LRDG Chevrolet 1533X2 Aero-screens

[Charlie Down]

The LRDG specially ordered 200 1533X2 trucks for operations in the North African Desert in 1941. Only 112 reached Egypt due to a ship being torpedoed on route. The trucks left the factory with a 'Jeep' style 2 window folding windscreen. Looking at photo's it shows, somewhat crudely I admit, that about a third were removed and replaced with Aero-screens, the other trucks retaining the windscreens and about half had screens completely removed. Aero-screens are much more common on trucks when they were initially issued to the LRDG, and seem to be removed later on as they fouled MG arcs which were more frequently fitted for the front passenger as the campaign progressed.

The question is from which type of truck did the aero-screens originally come from?

Were they recycled from old LRDG Patrol and Pilot trucks such as the Chevrolet WA and 1311X3's, and Ford 01 15cwt V8 pilot cars?

Were they a standard part available through the spare parts logistic system?

Looking at the shape of the Glass it seems that the Morris CS8 could be an alternative source for the Aero-screens.

Attached photos show assortment of close ups of 1533X2 aero-screens, Ford Pilot car, Morris CS8 and Chevrolet WA truck for comparison of details.

[Charlie Down]

Further photos of aero-screens.
First photo of a Chevrolet 1311X3 and then an early 1533X2.
Are they the same aero-screens, just mounted differently, or different designs altogether?

[Mike Kelly]

Hi

I have a original CS8 aero screen hinge if you need dimensions , it is a brass casting. Plus I have repro frames made by Dave Ballard in the UK . I believe Rory Ballard had some new hinges cast in brass. Some of the pics you posted do depict screens very similar to if not identical to CS8 screens.

[Charlie Down]

Hi Mike,
Any information such as photos and dimensions would be great!
I find it strange that these questions haven't been asked or discussed before about such a popular vehicle.
I don't recall seeing any photo's of Canadian built Chevrolets with factory fitted aero-screens. Indian built ones have them. Not sure about British assembled Chevrolet kits though, and this is the place to find out.
Photos of different manufactured aero-screens seem to follow a similar or identical set of dimensions, with a variety of different shaped glass, rounded and square designs, with a range of different heights. I assume, which is dangerous when researching this truck, that if they were produced by a Chevrolet factory or supplier, they would be a standard design across all the factories or suppliers.
The main differences between the aero-screens seems to be the hinge lock location (with Butterfly screw) and mounting plates.
Photos show the aero-screens locked at various angles, often leaning forward to prevent reflections from the sun being seen by the enemy.
Attached is the factory photo showing the 'Jeep' style windscreen supplied to all the trucks for delivery. (All photos from Chevrolet 1533X2 30-cwt trucks post)

[Grant Bowker]

Looking at the centre photo above, the windshield wiper system appears simailar to CMP (but mounted the other way up) and the arms to regulate the folding windshield also look like "parts bin engineering". The geometry of the arms is such that when the windhield is folded forward, the arms would be still be near vertical, risking damage to either the arms or vehicle users.

[Charlie Down]

Thanks Grant, that was my next question answered!
Do you have any photos/diagrams/dimensions? Also, either I'm being a bit thick, or I'm not quite seeing how they fit differently looking at photos on other postings of wiper motors. Maybe I'm looking at the wrong motors?
I've dug up some photos of the windscreen, which shows the motors fitted after the trucks were further modified with condenser, sand mat racks and stowage chest in the Ammo body, in Egypt prior to issue to the LRDG. However, all the operational photos show them removed from the windscreen. They are all on early issue trucks with no forward MG mounts.
Photos courtesy of Jonathan Pittaway and various other sites/authors including IWM.

[Charlie Down]

Ok, the motors look different but that may be due to the shadows being cast or the perspective. The square block looks like its attached to the semi circular motor at an angle on the LRDG truck, not square as on the CMP set up. All other details match up.

[Mike Kelly]

It's likely that some of the screens depicted were fitted at base workshops or even by the crews themselves. Anything is possible when necessity overides official channels.

[Charlie Down]

I agree, and the majority look like they came of the Chevrolet WA's when they were replaced by Ford F30's, which begs the question where did the aero-screens for the WA's come from?! Did Chevrolet make aero-screens? Or are they locally produced/acquired, or through the official spare parts system, but from which parts list?

The numbers look about right with 37 WA's originally acquired, losses due to enemy action would make that number in the mid to high 20's, add in screens from the Ford Pilot cars, a few through official channels and reclaiming off derelict/abandoned trucks would make about 40 trucks which is about a third of the 1533X2's. That tallies with the photo's. A lot of possibilities and a rather crude process admittedly!

