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  #1  
Old 30-10-16, 23:17
David Dunlop David Dunlop is offline
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Default Vehicular Land Navigation System C1

Does anyone know what the basis of navigation was for this system?

I think it was developed in Canada in the late 1950's, or very early 1960's, so may have predated the current GPS satellite system, and the concept was likely as an aid for AFV's.

David
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  #2  
Old 31-10-16, 00:41
maple_leaf_eh maple_leaf_eh is offline
Terry Warner
 
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Default Land Nav'

My guess would be gyros and inertial navigation system. The Navstar constellation didn't exist until the late 1980s, or at least its was not publically available until then.

The British had something in the same timeframe, and I sort of remember it mentioned in one of those slim AFVProfiles pamphlets.
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  #3  
Old 31-10-16, 00:57
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Richard Farrant Richard Farrant is offline
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The Churchill based mine flail, Toad, had a gyroscope direction finder I believe, and something in the back of my mind says it was a Sperry. This vehicle dated from early to mid Fifties.
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  #4  
Old 31-10-16, 00:58
David Dunlop David Dunlop is offline
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That's the direction I was leaning in as well, Terry.

Possibly an entirely new concept, or an evolution of the wartime two dimensional plotting system developed by the US Army that I have seen installed in the MB/GPW.

Maybe the postwar Canadian system was planned for the Ferret?

Interesting, Richard. The US wartime equipment took up quite a bit of space in a jeep. Might have been a challenging install for a Ferret, but heavier armour may not have been such an issue.


David
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  #5  
Old 31-10-16, 01:10
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Richard Farrant Richard Farrant is offline
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Quote:
Originally Posted by David Dunlop View Post
That's the direction I was leaning in as well, Terry.

Possibly an entirely new concept, or an evolution of the wartime two dimensional plotting system developed by the US Army that I have seen installed in the MB/GPW.

Maybe the postwar Canadian system was planned for the Ferret?

Interesting, Richard. The US wartime equipment took up quite a bit of space in a jeep. Might have been a challenging install for a Ferret, but heavier armour may not have been such an issue.


David
David,
If you have seen a mine flail working, there is no way you can visually see where you are going, to this gyro system would have been the cutting edge at the time.
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  #6  
Old 31-10-16, 01:12
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David: the WW2 jeep navigation system was the Land Odograph. It integrated compass direction with distance determined by the speedo cable. I have most of what I believe is the system that you refer to as used in the Centurion. There is a mechanical plotting board to plot the course on a map. A couple of years ago there was further discussion of the Canadian system here on the forum...Brian
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  #7  
Old 31-10-16, 02:52
Ed Storey Ed Storey is offline
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Default Navaid

Continuous display of the position of the vehicle was obtained by automatic dead-wreckoning. Distance travelled was measured by the speedometer and direction was measured by a compass. A computer automatically calculated the positon of the vehicle which was displayed on a map or by a digital readout. The complete unit could be mounted in a Ferret, M113A1 or Centurion.

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  #8  
Old 31-10-16, 04:18
David Dunlop David Dunlop is offline
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You continue to amaze, Ed! Thanks for posting that!

Who built them and when, and how long was the system in service?


David
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  #9  
Old 31-10-16, 07:08
Lang Lang is offline
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The direction indication would only have been reasonably accurate for an hour or so before resetting due to gyroscopic precession (caused by drag on the gyro bearings among other things) but this would normally be enough for most purposes. In a steel vehicle it would be almost impossible to fit a remote magnetic compass (as in aircraft) to feed continuous updates to the gyro to correct the drift.

Where they got their correction from I can only guess - the most obvious is for someone to stand well back from the metal mass of the vehicle with a prismatic compass and call out the centreline direction to be wound on to the indicator. If you were really stuck inside for long periods an educated guess could be taken from experience with that particular instrument to wind on 10 degrees, or whatever, East or West every hour.

The beauty of a gyro system is you can put anything you want on the dial so you can have true bearings to read straight off the map without worrying about magnetic variation calculations.

I think they were probably meant for circumstances such as an assault on a pitch black night or if you needed to be closed up (Churchill?) for comparatively short periods.

