The 105 mm L118 Light Gun has been in service with the British Army since 1974 and has been used continually since. Although it is a capable system, many now doubt the effectiveness of towed 105 mm artillery against modern threats.
The L118 Light Gun has an Out of Service Date (OSD) of 2030. The Defence Science and Technology Laboratory (DSTL) and QinetiQ are working on a Technology Demonstration Programme (TDP) to inform replacement options, the Lightweight Fires Platform (LPF).
In July 2021, Jon Hawkes from Janes tweeted…
A spot of info on the UK dstl pre-concept phase analysis of a Lightweight Fire Platform (LFP) in the Close Support Artillery workstream, considering unmanned successors to the 105 mm L118 Light Gun. #artillerytwitter pic.twitter.com/d9KW9UX1Nb
— Jon Hawkes (@JonHawkes275) July 2, 2021
The tweet describes autonomous uncrewed and self-propelled concepts. and with study areas to include;
- Increase range
- Increase end effect
- Improve accuracy
- Improve tactical/strategic mobility
- Reduce crew numbers
Potential options could include a more mobile 105 mm weapon, 120 mm mortar, or a 5 inch (127 mm) naval weapon. An artist’s impression, released by DSTL as an example, showed a mobile 4×4 platform armed with a 105 mm weapon.
The 105mm L118 Light Gun replacement question mirrors that of so many other parts of defence.
A tension exists between ambition and available budget, and the desire to get ahead of the need curve, versus what is good enough today. Does it contribute to the defence and governmental objectives? How it will fit into emerging force structures and technology maturity levels. Are we using the correct process, and do we need a like for like replacement?
DSTL will be very thorough, and it will be interesting to see what they conclude. I will in this post look at a handful of relevant issues and pose a few alternatives.
Pallets will feature!
The L118 Light Gun and Future Requirements
In these discussions we always come back to a discussion on requirements, what do we want.
Why do we need artillery guns in the first place? Especially when there are so many precision missiles, mortars and loitering munitions available?
Targets within the range of artillery can be engaged. If effective targeting and command and control arrangements are in place.
The long-range of artillery produces a large area of influence. A gun with a range of 10km can influence an area of over 310km2 for example. Distribute guns over a wide area or increase range and the area influenced increases. Many targets can be attacked in that area at the same time or fire concentrated on one.
Effects can include suppression, to cause casualties and damage, or destroy. Non-lethal effects include illumination or multi-spectral obscurants (smoke) for example.
Precision guidance kits allow them to attack point targets. sub-munitions dispensers, electronic jamming and even leaflet payloads are available.
For the UK, the L118 Light Gun is in service with light role forces such as 16AAB and 3CDO, although not limited to those. Mobility is a key success factor and concept of employment.
Some argue that the utility of such forces is low, even against non-peer enemy forces. The proliferation of low-cost ISTAR and precision systems results in low survivability. My view is that despite this, their utility and value remain. Not every force element can have the protection of a CR3. Not every force element will need to engage heavy armour. Mobility, even at the expense of protection and firepower, has enduring value.
Accepting enduring value means accepting equipment used must be mobile. The mobility of light role forces is compromised by heavy and complex equipment. Reliability is not guaranteed by simplicity, but simplicity has value. Maintainability is also valued, and extensive service support resources are less available.
Historical analysis is only ever one part of looking forward, but it is still important.
L118 Light Gun deployments often illustrate mobility as a key success factor.
Deploying them in ISO containers to the Balkans.
Flying them ashore from an aircraft carrier with helicopters in Sierra Leone.
Stripping and dragging them up a rocky pinnacle by hand in Afghanistan
All made possible by small size and low weight.
Enabling mobility means understanding the physical constraints of transport infrastructure and equipment. In practice, helicopter underslung weight limits, aircraft hold dimensions and ISO container capacity.
If mobility matters, so do size and weight, a lot.
