VICKERS MK6B's resto

[David Dunlop]

Wow, Colin, that is an entire project in its own right. There probably isn't a single movable fitting there that has actually done so in a VERY long time.

Interesting about the wheels and tracks being similar to the Australian Pattern Carrier. A couple of the suspension spring sets look a bit suspect. Do you know if they were shared with the APC as well? That could make things a bit simpler as you move deeper into this part of the restoration.

Hope the weather was cooler for you over those three days.


David

[Mike Cecil]

Lynn,

Good point regarding the effect (ie less likely to throw tracks) of the design changes, however the reasons for the variations in design from the British MG/Bren carrier were not in regard to improvements in performance but "...firstly to standardise certain parts with similar parts on the light tank [Vickers Mk6A] and secondly to suit Australian production methods. The War Office was not advised before the variations were taken in hand." (Dept of the Army Memo to Secretary Military Board, 22-10-1941).

These variations caused some considerable problems, particularly in the ME when units were handed both Brit and Aust built carriers, and the spares situation for the Aust carriers did not keep pace with the usage. Result: grounded Aust carriers where available Brit spares could not be fitted.

Mike

[Lynn Eades]

Mike, thanks for the info. my conclusions are based on what I have seen on the ground, and the odd old photo. My knowledge of actual history and details is somewhat lacking.
I made the incorrect assumption that the wider track/ wheels arrived with the MkVIB, but were obviously already in place with the MkVIA
There is a photo of new track going on A VLT in the desert and this is where I drew my conclusion that Australia had taken up Vickers track improvement when designing the LP2. If you know the photo, are you able to date it?
I assume these VLTs came from the Vickers factory already fitted with this wider wheel, design of track in the late 30s, when Australia first bought them?
With the longer track of the VLT, I see the potential for throwing track and I imagine the VLT would have had big issues with that problem, had it not gone to the wider rubber.
I note that in the same vein, the Loyd carriers had added cleats to its sprockets. (I am not sure if this was more about reducing the wear rate or to help "stabilise" the track?)
The Canadians later changed the design of the sprocket on its U.Cs. for similar reasons.
Again, thanks for the clarification.

[colin jones]

David, yes that was an epic and nearly as big as Ben Hurr fortunately it's winter here and around 18c most days. Most of the springs are more than just suspect but I have replacements.
Lynn/Mike, That is very interesting about the track. Unfortunately I don't have enough original wheels for both. For these tracks to come off, they would certainly have to be extremely loose as they certainly hug the sprocket at the front and the tensioner idler at the rear. Not to mention there is no track displacement. It is great that there is still information around about these tanks. The construction of these is really quite amazing.

[Lynn Eades]

For an attempt at clarity:
Australian carrier track is "lead plugged" (has a shorter plain pin, no head) The VLT (British wide horned) track has exposed formed heads as per British and Canadian carrier track.
The VLT in question came with wheels and rubber nominally 1/2"wider than carriers, but with spokes ("T" section) that look the same as British or Canadian wheels.
The Australian carrier wheels which (normally) have "H" section spokes are interchangeable, as is the track between the Aust. carrier and the VLT.

Colin, the track is most likely to come off when "sidling"(travelling along the side of a hill) It is not good practice to do this in a carrier. apparently we should go straight up and straight down. I don't know how the VLT goes in this situation.

[colin jones]

Here's a few pics of the numbers and markings on one of the original Vickers wheels.

[colin jones]

Now this raises an interesting question! As I am under the understanding that these tanks were made in 1936 as stamped on quite a few panels and the engine, but we never received the ten in Australia until 1939.
The date on the wheel looks to be 1938. So! were they made to aust specs in England prior to shipping, or were they made in Australia before they came here and changed once they arrived or needed replacing.
The Chicken or the Egg. I will have a close look at the other wheels to see if there is a clearer date.

[Mike Cecil]

Colin,

Tanks were normally purchased with a suite of spares, particularly fast wearing spares like wheel assemblies (the tyres chew out). It is rare indeed to have a tank survive its service life with the original 'when assembled' set of road wheels - normally these are changed as required. Spares were not always supplied 'up front' but on a yearly basis depending upon the terms of the contract. So it would not be unusual to have wheels manufactured and supplied after the tanks entered service.

In the case of the Vickers Mk6A, these were built as standard - I don't think there was any particular 'Aust standard' for that small batch - and they arrived circa Sept 1937, not 1939.

Wheels supplied as spares could have a number of production dates, and therefore those on the tank now could well have a range of production dates. It will be interesting to see what other dates/production details become evident as you blast the crud off the rest.

Mike