Landships II

James H · Legend

French (?) Wheel/track Vehicle to i.d.

Roger Todd · Legend

I did think about the Schneider but I've only ever seen a line-drawing and that doesn't have the massive overhang where the driver goes that the St Chamond has and which the vehicle in the film also has - maybe the unit in the film is a St Chamond with a petrol engine fitted, or maybe it's being run off cables we can't see because they're on the other side? I think both units in a pair (the one with the gun, the other with the ammo) had their own electric motors, so as long as you could feed power to one or other unit it should have been able to move on its own.

I've attached a copy I found on the net of the Schneider SPG which is identical to the line drawing I have (thus saving me the bother of scanning it). Also a colour illustration I've only seen for the first time just now.

EDIT: Hang on, which end does the driver go on a Schneider? In that colour drawing, if you took the housing off the left and had the driver there, it would correspond to the machine in the film.

-- Edited by Roger Todd on Friday 17th of February 2012 02:18:34 AM

Roger Todd · Legend

Looks like an adapted French St Chamond SPG or SPG ammo carrier (see attached).

CharlieC · Legend

�

Modest amount of digging around in the digital cesspool.....

The original image above is a 280mm Schneider SPG - the caption is wrong about the howitzer used. According to Guy-Francis at �http://pages14-18.mesdiscussions.net/pages1418/Pages-d-Histoire-Artillerie/Artillerie/obusier-sujet_1062_1.htm the Schneider SPG used a St Chamond hull with a Schneider track system. 25 of these SPGs were built but only the prototype made it into action at St Mihiel. Some captured Schneiders were used in WW2 by the Germans as�28 cm M�rser 602(f) auf Selbstfahrlafette.

The Schneider SPG in Roger's post is a post-WW1 220mm gun equipped SPG. These were definitely post-WW1 but were used by the Germans in WW2 as the�22 cm K. 532 (f) auf Selbsfahrlafette. First image is of the Schneider SPG next to a St Chamond 194mm SPG. I don't know what the function of the bodywork was on the Schneider.�

Just to add confusion - St Chamond built a single prototype of an SPG with a 220mm St Chamond howitzer. Follow on orders for this were cancelled at the end of WW1.

Some 50 of the St Chamond 194mm GPF gun SPG with tractors were delivered, some may have been built before the end of hostilities but they never were in action (afaik).

Regards,

Charlie

-- Edited by CharlieC on Friday 17th of February 2012 03:23:56 AM

Roger Todd · Legend

Looking through my Nov-Dec 2006 (No 74) copy of Histoire et Guerre Blindes & Materiel, I found the attached on p.28. I have included the caption - imagine the unit on the right with a tarpaulin over the gun cradle and the six-spoked elevating wheel in the side (the one that looks like a ship's wheel) stored higher up...

-- Edited by Roger Todd on Friday 17th of February 2012 03:53:42 AM

TinCanTadpole · Legend

I don't know Russian, but I believe the cyrillic caption for pic 4 says it's a Schneider.

Roger Todd · Legend

The vehicle's a St Chamond but it mounts a Schneider howitzer. There are more pictures of the type of vehicle I referred to here:

http://www.landships.info/landships/tank_articles.html?load=tank_articles/St_Chamond_SPG.html

TinCanTadpole · Legend

Okay, yes. The danger of offering one's opinion when not quite certain of the facts, made manifest. Would make a good subject for modelling.

Roger Todd · Legend

TinCanTadpole wrote:
Would make a good subject for modelling.

Wrap yer eyeballs round Arie Dijkhuis's model (made from a kit for which he made the master!) - on the old site:

http://www.landships.freeservers.com/ariedijkhuis_models.htm

Lovely jubbley!

There is also a 1/35 kit by Kolinec:

http://www.armour-models.co.uk/model_kit_cz_kolinec.html

Also lovely jubbley!

CharlieC · Legend

�

Not sure about the ident as a St Chamond SPG since this design relied on a pair of vehicles, a tractor unit with engine and generator and a unit with the gun and electric drive motors. There were substantial electric cables joining the units as well as the towing bar.

I think the film clip is showing the Schneider SPG - a much rarer beast which made it into limited service during WW1.

Many of the images of the St Chamond and Schneider SPG come from WW2, mostly from service in the Wehrmacht after the fall of France in 1940.

Regards,

Charlie

James H · Legend

Hmmm. Can't make my mind up now. Charlie has a point - the Schneider was a single unit. On the other hand, Saint-Chamond did a lot of experimenting with wheel-track designs. Can't find my Allied Artillery of WWI at the mo - there's a very good pic of the Schneider in that.

