A What If Amphibious Vehicle

[PFJN]

Hi,
I;ve started work on trying to build a 1/35 scale model of a "what if" idea that I had.  Right now I'm still playing around with some ideas, but the image below shows kind of what I am thinking.

The thought is to take a commercially available turret and main gun and put it onto a tracked vehicle hull that has some degree of amphibious capability.

Right now I am looking at usinga 3D model that I downloaded off the internet of something called a Cockerill 3105 turret.  Although the Cockerill 3105 turret is desined for weapons up to 105mm, from some of the stuff that I have read on the internet it can also accomodate a 90mm gun.  As such, I am thinking of fitting with a rifled Cockerill 90mm Mk 8 gun which, as I understand it, can fire a range of ammunition including an Armor Piercing, Fin stabilized, Discarding Sabot round, a High Explosive Plastic round, a smoke round, and a barrel launched anti-tank missile called the "Falarick".

Right now I am using the current 3D turret model as a place holder, and I hope to use it and other info off the internet to put together something that I might be able to 3D print at a 1/35 scale for my model.

Later I want to look at adding propellers or waterjets on the back end of the vehicle and some sort of ramp forward.

Regards

Pat

[Frank3k]

The HobbyBoss LAV-150 with 90mm Cockerill might be source for the turret.

Details on Scalemates

[PFJN]

Hi,
Thanks for the suggestion.
Pat

[Story]

Inspiration

ZTD-05 OR ZLT-05 VN-16
https://www.armyrecognition.com/china_chinese_heavy_armoured_vehicle_tank_uk/ztd-05_amphibious_assault_armoured_vehicle_technical_data_sheet_information_description_intelligence.html

https://en.wikipedia.org/wiki/Type_05_amphibious_fighting_vehicle

https://www.army-technology.com/projects/zbd-05-amphibious-infantry-fighting-vehicle/

https://navy-matters.blogspot.com/2019/08/chinese-type-05-amphibious-assault.html

[PFJN]

Hi,
Thanks.  I think I may have an unbuilt Hobby Boss model of this kit somewhere that I can try and use as a reference.
Pat

[Story]

IIRC, that V150 turret looks too small for your concept
http://beyondthesprues.com/Forum/index.php?topic=9083.msg169654#msg169654

How about a Cadillac Gage 105 Stingray turret?  They didn't crack like the hulls did.

[Story]

Check out the Cockerill Modular 3000 turret
https://www.youtube.com/watch?v=G9nZgk7x2Yc

https://militaryleak.com/2018/07/05/cockerill-3000-series-modular-turrets/

[PFJN]

Hi,

I think that may be the turret that I am currently using.  I am trying to convert it from a 105mm gun down to a 90mm gun, like shown in the video.  The relatively high angle of elevation (+42deg) shown in the video seems like it could be useful in an urban or semi urban environment including some of these artificial fortified islands that are getting built in the South China Seas. (https://www.scmp.com/news/china/diplomacy/article/3198504/fortified-south-china-sea-artificial-islands-project-beijings-military-reach-and-power-say-observers)

I have also added a rugh idea that I have for a bow ramp.

Regards

Pat




PS.  I still need to reduce the size of the aft turret overhang, which looks like it can be made smaller for a 90mm magazine, as shown in the video in the previous link above.

[PFJN]

Hi,
I looked around on the internet and found some images of an external hydro-pneumatic suspension unit from a company called Horstmann that I used to make up something kind of similar in 3D CAD, that I hope to 3D print for my model.  Apparently this type of suspension is similar to those used on other amphibious vehicles and allows the road wheels and treads to be retracted up when the vehicle is in the water.



Regards

Pat

[LemonJello]

Enjoying the development work going on here.

[Frank3k]

Does the bow ramp fold up to conform with the front o the vehicle? It might make a good armor shield when not in the water.

[apophenia]

... an external hydro-pneumatic suspension unit from a company called Horstmann ...

Excellent choice Pat    That's the Horstman InArm HSU as used on the Puma, Mobile Protected Firepower demonstrator, etc.

-- https://horstmangroup.com/horstman-products/horstman-inarm/

[PFJN]

Hi,

Thanks for the feedback everyone.  For the ramp, I'm still working on it, but its based on something that I mocked up previously in cardboard.  It's supposed to be hinged and articulated to be more boat like when deployed but flatter when retracted.

Pat

[PFJN]

Hi,
I've been working on updating some of the dimensions, escpecially in way of the suspension and tracks.  I've been trying to model the tracks to be similar to some of the newer composite band tracks like those made by a company called Soucy.  Below is an image of where I currently am.  I still need to modify the drive sprocket to mesh with the new tracks, and I also messed up my measurement just a little leaving me off by about half a "pad" width, that I still need to fix.

