The final part of this article on a concept for a lightweight version of the current Strike Brigade concept is to look at the vehicles that it would comprise of. The conflicts in Iraq and Afghanistan have diminished interest in lightweight vehicles simply because protection, rightly, had a greater priority than mobility. Nothing at all wrong with this but as the focus is returned to operations in Europe and Africa, mobility is somewhat back in fashion, or at the least, a more realistic balance between mobility and protection.
The British Army is also currently in progress with the Multi Role Vehicle (Protected) which, looking at the headline specifications, might fit within Category E but given their roles and likely weights, I am not going to specifically look at the contenders, will do so in a separate article.
A recap on the categories from the previous section.
|Category E||2.34m-4.0m||2.28m-3.85m||Not specified||10,000kg|
Example vehicles types…
Quad Bikes and Motorcycles
Quad bikes (ATV’s) and motorcycles meet the requirement of Category A. A quad bike with a trailer, Category B
There are recent artucles on both motorycles and quad bikes so will not repeat them here.
Quad bikes are derived from civilian vehicles, market mass is therefore able to drive down costs and support innovload carrier ation but there are some interesting ultra-lightweight vehicles long since out of service that were specifically aimed at military markets and might provide some measure of inspiration for modern versions, usually because they have features unlikely to be found on civilian designs.
The Faun Kraka could carry a 900kg payload and was in German airmobile forces service from the mid-sixties to the early nineties. The loading area could be used for stores, radio rebroadcast equipment, stretchers or used as a weapons mount; a recoilless rifle, TOW missile launcher, Milan missile post or Rh202 20 mm autocannon for example. One of the unique features of the Kraka was its ability to be folded, this made air transport easier.
From France, the Lohr Fardier was slightly smaller from the Kraka but had a similar role. With various components from the 2CV and other Citroen vehicles it was originally assembled in Belgium. Like the Kraka, it can be used as a cargo vehicle, weapon post or stretcher carrier but unlike the Kraka, it is still actually in service and available for purchase, from Soframe. It can tow up to 800kg.
The M274 Mechanical Mule entered US Army service in the late fifties and did not leave until the late eighties. Like those above, it was a versatile load carrier (400kg) designed to carry or mount a variety of equipment. Its unique feature was the ability to move the steering column so it could be operated whilst the driver was crawling behind it. They cost very little and their low height meant they could actually be carried internally inside a Huey, manhandled out on landing.
All of the above vehicles fit within the B Category which means they can be lifted by a Wildcat, two by a Puma or four by a Merlin. Because of their low height they are also extremely space efficient, simple, reliable and all of them cost peanuts. The unique military features like ability to fold or movable steering column demonstrates the thought that went into their design. One could make a reasonable argument that they are superior to a quad bike and trailer. The Italian manufacturer, Fresia, produce the F18, a modern day equivalent to the Mechanical Mule, with a similar specification.
All these vehicles a way of providing mobility for light role forces rather than as tactical fighting or patrol vehicles but they allow those forces to exploit lighter helicopters, Wildcat and Puma for example.
What about the UK?
In 2005 the MoD contracted with Roush Technologies Ltd to design and built an ultra-lightweight all terrain load carrying vehicle that could be slung load by a Lynx helicopter and internally carried in a Chinook, the programme was called Harewood with the resultant vehicle known as Balter. The contract was worth £3.3m but only a very small number of vehicles entered service, less than 15, the vehicle itself was pretty impressive though.
First, it used a diesel engine so no messing about with petrol. With ECM protection, standard NATO compliant electrical system and an engine that can use diesel, JP8, JP5 and B20 biodiesel, the LAS100Re is a fully militarised vehicle, not an adaption of a civilian type. Second, it could carry 1,000kg and yet weighed only 800kg because of its low weight aluminium honeycomb construction by Lola Composites. A lightweight trailer could be used to increase the payload by another 600kg. Third, it has excellent mobility, 6 wheel drive, an approach angle of 81 degrees and could be internally carried on Chinook and Merlin whilst being slung load by a Lynx. In 2007 Roush developed the concept into a 2 seater with a load bed shelter, the engine was uprated to a 1.4-litre turbocharged direct injection diesel engine developing 50 kW and 160Nm of torque. The fuel system could accept Diesel 1 and 2, JP8, JP5 and B20 bio-diesel, and top speed was increased significantly. They were fitted with C-IED ECM equipment (Balter) and it was even considered for the Springer requirement.
