Helicopter Transportable Vehicles

Usually seen as the sole domain of special forces, helicopter transportable vehicles provide a mobility advantage for all land and amphibious forces. They extend the range over which personnel can operate once on the ground and increase the amount of equipment that can be carried. Helicopter payloads and internal dimensions are relatively modest compared to contemporary defence vehicles so compromises in all areas have to be accepted. The proliferation of modern air defence systems means slow-moving helicopters may have to operate at stand-off distances from the objective, vehicles will be needed to cover this distance.

Introduction

The British armed forces have been using support helicopters to move vehicles since they had them.

During the early nineties, 24 Airmobile Brigade and the Multi-National Airborne Division (MNAD) was designed to be a highly mobile ATGW screening force, exploiting the mobility of small vehicles like the Longline Light Strike Vehicle (Ground Mobile Weapon Platform), quickly carried forward by Puma and Chinook support helicopters.

The UK contribution to KFOR (Operation AGRICOLA) in the late nineties employed 5 Airborne Brigade to secure the initial route to Pristina from Macedonia, enabling heavier forces to advance. The main lift was supplied by eight RAF Chinook and five Puma helicopters, escorted by Lynx helicopters from 659 Squadron AAC and a pair of US Army AH-64 attack helicopters. 99 lifts were carried out including 38 with underslung loads and a variety of vehicles including CVR(T) Scimitars.

The Bundeswehr maintain an integrated light armour force using Wiesel and Mungo vehicles that are wholly transportable by their CH-53G helicopters. Russia has continued to develop vehicles for air transport, the BMD-4 and newly announced Strela (Arrow) designed for external carriage by a Mi-8 or a Mi-26 internally for example. The US DoD has also taken delivery of a range of helicopter transportable vehicles over recent years, with the latest award being the Chevrolet Colorado ZR2 Infantry Squad Vehicle (ISV). At the smaller end of the scale, quad bike ATV’s continue to be used as helicopter transportable vehicles by support helicopter users.

Looking to the future, an emerging class of Uncrewed Ground Vehicles (UGV) will also need to consider air transportability. The US demonstrated uncrewed helicopters deploying uncrewed vehicles as underslung loads four or five years ago, it is not beyond the realm of imagination to foresee ‘swarms’ of armed UGV’s being deployed by helicopter, crewed or otherwise. Moving back to the mundane; logistics, medical, combat engineering and other support functions benefit equally from helicopter transportable vehicles.

Being able to transport vehicles and engineering plant by support helicopters is, therefore, an enduring need.

Exploiting the Mobility Advantage of Airpower

It is all about speed and reach; to quote from Joint Doctrine Publication 0-30;

  • Speed; allows the rapid projection of military power and permits missions to be completed quickly, generating tempo and offering the potential to exploit time, the fourth dimension.
  • Reach; seventy percent of the world’s surface is covered by water, but all of it is covered by air, providing airpower with unrivalled reach, usually unimpeded by terrain

Specifically describing the characteristics of Support Helicopters (SH), it says;

Support helicopters are the lynchpins of tactical mobility. Typically operating at lower heights and speeds than fixed-wing aircraft, they enable rapid tactical movement of personnel and materiel over difficult terrain. They are the fundamental enablers of ground manoeuvre, adding speed and surprise and allowing forces to leapfrog difficult terrain and bypass ground threats. Support helicopters are invariably in great demand and short supply.

Joint Doctrine Note 1/16 defines the UK’s approach to Air Manoeuvre, noting that whilst air manoeuvre is not solely about helicopters, it specifically defines air assault and airmobile operations, and their fundamental dependence on Support Helicopters.

Air assault and airmobile operations. Air assault and airmobile operations are specifically designed to be inserted, resupplied and extracted using support and attack helicopters as their normal means of operation

The image below shows the air manoeuvre spectrum;

The definitions in more detail;

Airdrop delivery involves the air movement of personnel and/or cargo by aircraft into an objective area and their subsequent delivery by parachute. Airdrop delivery reduces aircraft exposure to threats at the objective because they remain in flight. This has to be risk balanced with the cost of a relative dispersal of the ground force and cargo, and an increased risk of injury.

Air land delivery involves the air movement of personnel and/or cargo which are landed on or near their objective by a fixed-wing aircraft. Air land delivery offers greater unit integrity and usually maximises the use of aircraft cargo capacity. However, air landing requires a suitable airfield or airstrip and exposes the aircraft to threats at the objective

An air assault operation is defined as an operation in which air assault forces, using the firepower, mobility, and total integration of helicopter assets, manoeuvre on the battlefield under the control of the commander to engage and destroy adversary forces or to seize and hold key terrain.

An airmobile operation is defined as an operation in which combat forces and equipment manoeuvre about the battlefield by aircraft to engage in ground combat. Examples include moving engineers to clear a defile ahead of an advancing ground force; or moving a ground force to establish a hasty defensive position to block an enemy advance

Independent helicopter tasks are those which can be carried out by helicopters independently of other arms, though they may be part of a broader ground scheme of manoeuvre. They are primarily focussed on offensive actions. These are most likely to be shaping tasks but may be mission-decisive tasks in their own right.

What about enemy air defences?

One of the most significant trends in the employment of support helicopters in air manoeuvre is the increasing proliferation and capability of air defence systems. Helicopters are not the fastest of aircraft and will be even slower if carrying an underslung load. The odd MANPADS and 23mm automatic cannon-armed technical in Africa is one thing, but a modern integrated Russian air defence system in Eastern and Northern Europe is entirely another. The Missile Threat website provides an excellent interactive mapping tool that plots Russian strike and air defence missile range on a map of Europe, the circles shown below are S-400 engagement ranges.

Long-range surface to air missiles are prone to radar horizon issues if the aircraft is flying at low altitudes and the terrain advantages the aircraft. Modern air defence tactics negate this by placing shorter-range systems in concentric layers to catch any low-level penetrating aircraft which makes combinations like the S-400/Buk/Pantsir so potentially effective.

Despite the daunting nature of those circles on a map, they are not force fields.

They show ideal conditions maximum ranges without being subject to any kind of offensive action from NATO, aircraft defensive countermeasures, or terrain exploitation. Their engagement envelope is also dependant on radar performance and radar horizon, Justin Bronk at RUSI recently published a paper examining the effectiveness of Russian and Chinese air defence systems.

IADS are not impenetrable, however. When employed correctly, stealth aircraft, standoff munitions and electronic attacks can suppress and degrade an IADS for a finite period of time in a limited area to enable strike packages to get through to their targets. However, completely rolling back an IADS the size, depth and complexity of those of Russia or China would most likely take weeks and possibly months of full-scale warfighting. Furthermore, the experience of SEAD campaigns against Serbia and Syria would suggest that eliminating pop-up threats from isolated SAM systems altogether would be almost impossible without victory on the ground.

He explains that Russia will seek to prevent the employment of NATO airpower by forcing it to engage in politically risky counter-air defence activity. This complex air environment demonstrates why a group of Chinooks flying across the Suwalki Gap in response to a Russian incursion into the Baltic States is rather unlikely in the early phase, likewise a Company level airdrop into Lithuania. Where does this leave Support Helicopter delivered vehicles, either from land locations or naval shipping, the latter of which is complicated by a lack of terrain masking opportunities? Simply put, it leads to a conclusion that putting Support Helicopters into the engagement zone of layered air defence systems should be discouraged, putting it mildly.

If Support Helicopters are forced to stand-off from objectives, the light role forces using them will need to exploit one of humanities oldest inventions, the wheel.

Fly then drive

There are exceptions, but helicopters don’t have the ability to fly long distances, and the higher the payload, the shorter the range. A combat radius might be anywhere between 50km and 300km but once on the ground, those using them must move to their objective. That objective could be near or far but marching speed over ground will be highly dependent upon the terrain, individual fitness, loads being carried and whether personnel need to arrive at the objective ‘fighting fit’.

This video clip shows an example where using vehicles would be impossible.

But in other cases, using vehicles might be preferred for a number of reasons. The example below shows the UK invading Belgium, just for a bit of fun to illustrate the point :)

After a 90 minute flight from Dover, landing just south of Ghent, and assuming a 5kph marching speed, the deployed force on foot could cover 20km or hold a potential area of 1,250km2 under threat. If that force could fly the same distance (maybe a little slower) but had the benefit of a wheeled vehicle when it got there, assuming a road speed of 40kph, the distance rises to 160km and an area of 80,000 km2 (yes, I know they can’t drive on water!)

Although these maps are based on some very broad assumptions, I think it speaks for itself. 20km is inside the engagement zone of all but the shortest-range systems, 160km is not.