Hopefully things are moving along though.

Pat

[Buzzbomb]

Interesting approach, so far looking very good

[GTX_Admin]

I've been trying to model the tracks to be similar to some of the newer composite band tracks like those made by a company called Soucy. 

I have had discussions with this company in real life - some interesting stuff they do.

[apophenia]

... I've been trying to model the tracks to be similar to some of the newer composite band tracks like those made by a company called Soucy....

Another excellent choice 

Soucy Bandtracks: Quebec snowmobile gits make good! C'est bon, non?

I have had discussions with this company in real life - some interesting stuff they do.

Greg: Any idea if the neighbours at Camso (Camoplast/BRP as was) represent a genuine rival to Soucy? The Michelin acquisition of Camso would seem to add credibility. But Soucy has a hell of a lead!

[GTX_Admin]

Greg: Any idea if the neighbours at Camso (Camoplast/BRP as was) represent a genuine rival to Soucy? The Michelin acquisition of Camso would seem to add credibility. But Soucy has a hell of a lead!

Not sure to be honest.

[PFJN]

Hi,
I still need to modify the drive sprockets, but the images below show what the tracks and suspension would look like with the tracks in their operational position and with the suspension, roadwheels and tracks retracted for operations in water.

Pat




PS.  Unfortunately the above images aren't to the same scale.  But overall the Idler is pushed back about 11cm (I think) when the tracks, roadwheels and suspensipons are retracted.

[kim margosein]

When the track is retracted, how do you take up the slack?

[Old Wombat]

When the track is retracted, how do you take up the slack?

PS.  Unfortunately the above images aren't to the same scale.  But overall the Idler is pushed back about 11cm (I think) when the tracks, roadwheels and suspensions are retracted.

[PFJN]

Old Wombat,
Thank you for calrifying that for me.

Lately, I have gotten a little off track, trhying to figure out how a vehicle like this will drive either its tracks or its waterjets (when in water).

In looking at information on the canceled EFV program it looks like they used a regular gearbox driving the final drives to the track, but added in some sort of "splitter gear" between the engine and the gearbox that could be used to clutch in the waterjets and clutch out the main gearbox (if I am understanding correctly) as shown in the following links

http://www.army-guide.com/eng/product2418.html
https://www.fire.tc.faa.gov/2007conference/files/Materials_Fire_Safety/WedAM/GwynneMagnesium/GwynneMagnesiumPres.pdf

And data on the Korean KAAV II "appear" to show a similar configuration, if I am understanding the images that I have seen. https://blog.naver.com/jhst3103/221397823921

Alternately, I also came across a paper on the US Government's Public STINET site about a "test rig" that was built early in the AAAV/EFV program (I think) that was built to valaidate the ability to retract a vehicles suspension and shift from a "land based" propulsion, to a "seaborne/waterjet" propulsion.  And in that design it appears that the main engine there directly drove two hydraulic pumps which could either drive a hydraulic motor on each final drve or a hydraulic motor on each waterjet, depending if you were operating on land or water. https://apps.dtic.mil/sti/pdfs/ADA205397.pdf

Currently I do not know whch type of set up might be best for a combat vehicle, or if may be some mix of systems might be better.  But for now since I kind of used the M8 AGS as a starting point for my dimensioning I figured that I shouel maybe enlarge the vehicle a bit to account for th extra volume that would be required for a pair of waterjets and this added "splitter" gearbox or hydraulic pumps and motors.

Also, from my reading it looks like many of these type craft will use air cooling for the engine when operating on land, but will have an auxiliary water cooling system for seaborne operations.  I'm guessing that maybe this arrangment may also help with cutting down on the concerns on injesting sea water and spray through the air cooling system whan the vehicle is at sea.

Below is a CAD sketch showing some 300mm diameter waterjets placed aft and the main engine (an MTU 6V 890) and a notional main gearbox (a RENK HSWL 194) located forward. [I really have only used this specific gearbox for now since it seems more or less matched to the engine size I've picked and I was able to find numerous 3D models of it on the internet, and figured that any other gearbox with similar capabilities would hopefully be similarly sized.]

A couple bg concerns right now is just how tight it looks inside (especially in way of the driver and the adjacent gearbos and engine) as well as how big the turret ring is for the turret that I have picked, and the fact that I would need to find someway of getting the "power" from the engine forward to the waterjets aft, without the turret basket getting in the way.  As such maybe a fuly hydraulic transmission system, or a partial one where a hydraulic pump is only used to drive the waterjets, but the final drives for the tracks are still driven by a mecanical gearbox may be an option.

