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Thread: Designs for next-generation all-terrain armoured vehicles

  1. #1 Designs for next-generation all-terrain armoured vehicles 
    Forum Sophomore Peter Dow's Avatar
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    Quote Originally Posted by Wikipedia
    MRAP (armored vehicle)

    Mine Resistant Ambush Protected (MRAP) vehicles are a family of armored fighting vehicles designed to survive IED attacks and ambushes. IEDs cause the majority (63%) of US deaths in Iraq.
    ...
    A June 13 report by the Marine Corps Center for Lessons Learned indicated concerns about MRAP vehicles rolling over in combat zones.

    The V-shaped hulls of the MRAP give it a higher center of gravity and the weight of the MRAP can cause the poorly built or maintained roads in rural Iraq or Afghanistan to collapse.

    Of the 66 MRAP accidents between Nov. 7, 2007 and June 8, 2008, almost 40 were due to rollovers caused by bad roads, weak bridges, or driver error.

    In many of the rollovers troops were injured, and in two separate incidents five soldiers have been killed by rolling over into a canal and getting trapped under water. The report said 75% of all rollovers occurred in rural areas often when the road is above grade and a ditch or canal full of water is next to it.
    OK so that is the problem and there is an obvious vehicle modification to counter the roll-over problem which is to fit stabilisers, adopting the same concept employed in a child's bicycle.



    The simplest and cheapest way to do this would be have bolt on stabilisers which could be partially unbolted to fold up when not required while driving on good flat roads but where the additional width of the stabilisers would cause problems, such as when travelling along narrow roads, needing to negotiate dense traffic such as in urban roads.

    The high-tech and expensive solution would be stabilisers which fold-up or deploy automatically using hydraulics at the touch of a driver's button.

    However, when you compare the expense of a good solution to the expense of lives lost by MRAP rollovers then it is a small price to pay.

    OK that idea is adapting the existing MRAPs but here is an idea for a completely new design of MRAP.

    The catamaran tank - an MRAP which doesn't roll over!


    A catamaran - the inspiration for a twin-hulled armoured vehicle

    The catamaran tank or catamaran MRAP or catamaran armoured vehicle or catamaran armored vehicle - you heard it here first!

    One idea I have for a completely new design to counter ground-blasts yet retain stability would be a double-hull or catamaran tank.

    To explain, let us describe most simply the current MRAP vehicle design as an M-shape, looking at the vehicle from the front or the rear, with a high middle, and a V-shaped hull, armoured to deflect the blasts.

    Well the concept of the catamaran tank is to replace the M-shape with something more like a Y''Y-shape which is a lot wider for stability and so may not be so good in narrow streets or traffic admittedly.

    The central double quotes in the Y"Y-shape represents a line of strong blast-chimneys up through the middle of the vehicle, from front to rear, which some of the blast could go up without splitting the vehicle in two.

    This twin-hull, double-hull MRAP would give two distinct cabins on the left and right of the vehicle and however high you need the vehicle to get distance from a ground blast then make the Ys bigger and so further apart which keeps stability.

    The leg of the Ys could have blast ventilation holes so that blast gas under the vehicle can escape to the sides as well as up the central chimneys. The more ways the blast gas can escape from under the vehicle the less force the blast will apply against the vehicle itself.

    The bottom of the Ys could be either wheels or tracks depending on what ground conditions you are designing the vehicle for and need to cope with.

    This dear forum members is the catamaran tank - my idea and you heard it here first. Copyright © Peter Dow, 26th July, 2010.


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  3. #2 A vehicle of two halves! 
    Forum Sophomore Peter Dow's Avatar
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    Considering the wheeled version of the catamaran tank only for now.

    Maybe the left and right sides while separated are 4 wheeled vehicles which you can drive independently, call those "half-vehicles" Y-sides.

    The Y-sides are tall and narrow and even less stable than an MRAP while separated but loading and unloading on and off transport and manoeuvring the sides in position to connect together the stability is sufficient.

    Then, when you come to bolt the two Y-sides together there are a number of choices as to how wide apart the left and right hand Y-sides are fixed.

    I'll type in some figures so you can see what I mean.

    Say, the separated Y-sides are 4 feet wide.