Am now also wondering what the other vehicle is - the one at the beginning, with the canopy.

James H · Legend

Oooh! Didn't we have a picture of them side by side, a few months ago? In a warehouse or something?

Roger Todd · Legend

�

If you click on 'view as stills', the stills are actually much clearer than the video. I've attached some - each number corresponds to how many seconds in. As far as I'm concerned, in the absence of a decent image of a Schneider, it looks most like a St Chamond chassis.

Roger Todd · Legend

Hang on, just found these, which appear to be the elusive Schneider:

http://forum.axishistory.com/viewtopic.php?f=70&t=142991

Also attached. The designation of one image as 'French half track' is not mine, it's unaltered from the image as downloaded from the above link.

I still don't think that thing in the Pathe newsreel is a Schneider.

Roger Todd · Legend

CharlieC wrote:
The French caption says the vehicle is the prototype 220mm St Chamond SPG. Note the gun part is being towed rather than driven like 280mm Schneider SPG. The movie clip shows a vehicle moving under it's own power.

Each unit was motorised. The gun unit wasn't 'towed' as that implies an unpowered passive unit being pulled. The ammo unit carried the generator powering both units' motors, but if you got rid of the ammo/generator unit or uncoupled it and put it somewhere else, as long as you ran power to the motors of the gun unit it would still move.

Now, take another look at the video clip - better still, examine the stills, which are clearer. I have attached two, with brightness and contrast increased. They show what I believe to be a cable running from the far side of the moving unit to somewhere on the left of the picture - probably that mysterious other vehicle. I believe that vehicle has a generator and is feeding power via that cable. The cable is not an artifact of a scratchy film as it appears throughout that part of the sequence before being obscured by the body of the moving unit.

EDIT: Upon further examination of the stills, the 'mysterious' other vehicle on the left is not at all mysterious - it's tracked. I think it's simply the ammo/generator unit. Instead of being coupled with a rigid coupling bar, it's been parked some distance away and the cable run to the gun unit. As far as I'm concerned, it's simply the prototype 220mm howitzer on a St Chamond SPG chassis being tested uncoupled from its generator car.

-- Edited by Roger Todd on Friday 17th of February 2012 12:02:40 PM

CharlieC · Legend

�

The French caption says the vehicle is the prototype 220mm St Chamond SPG. Note the gun part is being towed rather than driven like 280mm Schneider SPG. The movie clip shows a vehicle moving under it's own power.�

I've attached another image of the 280mm Schneider SPG without the auxillary wheels. I suspect it's a WW2 German image.

I think the auxillary wheels were an attempt to reduce the bearing pressure of the tracks when the vehicle was driven on roads, i.e. reduce the damage to roads - the wheels don't seem to be driven.

Regards,

Charlie

�

Roger Todd · Legend

Well, I'm relying on the evidence of what I can see in the video and stills and what I see is something that looks like the St Chamond 220 Prototype. What the arrangements were for powering it I don't know, maybe it was what I think is the cable which you deride as too thin, maybe not, but I'm using my eyes and not trying to shoehorn it into any preconceptions.

EDIT: In any case, having carefully studied some decent photographs of St Chamonds - and incidentally you can also see it in the image I scanned above if viewed full size - the cable conecting the units is not 'quite massive' as you claim, but looks to be no more 'massive' than what I believe to be the power cable in the video/stills.

-- Edited by Roger Todd on Friday 17th of February 2012 02:00:31 PM

CharlieC · Legend

�

In this YouTube video -�http://www.youtube.com/watch?v=86usoTys4nc - there's an image of St Chamond SPGs under construction. One of the units has the wheels attached. Not sure the rear wheels were powered but it's possible.

The St Chamond dynamo chucked out a serious amount of power, 130A, 400V at 1450 engine rpm - if that's a cable supposed to handle this sort of power then the bystanders in the film clip are seriously brave (or stupid). The normal electrical cables between the tractor and gun carriage on the St Chamond SPG were quite massive, as you'd expect from the power output.

Regards,

Charlie

James H · Legend

This is getting complicated, isn't it? The version with the wheels, which Charlie describes, is below. That looks like it to me. No definite date, though. I suppose the nautical steering wheel is a powerful argument.

If you want an expert guided tour of the Saint-Cham SPG at Aberdeen, try this: http://www.youtube.com/watch?v=HPlOa9OQq7g&feature=endscreen&NR=1 "This is this part, here." Excellent direction, though.