Again, a dedicated military design produces features not found on civlian derived equipment, unfortunately, they have all been disposed of although they are still listed in the manufacturers website.
Multi Wheeled Skid Steer
With no suspension but 6 or 8 wheels, the skid steer all-terrain vehicle has also been available in both civilian derived and bespoke military designed versions. The most obvious is of course the Supacat All Terrain Mobility Platform (Think Defence long read on it here)
ATMP is a 6×6 design that used low-pressure Terra-Wrangler tires, and with a ground pressure of 0.2 kg/cm, it was highly mobile. 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, maximum loaded weight of 1.6 to 1.8 tonnes, limited amphibious capability, a top speed of 65kph and 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. A simpler platform could also be used to decrease time to rig and de-rig, this was called the ‘oversill’ scheme. Given the length of time the ATMP had been in service, all necessary Joint Air Transport Establishment (JATE) clearances were obtained, including various combinations of slinging and air drop with different aircraft. The 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 sling load and even the Blackhawk were certified. Multiple stacking options also exist for carriage in larger aircraft such as the C130 and C17.
The second focus area was cargo handling. Using 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 driven away. To increase carrying capacity a pair of specially developed trailers were also introduced, the FLPT (Fork Lift Pallet Trailer) and SLLPT (Self Loading Lightweight Pallet Trailer). Although there are a number of variations, the basic trailer had a hydraulic tipping mechanism and pallet forks. The driver would simply tilt the trailer into the down position, reverse onto the pallet, tilt the trailer back up, and drive away. Maximum payload for the ‘flipit’ trailer was 1,400kg and it could also be converted to carry three stretchers. Demountable corner posts could also be used to form sides for loose loads, with ratchet straps used to secure the load. Conversion took only a few minutes and the posts were carried on the trailer. In addition to clearing landing sites, the ATMP was also used for towing the L118 105mm Light Gun complete with ammunition trailer, total carried and towed payload being in excess of a whopping 3,500kg.
Because the basic design was so versatile, it was modified and used for a number of different applications. A number of hard or soft cabs, winches, hydraulic jibs, ambulance, recovery, firing posts, firefighting equipment and even a track kit to improve mobility were available. It was also used for unmanned autonomous trials.
The final ATMP version of relevance was the GKN FuelCat. GKN 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. This was a system designed to support Forward Arming and Refuelling Point (FARP) operation for helicopters and fixed wing aircraft. One vehicle contains 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.
Deployments included Kosovo, Iraq (both outings) and the early stages of Afghanistan. They were in fact, a direct result of lesson learned during the Falklands Conflict, specifically a lack of all-terrain mobility for light forces, especially their artillery support. Mostly out of service, one is still used to support the Royal Navy Maritime Autonomous Trials Team (MASTT).
One (light loaded) can be carried by Puma, two by Merlin or one fully loaded by Merlin. It is also internally carriage possible by Merlin and four can be carried by a Chinook if two are carried inside and externally. It is hard not to be enthusiastic about the ATMP, simple, versatile and with all the relevant clearances in place, relatively easy to bring back into service. A new engine would probably be needed but the fundamentals remain, especially the cargo handling which is easily unsurpassed by anything else currently available.
Despite the many qualities of the ATMP, in the interests of looking at alternatives, the MoD is currently trialling the Hippo-X from Multipower, supported by Pardus Defence and Security. Multipower is a US manufacturer of mobile power systems and Pardus is a former soldier and commander of the UK Infantry Trials and Development Unit (ITDU).
Neither manufacture the Hippo-X, it appears to be a Mudd Ox XL but in the marketing literature for the Hippo-X there is a description of the power export capability which one would assume is by virtue of the Multipower system. Specification seem 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 would appear to be better suited in this area and 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. An unmanned version is also being trialled, in conjunction with Pearson Engineering and Torc Robotics.
Where the ATMP would seem to be more capable and versatile is cargo carrying and the maturity of the various options and clearances. It would certainly be interesting to see an ATMP with a similar power unit and a side by side trial conducted in scenarios that cover the infantry mobility support and logistics roles.