Just need some dimensions to work with, and hopefully some cleared photos.

[Tony Smith]

Certainly look like Morris Aero Screens, not WA Chev (unless they were also scrounged from Morris vehicles).

[Charlie Down]

So Tony, you think it's most likely a Morris Aero-screen with the mounting plates screwed onto the vertical wooden Dash Board surround, not horizontally onto the bonnet/hood as on a Morris truck as shown in your photo. That accounts for the large butterfly locking screws pointing upwards at an angle.

I'm happy with this, until proved wrong of course!

As always thank you Tony, Mike and Grant.


All I need now are some dimensions!

[Grant Bowker]

Originally Posted by Charlie Down

Do you have any photos/diagrams/dimensions? Also, either I'm being a bit thick, or I'm not quite seeing how they fit differently looking at photos on other postings of wiper motors.

1. To follow
2. My apologies, I may have been warped by too many "alternate reality" CMP installations, will need to look for more period photos of all three cabs for CMP to refresh my view.

[Charlie Down]

Hi Grant,
Thanks for your help with this.
I've compared the 1533X2 and CMP motors and have reached the conclusion that they are the same fixture. The problem, I believe, is the lighting which seems to have caused a bit of an optical illusion, with the shadows on the 1533X2 causing the rear box on the motor to appear fixed a 45 degrees instead of square. That's not to say the confusion hasn't being added to by me having a bit of a thick moment!
Any more photos may help and looking forward to any help with the dimensions.

[Charlie Down]

Here's a drawing of the Aero-screen fitted to the wooden Dash Board surround on a 1533X2, produced by overlaying a photograph to get the right proportions.
The screen works out at about 380mm/14" wide and with the hinges 430mm/16". It's about 240mm/9 1/2" high.
I'm fairly happy with the proportions, but can anyone confirm the dimensions, as I think they are too small, but I don't have anything to measure against. Anyone have any idea about glass thickness too?

[Bob Carriere]

At the very least "safety glass" with a plastic membrane like a regular windshield. PPG USA do make heavy safely glass in 1/2 in. for jewelry stores.....not to be considered bullet proof but rather smash and grab proof and fully glued in place with some form of polyurethane black goo!!

The complicated parts would be the two brass support pieces....sculpted in wax, plaster molded, they could be poured in brass or even aluminum....then hand finished. Could be made LH or RH version to account for the curve of the dash.

Cheers

[Mike Kelly]

My old drawing .. have to check the dimensions for accuracy. This drawing is provisional only ... needs to be verified

http://www.oocities.org/vk3cz/CS8page.html

The best method is to buy 3/4 tube and solder the lower channel section onto the tube , brass would be a good material , easy to solder . Looking at the original pics, the lower section, it appears to be a one piece steel shape , which is nigh on impossible to replicate unless you have a big press.

[Charlie Down]

Hi Mike,
Thanks for the drawing, I should be able to scale the length of the brackets now I know they were 1" wide. The same with the glass height. I presume the glass channel is about 3/8", 9.5mm wide.
My drawing was 2", 50mm out on the width and 1/4", 6.5mm out in height for the frame, I thought it was a bit small.
I'll redo my drawing later and post here with bracket details.
Nice to find out the origins and details of the aero-screen for the 1533X2. I believe they were originally fitted (nicked) to the Chevrolet WA trucks, and re-used for the Chevrolet 1533X2 which would explain why the canvas covers often look really ragged. That would also explain why only about a third of the 1533X2's had aero-screens, sometimes only for the driver. Also in your article you posted a link to it says that in late 1940 Morris CS4 production stopped fitting aero-screens and instead fitted a full windscreen and side doors. Could this also be another factor in fitting them to the Chevrolet WA's and later the 1533X2's? It was a bit later than the first operational use of the WA's though, but could mean spares were readily available maybe....

Next is the original windscreen!

[Andrew H.]

I am interested in the tightening/locking mechanism. Do you have drawings for that?

[Mike Kelly]

Originally Posted by Andrew H.

I am interested in the tightening/locking mechanism. Do you have drawings for that?

I have one of the locking brackets , I will sketch it for you.

Charlie, the CS8 cab change seems to be something of a mystery , as far as I know the only examples of these later full cab CS8 trucks are to be found surviving in Australia . A cast brass tag ON THE CAB states : contract nr. V4154 1941. I cannot see how the Morris cab change is related to Chevy LRDG trucks as we are discussing a totally different scenario. I believe those Chevy setups were ad hoc in nature but we can't be certain of anything .The people involved have all passed on.