Light infantry and cavalry

The Op HERRICK Campaign Study noted that a Brigade Reconnaissance Force was of great utility because of their ability to use vehicles or helicopters to achieve tactical surprise to gather useful intelligence and facilitate strike missions. It also noted that in the future, this will be delivered by the Light Cavalry Regiments. With the withdrawal of CVR(T), a vehicle that is helicopter transportable, and replacement with Ajax, that most certainly is not, the rapid response helicopter transportable light armour capability that has been a feature of a number of operations in the past is no longer available.

Although now removed, a recent article at the Wavell Room from a Light Role Infantry officer noted that recent operations have never really been light role in the truest sense, vehicles have always been a constant feature; commenting on vehicles;

They enable increased firepower, manoeuvrability, protection and sustainment across a larger operational area. They contribute to increased tempo and allow greater inherent flexibility, as well as providing organic means to concentrate or disperse forces as desired. Vehicles provide a mobile platform for crew-served weapon systems and increased ammunition carriage; the firepower that such systems can inflict and sustain is far greater than light role infantry. The manoeuvrability of combat elements to arrive at speed, gain surprise and seize the initiative as well as generate mass, can also be increased as vehicles allow mounted infantry to travel at greater speed and cover more ground than their light role peers.

Using a light mobile force that has a lot of firepower to fix an enemy force (briefly) against which the newly formed 1st Aviation Brigade could strike starts to be really powerful, especially if that force also has the support elements to enable forward arming and refuelling. Even when not using helicopters at all, a light mounted force provides a heavier force with options for rapid outflanking and dispersal and concentration at speed where they can bring their anti-tank and sniper weapons to bear.

Emergent Uncrewed Ground Vehicle (UGV) capabilities

There is a great deal of development work ongoing with Uncrewed Ground Vehicles (UGV) at the moment; whether in the infantry platoon ‘mule’ role, paired with crewed vehicles in mounted close combat or operating alone at distance. In 2016, the National Robotics Engineering Center demonstrated an autonomous UH-60 Blackhawk helicopter delivering an autonomous UGV to a target location from which it carried out a range of CBRN survey tasks. This was followed up with a different helicopter/UGV pairing to deliver a different task.

Vehicle Design Requirements and Constraints

The issues above lead me to believe that whether we are looking SF and 16AAB, the Royal Marines, conventional light role infantry and cavalry, or future UGV’s, any requirements setting exercise must consider helicopter transportability at the core. This does not necessarily mean a single unified requirement, but instead, a common understanding of the breakpoints and virtual loading gauges to achieve levels of commonality that often elude us.

It is also important to be realistic about these niche vehicles that trade protection for mobility in the broadest sense, and their roles and capacities. Most of the stuff you see in the defence press about light vehicles see them festooned with machine guns and missiles but we should not ignore logistics and support, being able to fly forward a small team to repair a couple of holes in a runway or set up a small medical facility will require a different set of vehicles but maybe just as important to campaign success.

i.e. don’t ignore the pallets!

Vehicle Design Requirements

Speed, capacity, terrain accessibility, protection, temperature ranges, reliability and range are some of the more obvious requirements, to be joined by the less obvious ones like tie-down underslung load rigging points, self-recovery capacity, acoustic and thermal signature, power export, fuel types, maintainability, ergonomics and towing capacity. Each of these will be balanced but inevitably, one vehicle design cannot do everything.

If a vehicle has high terrain accessibility requirement, especially in snow, muskeg/bog, intertidal areas and swamps, it will usually have to sacrifice road speed and range. The enduring ‘tracks v wheels’ debate is just as valid for airmobile vehicles as it is for any other but for vehicles that must have low surface compaction and high tractive force, the many penalties of tracks have to be accepted. Extra-wide tracks can reduce ground pressure even further but the additional width might push a vehicle from internal to an underslung carriage. An amphibious capability may also be an important requirement, with an additional set of qualifications such as wave height tolerance or ability to climb out of a river. Load-carrying capacity might come in the form of pallets, role-specific equipment, bulk fuel and water or seating for passengers. A vehicle might need to mount crew-served weapons, tow mortars or artillery, mount hydraulic jibs or have enough space for electronic equipment. Mounting complex equipment like weapons and sensors has a weight and power penalty, especially if mounted higher up where centre-of-gravity issues might reduce mobility.

In the logistics support role, the requirement might be as simple as having lashing points for cargo nets and ratchet straps to secure ammunition boxes, jerrycans and bags, with everything being loaded and unloaded manually. But in a larger vehicle, there is scope for pallet carriage and hydraulic loading/unloading equipment, shelters and equipment housing. Whilst focusing on an individual vehicle is important, wider requirements should also be considered. Some roles could use a range of vehicles, an example being half a dozen ATV’s supported by a larger logistics vehicle. The package as a whole also has to be transportable by the available helicopter lift, no point in defining missions if there is not enough aircraft to support and sustain the package. The UK armed forces are reasonably well provided with support helicopters but we must not assume they would all be available, they are always in high demand.

These trade-offs and decisions can be seen in the GM Defense Infantry Squad Vehicle for the US Army. It has a high speed and can carry 9 soldiers but clearly, is not able to carry a pallet of mortar bombs or negotiate very soft terrain. Requirements have resulted in a very specific vehicle, by design.

Primary Constraints

Vehicles can be carried inside helicopters or as an underslung load, each method has advantages and disadvantages. An underslung load imposes limitations on helicopter speed, range and manoeuvrability, the vehicle will need to be de-rigged once on the ground but feasibly, a helicopter could land the load into a confined space. Carrying vehicles internally will negate the need for complex rigging, will be safer and avoid compromising aircraft performance, but they utilise volume that might otherwise be used for low-density cargo like people. Loading and unloading will be a deliberate and time-consuming activity that means the aircraft will be on the ground longer. No one method is necessarily better than another.

Helicopter Interior Dimensions

The UK only operates two cargo ramp equipped helicopters but it might also be useful to consider others.

Seat arrangements, differences between the ramp and internal dimensions, ramp break-over dimensions, cargo floor equipment and other internal obstacles might ultimately result in a vehicle not being able to actually fit inside so the dimensions shown below and indicative only, from open sources.

 HelicopterWidth (m)Height (m)Length (m)
Merlin2.01.86.5
Chinook2.11.99.3
NH901.71.54.8
Mil 82.31.85.3
CH-53K2.71.99.1
V-221.81.87.4

Helicopter Underslung Loads

Using helicopters for external loads is quite commonplace, but it is a complex and potentially dangerous business where the limits and operating procedures have evolved over many years. All UK helicopters (except AH and some training type) have external lift capabilities.

Simply saying X vehicle weighs Y and will therefore be able to be slung load from Z helicopter might not be true, clearance will depend on many factors and in general terms, more weight equals less range or ability to operate at higher altitudes. The table below shows external load clearances obtained from open-source data and is only indicative.

 HelicopterSling Load ClearanceNotes
Wildcat1,000kgequipped with a Drallim Semi-Automatic Cargo Release Unit (SACRU) No 2 Mark 1 cargo hook with a design load of 1,497kg
Puma Mk22,250kghas a SACRU Number 1 Mk3 with a safe working load of 2,724kg
Merlin HC4,100kghas a Talon SACRU with a safe working load of 5,443 kg
Chinook11,300kgthe centre hook has a safe working load of 11,300kg
Mil 83,000kg 
NH904,000kg 
Blackhawk4,082kg 
CH-53K15,900kg 
V-22 6,800kgthe single hook is rated at 4,536kg although with a two hook system, this is increased

Strops, slings, spreader bars, nets and other equipment falls into the general term of Helicopter Underslung Load Equipment, or HUSLE. Taken together, these can weigh up to several hundred kilograms so, in addition to operating margins and clearances, it is also important to take these into account.

Secondary Constraints

Before getting into categorising vehicle by helicopter transportability (the subject of this article) there is a group of other design constraints to consider.

Driving Licences

One of the problems with recent experiments with light mechanised forces was the training overhead for the heavier vehicles that required higher classes of driving licence than commonly found in infantry units. Vehicle weights and driving licences require management and training, it is important. As an example, a Class B car licence qualifies a person to drive a vehicle with a Maximum Authorised Mass (MAM) of up to 3,500kg with up to eight passenger seats. On a Class C1 licence, vehicles with a MAM between 3,500 and 7,500kg with a trailer up to 750kg. With a C1E, the combined weight of a vehicle and trailer is 12,000kg.

Landing Craft and Hovercraft

The UK does not have any hovercraft that can transport vehicles but there is an aspiration for the Griffon 8100TD which has a vehicle ramp and deck that is sized for a 12-tonne maximum weight and 20ft ISO container dimensions. Landing Craft Vehicle Personnel (LCVP) Mk5 can carry an approximately 6-tonne payload with a ramp width of 2m. The much larger Landing Craft Utility (LCU) Mk10 have a large payload and ramp width in excess of 3.5m but a light vehicle under 2m width and 6 tonnes in weight would be able to use the more numerous LCVP’s.