The Department of Bigger Bangs – Or Why Everyone Likes 155mm
Whilst not directly relevant, it is still worth observing that the 105mm Abbot Self Propelled Gun was withdrawn from service because the fragmentation effect of 105mm was not effective against Soviet armour, which is one of the reasons why the AS90 is 155mm.
How artillery works…
Shell fragments create casualties and damage equipment.
Fragments weighing less than a gram are lethal because of their high velocity.
Large fragments from a burst within about 10 metres of a lightly armoured vehicle may penetrate.
Beyond 10m from the burst, fragments damage to optics, antennae and other external fittings of armoured fighting vehicles.
Tyres are likely to suffer.
Fragment density influences hit probability and will decrease with distance from the burst.
The number of fragments is a function of shell size and the amount of High-Explosive. Good fragmentation is a result of approximately 25% of the weight of High-Explosive. The UK 105 mm L50 shell weighs 15kg with approximately 3kg of HE fill.
The distance from a burst at which there is a 50% chance of a person in the fragmentation zone being hit by a ground burst fragment is about 30 metres for L50,
This increases a bit for 105 mm airburst and lot for 155 mm airburst.
The shape and area of this zone depend on the height of the burst and the angle of descent.
Multi-function fuzes are now standard, giving choices of proximity height of burst, point detonating, or delay.
Safe distances for own troops will be greater with 155 mm than 105 mm
This is particularly significant when suppressive fire is being delivered to cover assaulting troops.
155 mm provides much greater volume than 105mm for ‘smart features’
A recent article from the Wavell Room by Dermot Rooney explored the Psychology of Artillery Effectiveness and drew some very interesting conclusions
No doubt the Army needs better long-range artillery to compete with likely threats in the deep battle, but it is in close support that the guns are decisive, and only then when they are closely coordinated with armour and infantry. There is a chance that current studies will repeat the Cold War error of garbage in, garbage out, and buy bigger guns and bigger bangs, when the evidence points to the most profound effect coming from smaller bangs in a close combined-arms battle.
For creating damage and casualties, 155 mm is better.
105 mm is better for suppression and supporting troops in close contact.
105 mm ground bursts produce less ground upheaval which might be a factor for troops closing on enemy positions.
For smoke and illumination, 105 mm is more than adequate.
For light role forces, 105 mm could be better suited, all things being equal.
All things aren’t equal though.
There is a significant challenge with light forces and 155 mm.
The deciding factor in 105 mm v 155 mm for light role forces is the available lift.
Light role forces will always have limited lift capacity, none more so than UK light role forces.
I cannot see how 155 mm works for UK light role forces without significant investment.
105 mm is also in service.
All the various HE, smoke, illumination rounds, fuzes, practice and ceremonial natures.
We can manufacture them in the UK or buy them from several overseas allies.
Discount moving wholly to 155 mm, as bad as that might be for BAE Barrow and advocates of the M777
120mm Mortars, Other Calibres and What About Those Loitering Munitions eh
The reporting on the DSTL concept study mentioned 127 mm, an intermedia calibre. The 5-inch (127-mm) 62-caliber Mk 45 Mod 4 Naval Gun system offers potential for commonality. Sharing ammunition logistics with the Royal Navy and development for smart munitions. The is attractive, and the fragmentation and target effects will be superior to 105 mm.
Unless there is some collaborative programme do we want another UK only system? Do we want to carry all the technical risks in developing a land-based 127 mm gun?
Soviet-era 122 mm is also an interesting option but are we going to introduce another calibre? I suspect not.
I also discount 122 mm and 127 mm
Replacing 105 mm guns with 120 mm mortars also has many advocates. You would be hard-pressed to find many that think it would be a bad idea.
Our allies use 120 mm mortars.
120 mm mortars have a high trajectory, well suited to mountainous, forest and urban terrain, they can use traditional bipod and baseplate as above.
Fragmentation patterns tend to be more circular, which can be either a disadvantage or an advantage depending on circumstances.