Anyway, I'm trying not to get too far down in the weeds (since my knowledge of all this stuff isn't that great) but I do want to at least try and make an effort so that I can kind of say that I "think" that there may be enough space to do this, and its kind of interesting to me, and a learning experience, to research and look through how other "real" vehicles tried to do similar things.  And from what I am currently seeing, I'm beginning to think that I probably need to make my vehicle a little bit bigger to fit everything it will probably need. 

Pat

[PFJN]

Hi,

Sorry for the delay in making any new posts, I had a couple things around the house that I needed to take care of.

Below is a partial update showing the hull widened by about 300mm and lengthened by about 500mm (if I am recalling correctly).  I think that this will allow for the turret ring and basket to better fit (I hope) and will also hopefully provide some extra internal space for the waterjets, bilge pump(s), water cooling sustem, and the use of a hydraulic otentially electric) transmission system.

In general I have just been taking some stuff off the internet or dimensions from reports for pieces of machinery and outfit that appear to be close to the right size to kind of see if it looks like ev erything could fit into a vehicle the size of what I have shown.  Specifically the information for waterjets in the model come in part from info in a report on an amphibious test craft (called the Automotive Test Rig or ATR) that was built awhile ago paired with part of a waterjet 3D model that I found on the internet and scaled to the dimension in the report.  One of the things that I realized since I last posted anything was that the waterjests used on the ATR had two stages of blades, so I updated my model accordingly as shown below.

Additionally I also found some information on the internet for a splitter gearbox with a clutch (shown in dark blue below) to connect the main engine to two hydraulic motors (which I am still in the process of trying to model).



Overall the final system should look kind of like this sketch for the ATR taken from the report ADA205397.pdf - Automotive Test Rig Final Design Report.



Regards

Pat

[PFJN]

Hi,
Here's a quick update showing the hydraulic pumps and motors.
Regards
Pat

[PFJN]

Hi,

After messing around with stuff for awhile I finally seetled on a length for the hull of about 6.35m (20.83ft), a width of about 2.99m (9.8ft) and a height of about 1.24m (4.1ft), and a ground clearance of about 0.41m (16in), making the top of the hull about 1.65m (5.4ft) above the ground.  I think that this should hopefully be able to fit all the large pieces of outfit and equipment, with some space left over for the smaller stuff I don't really have the ability to try and figure out.

With the longer length I've added one additional road wheel and one additreturn roller per side.  And I still have to redo the tracks, and maybe the drive sprocket to match.  Othe than that I still need to clean up the lower back end to try and keep it from hitting the ground when starting up a slope, and to also accommodate the waterjets better.

In addition, I also want to try and revise the turret to show a 90mm gun and the smaller aft overhang (I think)  that the turret would have with that gun, and also add the turret basket, plus check the gunner and commander's chair heights.  For the driver I have moved his chair to now be on centerline.

Once I get all that done I hope to start laying out the hull for 3D printing.

Pat

[GTX_Admin]

Looking good

[PFJN]

Hi,

Sorry for the delays in getting anything new posted.  I've started changing the hull over from a solid shape to a "hollow" shape, and making cut outs for accesses, as shown below.




Regards

Pat

[Buzzbomb]

Interesting crew placement.. .getting interesting

[PFJN]

Hi,
Here's a few images of where I currently am.  I know thta sometimes the images don't necessarily do a good job of showing progress, especially since some of the work that I have been doing is cleaning uo and/or revising some areas where I may have had a place-holder, such as the road wheels.

Recently though, I have;

• revised the road wheel based on a cross section drawing that I found for some wheels designed for the AAV7
• started adding additional bolt on armor plates
• added a drivers hatch
• began revising the geometry of the bow ramp
• added skirt plating and adjustable chine flap plating (that would be rotated under the retracted roadwheels and treads, when operating in water
• adjusted the geometry of how far the road wheels can retract, and their locations/spacing along the vehicle's hull
• added an access door aft for engine maintenance

In addition to the above I also need to;

• rework the treads and sprockets for the new roadwheel geometry
• add "mounting bolts" for the add-on armor
• rework the turret to correctly reflect the smaller overhang that would be used with a 90mm gun, and modify the geometry to make it more "3D printable"
• add additional openings for cooling fans and ventilation
• figure out what the exhausts might look like
• add in other small bits and pieces like towing fittings and cable, headlights and tail lights, fuel caps, and miscellaneous openings etc

Hopefully it will all start coming together better soon 

Pat

[PFJN]

Hi,
It doesn't look like I''l get around to trying to 3D print my model beofre the deadline, but I hope to at least the 3D model complete (more or less) by then.