    Well for example, the connecting bars or tubes could hold the left and rights Y-sides together separated by these example widths:

    • 1 foot, Y1Y so the total width is 4 + 1 + 4 = 9 feet - no wider than a Cougar MRAP and so as stable as todays MRAPs and narrow enough for urban roads and traffic.
    • 4 feet, Y4Y so the total width is 4 + 4 + 4 = 12 feet, the same as an M1 battle tank, good for country roads, stable but narrow enough to get across most bridges no problem.
    • 8 feet, Y8Y so the total width is 4 + 8 + 4 = 16 feet, super-stable for open cross country off road where the extra width is no problem for crossing bridges or fitting on roads because there are no roads maybe nothing more than a dirt track of uncertain width itself, maybe nothing but rough ground and rivers need to be forded or not crossed at all and then the extra stability is purely a bonus with no disadvantage of extra width.

    The vehicle could even carry the different lengths of connecting bars or tubes for the crew to swap round to change vehicle width which they can do themselves anywhere they can find a flat piece of ground - no special facilities required.

    The deluxe version could have a hydraulic telescoping connecting tubes to change vehicle width at the touch of a button!

    When the two Y-sides are connected together, the steering mechanisms of the two Y-sides are mechanically coupled together, somehow! There could be power steering as well!

    The catamaran tank still has V-shaped hulls to deflect the blast. It just has 2 V-shaped hulls, each of half the width of a single V-shaped hull.

    The catamaran tank can have the same total area of V-shaped hull measured in the horizontal plane as a single-hulled MRAP!

    There is not much more area for the explosive force to react with in the catamaran tank because the space between the two hulls is mostly empty space with just connecting bars or tubes!

    The benefit is this - it doesn't roll over!

    The catamaran tank - an MRAP which doesn't roll over!


    Peter Dow
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  4. #3  
    Forum Ph.D. Leszek Luchowski's Avatar
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    It might be more difficult to knock over by means of an IED, but on a poor road infrastructure it will often have to keep one of it's half-vehicles on either shoulder of the road, running into no end of trouble, sliding off the road into ditches or worse. Not to mention places it will be too broad to pass.

    PS: if the vehicle is to contain the masses and volumes it has to: engine, weapons systems, crew, fuel, ammunition etc - and your design moves it away from the mine-infested ground, then the center of gravity will move upwards, reducing stability, and the shape of the vehicle will stand taller, exposing itself more to incoming fire. In a battlefield, you want to keep a low profile.
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  5. #4  
    Forum Sophomore Peter Dow's Avatar
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    For the same area in the horizontal plane, the hulls of the catamaran tank and the MRAP have quite similar surface areas and weights.



    To lessen the blast forces tending to split the two V-shaped hulls apart, the Vs can be angled slightly to form a vertical blast chimney.

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  6. #5  
    Forum Sophomore Peter Dow's Avatar
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    Quote Originally Posted by Leszek Luchowski
    It might be more difficult to knock over by means of an IED, but on a poor road infrastructure it will often have to keep one of it's half-vehicles on either shoulder of the road, running into no end of trouble, sliding off the road into ditches or worse. Not to mention places it will be too broad to pass.
    Well poor roads will be a manageable problem because you have the option to take up the whole road and drive down the centre. Remember there are 4 wheels front and back and it is likely the inner wheels will find a rut to get lateral grip to stop you sliding off - so long as each wheel is independently suspended.

    I'd rather go down a poor road in a 12 feet wide Y4Y for stability than a 9 foot wide MRAP which is more likely to roll over.

    When you are forced to the side to allow traffic past and towards a hazard there then slow up and if necessary stop until you can hog the whole road.

    The Y4Y is only 12 feet wide, the same as a M1 tank, so where it goes, the Y4Y can go too.

    Yes the Y8Y at 16 feet will be too broad for some gaps but it is meant as a cross country configuration across open ground.

    Quote Originally Posted by Leszek Luchowski
    PS: if the vehicle is to contain the masses and volumes it has to: engine, weapons systems, crew, fuel, ammunition etc - and your design moves it away from the mine-infested ground, then the center of gravity will move upwards, reducing stability, and the shape of the vehicle will stand taller, exposing itself more to incoming fire. In a battlefield, you want to keep a low profile.
    Well I am thinking of an MRAP replacement and it will be no taller than existing MRAPs which have sacrificed low profile to get away from mines and IEDs in the ground at the expense of the problems you state.

    The idea of the catamaran tank is to provide greater width to prevent rollovers despite the higher centre of gravity.
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  7. #6  
    Forum Sophomore Peter Dow's Avatar
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    When you change configuration you are changing the connecting bars between the two Y-side vehicles.



