Landships II

I'm a little surprised that there hasn't been a reply to this already.

How much have you looked through the photos available on Landships? Roger Todd posted a couple of factory photos, showing either MkIII or IV in one pic (I think)

and MkV** in another, in this thread;

You may gain some ideas from scrutinizing the pics of D51 Deborah in this one;

There are also some handy photos of wrecked tanks on the old Landships site, towards the bottom of the article "Mk IV Tank", under the section entitled "Mk IV

Wrecks". I'm not sure if links to the old site will work, so you can copy/paste this address: http://www.landships.freeservers.com/mk4_survivors.htm

Whether you're unsure of the panels involved in joining inner and outer track-frame plates, or the angle-iron used, is not clear in the original post (both, perhaps?),

but the track frames are essentially box sections with front and rear vertical bulkheads (respectively situated behind the idler and before the sprocket); along the top

of the box section runs another plate (or series of plates), a little below the top edge of the side armour, curving/kinking downwards at each end to follow the profile

of the side armour, and bearing rails that the top run of the track scraped along.

The bottom of the box section will have a series of plates across also - there may be a drawing or something (in relation to the roller 'road wheels') somewhere here

on the forum, if memory serves.

Looking at photos of wrecks, it seems clear that the box-section track-frames were more robust than the central hull - some tanks destroyed by internal explosions

have had their track frames collapse outwards more-or-less intact (see photos on landships.freeservers.com, as listed above)

As for methods of joining plates, more research is needed, but it seems likely that L-shaped beams (angle iron) were used to connect plates at right angles to each

other, although the photos of Deborah linked to suggest (if you look closely at the ends of damaged plates at the front right quarter of the tank) that the upper track

run plates were connected to the outer side armour by  the same angle iron that forms the 'lip' visible along the edges of the side armour (around the perimeter of

the rhomboid shape): this angle iron looks to have had two horizontal flanges - the obvious one at the top edge sticking out to form the 'lip', and a hidden flange at

the bottom edge, pointing inwards and being riveted to the horizontal plates across the top of the box section of the track frame.

If that description of the section of this angle iron sounds confusing, then, without lifting your pen/pencil from the paper, draw a short line from left to right, followed

by a short vertical line downwards, then another short vertical line from left to right and you will see the beam section I am referring to, as seen for the top outer

angle iron of the right track frame when viewing the tank from ahead (the right track being on the left when viewed from ahead, of course!).

Hope this is of some use; sorry for the wordy answer!

Hi

I have exactly what you want but don't know if I can repeat it all here as it was sent to me privately. So to focus on the construction sequence alone:

Basically, the final construction was carried out in an erecting shop but large components were constructed elsewhere. These large components included the inner hull with the transverse diaphragms, the outer frame with the angles, and the engine and control levers. Basically the inner hulls were connected by the floor and frontal plates and the rollers put in position supported on temporary axles. Next the outer frames were put in place using rigid axles through the sprocket bearings to line them up (the same technique was used on Churchill tanks in WW2 and visible in the first photo in the last post). The track was drawn into place along the rollers and the tank lowered to the floor. The transmission gearwheels and sprockets were added and the temporary axles for the rollers replaced. The separate engine assembly was added with the rear hull riveted into place and the roof bolted on. Finally the petrol tank, internal and external fittings, sponsons and pipes were added, the tracks connected, the tank painted and driven out of the erecting shop.

Hope that helps

Gwyn

Thanks for the replies, I have attached all of the photos I have found of tanks under construction I you know of any more I would be grateful if you could share them with me. I do have the full set of Bovinton prints of the Mk IV, but they only comprise of about 50% of the tank. Thanks to the link to you plans, this is all valuable information.

I am trying now to understand the construction sequence. I know that the inner and outer side hulls are separated by two box structures that run roughly around the track perimiter and the sponson outline, however there are many vertical joints between the side plates that do not coincide with these box structures, I believe they are joined by riviting to 'T' section pieces that run vertically on the inside, however how was this done on the forward inner plates and outer plates? at some point, once you have done one, yoy don't seem to have access to the interior to do the other. I am guessing that the construction sequence would have been floor and lower hull plates to the inner side plates, then most of the internals, then side box sections, then outer plates and finally the upper hull plates. I have searched extensively online, but have not found any references to how they were built (I was hoping to find 'memoirs of a tank builder' !) I have also searched for fosters, metropolitan etc history, but again scant details.

The 3D printer has huge possibilities - we have one at work, but my model is coming along very slowly as I am learning CAD as I go (I learned all of my drawiing skills at a drafting table with ruler, compass, french curves etc). I think I will try the 1/12 scale plastic model first and attempt to build it like the real thing - I think the logistics of that will help me in my understanding and maybe answer some of my own questions.

thanks again for all of the help

The roof is removable on all the tanks to enable engine removale and repair. Some panels are rivited together, then those two are bolted on. Finding out which panels are bolted and which rivited, was actually harder than I had first thought. The Mk2 is slightly different to the MK1, and so on. 

Look at my plans, then the MK2 at Bovi and then the MK5s I think they are, which the Russians restored... they are all different. If you also look at the interrior views you will see the pattern of bolts and rivits.

Another late entry - the eighth post by Mk1Nut in this old thread shows a MkIV without side plates.

Progress made so far....

 

 

Huuuge image though

Huuuuge image...

https://i.postimg.cc/3KQrRJQk/IV-Tank-Lo-Res.png

 

You can download the .stl files for Mark I - IV track links at Landships II (http://landships.info/landships/3dprint.html)

Charlie

 

MehdiT wrote:

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Cool, I had seen that image before, but much, much smaller.
I started the layouts for some of the side plates, I am hoping to machine them from styrene sheet on a small CNC mill.
I just pulled the trigger on a small SLA resin printer, so hopefully this project will finally start moving forward.
I’ll try to post some images as I go.

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I enlarged it with Gimp, from a smaller image.

Still don't know its provenance though.

 

Why machine?

outside plates are 8mm in 1/12 that is 0.66mm

Plusmodel do 0.6mm

RP Toolz do 0.7mm

Ok for perfection sandwich 0.4mm with 0.25mm.........

just some grooving and snapping and youre done!

no mention of the edges being milled.

I was thinking doing a full interior semi scratch Male using the Takom as a base, but scale thickness plate....

But the thinnest plate would be 0.13mm!

With one side removable it would bring home the realisation of how this the armour really was.

for reference the Takom kit outer sides are 1.5mm where they should be 0.23mm....

Hello MehdiT

Nice Cad work and interesting project. If I may I would like to comment on the bottom side of the differential. The bottom side would need a connection between it and the engine. There is also a "brake linkage" that connects to the underside controlled by a foot lever from driver station. Not sure how this all functions. Trying to follow control lever from a GA drawing and pics. Attached is what I believe the bottom of the differential may look like.