Vehicular Land Navigation System C1

[maple_leaf_eh]

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.

[Richard Farrant]

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.

[David Dunlop]

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

[Richard Farrant]

Originally Posted by David Dunlop

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.

[BCA]

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

[Ed Storey]

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.

Navigation Set Land Vehicular C1.jpg

[David Dunlop]

You continue to amaze, Ed! Thanks for posting that!

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


David

[Lang]

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

[Grant Bowker]

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.