As a newbie, hope it's OK to ask some potentially dumb questions here. Anyone have solid info or quality drawing of MK1 female sponson? Is there a difference between MK1 - MK2 female sponsons? I'd like to get this right.
I can see the outer angle is for a better field of fire (with 2 m/c guns) but all MK1 dwgs I have just look wrong to me (and they vary a fair bit between each other too). To my eye, the Bovington MK2 female sponson seems to have a much shallower outer angle compared to MK1 drawings I found.
I've had a stab at it but spent too much time trying to figure this out and I'm not too happy with what I've ended up with. A reliable MK1 Female O/A width would help, I don't have that.
BTW I remember reading somewhere of a male tank being too wide to cross a bridge, (indicating a female would have been able to make it). This is what threw me off, as all MK1 fem sponson stuff I have shows fem sponson to be quite a lot wider than male!? - Recently occurred to me tank in question was possibly/probably a MK1V - different animal.
below, some workup pics of my cogitations that may spark another idea on how to solve this...
I think we may have to wait for Helen's Mark I female sponson drawing to get a definitive answer.
The width of the tanks meant that the sponsons had to be removed on the Mark I tanks to fit inside the rail guage - the maximum size load which could be carried by rail. The British rail guage was more restrictive than the French guage. Removing the sponsons was a difficult task that the crews universally loathed judging from accounts of the period. The Mark IV sponsons were hinged so they could be swung inside the hull of the tank.
Thanks Charlie. Seems to me the Bovington Mk2 would be the best source material. Hopefully someone has run a tape over it (fingers crossed - Helen to the rescue?). Think it very unlikely MK2 would be different to MK1. With the drawings floating around it was a bit disappointing to find so much variation on a fairly simple thing, something that should be easy to get bang on. With a width dimension everything else pretty much falls into place. Yes I'd read that MK1V sponsons were hinged. Never seen any pics of it though. They all looked to me as though they were just unbolted and sort of 'pushed' in.
BTW Charlie while you're there - I'd read somewhere that QLD museum has copies available of some pretty exceptional drawings of Mephisto. Do you know anything about that?
Actually just thought of something else. Does anyone know the rivet pitch on these beasts? (I know the tanks were different from standard boilermaker pitch) Should be able to use that to get close from photos.
BTW Charlie while you're there - I'd read somewhere that QLD museum has copies available of some pretty exceptional drawings of Mephisto. Do you know anything about that?
I think you're referring to the set of drawings which were available with Mark Whitmore's A7V Mephisto book. This is long out of print (1989) and is as scarce as hen's teeth. I think one of the AMMS Brisbane guys has a set - I'll try to borrow them.
Thanks Charlie. Seems to me the Bovington Mk2 would be the best source material. Hopefully someone has run a tape over it (fingers crossed - Helen to the rescue?). Think it very unlikely MK2 would be different to MK1. With the drawings floating around it was a bit disappointing to find so much variation on a fairly simple thing, something that should be easy to get bang on. With a width dimension everything else pretty much falls into place. Yes I'd read that MK1V sponsons were hinged. Never seen any pics of it though. They all looked to me as though they were just unbolted and sort of 'pushed' in.
BTW Charlie while you're there - I'd read somewhere that QLD museum has copies available of some pretty exceptional drawings of Mephisto. Do you know anything about that?
Actually just thought of something else. Does anyone know the rivet pitch on these beasts? (I know the tanks were different from standard boilermaker pitch) Should be able to use that to get close from photos.
Hi Mark
Unfortunately my plans have for the moment come to a halt. I would love dearly to get the plans for the female sponsons done and on here... but can't see it happening until the new year.
As for obtaining measurements of photos... tried it... didn't work! :(
There really is to much distortion in photographs to get any worth while measurments from, and that's before you consider any photo you see is a copy and may have been distorted.
I may have to once more put out a request for someone to go to Bovington and get me the measurements I need. The members on here did me proud last time xx
Only difficulty there may be with measuring the female sponson on the MK2, is it's now in the main hall and permision will have to be asked.
As for rivet pitch, it's 'about' eight to nine inches... ish! :-s
When I started out on making my own MK1 plans, I soon realised I couldn't use the rivets as a means to work out plate sizes as I had hoped... there really is way to much variation.
Hi Charlie, I just had another look at photos I found. That must be the one. Unfortunately res is just (tantalisingly) too low on pics to even see dimensions. I don't know what the copyright situation would be, but seems they were OK for people to have them - says on dwg "Plans available by writing to QLD museum etc" (and that they went with the book as you said). It's a real shame to have such excellent work done and it not be used. Feel like it's too much too ask, please don't go to too much trouble but I can only promise my best effort at a first rate model with scans/plans like those.
Thanks Helen, it's fun to try and figure these out but you just can't beat real accuracy. Yeah, I can only get an approximate sponson width using track width as a guide from photo, I'm still in range of variations of the drawings, no closer. Have a lot of admiration for the work you put in, I have an engineering background so I know how even supposedly 'simple' things quickly get complicated.
I really liked that scale card you have in some of your photos, makes it easier to work out U bolt sizes, angle iron thickness etc that I hope I can incorporate into better models. (It would be really neat to have some of that rivet head shape variation in a model!) While you're there, do you have dimensions of any of any detail stuff - for instance the angle iron (Outer 'track guide' for want of better term) that runs around most of outside, angle iron looks shorter on one side. How far do the track roller shafts protrude from side?
Hmm, just had another look through my pics and another squiz at Bovington site. This Flying Scots-woman beastie has had a bit of surgery under it's kilt. Was originally male (and was male at Arras) then a supply tank, then back to UK had the MK1 tweaks and altered back as hermaphrodite (after they got their real MK1) I wonder where the female sponson came from. RH side one looks to be the real deal.
Pic below shows another sponson (male), behind tank. In same camo colours but oddly different pattern(?). Looks like left side sponson/s are mock-up. If that's the case I'm thinking they may already have a drawing based on right side one? Bit hesitant to bug Bovington, but are they OK with email enquiries about this sort of thing?
-- Edited by Enzedder on Thursday 13th of October 2011 01:13:39 AM
