WW1 Thornycroft restoration

[Tomo.T]

On 29/12/2017 at 6:19 PM, Old Bill said:

I think you have caught me there! Dennis definitely had a panel of transparent material in the window. I have no evidence that Thornycrofts left anything but a hole. However, it does stop the draught going down the back of the neck!

I don't know what Dennis used but we do have a couple of pictures which show something there although in each case, it is cracked. Could it have been a celluloid material at that period? Mica would have been too fragile, I would think. I will have to investigate early plastics.

Steve    

Steve,

Evidence may be seen here, previously posted by Charawacy back in 2015. Look out for the ack ack boys appearing at 6.18 and all will be revealed.

 

[Old Bill]

Thanks for that Tomo. They are certainly glazed with something so I now have precedent. Interestingly they are a different shape from most Thornys as they tend to have semi-circular ends rather than being plain rectangular cut-outs. You learn something new every time you look in this game!

Steve    

[nz2]

Steve; Does the Army specifications list a window material? Then again specifications changed over time and what was added at a local level as vehicles came in for repair. The realm of adaptations and improvement. Cellulose could well be standard after a certain date.

 Doug

[andypugh]

On 29/12/2017 at 6:27 PM, Le Prof said:

Transparent Cellulose Acetate film was certainly available at this point

....

That is about the only transparent plastic option.

As Steve mentioned, there was also celluloid (cellulose nitrate) which was in common use for film stock. 

I have a vague recollection of hearing a mention of celluloid curtains on horse drawn hackney carriages. 

(But all those words are hopeless google search terms)

[Richard Farrant]

This link is regarding the same period of time, they are describing isinglass and mica;

http://theoldmotor.com/?p=134906

 

 

[andypugh]

Thanks for the link. I was misremembering. The phrase I recall was indeed “isinglass curtains”. 

Interestingly the Wikipedia page on isinglass begins with “ for the material used in window sheets see “mica””

FWIW RS still sell mica sheets. It’s still a useful material where you need a high temperature insulator. 

[Minesweeper]

Oklahoma!

"Isinglass curtains that you can pull right down in case there is a change in the weather!"

[Tomo.T]

Whatever the material was, the transparent sections would need to be flexible and able to be stitched into the canvas surround, which rules out Mica in my opinion. The effect of the wind is visible in the film clip. Also, the rectangular openings appear to have a small radius at the corners which would make sense for stress relieving purposes. I would hazard a guess that celluloid would be the most likely choice. 

[john1950]

2 hours ago, Minesweeper said:

Oklahoma!

"Isinglass curtains that you can pull right down in case there is a change in the weather!"

From the days of music and relevant, well remembered.

[Old Bill]

On ‎01‎/‎01‎/‎2018 at 3:43 AM, 42 chevy said:

When you installed the gas tank, did you use a "anti squeak" welting between the straps and the tank. I did not see it in your pictures. If you did not, may I recommend that you do. Besides one less rattle noise it will keep the strap from rubbing into the tank.

Thanks John. We didn't use any padding as I have seen no evidence of it in any of our photos. Seems like a good idea though. There are enough rattles without adding to them! We will put something in there next time we get on to it.

Steve       

[42 chevy]

Steve,

 

On our big trucks, Ward LaFrance Diamond T etc, we use a welting that is 1 1/2 to 2 inches wide depending on the width of the strap and 1/16 inch thick, sometimes 1/8 inch.

regards

John

[Kufra Kiwi]

WW1 pilots occasionally refer to the windshields of their aeroplanes (Sopwith pup, camel, etc) being made of clear material like perspex. On page 69 of "Sagittarius Rising" WW1 pilot Cecil Lewis writes:

" ....there was a sharp crack, and the little windscreen a foot in front of my face showed a hole with a spider's web in the glass around it. It was Triplex: no splinters but another foot behind would have put a bullet through my head"

This was in 1916.

[Citroman]

Triplex is two sheets of glass with some plastic like stuff in between.

Edited January 3, 2018 by Citroman

[Le Prof]

Hi, All,

certainly not Perspex, which was not developed until 1928.

https://en.wikipedia.org/wiki/Poly(methyl_methacrylate)

Perspex is often used as a generic word for transparent plastic, like Hoover for Vacuum cleaner.