    So the mechanic or the trained crew would
    • unbolt and remove the connecting bars you want to change
    • drive one of the Y-sides to about the right new position for the new bars
    • attach the bars and tighten them up to bring the Y-sides to the right distance apart.
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  8. #7  
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    First I'll quibble.

    Of the 66 MRAP accidents between Nov. 7, 2007 and June 8, 2008, almost 40 were due to rollovers caused by bad roads, weak bridges, or driver error.
    Many of those "driver error," aren't so much driver error but exceedingly restrictive performance standards--namely the maximum angle is very small before you're at risk, too small an angle to scare the driver and crew until it's too late.

    My recent tour which is coming to and end in a next few weeks involved commanding, gunning and driving a MAXPRO MRAP all over Iraq. While we came to love it's protective capabilities, and survived an IED attack, we grew to loath it's limitations. Off road it was limited to flat dirt terrain; crossing minor obstacles was a major headache. It was too high and meant it was stuck on the main roads because of the web of entangled overhead electrical and communications wiring across every street. We ended up using our HMMWVs a lot more than our MRAPS simply because they could go were we needed to operate.
    --

    The main problem with the catamaran idea is obviously width. To travel the roads in 3rd world countries your max width is probably about 10.' If you can get it down to 8' that's a lot better and vastly improves your options. As already mentioned, for off road and primary roads you could go wider.

    The vertical blast "chimney" is under the gunner butt. While it might make for a fast exit (j/k) it would force an entire relook of where you put the gunner. I imagine the engine compartment would be between the Vs.

    I've never seen the concept before.
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  9. #8  
    Forum Senior Kukhri's Avatar
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    First Peter, you're calling it a tank. The MRAP is a mid-sized armored fighting vehicle or armored car built to carry personnel with moderate mobility. A personnel carrier like the MRAP is required to negotiate narrow donkey roads in Afghanistan. That's why you're not likely to see a Main Battle Tank like the M1 Abrams bumbling about in Kunduz. This 12 foot wide monstrosity will be too heavy and unable to traverse these roads. You can't just stop and wait for traffic in linear danger zones. This would turn the vehicle into an ambush magnet.

    Quote Originally Posted by Peter Dow
    The vehicle could even carry the different lengths of connecting bars or tubes for the crew to swap round to change vehicle width which they can do themselves anywhere they can find a flat piece of ground - no special facilities required.
    Armored vehicles aren't transformers. This would not be a survivable frame. It also seems that these are two independent vehicles. Tanks of this size like the Abrams and Challenger II are already in existence and are extremely survivable. I am aware of only a single Abrams lost to an IED, and that was not penetrated, but just flipped into the air and upside-down by five 155mm howitzer shells. If one were dead set on survivability, disregarding weight and size, this chassis would be desirable.

    So you're taking the interior volume of an MRAP and splitting it in half. Now there's just no room for the mountains of gear the dismounts are lugging inside.

    This, all to resolve what isn't the issue the primary issue in a combat zone. The vehicle isn't only rolling over in high speed turns or severe grades. It can collapse the road underneath it. The necessary armor packages for the vehicle you propose would make it much heavier than the 14+ ton MRAP (more exposed surface area, more armor) and compound the weight issue. You're designing something around the comparatively minor issue of roll-overs. IED's are much more significant than roll overs, and the MRAP is proven effective in retarding their effects.

    A partial solution is already available. Ensuring proper route recon by trained units like Cavalry Scouts will determine that the grade and width of the road will accommodate certain vehicles and that the road will support their weight.
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  10. #9  
    Forum Sophomore Peter Dow's Avatar
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    Quote Originally Posted by Lynx_Fox
    First I'll quibble.

    Of the 66 MRAP accidents between Nov. 7, 2007 and June 8, 2008, almost 40 were due to rollovers caused by bad roads, weak bridges, or driver error.
    Many of those "driver error," aren't so much driver error but exceedingly restrictive performance standards--namely the maximum angle is very small before you're at risk, too small an angle to scare the driver and crew until it's too late.
    Agreed it is the vehicle's designer's error, or the initial MRAP specification failed to specify stability and so the designers never thought to take stability into account.

    Quote Originally Posted by Lynx_Fox
    My recent tour which is coming to and end in a next few weeks involved commanding, gunning and driving a MAXPRO MRAP all over Iraq. While we came to love it's protective capabilities, and survived an IED attack,
    Impressive. Well I have no such personal experience to compare with your service.

