I started a Mk VIII "International" or "Libery". two sets of views of the 3D model are attached. The lower views on sheet 2 are "wireline" views, like an x-ray, to show some otherwise hidden parts. I need some feedback, particularly on the layout of the sponsons before I get too far into it to make changes easily.
Small stirring in the sludge I call my memory - went digging - found an old drawing which I think was published in the Russian magazine "Modelist Konstructor" many years ago. I don't know how accurate the drawing is, but, if it is, it seems to suggest the guns were a bit closer to the hull than in your model. The rear (engine) deck also looks a bit higher than in your model.
The attached photo of the rear deck shows a couple of vertical flat plates along the line of the top of the rear deck, that might be interpreted in a drawing as a raised deck. Otherwise, I am already using the Russian drawing. The two screen shots show the model as I develop it from the drawings. Screenshot1 shows the construction lines in green, the section lines in red. Screenshot2 shows the 3D model overlying the drawing. Here the guns in the model seem to have approximately yhe same center of rotation as those in the drawing. It looks like i need to make my guns a tad longer.
In some photos of the right sponson, the circular shield seems closer to the outside of the sponson than it is on the left gun. As I recall from making the MkIV and MkV, the two sponsons are not exact mirror images, possibly beacause of the gunsite and its slit in the shield being on the left side of both guns. The other two photos show the two sponsons. I am trying to interpret the small vertical closure plates at the sides of the circular shields. The one on the right side is much narrower than the one on the left.
Another shape issue - the rear plate of the sponsons are shown on the russian dwg as angled slightly like those on the MkIV/MkV. They appear almost squared off in some photos, more like the ones on the MkI. Has anyone first-hand experience with this beast, and can confirm the rear plate angle?
I found the answer to the question I had as to the differences between the right and left sponsons. There was also some discussion of this topic in another thread on this forum, for the MkV tank, I think it was. Any way, I found a cut-away drawing in a Bronyekollektsia monograph on the British tanks of WW1. The gun arcs of fire are 100 degrees total on both sides, but are different in details, due to the sight being on the left side of the gun.
I note there are some differences between the US version and the UK version...MG mounts in the superstructure and perhaps in the exhausts.
I tried twice last night to post images of the sponsons and screenshots of the revised 3D model but my computer locked up and wouldn't cooperate.
Any chance you could smooth out the contours of the front track horns - at the transition from the flat upper run abreast the turret to the droop moving forwards towards the idler (which as far as I can tell does not have the kink which the Mks I-V have, but is genuinely curved), and below the idler as it curves down towards the ground?
I'm glad you didn't wait till after I "exploded" the 3D model to make the parts. <Grin> Yes, I have refined the front end of the profile a bit. When I get home from work tonight, I'll post the track profile for comments before I use it to change the 3D model. Once I start making the parts from the 3D model, some changes might become a bit of a headache. there's no hurry on this as I'm still working on the St. Chamond late production version also.
Any idea what the triangular plate on the tail is for? It seems to be attached to the semi-circular "hoop" at the tail.
I see there are some differences between the US version and the UK version:
UK version has MG's on the superstructure sides - US version doesn't.
One pic of the rear deck of what I think is a US version shows a large tubular object on the left side, forward of the exhausts. Another shows the exhausts to be straight instead of kinked to go around the rear deck hatches.
One drawing of a MkVIII shows an exhaust pipe on the outside of the track frame, right at the rear. This doesn't shjow on any photos I've seen, so I will disregard it for now.
All of these differences can be easily accommodated in two distinct models.
Can you think of anything else I need to take into consideration?
From what I've read, the triangular plate at the tail was a deflector, so that bullets from the aft MG could be ricocheted into the blind spot low down behind the tank.
The can on the engine deck is a puzzle; definitely American, but not all seem to have had it - you can see it in at least one photo in the Landships II article. I had wondered if it was some sort of silencer for the engine, but it's not connected to the exhaust pipes, so I have no idea what it was for.
The British Mark VIII had two additional machine guns on the sides of the "turret" and had two more crew members to service these. The US version didn't have these - probably quite a sensible change since the space inside the turret for both MGs must have been very cramped. Another difference was that the British Mark VIII used Hotchkiss MGs, the US 0.3" Browning MGs.
The cylindrical object behind the turret on the US Mark VIIIs is a puzzle. It certainly isn't part of the exhaust system. Perhaps it was an external fuel tank?
The attached image has two track frame profiles. The green one is the original, and the red one is the revised one. I used a 1" radius on the top knuckle and on 4 knuckles under the front idler. The top one might need to be 2" or so. What do you think?
The third curve is a definite improvement, Wayne, but I think what needs done is to insert a fluid curve from there to the idler, without a flattened section. Below the idler I recommend a similar approach, with a slightly steeper downwards curve leaving the idler and going not into a straight(ish) section, but another fluid curve, giving a stronger curve to the profile. Likewise the flattened section below the sprocket at the back of the tank wants to be a smooth, continuous curve down and forwards to the ground contact patch. It looks to me like a case of much larger curve radii, with one curve meeting the next, and few straight sections or kinks (the only kinks look to be at the end of the horizontal upper track run, heading backwards towards the engine deck, and a very slight kink, visible in close-up photos, on the lower track run just behind the sponson - I think this is where the ground contact patch should end when the tank is on a hard surface like tarmac, but the angle of rise from this kink to the more obvious curve upwards further forwards, is very slight.
You can just make it out at the bottom of this photo from Landships II, but the change is so small that it can be ignored at 1/72.
We have reached the point of dimishing returns in tweaking the profile. I am proceeding based on the 4th curve. I still have some work on the St.Chamond late production hull before I do much more with this one. Thanks for the input. I'll keep you posted on the MkVIII when I get back to it.
Wayne has finished his Mark VIII model. It's available at landships.info in two versions - Plan 1919 (hypothetical US Army tank on the Western front) and as a white model.
The finished model looks nice, but I was wondering if red-white-blue would be correct for a hypothetical Plan 1919 tank? AFAIK, the US tanks of 1918 wore the same white-red-white stripes as British ones, with the other scheme used post-war. Is this correct, and would the US tanks not have been likely to retain a common allied marking until hostilities ceased?
The white model includes the parts for the two MG's on the superstructure sides. Hotchkiss MG's are there, too.
I've started a UK version with W-R-W RAC flashes. Can anyone recommend vehicle numbers and/or battalion markings?
The French might have used MkVIII's if they couldn't get their FCM 1A or 2C into production in time for the 1919 offensive. Multi-color French camo on a MkVIII?
IIRC, British Mk VIIIs had five-digit vehicle numbers starting 12 or 120 - Gwyn will know better, there was an earlier thread in which Mk VIII numbers were mentioned. I would suggest, unless anyone knows better, that any battalion markings suitable for Mk V/V* would also be suitable for Mk VIII, on the basis that units would have older machinery replaced with newer as production got under way.
The idea of French markings is an interesting one - I reckon the Mk VIII shape would lend itself well to such treatment. Wouldn't be surprised if someone fancies the idea of a "beute" Mk VIII either...
-- Edited by TinCanTadpole on Friday 26th of October 2012 09:39:37 PM