Triplex did exist, here's a 1916 article on it from Flight magazine:

https://www.flightglobal.com/FlightPDFArchive/1916/1916 - 0066.PDF

https://www.flightglobal.com/FlightPDFArchive/1916/1916 - 0067.PDF

Triplex glass was laminated with Xylonite, a modified (probably a different plasticiser, which changes the flexibility) form of Celluloid, so it could be your rear window would have been a sheet of Xylonite.

http://www.decolish.com/Xylonite.html

Meilleurs Vœux pour 2108 (-:

Adrian

 

 

Edited January 3, 2018 by Le Prof

[andypugh]

4 hours ago, Citroman said:

Triplex is two sheets of glass with some plastic like stuff in between.

Not directly relevant 

https://en.wikipedia.org/wiki/Triplex_Safety_Glass

But, perhaps it would be useful to know what the inner layer was made of at the time. 

https://en.wikipedia.org/wiki/Laminated_glass

In the history section says that cellulose nitrate was used in the first safety glass, to that is another suggestion that Celluloid is the likely material. 

Also interesting, but not particularly illuminating is

https://simanaitissays.com/2013/04/09/isinglass-curtains/

[MatchFuzee]

On ‎30‎/‎12‎/‎2017 at 8:39 PM, Old Bill said:

And then that the chassis has a 1/4" bow as well causing the ends of the cross-members to misalign with the kerb rail which is straight.

Is the 1/4" bow in the chassis enough to make the front and back axle unparallel to each other? If yes, won't the Thornycroft crab?

[andypugh]

52 minutes ago, MatchFuzee said:

Is the 1/4" bow in the chassis enough to make the front and back axle unparallel to each other? If yes, won't the Thornycroft crab?

Have you driven a WW1 vehicle? Not crabbing would be unauthentic. 

[MatchFuzee]

2 minutes ago, andypugh said:

Have you driven a WW1 vehicle? Not crabbing would be unauthentic. 

I've not been lucky enough but perhaps one day.

[G8RPI]

The Xylonite link Le Prof provided http://www.decolish.com/Xylonite.html Says that Xylonite was the material used for WWII gas mask visors. From my memory of these, especially the infant ones, the material would be very usable, if not ideal, as a hood window. British Xylonite Co Ltd  was founded in 1877 with expansion in 1887 and 1897 so timescale is correct. Note that it's highly flammable being made from nitrocellulose.

Edited January 7, 2018 by G8RPI
spelling

[43rdrecce]

I've just had a look through the 1920 edition of 'Priced Vocabulary of Stores' and the following entry might be of interest

Tents, Marquee, Hospital, Small - Window, sheet horn non-inflammable celluloid 

This pattern of marquee was pattern sealed in early 1915. Though the vocabulary contains several references to MT equipment for lorries there is no reference to canvas other than 'Cover, Canvas, for MT Vehicles- 22' x 16' Black'

Two other interesting entries are 'Matting, Rubber, pyramid pattern, for mechanically propelled vehicles. Length and width to be stated in demands' and 'Canvas, Prepared- 3 feet wide, for repair of tyres on mechanically propelled vehicles. Double Proof MKII, proofed both sides. Single Proof MkII, proofed one side' The matting and the Canvas Prepared were introduced in List of changes in July 1907, the MkII prepared canvas dates from July 1916.

[Old Bill]

Thanks for all of that information Chaps. It is amazing the discussion points that this thread raises! I'm afraid I can't answer Doug's question about the Subsidy requirements. That is one for Roy Larkin.

The Christmas break has highlighted to me how very tight for time we really are and it is going to need some serious effort and proper project management to make it all happen. To that end, I now have a job list of seventy five items on the back of my kitchen door They range from things like 'Bolt seat down' to 'Build body' so they are quite wide ranging in size! Next to the list I have a work plan which has weeks along the X-axis and outstanding jobs on the Y-axis. This shows that we need to complete a little over four jobs per week to meet the goal. I have drawn in the ideal line and am plotting our current state each Sunday. As you can see, we are a little ahead of the game today but I am not sitting on my laurels. It is getting a bit serious when one is project planning and undertaking a Critical Path Analysis on one's hobby!

This week, I have been concentrating mostly on drawing and have done the differential spider and the rear wings. The wing drawing will be sent out for quote tomorrow. In the workshop, I brazed the flange onto the end of the exhaust down pipe. Rather than risk silver soldering which might melt in service, I brazed the end on which is the first time I have used this process. As you can see, it has to be very hot (much brighter than the picture suggests) and doesn't run like solder.

Around the back, I didn't get it quite hot enough and the rod did not run.

Cleaning up revealed a 3/8" gap in the joint but it is not a pressure vessel so I decded to leave it rather than re-heat. Fitting of this pipe will complete the exhaust installation.