Lately I have been revising the treads, adding on some bolt on armor and attachments, and cleaning up the driver's hatch.  After that I hope to modigy the turret a little to better reflect a 90mm gun and add some vents and other fittings to the upper machinery space deck, etc.

Regards

Pat

[PFJN]

Hi,
Here are some images of my latest updates.  The 1st shows an ISO view where you can see the cleaned up driver's hatch and main gun, along with the vdnt gratings in the upper deck for ventilation and a "stern flap" in its stowed position.  Th 2nd image shows a side view of the vehicle when configured for land-borne operations.  In this image you can get a better viw of the stern flap.  And finally, in the 3rd view you can see the vehicle when configured for waterborned operations.  Unfortunately in this view I don't yet have the revised treads drawn in, and in all the views I don't yet have the bow ramp/flap drawn in yet.  Once I get those drawn in, and finish up my modifications to the turret (especially in way of the aft overhang) ther 3D model will be mostly done, except for maybe any small details (like tow brackets, fuel filler caps, and stuff like that) that I may want to add.

Hopefully I will be able to at least finish up the 3D model before the end of the group build.

Regards

Pat

[Buzzbomb]

A lot of great thought has gone into this.

the added feature of seeing the 3D design process has been a great ride so far

[PFJN]

Hi,
Thanks.  I don't know as much about modern armored vehicles as I'd like, and doing this build has been a fun way to focus on certain aspects of their design, and has been a fun learning experience for me. 

[PFJN]

Hi,
Here are some images with the shortened turret overhang.  I only had a few images of this shorter overhang that goes with the 90mm gun, so I scaled down the overhang from the turret with a 105mm gun as best as I could.





Regards

Pat

[PFJN]

Hi,
I managed to finish up the bow flap.  I ended up mounting the flap up higher on the vehicle than I initially planned, as shown below.  I kind of figured that while a bow flap mounted more or less flush with the bottom of the vehicle might be good for a high speed vehicle like the canceled EFV, but since I wasn't expecting this vehicle to have that high a water speed, it will be sitting much lower in the water and as such it might be better to locate the flap closer to the water surface.









As shiwn in the images above the bow flap is double hinged so that it can extend further forward when deployed.

Also I still need to add back in the treads when the suspension is retracted, and a few other small items and some clean up.  But overall it is close to being done (as a 3D model at least, for now).  Once I eventually get around to trying to 3D print it, I may also need to make some small modifications to make it easier to assemble all the parts once I print them 

[PFJN]

Hi,
I finished up the treads in the retracted position and added some headlights and tow fittings.  Other than that I think I probably just need some tail lights, the fuel cap(s), the muffler/exhausts and maybe a few other small thin gs like shovels, tow cable and such.

Regards

Pat






PS.  I may have to rethink the headlights, because right now they stick up a bit and are kind of close to the drivers hatch, but I wasn't sure where else to put them so they wouldn't get in the way of the the bow flap.

[PFJN]

Hi,
I'm almost pretty much done with the 3D model (though I just recently noticed that I inadverVuwe started messing around with trying to make some nicer looking images by importing the model into a program called VUE.  It's been awhile since I used that program so it may take me awhile to get everything correct, but here are a couple images that I was able to quickly do this evening.




Regards

Pat

[GTX_Admin]

 

[Buzzbomb]

Great stuff, it looks very workable to my eye.
Working through this design process has been interesting. One point that became apparent with my Hovercraft and also this build is around engine deck grating and how that would work in an amphibious vehicle with waves or wash moving over the rear deck. All vehicles appear to have them so the solution must be in there

[PFJN]

Hi,
Thanks GTX and BuzzBomb.  dFor the most part I think I'm basically done with the 3D model, though I may continue to make some small changes as I play around with trying to first "render" some images, and then later 3D print the model.  But for this Group Build I guess I'm pretty much done for now.

Here is a recent image that I have developed for the vehicle.

Regards

Pat

[PFJN]

Hi.
I've started to play around with trying to add a camouflage texture to my model to see how it looks.

The first image below, shows the vehicle with a sample texture that I downloaded off the internet to practice with.  If you look closely you can see the company "watermark" in the texture that the put on the free version of the image on the gun barrel and front ramp.  I wanted to first play around with a sample file since there are some settings in the VUE program that I don't fully understand yet, that can impact they way the texture gets added to the model, so I wanted to find a free texture to practice with.  And this gave me a chance to play around with stretching znd rotating the texture map, and tweaking some of the settings to see how it would impact how a texture would get rendered onto my model.