    I have simply seen on the TV news, these vehicles rolled over, especially in Afghanistan, and the trouble soldiers have getting them upright again, pulling on ropes out in the open, exposed to enemy fire - completely negating the whole idea of an armoured vehicle. Compared to this rolled-over scenario, I think soldiers dressed up as local Afghans and travelling by donkey might be both quicker and safer! :wink:

    I think there has to be a better way and I am not short of ideas in that regard.

    Quote Originally Posted by Lynx_Fox
    we grew to loath it's limitations. Off road it was limited to flat dirt terrain; crossing minor obstacles was a major headache.
    It has a too high a centre of gravity for its width. Two solutions really, lower the centre of gravity or increase the width (or both).

    Quote Originally Posted by Lynx_Fox
    It was too high and meant it was stuck on the main roads because of the web of entangled overhead electrical and communications wiring across every street.
    Is this the vehicle?



    Was it that pole sticking up at the back which was part of your problem? It seems to be the highest point in this photograph anyway.

    As you can see, I am wondering if it could be hinged so that the pole can be swung down to a "tail down" configuration to pass under overhead cables? I don't see why that can't be a simple modification which could be operated by a lever in the cabin.

    Also to fend the cables off the gunner's cabin, what about a light frame of plastic tube maybe? Just to give a snag-free lift to the cables as you pass under. It would need to be big enough so as not to obstruct the gunner's gun.

    Quote Originally Posted by Lynx_Fox
    We ended up using our HMMWVs a lot more than our MRAPS simply because they could go were we needed to operate.
    Well thank goodness you were not blown up in your HMMWV.

    Actually, I have a suggested use for the many HMMWVs in Afghanistan to help to secure the supply routes. I intend to post about that soon and I hope forum members will consider my ideas for that as well.

    Quote Originally Posted by Lynx_Fox
    The main problem with the catamaran idea is obviously width. To travel the roads in 3rd world countries your max width is probably about 10.' If you can get it down to 8' that's a lot better and vastly improves your options. As already mentioned, for off road and primary roads you could go wider.
    Well I am proposing a Y1Y version of my catamaran MRAP / tank which will only be 9 feet wide.

    Quote Originally Posted by Lynx_Fox
    The vertical blast "chimney" is under the gunner butt. While it might make for a fast exit (j/k) it would force an entire relook of where you put the gunner. I imagine the engine compartment would be between the Vs.
    Ah. In my proposed catamaran tank or catamaran MRAP, there is nothing in the centre except connecting bars - no gunner's turret, no engine, no nothing.

    My idea is to have two engines, one in each of the two halves of the vehicles. Two of everything really - the two halves of the vehicle will be able to be driven separately, so there will be two driver's seats as well!

    Since you have mentioned gunners, I'd like at least two gunners as well. 4 gunners sounds better to me. But have them sitting down with the rest of the crew and have the guns above them, reaching up or bringing the gun down to reload when necessary.

    There should be a video camera or two up there for each gun pointing at the target along the barrel the gun with a wide-angle and telescopic view option as well and the gunner could view the gun's target view on a LCD display in the lower cabin.

    It seems to me that you need the gun up high and the camera, but little else.

    With the gunner lower, the armour can be lower, which keeps the centre of gravity lower.

    Quote Originally Posted by Lynx_Fox
    I've never seen the concept before.
    It is my idea. I have only just published it a couple of days ago. 8)
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  11. #10 Don't you have luggage compartments or use trailers then? 
    Forum Sophomore Peter Dow's Avatar
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    Quote Originally Posted by Kukhri
    First Peter, you're calling it a tank. The MRAP is a mid-sized armored fighting vehicle or armored car built to carry personnel with moderate mobility.
    Understood.

    Quote Originally Posted by Kukhri
    A personnel carrier like the MRAP is required to negotiate narrow donkey roads in Afghanistan.
    Well donkeys can travel along mountain paths a few feet wide, where no vehicle, except maybe a motorcycle can go.

    My catamaran MRAP idea is to go anywhere existing MRAPs can go, only without rolling over.

    Quote Originally Posted by Kukhri
    That's why you're not likely to see a Main Battle Tank like the M1 Abrams bumbling about in Kunduz. This 12 foot wide monstrosity will be too heavy and unable to traverse these roads. You can't just stop and wait for traffic in linear danger zones. This would turn the vehicle into an ambush magnet.
    Well I am offering a Y1Y 9-feet wide version as well for those places where 12 feet wide can't go.