Containers and Flatracks

The standard ISO containers’ numerous advantages of protection, reduction in handling and compatibility with ships, trains and vehicles are obtained when the container changes mode of transport i.e. intermodal. The International Standards Organisation (ISO) defines standards through an International Classification of Standards (ICS), ICS 55 is for the packaging and distribution of goods and within that, 55.180.10 – General purpose containers include a range of standards for containers, with ISO 668 being the main one that defines dimensions and characteristics. If the vehicle can fit within the most commonly used ISO containers it makes deployment to theatre that much easier, though not necessarily any quicker.

Door WidthDoor HeightInterior Length
1F (5ft) Quadcon2.34m2.28m1.5m
1D (10ft) Bicon2.34m2.28m2.8m
1C (20ft)2.34m2.28m5.8m
1A (40ft)2.34m2.28m12.0m
1AAA (40ft) Hi Cube2.34m2.56m12.0m

Although the interior width and height are commonly quoted, the door aperture is more important for loading vehicles. Stacking multiple vehicles to maximise the volume of a container would also be advantageous. Flatracks are commonly used to transport vehicles and for planning purposes, width and length dimensions are roughly similar to 20ft containers.

Air Despatch Platforms

In order to airdrop vehicles using parachutes, they need to be suitably rigged to a platform. Platforms are available from Aeronet and Capewell, the latter of which has two designs, the Type V and a smaller system used for quad bikes and side by side ATV’s called the Multi Drop Platform. Triton has also developed a composite platform although it is not clear if it is in production or commercially available. Each of these has specific weight and dimension limits but they are generally aligned with the C-130J. Considered by many to be the most advanced is the ATAX Platform from Airborne Systems in Wales. This is a modular system that can be combined for heavier and longer vehicles or boats. It also features an airbag system for the heavier loads and integral shock absorption, and the flexible nature of the platform allows the platform to easily cope with ground undulation.

Each ATAX module supports a 4-tonne load and up to four modules can be combined for a maximum weight of 16 tonnes. As with helicopter sling loading, air despatch is a very complex and potentially very dangerous business. Platform characteristics often change with aircraft type and payload figures tend to be given as inclusive of rigging. Aircraft have ramp limitations and minimum weights for various types of platforms.

Tactical Transport Aircraft

The kind of light vehicles envisaged in this article will fit in most tactical transport aircraft but it is still important to understand capacities in order to determine multiples of vehicles in a single lift that allow aircraft volume and payload to be efficiently utilised. Exactly the same as with helicopters, the closer the aircraft gets to its maximum payload, the more performance (especially range) will be reduced. So when we talk of vehicle weights we must also talk about aircraft range/landing altitude and consider what might be ‘normal’ weights, not theoretical maximums in the brochures. The maximum payload of the A400M Atlas has yet to be fully released but the design objective was 37 tonnes. For planning purposes, I would tend to a figure of 30-32 tonnes, compared to 15-16 tonnes for a C-130J. Likewise, with the C-17, a more sensible figure to use is 60-64 tonnes rather than the absolute maximum. Even with these weight limits, there are many factors that might reduce the actual cleared figure; weight distribution, floor loading limits, uniformity of shape, securing practice and safety considerations for example.

 WidthHeightLengthSensible Max Payload
C-130J3.12m2.74m12.1m15-16 tonnes
C-130J-303.12m2.74m17.0m15-16 tonnes
A400M4.00m3.85m17.0m30-32 tonnes
C-175.50m3.80m26.0m (inc. ramp)60-64 tonnes

Packing density is important for inter-theatre lift and given a finite number of aircraft sorties available in a given time period,  it will determine the force build-up speed when utilising aircraft.

Aircraft Pallets

Vehicles would normally be driven on and off tactical transport aircraft so ordinarily aircraft pallets and load containers would not be a consideration, but for smaller and lighter vehicles, using aircraft pallets instead of driving on and off aircraft in the inter-theatre phase can lead both to space efficiency and open up opportunities for using non-tactical transport aircraft. Tactical aircraft will be at a premium in any deployment, rapid or otherwise, so if we can provide options to avoid using them and use the thousands of civilian freight aircraft available, all good. The 463L and ULD are two key systems used in the air carriage of goods.

The 463L pallet (also known as the HCU-6/E) is the main component of the 463L Materials Handling Support System. The pallet and handling systems are designed with rolling in mind, a Euro pallet is lifted and shifted, a 463L is rolled. Useable space is 2.13m by 2.64m and two pallets can be linked together with couplers as shown below left.

Pallets would not be used for tactical landing but if the vehicle can fit within the 2.64m length of a 463L and under 4.5 tonnes they could be loaded across the width of the cargo bay rather than longitudinally. An A400M can carry 9 such pallets, a C17, 18. They need offload equipment at the far end but it does demonstrate how working within existing constraints can enhance capacity and speeds. If the vehicle was no higher than 1.62, even an RAF Voyager could carry 8 such 463L pallets in its underfloor cargo deck.

The term Unit Load Device is a catch-all for a collection of pallets and containers used in the civilian air freight business. There is a great deal more variety in dimensions and configurations than with the 463L system as they are often designed to be aircraft specific in order to absolutely maximise volume efficiency. Specialist vehicle transport LD11 ULD’s are available from a number of manufacturers.

The RAF’s Voyager and all civilian transport aircraft use ULD’s, above bottom left is an RAF Voyager lower deck.

Proposed Vehicle Categories and Examples

Taking the primary and secondary weights and dimensions into consideration, a shorthand of 8 categories to describe many combinations and permutations can be defined.

CategoryLengthWidthHeightWeight
A01.1m0.6m0.6m25kg
A2.3m0.9m1.5m180kg
B2.4m1.3m1.6m500kg
C3.5m2.0m1.8m3,500kg
D9.0m2.1m1.9m3,500kg
EN/AN/AN/A3,500kg
F9.0m2.1m1.9m8,500kg
GN/AN/AN/A8,500kg

Informing each of these categories are a series of evaluations and trade-offs that try and balance the constraints various and needs and reference real-world vehicles. Some will have greater weight than others, for inter-theatre transport, helicopter limits are absolute but where they can be flexed slightly to improve efficiencies in inter-theatre transport that is also considered. This section is based on nothing but educated guesswork, comparing publically available aircraft dimensions and capacities against a range of vehicles. I must also stress that just because the dimensions and weights might be compatible with an aircraft, it is very far from being certain that could be the case in practice. There are too many variables to sensibly include here and all would be subject to confirmatory work by the experts at the Joint Helicopter Support Squadron and Joint Air Delivery Test and Evaluation Unit (JADTEU)

They are presented as nothing more than ‘food for thought’

Category A0 Examples

Category A0 is probably the smallest practical means of wheeled transport and is more or less the size of a large rucksack so numbers vary depending on seating arrangements and whether those seats would also be used for personnel. It is also assumed they would be in a cargo net when underslung in bundles of twelve. They would also be compatible with air despatch via a side door bundle and are light enough to be handled on and off aircraft without a ramp.

The well-known Brompton is joined by the Montague Paratrooper bicycle for human-powered movement, in good conditions, 60km should not be a problem in the 4-hour movement window described above. Perhaps a better option would be an off-road powered bicycle, the Radpower RadMini 4 being a good example. At less than £2k each, a top speed of 25kph would allow a soldier to move 100km in a 4 hour period with 2 charge packs, in relative silence.

There is even a modern-day Wellbike, the DiBlasio R7E folding scooter uses a 50cc two-stroke engine. With a maximum speed of 45kph, in 4 hours, if a rider could endure everyone laughing, they could move 180km, although the 3-litre fuel tank would need a top-up half-way. They only weigh 32kg and even come with their own bag, honest!

The problem with both these solutions is the lack of payload, limited range, poor terrain accessibility and all-round general comedy value but as mentioned above, included for completeness and to demonstrate a span of solutions.

Category A Examples

Category A is a motorcycle. It might be possible to carry one inside a Wildcat and two inside a Puma but that would likely mean no passengers or even removing seats if possible. For carriage inside a Chinook or Merlin, if they could be arranged down the middle with handlebars crossing over, the seats might possibly be utilised although not sure if this would be allowed for safety reasons. Motorcycles could make use of specialised pallets to enable easier carriage on 463L pallets and loading inside containers, or when clipped together, as an underslung load carriage frame instead of using cargo nets. The underslung numbers assume 4 on a single pallet frame as per the image below right, and for Chinook, one such pallet frame per hook.

Motorcycles represent a more realistic two-wheeled option that powered bicycles or scooters. Lithuanian special forces use them, the Finnish Army likewise in a similar role. This post describes the French Army’s use of motorcycles in Mali. In many cases they are supported by larger vehicles acting as a logistics hub, carrying additional fuel and other stores.