The MXI Buffalo Trucker is a 6×6 amphibious unit with a tilting load bed, 500kg payload on a 500kg highly durable polyethylene 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, now owned and produced by LMT Holdings. It weighs 1.2 tonnes, can carry 900kg and pull a 1 tonne trailer.
There is certainly no lack of choice and most confirm to the Category constraints.
In addition to the ATMP and Hippo-X unmanned conversions described above, both Land Tamer and Argo have also created unmanned variants. The Squad Mission Support System (SMSSS) is actually a Land Tamer base vehicle and Argo have a complete line of 2, 3 and 4 axle unmanned platforms for use in industry, mining and defence applications.
I remain scpetical of these unmanned platforms but it will be interesting to see how they develop.
Side by Side ATV’s
This type of vehicle has seen a great deal of interest and uptake in the last few years with the market evolving from modest adaptations of agricultural machines to much more specialised military designs.
The early adaptations were from agriculture and outdoor management industries; John Deere, Kawasaki, Polaris, Can Am, Yamaha and Arctic Cat for example. Finding one with the specific payload and weight range is not that easy but the John Deere HPX for example, has a 600kg payload with an empty weight of 700kg. In common with all these side by side ATV’s, the load bed is not particularly large. The larger XUV 855D has a diesel engine, weight of 770kg, payload of 635kg and towing capacity of 680kg. A number of the 3 axle variants have been used by various forces in Afghanistan. JCB produce a military version of their Workmax all-terrain vehicle which has a payload of 600kg with an unladen weight of 900kg but they no longer produce them.
Some of the category boundaries are quite close, height for example, but some of the vehicles can have parts collapsed to reduce height for carriage.
These are popular designs but might struggle in extreme terrain (although they may be fitted with wheel replacement type track systems) and have a fairly low payload, they are more people carriers than cargo carriers.
The US Army is currently in progress with its unmanned Squad Multipurpose Equipment Transport (SMET) programme. Polaris, ARA, and Neya Systems have submitted an optionally manned version of the MRZR platform, General Dynamics with its multi-utility tactical transport (MUTT), HDT with the Hunter WOLF (Wheeled Offload Logistics Follower) and Howe and Howe with the RS2-H1.
It must be said, none of these have a particularly high payload.
Agricultural and Municipal Vehicles
If we can get over the fact that this type of vehicle is normally to be found shifting manure and mowing grass, there is potential, after all, the uber-cool Polaris MZR’s have their roots in vehicles used for maintaining golf courses and going duck hunting!
Caron make a series of articulated load carriers, the smallest of which is the EVO 4 Series 100. The roll bar is foldable so it could easily be lower than the 1.8m needed for internal Merlin/Chinook carriage. It is powered with a diesel engine (not petrol like many ATV’s) and equipped with tipping load bed that can take a standard NATO pallet and PTO if needed, the best of this vehicle is the payload figures though. Unloaded, it weighs 1,460kg but can carry 2,040kg and tow up to 5,600kg. The larger Series 600 can carry up to 3,300kg payload and tow 5,600kg. So they might look like a cross between a sit on mower and tractor, but it they are real load movers, not very fast though. The Grillo P600 AWD weighs 1.8 tonnes and can carry 1.8 tonnes, at 1.5m wide, it can be carried inside a Chinook or Merlin, as long as the cab was foldable.
Don’t look at how uncool they look, look at the spec sheets.
The Unitrac 72 from Lindner, with a folding cab, could be internally carried by a Merlin or Chinook, 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.
The Group Vehicle weighs 5.3 tonnes and can carry 10 personnel and their equipment whilst being small enough to fit inside a CH-53 or Chinook. 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 Large Capacity variant has STANAG Level II protection and is slightly heavier at 5.9 tonnes and the final variant, the NBC Recce.
Pickup trucks, Vans and Land Rover Style Vehicles
As we move into this vehicle category the choice expands dramatically.
First of course, the iconic Land Rover Defender. Numerous models and revisions of the venerable vehicle, short and long wheelbase, winterised/waterproof and not, fitted for radio and general service and with different engines, the basic types are below. 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 ambulance (Ambulance Battlefield (Higher Specification)) is slightly heavier, approximately 3 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.