Lang
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  #10  
Old 31-10-16, 13:05
Grant Bowker Grant Bowker is offline
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The EME instruction to install the "NAVIGATIONAL SET, Land Vehicular, C1" in the M38 is dated July 1963. My copy came with several other EME instructions M38 and M38A1. There wasn't a similar instruction for the M38A1 in the bundle. I don't know whether that was because it was never done (obsolete???) or if the same instructions were used (seems unlikely as there were other mods where separate sheets existed).
The NSN for the Nav set was 6605-21-111-1843.
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  #11  
Old 31-10-16, 13:51
Ed Storey Ed Storey is offline
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Default NAVAID Capabilities

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.
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  #12  
Old 31-10-16, 14:07
Lang Lang is offline
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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

Last edited by Lang; 31-10-16 at 14:27.
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  #13  
Old 31-10-16, 15:14
David Dunlop David Dunlop is offline
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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
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  #14  
Old 31-10-16, 16:05
Ed Storey Ed Storey is offline
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Default NAVAID Installations

There are NAVAID Installation Instructions for both the M38A1CDN and M37CDN as well as the M38CDN mentioned earlier.
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  #15  
Old 01-11-16, 02:32
James P James P is offline
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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.
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  #16  
Old 01-11-16, 03:55
Lang Lang is offline
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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.
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  #17  
Old 01-11-16, 12:46
Ed Storey Ed Storey is offline
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Default NAVAID C1 - Use

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
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  #18  
Old 01-11-16, 13:05
Lang Lang is offline
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Ed

I found mention of it on a navigation tech site. No practical facts to ad to the great detail you blokes have already other than that comment in an historical overview of various early systems before it launched into the subsequent progress of the art to the present time.

There appear to be many systems tried and actually produced by various countries but, as far as we know, nothing seems to have reached universal daily operation until the inertial systems and subsequently GPS.

I did not bookmark it (and I clear my history daily) but will have a look to see if I can get it up again.

Lang
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  #19  
Old 02-11-16, 17:26
David Dunlop David Dunlop is offline
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Assuming the photo Ed posted of the 7 main components of this system, was in fact the standard basic system for all installations, we might have a rough basis available to us for establishing a size for the production run of this system.

The tricky bit will be in how many of these individual components bear their own data plates with serial numbers. For this, we would assume an order for 1,000 systems (not withstanding spares) would mean 1,000 of each item would be produced.

Brian: You mentioned you might have most of the components making up a system. If any of them have data plates, can you post the relevant serial numbers from them? The highest available number on any of them should tell us how far all the other bits should have gone as well.

David
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  #20  
Old 02-11-16, 19:57
maple_leaf_eh maple_leaf_eh is offline
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Quote:
Originally Posted by Lang View Post

...


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.
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  #21  
Old 02-11-16, 22:18
Lang Lang is offline
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Terry

I don't know if you remember but when GPS first came in (with lots of empty spots) the US only allowed high definition to the military and civilian (or foreign military) received a reduced accuracy. Still enough for general navigation but insufficient for such things as close instrument approaches by aircraft or survey calculations.

This of course has now all changed and the day of the surveyor's chainman have gone and you see them wandering around by themselves with a stick holding a GPS receiver for accuracy within inches.

As I said, in the event of a conflict, USA would have to have a serious think about messing with the satellite signals or they stand the risk of losing the lot - permanently

You may be right about the recent Russian problems but I have my doubts USA would risk such an asset in so petty a matter. A bit like killing the roses of the next door neighbour anonymously because their dog barks.

If they messed with the signals they would have to remember that at any time there are dozens of international airliners tracking over Russia using GPS and, although they have back-up systems they certainly would have reported it en mass.

Just my take on the matter.

Lang
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  #22  
Old 02-11-16, 22:24
Mike Cecil Mike Cecil is offline
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The CDN Navaid C1 was trialed in Australia for installation in AFVs, specifically Centurion.

The Gyro unit was placed behind the driver's position, replacing an internal stowage bin. The crew commander had the main read-out and adjusting component installed into the underside of the turret roof, asjacent to his cupolam and the driver had a simple bearing indicator in his compartment. The 'map plotter' was not installed for the Australian trials.

It was not accepted for service.

Mike
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  #23  
Old 02-11-16, 22:34
David Dunlop David Dunlop is offline
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Roughly when was the trial done, Mike? The British evaluation took place in 1961 when the system was apparently 'Experimental'. I'm not certain if that designation applied to a product still under development in Canada, or a product that was new and in production in Canada at that time and the British were simply 'experimenting with it'.

I am curious if the system had enough merit to attract foreign buyers or was just another Canadian development that never got beyond limited Canadian production/use.


David
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  #24  
Old 02-11-16, 22:37
Mike Cecil Mike Cecil is offline
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David,

Mid-60s, around the time that the British/Dutch IR system was being integrated into the Australian Centurion.

Mike
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