[Charlie Down]

Hi Mike,
Sorry, I wasn't very clear. The change on the Morris production line from aero-screens to full windscreens in late 1940, could have resulted in existing vehicles being upgraded (unlikely to be honest), but also that spare aero-screens kept in theatre could have become a bit surplus and available to retro fit to LRDG trucks. Its a bit of a reach I know.

That's the problem with thinking out aloud, let alone writing it down and posting it!

We've still got a couple of veterans here in the UK, including I believe and hope, Mike Sadler.

Andrew, I'm working on a new set of drawings with the help of info from Mike. I'll post them when done.

[Hanno Spoelstra]

These aeroscreens must have come not from converted, but from salvaged vehicles, most likely a variety of British ones as pointed out already. So the aeroscreens on the LRDG Chevs likely differed in detail as the British manufacturers all made their own variations.

[Mike Kelly]

Originally Posted by Hanno Spoelstra

These aeroscreens must have come not from converted, but from salvaged vehicles, most likely a variety of British ones as pointed out already. So the aeroscreens on the LRDG Chevs likely differed in detail as the British manufacturers all made their own variations.

Yes I agree !

[Charlie Down]

The majority, that are clear enough to identify, are very similar, if not identical to the Morris CS4 aero-screens. I wouldn't be surprised if there were other makes, but in most photo's the quality is too poor to get a positive ID on the origins of the aero-screens. The Bedford Aero-screens look like they could also be an alternative with possible examples attached. Looking at the details they would be easy to fix to the wooden dash surround.
Photo credit to Jack Neville - http://www.mapleleafup.net/forums/sh...-screen&page=2

[Charlie Down]

I've been looking through my images of various LRDG trucks and need to correct a previous assumption that the Ford F30's didn't have Aero-screens. There are numerous photos of them fitted, however apart from an image of an aero-screen fitted with a square piece of glass, there are no details in the photo's that really help with identifying the make of any of the aero-screens. Someone else might have images that could add to the discussion, though.

[Tony Smith]

Rather than being special part unique to a particular Morris military vehicle, is there a possibility that the screens are off-the-shelf item from a aeroscreen manufacturer?

There are any number of pre-war British touring cars that used aeroscreens for their vehicles (Alvis, MG, Riley, Triumph, Austin-Healey, Bentley, just to name a few). Did each marque design their own unique screen, or was there a specialist supplier who offered these items to the various makers as Original Equipment?

[Mike Kelly]

Originally Posted by Tony Smith

Rather than being special part unique to a particular Morris military vehicle, is there a possibility that the screens are off-the-shelf item from a aeroscreen manufacturer?

There are any number of pre-war British touring cars that used aeroscreens for their vehicles (Alvis, MG, Riley, Triumph, Austin-Healey, Bentley, just to name a few). Did each marque design their own unique screen, or was there a specialist supplier who offered these items to the various makers as Original Equipment?

Found this https://www.s-v-c.co.uk/category/aeroscreens/

https://www.completeautomobilist.com...wind-deflector

The generic MG style screens look to be smaller than what we are discussing.

[Charlie Down]

Interesting idea.
The original Chevrolet WA trucks were sourced from the GM dealership in Alexandria and the Egyptian Army, and the first patrol was sent out just 6 weeks after its approval for formation. So it seems unlikely that they could source aeroscreens from the UK in that time frame. They were very probably sourced in Egypt from British stock, or possibly Egyptian Army, from derelict/redundant trucks or spares in my opinion. Possibly from Egyptian civilian car dealerships, but I think that is unlikely bearing in mind how much most of them resemble the aeroscreens fitted to British Army Morris, and possibly, Bedford trucks. Aeroscreens from other trucks are a possibility, and most likely, but I haven't seen clear enough photos, or frankly, have the knowledge to identify other makes of aeroscreens.

At this point I would summarise the discussion so far, and say that a significant number, if not the majority, of aeroscreens seen on all LRDG trucks were of the same type used on Morris CS4 trucks, and that other designs and styles of aeroscreens from different trucks were most likely used, but have yet to be positively identified.

[Charlie Down]

Here are my interpretations of the dimensions of the aeroscreens and brackets. I'm hoping that Grant and/or Mike can confirm the dimensions, especially of the brackets, which are 'scaled' and 'guesstimated'.
The wing nuts looks too big in the drawing and would foul the sides of the aeroscreen, but that is how they are shown in the photos.
The brackets are screwed to the vertical wooden dashboard surround on the 1533X2 trucks with both flat face and curved face seen against the wood surface. Most photos show the curved face against the wood.

[Mike Kelly]

The hinge dimensions on your drawing look to be pretty darn close to the correct dimensions. I will try to measure the original hinge soon, using my chinesium digital calipers

[Charlie Down]

Thanks Mike
That will be really useful.