ALVF · Major

Hello,

The guns and mortars mounted on Saint-Chamond "aff�t-chenilles" had a complex history, between 1917 and 1918, many prototyps were made:
-the 220 mm TR Saint-Chamond mortar (truly an Howitzer with its range of 13500 meters), a powerful weapon, the prototyp was tested at Lassigny in 1917 on the german trenchs laid by the germans after 15th march 1917 retreat on "Hindenburg Line".Then the mortar is send in Verdun front lines at summer 1918 and it fired on several german Minenwerfer batteries with success.
-the 155 GPF on "aff�t-chenilles" prototyp, one made in 1918.
-the 120 L Saint-Chamond gun, one other prototyp of long gun.
-the 194 GPF mounting on "aff�t-chenilles": 50 were made in 1919.
-the 280 TR Schneider mortar on "aff�t-chenilles": 25 finished in early 1919.
The 220 mm TR mortar first prototyp had wheels for use on roads and "chenilles" tracks for battle use.
I have great Saint-Chamond works original books dated 1917 and 1918 with many drawings of this interesting mounting of the 220 TR (wheels typ included), 194 GPF and 280 mortar typs and also photographs of the Lassigny testing of 1917 on wheels and tracks and also of the first testing of the 280 on "aff�t-chenilles" in 84�me R�giment d'Artillerie Lourde � Tracteurs in 1919 spring.
All these documents are for a futur paper in a french Review.
Yours sincerely,
Guy Fran�ois.

TinCanTadpole · Legend

I'm glad Roger spotted that cable - I've just seen it myself, and noticed that there is another tracked vehicle parked close enough to supply the juice. On that subject, did the generator unit have two generators - one for itself and one for the SPG - or was it just one between the two? If just one, that output, 130amps x 400v=52KW would allow only 26KW per vehicle - about 35hp - so you wouldn't need a cable the thickness of an anaconda.

CharlieC · Legend

�

I think the electrical power on the St Chamond was DC. The cable size table refers to 3-Phase AC. Would need someone who knows about electrical stuff but I think you're looking at much larger cables for DC.

In the video clip of the Aberdeen 194mm SPG you can see the plug for the power cable on the left front of the vehicle. The commentator reminds me of the bane of visiting European historic sites - you always seem to get an American talking shit loudly (bad experience at Versailles and other places).

The first vehicle in Roger's last post is interesting - it seems to be the prototype with the 120mm St Chamond gun - it isn't a 155mm GPF gun since it has a falling block breech rather than a screw breech. The vehicle has the radiator installed implying that it was intended to be self-powered.

As Guy-Francois pointed out the development of WW1 French SPGs is a complex story. I know I'm looking forward to a definitive article on these.�

I really should update the Landships article on the French SPGs to try to convey the effort the French put into developing these vehicles. Other countries didn't seem to follow the French conception of an SPG (the biggest gun you could reasonably put on a chassis) until WW2 and later.

Regards,

Charlie

-- Edited by CharlieC on Saturday 18th of February 2012 12:55:06 AM

Rectalgia · Legend

TinCanTadpole wrote:
...that output, 130amps x 400v=52KW would allow only 26KW per vehicle - about 35hp - so you wouldn't need a cable the thickness of an anaconda.

�Yes, about 9.5mm total copper diameter would be more than adequate - http://www.openelectrical.org/wiki/images/2/2b/Cable_waterfall.jpg.� The insulation would need to be fairly substantial and "ruggedised" for field use.

CharlieC · Legend

�

Don't know - my only experience with large amounts of DC power is in Aluminium smelters - 150,000/175,000 amps at around 950V on a potline needs some serious conductors.

Anyway, an article for Landships II on the SPGs should include the'following vehicles.

1. Based on the St Chamond tank chassis:

120mm St Chamond gun - one produced? - powered by tractor vehicle? - I found an image of this one.

155mm GPF gun - one produced - self powered?? - never seen an image

220mm St Chamond howitzer - one produced - needed a tractor unit? - plenty of images

280mm Schneider howitzer - 25 produced post-WW1 - powered by a tractor

vehicle?

- I'm guessing this was the Mle 1914 siege gun.

194mm GPF gun - 50 produced - needed a tractor unit.

2. Schneider chassis

Different chassis to the St Chamond SPGs (although it looks similar, although larger) - 220mm gun - 5 produced post WW1 survived until WW2.