Then, for a bit of light relief, I made up the peg to secure the bonnet in place. I went back to silver solder for this one.

We were very fortunate to find a correct pattern Thomson Bennett magneto switch on an Autojunble stand many years ago and this has been in Father's book case ever since. It could do with mounting on the dash plate so I put my meter across it and then gave it a bit of a buffing. ALl was well and that will go on next time I am down.

Then back to pattern making. The tailboard hinges are a weird shape of block which would be a pain to machine so I determined to cast the three of them as a stick so Father can machine them. Rather than MDF, I used a piece of Big Mark's pine, lovely stuff!

That is now in the paint shop.

The next thing to go on the dash is the oil pressure gauge. This is a correct pattern Thornycroft gauge, found by Mike Jones who set me off on the project so long ago.

I pulled it apart and dusted the interior with a paint brush.

Cleaning the brass was the next challenge. It had obviously been nickel plated originally but most was long gone so I clamped my drill in the vice with a nylon brush in the chuck and used that. It took off the paint and corrosion and also the remaining nickel.

It was very effective but the surface so exposed was very pitted with corrosion.

Similarly for the main case.

A buff with some Autosol and back together.

I turned up a union nut and nipple for the pipe connection and the gauge ia also ready to be fitted to the dash.

More pattern making this week. Only three left!

Steve     

 

[Asciidv]

As braze has very little capillary action but more or less just sticks on top of the surface of the metal, is there a chance by cleaning it all off to make it look nice you have lost all your strength and the flange might crack off in service?  As you know the Dennis flanges always have a tube extension to allow them to be rivetted to the pipe.

However, I have to admire your determination as filing braze is a long hard unrewarding job!

[Great War truck]

On ‎07‎/‎01‎/‎2018 at 4:22 PM, 43rdrecce said:

Though the vocabulary contains several references to MT equipment for lorries there is no reference to canvas other than 'Cover, Canvas, for MT Vehicles- 22' x 16' Black'

Two other interesting entries are 'Matting, Rubber, pyramid pattern, for mechanically propelled vehicles. Length and width to be stated in demands' and 

That's very interesting. I have no idea what that matting would be used for. I wonder why the canvas would be black? I have never come across that before either.

All very interesting stuff

[43rdrecce]

Unfortunately, it doesn't specify which 'mechanically propelled vehicles' the matting was intended for. Interesting though that it appears to be so early, as 1907 is the date indicated by the List of Changes entry. Was it possibly used on cab floors?

The black canvas is the only one noted specifically for MT vehicles. The LoC for this dates from December 1911, so is pre WW1! There are other colours listed as well as black for waterproof covers, though these were presumably general purpose items. There is a range of black waterproof covers ranging from 40' x 20' to 10' x 6' and an identical range described as 'Green, Oriental or Willesden dressed'  Willesden canvas is that bright green colour which results from the application of copper sulphate based rot proofing applied to the canvas.

Manufacturers vehicle canvas supplied with vehicles must have been patched up as required by units.

Canvas was routinely painted during the war. Cutch (brown) is mentioned for darkening white bell tents for instance but ordinary camouflage paints were frequently used. The book lists 'Service Colour' which I presume is similar to the colour you use on your vehicles, a warm khaki drab.

It does appear to confirm the use of celluloid for windows in canvas. There is mention of Isinglass, but seemingly in bulk form as it is listed with paints and solvents and it could be used for specialised gluing processes. There is no mention I can see of Mica.

Regards

Paul

[Old Bill]

On 08/01/2018 at 8:21 AM, Asciidv said:

As braze has very little capillary action but more or less just sticks on top of the surface of the metal, is there a chance by cleaning it all off to make it look nice you have lost all your strength and the flange might crack off in service?  As you know the Dennis flanges always have a tube extension to allow them to be rivetted to the pipe.

However, I have to admire your determination as filing braze is a long hard unrewarding job!

Hi Barry.

I haven't actually cleaned much off, just the two pieces of stick which didn't run so it wasn't much effort. There is a nice fillet most of the way around. Mind you, the gap is a crack initiator in exactly the same way as the lack of weld on the leg of the Alexander Kielland accommodation rig which snapped off some years ago. I don't think my failure will be quite so catastrophic though as the pipe is trapped by the bottom elbow.

I have seen exhaust flanges with extensions on them but the Carlton Colville Thorny doesn't have one. Mind you it might not be the original exhaust system after 100 years!

Steve