The British Army’s Harley Davidson built Armstrong MT350 Motorcycles are now long out of use, although some Kawasaki KLR’s and Honda XR/WR 250/400’s were purchased from CJ Ball for specialist users, they were not used widely. Apart from some minor modifications, weapons panniers and lighting, for example, a military trail bike is not that much different than a sports trail bike. Where there has been some development is power, first with diesel engines and more lately, with hybrid engines. The Christini AWD Military has been refined over a number of years and now features foam-filled tires, GPS, anti-stall automatic clutch and additional protection for vulnerable areas. KTM and Kawasaki have also developed all-wheel-drive motorcycles with different approaches, hydraulic and mechanical connection to the front wheel. All-wheel drive cannot substitute for skill but it does help a skilled rider, although the extra weight might not be welcome. Probably be the most useful feature for a military motorcycle is the ability to use diesel or JP8 fuel. The US Marine Corps introduced a number of diesel motorcycles from Hayes Diversified Technology. Interestingly, much of the technology was apparently developed at Royal Military College of Science (Cranfield), its key feature is the ability to use military/civilian diesel, Bio-Diesel (B20 or B100), JP4, JP5, JP8, AVTR and even Kerosene. Bringing this work on all-wheel-drive, small diesel engines and hybrid drive technology together, DARPA awarded a technology development contract to Logos Technologies, for the Silent Hawk hybrid military motorcycle.

It weighs 160kg, can carry a rider and 35kg of equipment approximately 270km (including 2 hours of that in quiet mode) at a top speed of 80mph. In the notional four hour journey, 500km. Real-world distances and speeds would be much lower, but clearly, they are built for speed.

A more sedate Category A vehicle but with improved soft ground performance is the Rokon Ranger all-wheel-drive motorcycle. The tyres can be filled with water or fuel, both wheels are powered and with the 200cc petrol engine can tow 900kg loads. The King Abdullah II Design and Development Bureau in Jordan has developed a specialist military version of the AB32 Rokon Desert Ranger and it is in service with Jordanian forces.

Category B Examples

Category B is typically a quad bike style all-terrain-vehicle (ATV)

With a maximum weight of 500kg and a width of 1.2m, it would have to be an underslung load for Wildcat and Puma, although in both cases, they would be pushing the maximum weights and impact performance so much more practical would be 1 and 2 respectively. Chinook and Merlin can carry them internally although the use of seating would be subject to confirmation. The weight would be less of a problem for Merlin and Chinook but they would still need some form of specialist platform to achieve the higher numbers, a cargo net would not likely suffice for four at a time. If using a frame pallet as shown below, this would add sacrificial weight as they would be single-use. Without these, the underslung load figures would likely be reduced by half.

These larger quad bikes are an awkward fit inside ISO containers as their height prevents stacking, and two inside a Merlin and three inside a Chinook is not brilliant, 463L is only one per pallet.

Driving motorcycles, especially off-road in challenging circumstances, requires not inconsiderable skill and experience, and they do not have a great deal of load-carrying capacity, for both weight and volume. Quad bikes, on the other hand, can tow trailers with significant loads and although driving quad bikes off-road safely, is far from a trivial task, they do seem to have displaced motorcycles in most forces, the UK is no exception. The first models were off the shelf petrol engine designs from Honda and Yamaha but these eventually changed following work on the Resolve/Roush DRV that used diesel or JP8. One of the first UOR’s was fulfilled by Roush, taking the standard Yamaha Grizzly 450 units and adding a NATO towing hitch, winch, run-flat sealant for the tyres, IR lighting, left-hand throttle and other minor modifications, in addition to the diesel engine. Subsequent contracts were with Yamaha direct. In Afghanistan, Quad Bikes proved to be enormously useful for running replens, casualty evacuation, transferring stores to and from helicopter landing sites and a million other odd jobs. A couple of trailers models (SMT 171B and SMT 120B) were obtained from Logic, bringing the payload up to approximately 150kg, including the ability to carry stretchers.

There are many instances were quads have been used as weapons platforms and the UK company, C4i Systems, market the C-QUAD, a C4ISR system built on a quad bike, just one example of using them as something more than the traditional transport role.

Most weigh around 350kg empty and 500kg fully loaded so a significant step up from Category A0 and A, a quad and trailer could be considered as 2xB as they can be transported separately if needed. The C-Quad shown above is based on the Polaris MV850 Sportsman that has a curb weight of 444kg. For helicopter portability in multiples, quad bikes are arguably not as efficient as a large vehicle and would require a lot of time to rig and de-rig if more than one or two were carried at a time. There are many variables, so meaningful ranges are difficult to define but 200km on a single tank at 40kph seems a good working average, certainly 160km in four hours.

There is a huge ‘accessories’ market for quad bikes, trailers especially, but also include track conversions and even hydraulic lifting and earthmoving, this ecosystem of integrators and manufacturers makes quad bikes especially valuable.

Airless tires seem to be maturing to the point where wider adoption becomes feasible.  They have been ‘coming soon’ for a long time but Polaris seems to have the confidence to offer them as a standard addition to their product line, selling their damage and puncture resistance as key attributes, especially in urban environments. For use in cold environments, tracks can also be fitted, again, it might be worth trialling these against conventional snowmobiles for cold weather use, Matracks are the market leader, although there are others such as Camso. Occupying a position between wheels and tracks is the J-Wheelz wheel extension.

The Logic trailers are simple, robust and strong. In some roles, there may be an argument for specialist trailers like water bowsers or perhaps log trailers but in many cases, it is probably easier to just use jerrycans or ratchet straps. Tipping and hooklift (DROPS style) trailers might also be useful and could be used for recovering unserviceable quads and quickly dropping off stores, without manual handling. Powered trailers can be used for larger loads. If the track attachments are fitted, ski-equipped trailers are available. The final trailer to look at it is Tetra-POD that is interesting because it is a) plastic and b) turns into a boat.

The gap crossing system (folding ramps) described above is perfect for irrigation ditches and other short gaps, it is quick to install and requires very little training. For longer gaps, an improved system may be desirable. General Dynamics picked up the concept and produced the Quad Bike Bridge (QBB). The QBB can bridge gaps up to 2.5m and installed in less than 5 minutes. Where the gap is longer, wet and where the banks are relatively low to the water a floating pontoon-style system can be used. MSS Defence in the Netherlands has a system called the GXS Rapid Deployable Gap Crossing System. It is aimed at larger vehicles, up to 2.5 tonnes but still useful for quad bikes. It is available in 5m and 10m kites with both, deployable very quickly, less than 10 minutes. The system comprises inflatable floatation elements, a road-mat and various ancillaries. A final system worthy of consideration is the Tactical Assault Bridge (TAB) from Easibridge. The Tactical Assault Bridge is an optimised sectional ladder, but a sectional ladder that can be used for gap crossing, fence breaching, overhead cover support and other application using a single 1.5m long section with a wide collection of fittings and accessories. For providing light engineering support (excavation, razor wire emplacement and field fortifications) some hydraulic attachments are available.

Because they are relatively inefficient internal loads for helicopters, Quad Bike ATV’s only become optimal where high terrain accessibility is required of the load-carrying capacity and efficiency of trailers and attachments/payloads can be utilised, or where there is little other choices i.e. small helicopters.

For a bit of Gallic flair, the Lohr Fardier had various components from the 2CV and other Citroen vehicles, it was originally assembled in Belgium. It can be used as a cargo vehicle, weapon post or stretcher carrier and is still available for purchase, from Soframe. It can tow up to 800kg although with a dry weight of 680kg is technically overweight for this category. Although they are Russian made, the UK arm of Tinger ATV’s market a UK road-legal version of the Tinger Scout tracked amphibious all-terrain vehicle. They fall slightly outside the width limit of Category A but mobility versus a quad is vastly improved in marshy or snow conditions.

The Roboteam Probot is a quad sized autonomous load carrying platform that can also be used as a weapons platform. Although they are really slow (max speed is 12kph) they have an impressive payload of 750kg.

Although falling somewhere between B and C, the 3 axle quad bike ATV’s seems increasingly popular as they maintain a high degree of commonality with the more familiar two-axle variants. In the simplest of terms, they are a conventional quad bike ATV with an additional axle that supports a load platform. In many cases, this load platform can be tipping and negate the need for a trailer although the same trailer as described above can still be used. Personnel capacity tends to be small, one or at most, two. Another advantage is their low height, as with quad bike ATV’s, usually no more than 1.3m. Width tends to be 1.3m and most have a length of approximately 3m, with an average payload of 500kg across most models from Polaris and Can-am being most common. Their length and weight place them outside of CATEGORY B, but not by much. 