The St Chamond chassis vehicles had an uprated engine compared to the tanks 118 hp (120 CV) compared to 90 hp for the tank.

Assuming the St Chamond chassis retained the Holt suspension how did they organise all the locating plates and bars of this suspension.? The 194mm version seems to have had a slot through the centre of the chassis for the gun recoil - on the Holt suspension the bars and plates were pivoted along the centreline of the hull.�

Any help filling in the queried items gratefully received.

Regards,

Charlie

�

-- Edited by CharlieC on Saturday 18th of February 2012 05:49:35 AM

-- Edited by CharlieC on Saturday 18th of February 2012 07:21:50 AM

Rectalgia · Legend

CharlieC wrote:
I think the electrical power on the St Chamond was DC. The cable size table refers to 3-Phase AC. Would need someone who knows about electrical stuff but I think you're looking at much larger cables for DC. ...

No expert but ... DC transmission is actually more efficient than AC - provided you don't need to transform the voltages.� That means you can get away with smaller cable diameter at the "same" (RMS) voltage and power though this is not really an appreciable factor for short cables.� See James' favourite resource - http://en.wikipedia.org/wiki/High_voltage_direct_current#Advantages_of_HVDC_over_AC_transmission specifically and http://en.wikipedia.org/wiki/War_of_Currents for the more general considerations of long-distance, wide area distribution.

I think the confusion/perception about larger DC cables maybe comes about through low voltage transmission (typical for DC in day-to-day application, not much seen for AC) where large conductors are needed to keep voltage drop to a reasonably small proportion of the working voltage at high power levels - and to keep excess heat down.� 12 volt versus 240 volt is of course an "apples and oranges" comparison.

Anyway, not so important.� The real story, as you say, is the initiative of the French in self-propelled artillery and that is a most worthwhile subject for documentation.� Looking forward to it.

ALVF · Major

Hello,

All the tracked Saint-Chamond guns or mortar on "aff�t-chenilles" had two vehicles.
I have photographs of all these guns (120L, 155 GPF, 194 GPF guns and 220 TR, 280 TR mortars).
My english writing is poor, so I write some technical words in french.The primary sources are the "R�glement de manoeuvre de l'Artillerie-Description et entretien du mat�riel et des munitions de 194 GPF sur chenilles" 1926 printing (92 pages, 27 drawings) and the book "Artillerie � chenilles" of lieutenant-colonel Balli-Ecole d'application de l'artillerie-1921 which depicts Saint-Chamond and Schneider "artillerie sur chenilles":

-the first vehicule is the "Avant-train, voiture automotrice, il contient le groupement g�n�rateur qui sert � produire l'�nergie �lectrique, soit � l'avant-train, soit, par l'interm�diaire d'un c�ble conducteur, � l'arri�re train.L'avant-train a deux moteurs �lectriques, il peut aussi servir de tracteur avec une barre d'attelage pour remorquer une charge.L'avant-train transporte les munitions, les agr�s et l'outillage".

-the second vehicule is the "Arri�re-train, voiture canon portant l'aff�t et le tube du 194 GPF, il contient deux moteurs recevant l'�nergie �lectrique de l'avant-train par l'interm�diaire d'un c�ble souple".
The "c�ble souple" is 50 meters long.

La transmission �lectrique est du syst�me Crochat-Collardeau.
Moteur �lectrique Thomson-Houston � 4 p�les, puissance 20 kw � 1200 tours/minutes (t/m).
400 V-65 A.
200 V-130 A.
Moteur � essence Panhard-Levassor de 4 cylindres (165-180) 120 chevaux � 1200 tours.
Yours sincerely,
Guy Fran�ois.

-- Edited by ALVF on Sunday 19th of February 2012 11:25:21 AM

James H · Legend

Ian Hogg's book is available online here:

http://www.amazon.co.uk/Allied-Artillery-World-War-One/dp/1861261047#reader_1861261047

P.103 - 105 for the Schneider and Saint-Chamond SPGs.

-- Edited by James H on Sunday 19th of February 2012 12:21:40 PM

CharlieC · Legend

�

Thank you for the additional detail. The length of the cable is interesting (50m) - it seems as if the gun was intended to operate somewhat independently of the tractor vehicle. I think that's shown in the Pathe film clip which I concede is of�

the prototype with the St Chamond 220mm TR howitzer.

The St Chamond chassis would have been very useful for an SPG since the tank and presumably the SPG could "turn in place" - essential for traversing the gun accurately. I can't think of any other WW1 tracked vehicles that could do this.

Regards,

Charlie