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. Filling a Pinzgauer shaped shoe is a tough job, simple, reliable and highly mobile they have served in numerous conflicts with great distinction. Ricardo have proposed a number of solutions that replaces the engine and transmission with an Iveco engine and DC722 transmission, upgrades the electric system and increases payload to 1.5 tonnes whilst adding basic mine and ballistic protection.
The Bucher (now General Dynamics) Duro is used for satellite communications equipment carriage. The base vehicle weighs approximately 4 tonnes. The bearer modules also a similar weight.
They would fall across Category C and D
All these are in service and could be selectively upgraded as needed, they would probably make the Light Strike Brigade cut quite easily. The problem of course, as we all know, is that neither the Defender nor Pinzgauer is in production so there is an expiry date for them.
Toyota, Ford and Isuzu pickup trucks are an obvious alternative and can be discretely armoured by many systems integrators such as Jankel and Penman. They can also be carried internally in a Merlin/Chinook and fit easily within Category D. Supacat have taken the Land Rover Discovery drive train and created the LRV400 and LRV600 reconnaissance vehicles. With a slightly reduced payload, the LRV400 sits at Category C and the LRV600 at Category D, the former liftable by Merlin and latter, by Chinook. Both could fit inside a Chinook. Ovik Crossway have a number of options, including the Crossway vehicle
Not as well-known as some of the above, the Brazilian Agrale company make several Land Rover style vehicles. Achleitner make the Volkswagen Geson, Speedfighter and Mantra vehicles, available in single and double cab designs. An Austrian engineering and automotive production ﬁrm called Oberaigner use Mercedes Sprinters to create off road versions. Their 6×6 Sprinter has the loading height of a standard Sprinter but with it’s twin rear axle the maximum weight is 7000kg. This gives a payload of the best part of 4 tonnes.
The Iveco Daily 4×4 is a versatile platform, Oviks created the Cameleon. The Cameleon is certainly a low cost option but it is nonetheless innovative and reliable. The UK manufacturer, Ibex, make 4×4 and 6×6 vehicles with double, single and crew cab configurations. Quantec AWD in Devon have recently launched a walking beam 6×6 Defender.
Other Light Trucks
The next obvious choice is a Mercedes Benz Unimog
The Unimog is available in two major variants, the implement (or tool) carrier and the all-terrain, each having a number of models and options. The implement carrier can be fitted with numerous attachments for many different industries and the all-terrain is optimised for load carriage in difficult terrain.
Both would be pushing the 10 tonne boundary when fully loaded but I wanted to include them to demonstarte the extent of similar light vehicles, and of course the lightest of MAN SX/HX SV currently in service would also be around that area.
Supacat HMT Family
Getting into a more military oriented family of vehicles, the Supacat HMT family has quite a long heritage and has achieved great success with a number of nations in addition to the UK. Although the HMT is a family of adaptable vehicles the two main versions are the HMT400 and HMT600, called Jackal and Coyote in UK service.
With a payload of 2.1 tonnes the Jackal has a maximum weight of 7.6 tonnes. The Extenda is a version designed specifically for Sf use and internal carriage in Chinook with the ability to add a self-contained third axle unit to extend the length. The HMT platform has also been used for a number of variants, none of which entered service, the Soothsayer ECM system, GMLRS and 155mm M777 portee.
All of the HMT vehicles would be broadly defined as Category D or E.
All of the vehicles above are wheeled, and although some can be converted into ‘tracked like’ vehicles with the addition of tracked wheel replacement units if one wants extreme mobility in the softest of ground tracks are the obvious choice.
3CDO in particular has a problem here because the Merlin cannot lift a Viking even if it is split apart and in order to lift their relatively old Bv206’s, they need to split. This of course means the two halves of the vehicle have to be manoeuvred and linked together once on the ground. A Chinook can lift a Bv206 in one piece but given a Chinook is not common at sea, and not optimised for carrier operations (blade folding etc.) it might be a good idea to seek alternatives. The Royal Marines have been in the market for a Bv206 replacement for some time but the programme seems like many to be continually extended, recast and delayed. Many seem to assume the BAE Beowulf would be the natural replacement but are there alternatives that address the Merlin transportability issue, given it weighs 15.5 tonnes?
The British company Loglogic make a range of compact tracked all-terrain vehicles, some of which are actually used by the MoD on range management duties. The Softrack is slightly too wide for internal carriage but with narrower tracks and a collapsible roll cage/cab would fit easily. It weighs 2.2 tonnes and can carry 2 tonnes. The Larger Softrak 120 weighs 2.9 tonnes and can carry 2.4 tonnes.