    Quote Originally Posted by Kukhri
    Quote Originally Posted by Peter Dow
    The vehicle could even carry the different lengths of connecting bars or tubes for the crew to swap round to change vehicle width which they can do themselves anywhere they can find a flat piece of ground - no special facilities required.
    Armored vehicles aren't transformers.
    Yet.

    Quote Originally Posted by Kukhri
    This would not be a survivable frame. It also seems that these are two independent vehicles.
    Yes two vehicles. So the catamaran MRAP has more chance of spliting down the middle than the existing mono-hull MRAP design. However, the individual half-vehicles, the cabins should be just as survivable as existing MRAPs.

    After all it is the people we want to survive, not every part of the vehicle frame.

    Cars have crumple zones to absorb some of the energy of a crash to protect the passengers from absorbing more of that energy.

    The central blast chimney in the catamaran MRAP will provide an escape route for some of the blast under a vehicle and so reduce the blast as it imparts upon the vehicle cabins.

    Yes the connecting bars between the vehicle might indeed get bent or split but in doing so will do their work of providing a blast chimney as a kind of crumple-zone, sacrificing themselves to save the passengers.

    Quote Originally Posted by Kukhri
    Tanks of this size like the Abrams and Challenger II are already in existence and are extremely survivable. I am aware of only a single Abrams lost to an IED, and that was not penetrated, but just flipped into the air and upside-down by five 155mm howitzer shells. If one were dead set on survivability, disregarding weight and size, this chassis would be desirable.
    By all means travel by M1 whenever you can in a war zone.

    Quote Originally Posted by Kukhri
    So you're taking the interior volume of an MRAP and splitting it in half. Now there's just no room for the mountains of gear the dismounts are lugging inside.
    You carry luggage in the passengers' cabin? Haven't you guys heard of a luggage compartment?

    If your MRAP doesn't have a luggage compartment then at least tow a trailer and put your gear in that. Also it will spread the weight over more wheels and lessen the chance of collapsing roads. 8)

    Quote Originally Posted by Kukhri
    This, all to resolve what isn't the issue the primary issue in a combat zone. The vehicle isn't only rolling over in high speed turns or severe grades. It can collapse the road underneath it.
    See above for note on using luggage trailers.

    Quote Originally Posted by Kukhri
    The necessary armor packages for the vehicle you propose would make it much heavier than the 14+ ton MRAP (more exposed surface area, more armor) and compound the weight issue.
    Not necessarily. I could design smaller armoured cabins for the same number of passengers and insist that they put their gear in the luggage trailer. 8)

    Also the inner armour can afford to be somewhat thinner for the same protection because it is

    • shielded from square-on attacks from RPGs being somewhat shielded by its neighbouring half-vehicle.
    • ground blasts from IEDs and mines are imparting against the inner surface of the vertical blast chimney at an oblique angle which presents less of a danger.

    Quote Originally Posted by Kukhri
    You're designing something around the comparatively minor issue of roll-overs. IED's are much more significant than roll overs, and the MRAP is proven effective in retarding their effects.
    Well my concept is for MRAP plus, plus it doesn't roll over, it isn't minus in its IED effectiveness.

    Quote Originally Posted by Kukhri
    A partial solution is already available. Ensuring proper route recon by trained units like Cavalry Scouts will determine that the grade and width of the road will accommodate certain vehicles and that the road will support their weight.
    Well I hope the scouts don't get blown up by an IED.
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  12. #11 MRAP luggage compartments / trailers / passenger trailers 
    Forum Sophomore Peter Dow's Avatar
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    MRAP luggage compartments / trailers / passenger trailers are something I want to feature in my new design.

    It isn't really a "catamaran" feature particularly because a mono-hull MRAP could have a luggage compartment, outside the armour-protected volume and trailers are already available for today's MRAPs. A trailer is a trailer, right?

    But I hear complaints from many sources about passenger cabins not being spacious, can't afford to make them smaller and so on.

    The thing is, if you always put the gear the troops are carrying (heavy guns and ammunition etc.) in a trailer it saves space in the passenger cabin right?

    So then the armoured passenger cabins could be made smaller, and the gear stored in a non-armoured volume, either a luggage compartment - a boot or a trunk which can be low, lowering centre of gravity, or in a trailer, which also takes the weight off the MRAP wheels which helps to prevent road collapse.

    So for all kinds of reasons I am thinking that pulling a luggage trailer and a non-armoured boot/trunk should be integral to a good MRAP design, not just an optional extra.

