the appetite for more information about it.

David

[Ed Storey]

There are NAVAID Installation Instructions for both the M38A1CDN and M37CDN as well as the M38CDN mentioned earlier.

[James P]

NavAid was talked about during my training to drive Lynx C&R, even had the power sockets and some fitting inside the vehicle but outside of it being mentioned I never saw one (NavAid) in either Pet or later Germany.

[Lang]

It appears that the system was not widely used as it was very inaccurate in use and required a high level of skill and practice to use well.

Three things killed further development:

OMEGA the VLF signals developed for underwater use by submarines and subsequently available for aircraft and vehicles, both military and civil (70's and 80's). This required a start from a known point and used crossing radio waves from about 4 stations around the world (like ripples in a pond from 3 different stones thrown in a distance apart).

This of course was subject to electronic warfare interference.

Inertial Navigation was sort of a development of the NAVAID system but here it used very sophisticated gyros which measured movement also from a known point. Very accurate - down to a couple of metres. It was fully self contained in the vehicle or aircraft and not subject to outside interference. Used by all airliners and military aircraft and vehicles for 30 years. Aircraft have now gone to GPS but the military have retained inertial capability because GPS is subject to electronic interference.

GPS needs no introduction. It is so universal that attacking GPS satellites or creating spurious signals other than in a small local area is as counterproductive to the attacker as the defender. Everything uses it. It would appear that GPS will be treated like gas warfare - everybody has the capability to do bad things with it but by mutual agreement it is off-limits.

Although they have their own system, turning off US satellites over Russia in a conflict, or programming them not to talk to certain receivers, so the Russians can not use them will not happen because the Russians have the capability to knock down the satellites. Everybody loses. GPS has just become a modern version of the earth's magnetic field available to everyone.

[Ed Storey]

Lang:

"It appears that the system was not widely used as it was very inaccurate in use and required a high level of skill and practice to use well."

Interesting comment, do you have a document to support this or is it just conjecture on your part?

ED

[maple_leaf_eh]

Originally Posted by Lang

...


GPS needs no introduction. It is so universal that attacking GPS satellites or creating spurious signals other than in a small local area is as counterproductive to the attacker as the defender. Everything uses it. It would appear that GPS will be treated like gas warfare - everybody has the capability to do bad things with it but by mutual agreement it is off-limits.

Although they have their own system, turning off US satellites over Russia in a conflict, or programming them not to talk to certain receivers, so the Russians can not use them will not happen because the Russians have the capability to knock down the satellites. Everybody loses. GPS has just become a modern version of the earth's magnetic field available to everyone.

The conventional GPS constellation is a USAF controlled asset used by everyone. The signal is unencrypted now, but it can be switched on selectively for military purposes. There was a story a week or two ago about Uber cabs and personal navigators going wonky in Russia for a period. No one wanted to say it out loud, but my suspicion is the US was retaliating to Russia for some of the latest Luke Warm War conflicts over cyber attacks.