Alltrack and Track Industries, both from Canada, produce a range of tracked high mobility work vehicles. The Track Industries HT 40S weighs 5.4 tonnes and can carry a 1.8 tonnes payload, enough for a single NATO ammunition pallet, although this would not be sling load carried by a Merlin. The larger HT 60WB weighs 9 tonnes, but has a 4.1 tonnes payload.
The Alltrack AT 20HD is only 1.5m wide and weighs 2.1 tonnes but can carry a 1.1 tonne payload. The larger AT-50HD weighs 3.8 tonnes and can carry a payload of 3.2 tonnes, two NATO ammunition pallets in a basic vehicle that can be sling loaded by a Merlin (or two with a Chinook) and carried internally in either. The largest model, the AT-150HD can carry a 15 tonnes payload in a footprint no longer than a BV206, it can also be internally carried inside a C-130 Hercules without preparation. These are excellent machines.
With an emphasis on amphibious capability, the 2.6 tonnes Hydratek D24488B can carry a 1.4 tonne payload.
All these manufacturers eschew the articulation and twin cab approach taken with the Viking and BV206.
Other manufacturers of tracked all-terrain vehicles for use in demanding terrain include Lynx Technologies, Gilbert, Pinroth, UTV, Fecon and PowerBully. Some of these exceed the maximum weight constraint but included for information and to demonstrate that there is plenty of choice for those seeking all terrain mobility.
What characterises all these designs is a complete lack of protection, instead, they focus on mobility and payload, as might be expected for civilian equipment.
There are very few sub 10 tonne tracked combat vehicles, the two most notable are the UK CVR(T) and German Wiesel families of vehicles.
The new CVR(T) Mlk2 vehicles go over the 10 tonne limit and their future is uncertain, seems likely they will all go out of service as Ajax enters. Whether the UK has access to enough 30mm ammunition for the RARDEN or the basic vehicle could be upgraded with new optics, band tracks and electronics but still keep under 10 tonnes is not clear, it would be an interesting project though. Going up to 40mm CTA or even down to something like a 25mm might would still be a firepower improvement over the GPMG/HMG/GMG combination that the Light Cavalry currently has and using one as a carrier vehicle for Javelin, Exactor or Brimstone would also be a significant firepower uplift.
A number of manufacturers have made various attempts and squeezing more life from the CVR(T) platform, Oviks and AVST. Kembara Suci Sdn Bhd announced an upgrade package the Malaysian Army CVR(T) Scorpions a ciupe of years ago that includes a new Deutz engine and replacing the 90mm Cockerill gun with a 20mm Oerlikon automatic cannon. The King Abdullah II Design and Development Bureau (KADDB) has partnered with UKROBORONPROM to upgrade CVR(T) Scimitar and Scorpion vehicles with both manned and unmanned turrets. The 1.5 tonnes unmanned turret is the ‘Kastet’ that includes a ЗТМ-1 30 mm automatic cannon, KT 7.62mm machine gun, KBA-117 30mm GMG and a pair of Barrier ATGW’s.
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 penetration radar.
As can be seen from the brief scratching of the surface above, there is a smörgåsbord of vehicles to choose from; everything from a motorcycle to a tracked armoured fighting vehicle. So when it comes to setting a specification there are many factors but if the Light Strike Brigade is to maximise on air mobility there is a long list of compromises that have to be taken.
The British Army already has many of the building blocks in place and the Light Strike Brigade concept could conceivably be realised with an initial investment of very little. As it then evolved, firepower and logistic support would follow.
This is not a proposal for an air deployable force, it is one for an Air Mobile force, the two are very different. It really doesn’t matter that their vehicles are relatively lightweight, it would still need much more air lift to get them in theatre en-masse than we possess.
The French experience in Mali does show that as part of a wider plan, pushing light forces into an area quickly, to be joined by medium weight forces after, is not impossible and certainly in that case, desirable. People may like to remember that even at the height of the ‘Go Fast Go Light Go Home’ trend that resulted in FRES, there was still ONLY an aspiration for a small battlegroup to deploy quickly by air.
Is the whole concept achievable or desirable, you decide.