In the same way that 6×6 quad bike ATV’s straddle Category B and C, so do snowmobiles. Although they fit within the width constraints of B, their length does not. Officially called Oversnow Reconnaissance Vehicle (ORV) in UK service, centre drive single track snowmobiles are available in sports and utility models from a number of manufacturers. The newer Royal Marine models seem to be the BRP Lynx/Skidoo Expedition which is 3.4m long, 1.14m wide and 1.33m high, weighing in at approximately 400kg. They are powerful machines designed for high speeds over deep snow, much more efficient than a quad bike ATV with track kit.

Both the Snowmobile and 6×6 quad bike ATV’s would be underslung load compatible with Wildcat and Puma

Category C Examples

This class of small ATV’s is defined by carriage inside a Merlin or Chinook, as an underslung load by Merlin/Blackhawk/NH90 and the ability to carry two or more people at a time i.e. compact and 3-4 tonnes. The internal carriage constraint significantly reduces choice but is an important factor for aircraft performance. 

Side by side ATV’s are more common than the 3 axle quad bike ATV’s and used widely in the agriculture, outdoor sports and construction sectors. As with quad bike ATV’s, the large volumes and supporting ecosystem of manufacturers and integrators works in our favour. Manufacturers include Polaris, Bobcat, Yamaha, John Deere, Honda and Tracker. Sizes and capacities vary with some focussing on load bed space and others replacing that with seating.  

As defence customers have refined requirements, these civilian derived models have been increasingly modified, with Polaris and John Deere appearing to dominate the market.  In order to allow internal carriage, demountable rollover protection has replaced enclosed cabs. The John Deere Gator family have been adapted by International Automated Systems for defence markets and called the Mach 2 and Mach 2XL, the latter having a stretched load-bed.  Both have diesel engines and a maximum speed of 50kph. The fuel tank holds 26 litres and they have a maximum weight of just over 1,500kg, well inside the maximum for this Category. One could even be carried by a Puma as an underslung load. Polaris makes a similar model with demountable rollover protection, the MRZR Alpha.  This is quite an advanced design with exportable power, sling load attachment points and is available in two and four-seat models.  The two-seat model has a payload of 635kg and the four-seat model, 900kg. Both have a range of approximately 360km. 

A couple of other interesting vehicles are the Australian Bale Defence RTV Death Adder and French Unac Rider.

In 2005 the MoD contracted with Roush Technologies Ltd under Project Harewood to design and built an ultra-lightweight all-terrain load-carrying vehicle that could be an underslung load by a Lynx helicopter and internally carried in a Merlin and Chinook, called alter. The contract was worth £3.3m but only 15 vehicles entered service and have all since been disposed of. What was unusual about Balter was it was designed from scratch to be a military vehicle, not adapted from agriculture or recreational designs. It had a multi-fuel engine (diesel, JP8, JP5 and B20 biodiesel), NATO compliant electrical system and tie-down and sling load points. By virtue of its Lola Composites aluminium honeycomb construction, it only weighed 800kg yet could carry a 1,000kg standard pallet. A lightweight trailer could be used to increase the payload by another 600kg. Roush developed the concept into a 2 seater with a load bed shelter and uprated engine developing 50 kW and 160Nm of torque. The Roush Balter (LAS100RE) is an interesting case study in simplicity and weight reduction although the manufacturer has since moved on to other things, described here for information only.

All these are sophisticated vehicles with features matched closely to user requirements, but they are optimised for relatively firm terrain and mostly for the high-speed carriage of personnel, with relatively small amounts of stores; given their roles, this is not surprising. If one needs a much higher payload and higher terrain accessibility, inevitably, trade-offs must be made against speed, this leads to the 6×6 or 8×8 skid steer type of medium-sized ATV.

The Supacat All Terrain Mobility Platform (ATMP) is a 6×6 design that uses low-pressure Terra-Wrangler tyres to deliver a ground pressure of only 0.2 kg/cm, making it highly mobile on soft ground. Originally powered by a 1.3L Citroen engine, the later versions had a 1.5L VW-Audi engine and automatic transmission. Specifications included a 750-1,000kg payload, increasable to 1,600kg with reduced performance, a maximum loaded weight of 1.6 to 1.8 tonnes, limited amphibious capability, and a top speed of 65kph with permanent 6 wheel drive. Because the focus for ATMP was air manoeuvre and logistics, a great deal of thought was put into cargo handling ad weight/dimensional compatibility with in-service aircraft. Air portability was a key requirement; they can be parachute dropped on Medium Stressed Platforms (2 per platform), carried by helicopter as a sling or netted load and are internally transportable in a Chinook. Given the length of time, the ATMP had been in service, all necessary Joint Air Transport Establishment (JATE) clearances were obtained for different aircraft and loading schemes. Chinook was cleared to carry 2 ATMP’s internally without lowering the roll cage or 4 as a single underslung load. Merlin internal carriage, Puma underslung load and even the Blackhawk were certified. Multiple stacking options also exist for carriage in larger aircraft such as the C130 and C17. The ATMP and air portability go hand in hand

Vehicles like ATMP really shine in the logistics role, the load carrying and towing capacities are extremely impressive. Aided by smart design such as an integral winch and pair of ramps that were stored in internal compartments parallel to the vehicles long axis, pallets could be simply winched onto the ATMP load bed, secured and the vehicle drove away. A pair of specially developed trailers were also introduced to increase overall load-carrying capacity, the FLPT (Fork Lift Pallet Trailer) and SLLPT (Self Loading Lightweight Pallet Trailer).

Although ATMP is officially out of service, it remains in use with various test and trials units and is subject of a DSTL research programme for low carbon hybrid drive technology. Supacat still lists it on their website.

It is hard not to be enthusiastic about the ATMP, simple, versatile and with all the relevant clearances in place, and relatively easy to bring back into service. In the interests of looking at alternatives, the MoD has trialled the Hippo-X from Multipower, supported by Pardus Defence and Security. The Hippo-X appears to be a Mudd Ox XL, specification seems broadly similar to the ATMP; although the ATMP can perhaps carry more it does not have the very useful power export capability of the Hippo-X. Like the ATMP it can be fitted with ‘over tracks’ to improve mobility in extreme terrain. Both are amphibious but the Hippo-X can be used to cross wet gaps without preparation. The 5Kw power export system would be very useful with the marketing material suggesting it could be used in the radio rebroadcast role or with a tethered UAV. It also suggests hydraulic power could be used for a crane or small excavator.

There are a number of other manufacturers of similar small utility vehicles designed for high mobility; Argo, MXI and Hydratek. The MXI Buffalo Trucker is a 6×6 amphibious unit with a tilting load bed, 500kg payload on a 500kg highly durable polyethene body. With a payload of between 411kg and 479kg, the Argo Conquest range can be fitted with a tipping load bed, roll cage and other accessories including a number tailored specifically for medical evacuation. Hydratek recently acquired Land Tamer and between the two ranges, have a broad range of 3 and 4 axle vehicles including tracked models. The South African LMT-1 Gecko is now owned and produced by LMT Holdings. It weighs 1.2 tonnes, can carry 900kg and pull a 1-tonne trailer.

Small 6×6, 8×8 and tracked ATV’s have also proven to be popular as base platforms for a number of robotic vehicles, the Lockheed Martin Squad Mission Support System (SMSSS) is actually a Land Tamer base vehicle for example, the Rheinmetall Mission Master based on an Argo Rover. The US DoD recently selected General Dynamics MUTT (another Argo variant) for their Small Multipurpose Equipment Transport (S-MET) requirement,. The UK is currently evaluating this design along with others like the Rheinmetall Mission Master Cargo, MIRA Viking, Hippo-X, Marlborough (Praesidium Global MAPS) and QinetiQ Titan (Milrem Themis) UGV’s under the Robotic Platoon Vehicle (RPV) programme. The robotic version of the Hippo-X is being developed in conjunction with Pearson Engineering, Digital Concepts Engineering and Torc Robotics. DCE also recently won the MoD ‘map the gap’ competition to develop an autonomous gap crossing survey system. Argo has a complete line of 2, 3 and 4 axle uncrewed platforms for use in industry, mining and defence applications. The HDT Hunter Wolf, like many of these vehicles, has been shown with a number of weapons, sensor and C-UAS systems

China continues to push the boundary of what is possible to mount on an ATV with their CS/VP4 ATV Lynx.