    So why don't MRAPs use trailers more, when road collapse, heavy weight on the wheels is such a problem?

    I know that to use or not to use a trailer is an operation decision that the military make but if anyone knew if trailers were a bad idea for some reason, then would you please point that out.

    OK for existing MRAPs (some of which don't have a fixed gun) I can see why the passengers want to keep their weapons with them so that they can dismount guns blazing.

    Frankly, a "no fixed gun" APC is a really bad design in my opinion. Even one gun is too little in my opinion.

    Defence against ambush is why you need fixed guns on every APC roof.

    My design would include a minimum of one gun on each side of the catamaran MRAP.

    Actually, I would like 4 guns on top; that is possible and if you read on I will explain how.

    Only the guns and video cameras (2 per gun, one wide-angle, the other telescopic sights) need to be on the roof. There is no need for a gunner up top in a gunner's turret with all the high up weight and instability that causes.

    The gunner can be sat in the cabin with the rest of the crew and fire and aim the gun from below.

    Think of a submarine periscope in terms of turning and aiming the gun, although the gunner would remain seated in one position if he (or she) views the gun camera views on a LCD display. Push buttons to change camera view and push button to fire.

    For reloading "the periscope" can come down to allow the gunner to reach the gun to reload in safety.

    2 or 4 guns, medium machine guns can be up top and because there is no armour up there, it could work out with a lower centre of gravity than one gunner with an armoured turret.

    Of course an armoured passenger trailer would have guns of its own as well.

    There is no reason why passengers cannot always carry a handgun which takes up no space. That and cover from fixed guns should be sufficient I would have thought.

    Sure I could imagine a scenario when you'd really like to fire a guided missile the second you open the passenger door.

    Well you still could do that and carry weapons inside in a smaller cabin if you were not carrying a full load of passengers.

    MRAP armoured passenger trailers

    In fact, why not have an armoured trailer with a V-shaped hull (or two V-shaped hulls for a catamaran trailer) and carry some of the passengers there?

    Then you could really reduce the weight of the MRAP - a much smaller front cabin, much less volume needing protecting in the front vehicle, spreading the weight across more wheels.

    I think my armoured passenger trailer idea is a winner, catamaran or no catamaran.
    8)
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  13. #12  
    Forum Sophomore Peter Dow's Avatar
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    Conjoined All-Terrain Anti-Mine Ambush Repellent Armoured Next-generation (CATAMARAN) Vehicle
    © Peter Dow
    The CATAMARAN vehicle concept is the original idea of Peter Dow of Aberdeen, Scotland and was published on 26th July 2010. All copyrights are retained by Peter Dow.
    More details of the CATAMARAN Vehicle here.
    Peter Dow
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  14. #13 The CATAMARAN vehicle can rotate on the spot! 
    Forum Sophomore Peter Dow's Avatar
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    The CATAMARAN vehicle can rotate on the spot!

    It is proposed that the CATAMARAN vehicle will have impressive manoeuvring and tight turning abilities, despite its size - including an ability to rotate on the spot as tracked tanks can do.

    The trailer, although optional, when it is fitted, it will be attached to the powered and driven front of the vehicle by hinges allowing the front and rear parts of the vehicle to pivot relative to each other in the vertical plane thus keeping the driven rear wheels on the ground but the hinges will not allow any relative movement to the left or right, so as to keep the body and the wheels in alignment.

    There are 3 pairs of axles -
    1. front wheel drive steered axles, (left and right)
    2. rear wheel drive fixed axles, (left and right) and
    3. trailer wheel steered axles, (left and right).

    The trailer wheels will steer coupled to the front wheels but in an opposite clockwise / anti-clockwise sense to the front wheel.

    Each Y-side of the vehicle will have 4-wheels driven so with "4-wheel drive" on both the left and right Y-sides, one might note that the whole vehicle has 8 driven wheels, not just the 4.

    CATAMARAN Vehicle Steering Geometry Normal steering


    What this arrangement allows is that even with the trailer fitted, the vehicle can be reversed easily. Normally trailers are a nightmare to reverse. The CATAMARAN vehicle will be a dream to reverse.