In the second image you can see a texture that I tried to develop myself that is supposed to kind of be similar to the Cold War era Berlin Brigade Urban camouflage but using colors more suitable for a Pacific artificial island type setting.  Unfortunately with the current lighting setting that I have used the colors came out a bit brighter than I had anticipated for now.  Hopefully as I experiment more I may be able to improve and soften the look a little.

Regards

Pat

[GTX_Admin]

The first one makes me think of it as a Norwegian or Swedish vehicle.  The second I think more someone like someone in the Middle East.

[PFJN]

GTX,
Thanks.  Here's a new one where I found another free texture (without watermarks) and I've also tried to add in some background scenery.  The ground color should probably be changed to something more beach or desert like, but I really like the (Banana) tree and clouds. 

Pat

[GTX_Admin]

 

[Mig Eater]

Looking forward to seeing the 3D print in the future

[Buzzbomb]

Very good 3d render work 

[PFJN]

GTX, Buzz Bomb, Mig Eater, Frank 3K, Story, Lemon Jello, Apophenia, Kim Margosein, & Old Wombat,

Thanks for your comments and feedback.  I've gone ahead and posted some images in the Digital Amphibians folder, since this Group Build is about over.

It was fun seeing Buzz Bombs Hover Tank and Robomog's Helo/River Taxi builds, and I hope to see MAT's final PBY build when he gets a chance to complete it.

Best Regards

Pat

[ysi_maniac]

Can you introduce your design into a 3D printer?

Hard comprehensive job, I would say.

[PFJN]

Hi,
I hope so, though I will probably need to modify the model a little.  My intent was to try and print it in parts at 1/35 scale, and assembbler it kind of like mormal model.  Most (though not all) of the parts right now are modeled as 3D solids, with the hull being built up of thin 3D solid plates.  I may need to thicken them up a little for printing, but I think it should work OK, based on my experience with other 3D models.

Regards

Pat

[PFJN]

Hi,
I found a site with alot of free textures, though only one real camouflage one.  So I decided to try and see what the vehicle might look like with some different textures ranging from rocks, to a pool surface, a snake and a giraffe amoung other things. 

[Robomog]

True chameleon armour.  Interested to see this in solid to form

Nice one !

Mog
>^-.-^<

[PFJN]

Hi,
I finally got a chance to start trying to 3D print my model.  I had a little trouble initially since I am using a new printer and a new slicer program, so it took me a while to figure out some of the settings and such, and I had a few mess ups along the way.  In the image below you can see the main body of the waterjets, the road wheels, suspension arms, drive sprokets, final drives, gun barrel(s), gratings, and a messed up print of the turret.

Now that I think I have a better handle on the printer and the settings that I should be using I'm working to clean up the model of the turret and hope to reprint it soon.  Its also been a little trail and error figuring out how small I can print some stuff, and I've had to go back and revise the model of some parts to make them a little more sturdy.  If you look closely at one of the gratings you can see a small chip in it that I need to fix.

Anyway, I will probably start posting the rest of this build on the physical models sub-board, since this group build is now over, but I wanted to show a pic of how things are coming out.

Regards

Pat

[Kerick]

That’s all amazing to me as I haven’t a clue how to do that! Keep it up! I’m waiting to see more.

[Old Wombat]

Woh! That turret looks like someone/thing hacked into it with a HUGE axe!

[PFJN]

Hi,
My second attempt at printing the turret came out alot better. 



Pat

[PFJN]

Hi,

I've gotten most of the small detail parts printed now, and am almost ready to start on the bigger parts.  I decided to print alot of the derail parts separately since it makes it easier to clean them up and it also allowed me to play around a little with settings to see what worked best.




Overall I found if I made the parts about 2cm thick full scale (which scales out to about 0.57mm model scale) things came out ok, though for some parts I found that I could potentially go a bit thinner, though the parts became very fragile.

In the picture below you can see two different attempts to print the 50 calibre machine gun.  In the top part of the image I tried to use too small of supports, and the part separated from them during printing and got all messed up.  In the bottom part of the image you can see a much nicer print out, that I got just by changing to medium sized supports for the print. (sorry that the image is a little fuzzy). 



And finally, here is the forward seakeeping flap, printed in three pieces.  I wasn't able to make the holes in the hinge parts print properly but I hope to try and drill out at least the outer parts to see if I can fit a wire in to allow the flap to fold and unfold.



Next I just have to print out the return rollers, and tracks before trying to tackle the main hull 

Pat