The Caron EVO 4 is an agricultural utility vehicle available as an articulated or steering wheels version, with an open or enclosed cab, and in a number of engine and size variations. In the middle of the range is the Series 300/400, and whilst they are certainly ugly, look at the numbers. With a top speed of 40kph, they have a whopping 2-tonne payload whilst weighing only 1.5 tonnes, they can also tow 2 tonnes. And, fit inside a Chinook if the open cab with folding rollover protection option is chosen. Although the length would be outside the Category C limit at 4.8m, the load-bed could fit four NATO standard 1.2mx1m pallets. In order to reduce the height to fit inside a Chinook, these pallets would have to be half loaded so although there would be four physical pallets, the equivalent load would be for two. Two NATO pallets could include 256 81mm mortar rounds, just under 40,000 7.62mm rounds, over 1,000 litres of fuel in 25 Litre jerrycans or 800 operational ration packs. A trailer would nearly double these and the whole package would still be inside Chinook limits.

Another interesting agricultural vehicle is the Antonio Cararro Protector 100 orchard tractor. The requirement for narrow tracks and to operate under the canopy of fruit trees results in a low profile vehicle that can be internally carried in a Chinook or Merlin. Because it is a tractor, it has no payload of passenger capacity but it is highly mobile, weighs less than 2.5 tonnes and can operate at speeds up to 40kph. It can tow a 2-3 tonnes trailer, a 2,500-litre fuel bowser for example.

The final class of vehicles in this category is engineering plant, and a question; why am I flying engineering plant inside a Chinook? It would certainly be for a niche application, perhaps being flown forward to clear a wooded area for a small Forward Arming and Refuelling Point, repairing a couple of holes in a runway to enable a tactical transport aircraft to land or creating small fortified positions for an ATGW ambush. They might look toy-like but would certainly be quicker than completing tasks with hand tools and muscles. Another advantage of these is the possibility of hydraulic, power and compressed air offload for cutting tools or post drivers.

None of these machines will be configured for road movement so would normally be carried on a trailer. A flatbed or tilting trailer will have to balance bed width against height, placing the load-bed above the wheels maximises available width but will result in a taller loading height. This load height would have to be subtracted from the helicopter internal hold height to arrive at maximum height for the plant, in a space that is already heavily height constrained. A narrower load bed will be lower, thus taller equipment can be carried. Carrying it separately to the trailer might help but that would be very space inefficient and take time at the helicopter landing site.

Because of the height and width limitation, the choice is limited, and they are all light duty. Sit on micro-excavators like the Yanmar SV108 have fold-down roll-over protection which brings the height down to about 1,300mm, so with 400-500mm trailer, just about doable. In addition to buckets, it’s hydraulic jib can use breakers, augers and post drivers. Ride on dumpers like the Wacker Neuson DF105 can be used in conjunction with vibratory rollers and tracked loaders like the Bobcat MT55 for small construction and demolition tasks, the MT55 can also be fitted with a backhoe attachment. Another interesting product is the Struck Magnatrac Bulldozer and Backhoe

Although the above are all under 3.5m long, which means two could easily fit inside a Chinook, if we accept a longer vehicle, but only internally transportable by both Chinook and Merlin, a couple of interesting options become available, smaller pickup trucks and vehicles specifically designed for V-22 internal carriage, so if the Royal Marines are looking for tactical vehicles for the Merlin, the V-22 market is not a bad place to start.

Although it is longer than the 3.5m limit of Category C vehicles by about a metre, Toyota and the RAF demonstrated a double cab Hi-Lux in a Merlin but that is quite a narrow vehicle at just over 1.8m wide, the payload would be relatively limited but it does at least show what is technically possible. A Land Rover 110 or PInzgauer with folding windscreen also fits inside a Merlin.

Ricardo and Polaris have recently demonstrated a militarised Ford Ranger, like the Toyota Hi-Lux above, it would technically be too long for two inside a Chinook, but would be small enough to fit inside a Merlin.

Both of these might even be considered as a Land Rover replacement.

Another impressive vehicle that straddles C and D is General Dynamics/Flyer Defense Flyer 60.

It is 1.52m high and wide, 4.6m long and with a gross vehicle weight of 3,402kg, of which 1,600kg of that is payload. Flyer 60 is available in standard, up-gunned, as a rescue vehicle with stretcher attachment points and even an armoured version which adds basic small arms protection for the crew and passengers. Although it has a maximum speed of 70mph (112kph), at 40kph it has a range of in excess of 500km. The up-gunned version has been demonstrated with 7.62mm GPMG, 40mm GMG and 12.7mm HMG.

Category C has a broad range of vehicles and equipment but they tend to be limited to a specific choice between speed, carrying capacity and terrain accessibility. Weapons carriage is certainly a possibility, as are advanced sensors, communication and C-UAS capabilities. The emerging autonomous support vehicles conveniently utilise the types of vehicle that fall into this class even if they are not specifically designed for helicopter portability. They are advancing quickly with plenty of choice and growth potential, and new concepts of employment will start to be developed where their rapid portability by air offers distinct advantages. And as ever, if one wants to dig holes, clear space and move earth, there are solutions available that are much faster than hand tools.

Category D Examples

Category D vehicles dispense with the dimensional constraint of internal carriage for Merlin but keep it for Chinook, weight remains at 3-4 tonnes in order to be carried as an underslung load by Merlin/Blackhawk/NH90, or two underneath a Chinook. This class of vehicles aligns very well with the US Army Blackhawk/Chinook combination as they do not have a 4-tonne lift helicopter with a cargo ramp like Merlin. Category C vehicles are short, designed to fit two inside a Chinook or one in a Merlin although Merlin has a 6.5m internal hold length. The actual cargo hold height and width of a Chinook and Merlin are not all that different but the 2m ramp width on a Merlin is the constraining dimension even though the hold is wider. The Chinook ramp with and the cargo hold is 2.3m wide. Moving the width of the vehicle up to 2.2m to 2.3m means a vehicle can technically fit inside a Chinook but not a Merlin, although it would be a ridiculously tight fit, a 2.16m wide HUMVEE fits, just, but would you want to? When vehicles are so close to the constraining dimension, time to load and unload becomes a factor, escape routes for the crew, and protrusions such an antennae mounts start to be an issue.

Category D, therefore, sets the constraining width to be 2.1m and a slightly higher maximum height of 1.9m. Maximum length is set to the length of a Chinook cargo hold at 9m, although shorter vehicles will allow multiples or a trailer or artillery weapon to be included. Most Land Rover, Pinzguaer and pickup truck type vehicles are about 2 to 2.1m wide and 1.8 to 2m high, making them possible inside Chinook but certainly snug. The later WMIK Land Rovers would be just slightly overweight for this Category which would put them at the outer edge of practicality for Merlin external loading but two would be well within limits for Chinook.

In 2019, the US DoD selected Ricardo/GM Defense, SAIC/Polaris and Oshkosh/Flyer to build a number of prototypes for the US Army’s Infantry Squad Vehicle requirements. The GM entry was based on their 2020 model Chevrolet Colorado ZR2 and ZR2 Bison, Polaris with their Dagor vehicle, and Oshkosh with the Flyer 72 (built previously by General Dynamics). GM Defense won the competition and have been awarded a $214 million contract to build the first 649 vehicles of a total requirement in excess of two thousand. It makes use of a high proportion of commercial components, designed to keep through life costs down and is designed for UH-60 underslung and CH-47 internal carriage, uses a 2.8L Duramax diesel engine. The rear cab rollover protection is folded down for transport.

The losers of the ISV competition are equally impressive, and arguably more mature, with a greater number of variants and equipment integration. Both the Flyer 72 and Polaris DAGOR have similar specifications to the GM Defense ISV, with the former already being in service under the Ground Mobility Vehicle 1.1 guise. It has been demonstrated with a variety of weapons including the 30mm M230LF. With a top speed of 153kph and maximum range of in excess of one thousand km at 40kph, it has a gross vehicle weight of 5,080kg, of which 2,585kg is payload.

Based on their four-wheel steering GRF 5.12 platform, the Dutch company Defenture have developed the Air Transportable Tactical Vehicle for the Dutch special forces. Its width if 1.8m and transport height, 1.87m. Jankel offers four vehicles based on either the Land Cruiser or Hi-Lux platforms in two or three-axle variants, with the FOX Rapid Reaction Vehicle in service with Belgian special forces.

Also from the UK, the Supacat Mk2 LRV 400 and 600 are based on commercial components, in this case, the Land Rover Discovery. At 1.7m wide, it is slightly narrower than many others, which makes loading and unloading from a Chinook much quicker and arguably, better suited than others which only just squeeze in. Kerb weight is 2,500kg with a payload of up to 1,700kg. Maximum range is 800km and it can be converted into 6×6 for additional payload, this variant has a kerb weight of 3,150kg and payload of up to 2,350kg.

We should not forget in-service vehicles either.