    In addition the CATAMARAN vehicle can rotate about a spot in the middle between the powered rear wheels. It achieves this special ability by virtue of certain design features -

    • A first gear which is a low gear for manoeuvring and has a gearing ratio precisely the same as the reverse gear

      Two additional rotational gear modes -
    • Clockwise - when the left side gearbox of the vehicle is automatically put into first gear and the right side gearbox of the vehicle is automatically put into reverse gear.
    • Anti-clockwise - when the left side gearbox of the vehicle is automatically put into reverse gear and the right side gearbox of the vehicle is automatically put into first gear

    When either clockwise or anti-clockwise gear is selected, the mechanical coupling normally engaged between the left and right hand steering is automatically disengaged and the left hand wheels are automatically turned to hard right hand turn lock and the right hand wheels are automatically turned to hard left hand turn lock; those two hard turn lock stops are designed so that the steered wheels are pointed in the correct direction for vehicle rotation.

    Whenever either of the two rotational gear modes is deselected and the gear shift is put into neutral, the mechanical coupling between left and right hand steering is re-engaged and the wheels returned to the appropriate direction as determined by the driver's steering wheel which was redundant during the selection of either of the rotational gears.

    CATAMARAN Vehicle Steering Geometry Rotational steering


    The CATAMARAN Vehicle vs. the MRAP. Which is better?

    Compare and contrast the features of the CATAMARAN Vehicle against the MRAP it is designed to replace.

    • The CATAMARAN vehicle is not taller than an MRAP with a gun turret.
    • Yes the CATAMARAN vehicle will be taller including the height of its guns than an MRAP without a gun turret but the CATAMARAN vehicle's automatic guns are quite light and don't raise the height of the centre of gravity much and maybe has a lower centre of gravity than an MRAP with a gun turret with armour and gunner up top as well.
    • The CATAMARAN vehicle can be the same width as an MRAP when configured narrow, such as Y1Y at 9 feet wide. It can be narrower, the same width or wider than a tank to suit the roads or terrain.
    • The CATAMARAN vehicle will be as fast as an MRAP without the trailer on a straight road. It will be much faster off road, with or without trailer, because it won't roll over and a rolled over MRAP is a slow as you can get; you'd be faster on a donkey!
    • The CATAMARAN vehicle will be as well armoured as an MRAP.
    • The CATAMARAN vehicle will have as much internal cargo space without the trailer and more internal cargo space with the trailer compared to an MRAP.
    • The CATAMARAN vehicle offers the possibility, depending on the width configuration, of additional external cargo space by strapping certain loads, which don't require armoured protection, to the connecting bars in between the two halves of the vehicle.
    • The CATAMARAN vehicle will very manoeuvrable even with the trailer attached so its length is no big deal.
    • The CATAMARAN vehicle will have more firepower than an MRAP. Two roof mounted machine guns without the trailer, 4 guns with the trailer.
    • The CATAMARAN vehicle is "ambush repellent". whereas the MRAP is only "ambush protected".
    • Terrorists going up against a CATAMARAN vehicle with RPGs and the like is a more risky proposition for them because the defenders have got 2, 4 or 6 pairs of eyes watching for ambushes with their fingers on triggers to fight the attackers off.

    Conclusion

    The CATAMARAN vehicle is a better vehicle than MRAPs for any conflict where MRAPs are now the vehicle of choice.


    CATAMARAN Vehicle & trailer - 6 machine guns, 16 seats!



    The image shows some vital statistics for my proposed CATAMARAN vehicle, only one Y-side is pictured.

    The front powered and driven vehicle seats a maximum of 10, 5 in either Y-side.

    Each side seats 5 =
    • 1 - one driver or reserve driver or front passenger +
    • 2 - one front gunner and one rear gunner +
    • 2 - two passengers

    The trailer seats a maximum of 6, 3 in either Y-side

    Each side seats 3 =
    • 2 - two passengers +
    • 1 - one tail gunner

    So the vehicle with trailer attached seats a maximum of 16, 8 in either Y-side.

    Each side seats 8 =
    • 1 - one driver or reserve driver or front passenger +
    • 3 - one front gunner, one rear gunner and one tail gunner +
    • 4 - four passengers.

    The driver can be either on the left or on the right Y-side and then the reserve driver or front passenger would be on the right or left Y-side, respectively.

    Weight distribution

    The image also shows the ideal weight distribution in relation to the axles.

    Each square represents the same weight and length which is
    • one eighth of the weight and length of the combined vehicle with trailer,
    • one fifth of the weight and length of the front powered and driven vehicle and
    • one third of the weight and length of the trailer.