There are numerous models and revisions of the Land Rover in service; short and long wheelbase, winterised/waterproof and not, fitted for radio and general service and with different engines. Payload is approximately 600kg and the short (Truck Utility Light (Higher Specification) – TUL(HS)) and long wheel-base Truck Utility Medium (Higher Specification) TUM(HS)) variants weigh 2.7 tonnes fully laden. The Truck Utility Medium (Higher Specification) TUM(HS) Revised Weapons Mounted Installation kit (R-WMIK), weighs approximately 3.8 tonnes fully laden although later models take this up by two or three hundred kilograms, at the margin for Merlin. The video below shows a Royal Marines WMIK being loaded and unloaded into a Chinook

There are also various combinations of hard and soft top Pinzgauer vehicles, maximum payload is approximately 1.4 tonnes, 2 tonnes for the three-axle. Truck Utility Medium (Heavy Duty), two-axle, approximately 4 tonnes fully laden. These are also used to tow the L118 Light Gun when lifted together, weighs approximately 5 tonnes with a maximum of 6 tonnes if more ammunition is carried. Pinzgauer 6×6 TUM (Heavy Duty), three-axle, approximately 5 tonnes fully laden.

What characterises many of these vehicles is that the kerb and fully loaded weights straddle the Merlin weight limit. Empty, they are by and large within sensible limits, but transporting them fully loaded is going up against or over the weight limit for Merlin.

Category E Examples

Category E dispenses with the internal carriage for BOTH Merlin and Chinook but remains at the 3-4 tonne limit for Merlin underslung load and two with a Chinook. What this means, for the most part, is the ability to carry as an underslung load Category C ATV’s and other vehicles that are too tall because they have sensors, weapons or logistics equipment.

The GKN FuelCat variant of ATMP is a good example of this. They operate in pairs, one vehicle contains a generator, pumping equipment and fuel tank, and the other, a crane and trailer for another fuel container and pipelines. Between the two vehicles, they can carry 4,000 litres of fuel, pump it to multiple aircraft simultaneously and, provide aircraft towing and a gas turbine starting rig. GKN also make the Air Portable Fuel Containers, currently in service in the Mk5 guise. The balloon-like, Kevlar-reinforced, containers, can hold up to two tonnes of fuel. When full, the containers are 1.37m in diameter and can be towed, slung load under a variety of helicopters and parachuted from tactical transport aircraft. Quantec AWD has developed a refurbished ATMP design with either a 2 tonne Palfinger hydraulic jib and manual outriggers, and 4 person rollover protection frame, both of which make it too tall for internal carriage,

Although this might be verging on the heretical, there are Bandvagn206 alternatives for the Royal Marines that fall in this category. Apart from putting ‘over-wheel’ track kits om a Class C ATV, there are small tracked only vehicles from a number of manufacturers. Most of these tend to be too tall for internal carriage unless a folding cab of some sort was engineered. For the purpose of this section, no modification is assumed. Also, as with Category D, some of them straddle the weight limits of Merlin when loaded and unloaded.

The Canadian Alltrack AT-20HD has a kerb weight of just over 2,700kg but with a payload of nearly 1,600kg, has a gross weight of 4,309kg. I have included it here as an example, as is the UK manufactured Loglogic Softrak 75, one of which is actually in use as an MoD range vehicle. It has a kerb weight of 2,550kg and a payload of 2,000kg, with hydraulic and hydrostatic power take-off should it be needed. With a top speed of 16 kph, it would take some to cover any distance but with a ground pressure of less than 2PSI, it’s terrain accessibility is excellent. It can use a tracked or wheeled self-loading trailer and is available in a couple of larger sizes. The load body can be replaced with a tipping body or 8 seat crew pod (in addition to the three seats in the cab). It can also be fitted with a demountable cargo module, akin to a manual DROPS style arrangement. Another small tracked carrier is the 8 seat Pioneer from UTV Canada.

Dipping back into the agricultural and municipal maintenance markets there are a handful of vehicles that could also be used to meet logistics needs rather than carrying personnel. Again, put aside the embarrassment of driving bin wagons and glorified sit on mowers, the numbers are actually quite impressive. First up is the PK600 AWD from Grillo in Italy, with a tipping load body that could comfortably carry a NATO standard pallet it weighs in at 1,150kg yet has a payload of 900kg, with a maximum speed of 40kph

The Hako Multicar M27 is actually the base vehicle for the KMW Mungo, in service with the Heer. It has a maximum speed of 80kph and a 2 or 4 wheel drive option. Unladen weight is 2.2 tonnes with a payload of 2.3 tonnes

Both of these are quite narrow, and with some engineering work to create a folding rollover protection system, could easily qualify into Category C i.e. internal Merlin carriage.

Removing the dimensional limitation opens up a much broader range of engineering plant, although the vast majority would still need a trailer and towing vehicle to progress more than a very short distance from the landing site. Some of the in service ultra-light equipment dump trucks and excavators from JCB and Terex would be an easy lift for Merlin. Apart from that though, there isn’t a great deal, most of the air portable equipment assumes Chinook underslung, not Merlin. There are options, of course, the global construction and agricultural markets have a wide range of excavators, wheeled loaders, dump trucks, telehandlers and backhoe loaders. Assuming 500kg for a trailer, examples include the JCB 1CX backhoe loader, Ausa T144 telehandler, Bobcat T450 tracked loader, MCM Compact Dozer, Norcar A7545 tracked articulated loader and MultiOne Series 10 articulated loader

Again, these are all light duty machines.

Category F Examples

These would be a vehicle between approximately four and eight tonnes 8 tonnes that can fit inside a Chinook. Many of the vehicles in Category D would move into this one once fully loaded.

The ISV majors on seating, it has 9, with no space for pallets or anything other than personal stores. The Flyer 72 has been developed to address this gap with the Flyer 72 Tactical Utility Vehicle in a number of proposed variants. The additional weight pushes it beyond Merlin/NH90/Merlin undersling load capacity but it retains dimensional compatibility with Chinook internal carriage (except for the shelter version). Two are also possible to be carried as an underslung load by Chinook but this would be pushing towards the 9-10 tonne limit.

The Supacat HMT/Extenda is also Chinook internal possible, although the images below show just how marginal that is.

A final example vehicle in this category is the well known Rheinmetall Wiesel, equally as snug, but demonstrably possible.

The first video above shows a folding weapons mount on a prototype vehicle to meet the US Army’s now cancelled Light Reconnaissance Vehicle requirement, the vehicle is the larger Wiesel 2 (larger and with an extra road wheel). The end of the second video shows a Wiesel 1 being loaded and unloaded into a US Army Chinook. Wiesel 1 is smaller and thus an easier load for Chinook internal carriage but whilst more challenging, Wiesel 2 is certainly possible. The Rheinmetall Wiesel 2 is a slightly larger version of the original, with an extra roadwheel. The family of vehicles includes a Light Reconnaissance Vehicle, air defence systems, command post, ambulance, mortar and personnel carrier. Depending on variant, the original weighs up to 4 tonnes and the Wiesel 2, no more than 4.8 tonnes. They have also been used in umanned trials and as a carrier vehicle for C-IED ground penetrating radar.

Whenever Wiesel is mentioned, so must CVR(T).

CVR(T) is old and heading out of service as Ajax enters but we have seen over the years that CVR(T) has been used a number of times as light armour and one wonders if with the same attention as Wiesel, whether CVR(T) could get a second life as an air mobility focussed vehicle. It is compatible dimensionally with Chinook internal carriage, just? Perhaps there is zero life left in them, but still a food for thought.

There are a number of the military specification pickup trucks that keep within the Chinook internal carriage dimension but go over 3,500kg when loaded, some by a good margin, most of these being extended loadbed 6×6 conversions. The Pickup Systems Toyota conversion has a gross vehicle weight of 5,500kg including a payload of 3,200kg.

Category G Examples

The final category also dispenses with dimensional constraint and would be as an underslung load only for a Chinook.

This Category would potentially be compatible with MRV-P, at least the Group 1 vehicle, when and if this gets ordered, and would also include all variants of Jackal and Coyote already in service, and Panther, Pinzgauer and Land Rover for good measure. It also includes a number of C Vehicles like the telehandlers, light wheeled tractors, multi-terrain loaders and site equipment.

It would also include the heavily loaded and/or larger variants of some of the pickup-up truck-style vehicles described above, a sensor mast or ambulance body for example. In many ways, there is less value in this category as underslung loads at larger weights will severely restrict helicopter performance and tie up a valuable helicopter for a single vehicle. The UK has a decent number of Chinook’s but they will always be in high demand. Still, worth a look at vehicle types beyond those already in service.

The Rheinmetall Wiesel 2 and Mungo combination an obvious pairing.

The KMW Mungo is actually based on the Hako Multicar 30 municipal maintenance vehicle like those described above. The ESK variant has a maximum weight of 5.9 tonnes and can carry 10 personnel and their equipment a total distance of 500km with a top speed of 90kph. Designed for carrying cargo, the Multi-Purpose Vehicle has a payload of 1.5 tonnes and uses a skip loader rather than a hooklift in order to reduce height. The High Capacity variant has STANAG Level II protection and provides a protected volume for command and control personnel, and the final variant, the NBC Recce.