    Designing the vehicle to have this weight distribution helps to keep the vehicle well balanced in terms of equal weights over each axle which allows for the same suspension and tyres to be used through-out and maintains this balance with or without the trailer attached.
    Peter Dow
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  15. #14 Another Way to Improve the Double V-Hull 
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    I believe current MRAP double V-hulls are made with 2 steel plates and an air gap. Studies by the NATC have shown that a double v-hull made of two aluminum plates with a layer of stabilized aluminum foam absorbs almost 90% of an IED's shockwave which is better than the steel plate version while being significantly lighter. This configuration would enable the MRAP to be lower making it less prone to rollovers.

    FWIW

    J
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  16. #15 Telescopic rear axle armoured vehicle - easy! 
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    OK well I have to admit there are a few problems with my CATAMARAN vehicle design.

    • Heavier armour for the same volume protected
    • The inner sides required to be armoured and connected together and that all adds weight. Precisely how much more weight is difficult to predict but a significant thickness of additional armour required certainly

    Therefore I am now turning to a different and easier idea to solve the roll-over problem for MRAP armoured vehicles - telescopic rear axles.

    Telescopic Rear Axles. Extended - Wide.


    Telescopic Rear Axles. Collapsed - Narrow.


    Hydraulic cylinders components are available to be adapted for this purpose.

    The axles would need to be braced vertically to stop them bending under the weight of the vehicle.

    Certain design concepts I have previously described for the CATAMARAN vehicle which I do want to retain for the telescopic rear axle design, such as

    • Trailer wheel steering
    • Armoured passenger trailer
    • Rotation on the spot
    • Roof mounted remote-controlled machine guns
    • 5 : 3 ratio, 5 (vehicle) : 3 (trailer), weight and length distribution

    Therefore the telescopic rear axle design although it is perhaps a less radical and innovative mono-hull design than the CATAMARAN Vehicle design, nevertheless it has many excellent features which greatly enhance the performance over the standard MRAP.

    So I await with interest to see if anyone can identify flaws with my second major design iteration.
    Peter Dow
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  17. #16  
    Forum Sophomore Peter Dow's Avatar
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    Armoured Personnel Carrier Designed by Peter Dow.

    Features
    • Front vehicle seats a maximum of 11 people
    • Armoured passenger trailer seats a maximum of 7 people
    • Vehicle with trailer seats a maximum of 18 people
    • Roof mounted remote-controlled machine guns
    • Trailer wheel steering
    • Telescopic Rear Axle & Wheels
    • Rotation on the spot
    • Even axle weight distribution
    • 5 : 3 weight & length ratio, 5 (vehicle) : 3 (trailer)

    Peter Dow
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  18. #17 Air-Powered Steering for rotation in a vehicle 
    Forum Sophomore Peter Dow's Avatar
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    Air-Powered Steering for rotation in a vehicle

    Here is an idea. If you need to, please review this diagram of a steering mechanism from Wikipedia on Steering.

    OK my idea is you replace parts of the steering rod with pneumatic pistons, either side of the connection to the steering column as follows.



    There is an air tank topped up by an air pump which when its valve is turned on inflates the pneumatic pistons now integral to the steering rod. (This should only ever be done while the vehicle is at rest and the driver has selected clockwise or anti-clockwise gear - some kind of safety cut out.)

    The air pressure quickly rises (that is why you use air, not hydraulics, it is so much faster if you supply from an air pressure reservoir - there is not a need for huge force, just speed, so pneumatics is the driver of choice I think) and when the air pressure exceeds a critical amount, retaining catches, which normally hold the pistons firmly closed against all manner of road bumps, suddenly break open and the pressurised air forces the pistons open against a spring and the steering rod lengthens to a maximum and the wheels are turned inwards to their respective stops - hard right hand turn for the left hand wheel and hard left hand turn for the right hand wheel, ready for rotation.

    It is clear to me that the 45-50 degrees or so maximum turning angle normally is limited by the steering rod at full stretch - not by the wheel bumping into the axle - so 75 degrees in this diagram looks easy.

    When you want to revert to normal steering, the system simply releases the air pressure in the pistons and the pistons close with the spring and the pistons snap shut into their retaining catches ready for normal steering.

    As you can see this is for rotation about a point mid-way between the rear axle. It is only when I add on my trailer to my armoured personnel carrier that the vehicle does zero turning radius, strictly speaking.

    Hence I have always called it "rotation on the spot".

    So do you think that would work? I would doubt that is the way that lawnmowers do zero turning radius.
    Peter Dow
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