Back on engineering plant, Chinook has been cleared to carry a number of pieces of equipment as an underslung load.

These are all relatively light-duty and other options might be useful. The Unac TNA is a good example, the UK’s equivalent, a Caterpillar M105 Deployable Universal Combat Earthmover (DEUCE) used in deployable airfield engineering, weighs just over 16 tonnes, fine for tactical transport aircraft but not Chinook, unlike the TNA, which weighs just under 7 tonnes. The capacity of either machine cannot be the same but this shows how weight limits might influence equipment decisions, or we could just accept a lower speed and get a Cat D4K2 or one of the larger hybrid skid steer loader/dozers that are now on the market and paint them green.

The Bv206 is an extremely versatile tracked articulated amphibious vehicle and with a ground pressure of less than 14kPa/2PSI, highly mobile. The basic vehicle weighs approximately 4.5 tonnes and with a maximum payload of 2.2 tonnes or 12 personnel and their personal equipment, and can be an underslung load for Chinook. It can also be carried on the LCVP Mk5. The Royal Marines Bv206D is generally used for non-protected mobility tasks, logistics, mortar carrier and communications, they are exceptional machines with a very long pedigree, but will eventually need replacing. Replacement programmes seem to have come and gone with some regularity but given the market size, and active integrator market, hard to see this happening. The larger and protected Viking (BvS10) can also be carried as an underslung load by Chinook. BAE has proposed the BvS10 Beowulf as a replacement for both, it has a Gross Vehicle Weight of nearly 16 tonnes although unloaded, the front and rear cars can be separated for air transport. This would be far from ideal though, it is a time-consuming process, although unloaded, it would be possible to use a Chinook. If the Royal Marines wanted to depart from the Bv206 market and look at alternatives, yet still inside the sling load limit, there are a number of models available that are more compact, and have greater payloads, although none of them would be protected like the BvS10. At 8,000kg gross weight, the UTV Achiever RT-04 has a 4,000kg payload, just one example from many available might need some insulation though!

The final set of vehicles in this category is light trucks, and 6×6 conversions of pickup trucks, all of which tend to go over Merlin lift and Chinook dimensions. Australian Patrol Vehicles, 6×6 Australia and Multidrive being good example of pickup conversions. Closer to home, there are a number of commercial vehicles that have good mobility and load carrying capacity, including the Ibex 6×6, made in Yorkshire.

Based on the Iveco Daily 4×4, the Military Utility Vehicle (MUV) is available in a number of cab configurations, and even a minibus. Depending on configuration gross vehicle weight can be up to 7,000kg. The Dutch company DMV also uses the Iveco Daily platform, the latest version being the Anaconda, entering service with the Royal Netherlands Marine Corp, it has a gross vehicle weight of up to 7,100 kg with a payload of 3,000kg. A number of configurations are available.

The Iveco Daily 4×4 has a very large user base and has been widely adapted in the defence and utility sectors.

Urovesa (Spain), Bremach (Italy), SCV (Italy), Oberaigner (Germany) and Auchleitner (Austria) all have similar vehicles to the Daily, between 4 and 8 tonnes gross vehicles weight.

As well as these more established ‘trucks in green’ are some interesting agricultural and municipal vehicles to look at from Alke, Hako, Exelway, Ladog, Caron, Aebi Schmidt and Reform. The Unitrac 72 from Lindner weighs just under 3 tonnes empty and yet can have a maximum payload of over 4.5 tonnes. It also has a number of hydraulic tool attachment points, four-wheel steering, Perkins diesel engine and can have a tipper body fitted. An interesting feature of the Unitrac is its ability to quickly de-mount its load bed, like a European swap body container. The larger Unitrac 1 12 L Drive is 5.07m long, 2.08m wide and 2.47m high. With an empty weight of 3,475kg, it has a maximum payload of just over 6,000kg. It can also tow a maximum weight of 10,000kg. AEBI make a similar range of vehicles, the VT450 for example. These are versatile vehicles that generally fall under 10 tonnes maximum weight and all have multiple tool attachment options such as loading jibs, tipping bodies and hooklifts. For snow and soft terrain, they can also be fitted with tracked wheel replacement units.

Back in green, General Dynamics and Pratt and Miller to develop the TRX, just under Chinook underslung load limit.

And finally, just for fun, the Gibbs Phibian is a vehicle, and light enough for a Chinook underlung load.

Summary and Thoughts

The categories above are not completely arbitrary but do have soft boundaries in some cases, one vehicle might move between them based on how much load is being carried, or they might be possible to lift but would degrade aircraft performance so much it would only be an exceptional use case. Hopefully, you can see how complex this subject is, all the above are the estimations based on open source information, there are many reasons why one vehicle or the other would not work in the category, and as always, we have to ask why would we bother.

Also, for most of these classes, one gets into a wider discussion about replacement programmes, want a 3-5 tonne vehicle for light role mobility, you have to discuss the eventual replacement for Land Rover and Pinzgauer. Something heavier but under 10 tonnes,  that is MRV-P Group 1 territory, even things like the venerable Bv206 replacement runs into a discussion about what the future role of the Royal Marines before we even think about vehicles. The simple fact though, is that many of the current vehicles are looking at the end of their service lives, so we really should start discussing replacements. Plus of course, the elephant in the room of funding.

For what it is worth, I do think 16AAB needs to be more mobile on the ground, and why would you not peg that to Chinook, the same with the Royal Marines, but there, I would focus on Merlin, not Chinook. Light Role infantry also needs to be more wheels and less shank’s pony. Certainly, all of these can make better use of quads and motorcycles, the equipment options are all there. I have avoided discussion on weapons, but I think we should be careful about festooning them with too much direct fire equipment; Exactor and Brimstone, mortars and artillery, anti-aircraft and C-UAS can all be mounted on this class of vehicle, and the emerging concepts of employment for armed UGV’s look extremely interesting.

Finally, I would urge anyone looking at this subject to look beyond the traditional defence primes, there are loads of manufacturers out there with interesting and high-performance vehicles, even if they are used more to spray manure or shift oil drilling equipment.

Right, off for a spin, see you in the comments…

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Orlok
Orlok
October 15, 2020 9:24 pm

An interesting vehicle that looks like a lot of fun by maybe difficult to adapt to military use is the Russian Sherp. Full amphibious, genuinely all terrain and can carry 1ton load.

Jed
Jed
October 15, 2020 11:53 pm

Excellent and very thorough update!

Deja Vu
Deja Vu
October 16, 2020 8:16 am

Great Article.

There has recently been a tweet about Royal Marines doing a course on using ponies for load carrying.

Thinking outside the box here.

Last edited 11 days ago by Deja Vu
ArmChairCivvy
ArmChairCivvy
October 16, 2020 10:48 am

Thanks, TD!

if with the same attention as Wiesel, whether CVR(T) could get a second life as an air mobility focussed vehicle. It is compatible dimensionally with Chinook internal carriage, just? Perhaps there is zero life left in them, but still a food for thought

  • they did get the attention, abt in 100 copies, but the weight went up by a lot… are any of the versions still “Chinook liftable”?

The other thing that might also be in the margins for this topic is that the Bundeswehr got offered a 50% up-powered Chinook as their CH53 replacement; don’t know if anything came of that (and our 16 new are differently specced)

  • but regardless, one avenue to consider. While I fully agree that going up in armour (from what was already covered) or in direct fire weapons will soon start to defeat the whole purpose
Andy
Andy
October 17, 2020 12:58 pm

“The contract was worth £3.3m but only 15 vehicles entered service and have all since been disposed of.”

The number of times I see this! No wonder the British Army/MoD is broke and still having kit shortages and personnel still have to cope with a “make do” attitude.

S O
S O
October 18, 2020 10:46 pm

TD, I think you missed the one interesting point on heliborne motor vehicles.

Helicopter-mobile vehicles were mostly a dud for the tasks that you seem to think about. Motor vehicles were already moved by cargo gliders in WW2 and were no game changer in airborne ops.
There was AFAIK one significant success for vertical heliborne envelopment in Ogaden during the 70’s, but its effects would have been feasible with a simple overland convoy as well.

Helicopter-carrier motor vehicles are hugely promising in alpine/mountain warfare. That’s a niche that they could actually shine in. All the flatlands air mechanization dreams have in my opinion proven to be

  • silly dreams of non-establishment authors

AND

  • a racket of the establishment to get funding for gold-plated helicopters to play with well beyond the actual needs

That’s how it played out in Germany: Sci-Fi air mechanization concepts that were obviously impractical (while inspired by that forward helo base in ODS) were dropped almost immediately once the funding for army NH90 and Tiger helicopters was secured.

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