They can be towed by light vehicles.
Lightweight vehicle carriage systems have been used for many years.
A more modern interpretation from NTGS in Spain is shown below.
120 mm mortars such as the Elbit SPEAR can be mounted on light tactical vehicles
Turret mounted, such as the Patria NEMO.
Light role to armoured forces can use the same basic 120 mm mortar bomb.
They have utility for maritime forces also, commonality advantages are obvious.
Imagine the MoD pulling off a joint RN/RM Army programme to deliver a common munition.
Difficult, isn’t it?
120 mm mortars offer the UK a significant capability uplift at low risk.
120 mm mortars have a tangible commonality and market benefit.
It is difficult to argue against them.
Despite the many advantages, 120 mm mortars do have downsides.
Compare the generally accepted maximum range of 10 km for 120 mm mortars to the 17-20 km range for 105 mm guns.
The area of influence for a 105 mm gun is three times larger.
Can we ignore this, especially for light role forces that do not generally have higher echelon support fires?
This is not a theoretical question.
It is critical if opposing forces have 122 mm artillery.
Operation Anaconda in Afghanistan. The 10th Mountain Division (Combined Joint Task Force Mountain) deployed without M119 105 mm guns and used 120 mm mortars instead.
The mortars only managed to fire 16 rounds before they were challenged by 122 mm D30 guns and 107 mm rockets fired by the Taleban.
Not only were they outgunned, but they were also outranged as well.
This caused them to over-rely on airpower.
The unexpected level of Al Qaida resistance forced CJTF Mountain to rely on airpower to provide much needed fire support, including close air support. While not prepared for this, the air component accomplished this feat primarily because it had no major operations other than Operation Anaconda to support. The presence of 105mm artillery might have mitigated this transition from a “metered” air tasking order set up for continuous coverage, to the ability to surge operations and place more responsive fires when and where needed to support ground forces’ operations.
Al Qaida fighters often heard approaching aircraft and retreated into the protection of their heavily fortified defensive positions, often in caves dug well into the mountainsides, and emerged unscathed to continue the ground fight upon the aircrafts’ departure. Adding to the problem, non-emergency close air support to troops could take up to forty-five minutes to materialize. Artillery could probably have provided much more responsive and continuous suppressive fires, with almost three times the range of 120mm mortars, enabling infantry units to maneuver more effectively against defending Al Qaida defensive positions.
Another problem caused by relying solely on mortars involved the clearing of “hot” landing zones before air assaults. Artillery officers later decried the absence of 105mm howitzer fires to suppress enemy resistance on landing zones, which CJTF Mountain faced during aerial insertions, as a failure to remember the lessons of Vietnam and the Soviets in Afghanistan. CJTF Mountain relied far too heavily on the ability to surge airpower assets during the Shah-I-Kot battle due to the lack of artillery.
While airpower ultimately overcame initial difficulties, enemy capabilities, terrain, and system constraints still left mortars at a significant disadvantage. Unlike artillery, mortars required much closer placement to targets, along with stable seating of the baseplate to obtain maximum range effects, thus putting them in the effective fire range of Al Qaida mortars and artillery. The 10th Mountain Division’s 105mm howitzers would have possessed the range to engage Al Qaida positions with little concern about mortar or howitzer counter fire. In addition, several US Army officers with experience in Afghanistan argued that deploying a minimally equipped and staffed 105mm artillery battery to support Operation Anaconda would require only slightly more transport capability than a platoon of 120mm mortars.
Read more: Field Artillery and the Combined Arms Team
Can deployed UK forces rely on such an abundance of close air support and attack helicopters?
I don’t think so.
Mortars cannot be used in the direct mode at low elevation, this flexibility should not be dismissed easily either.
Other factors such as flight time, detectability and air clearance should also be considered.
There are many arguments for getting rid of the Light Gun in favour of a mounted or dismounted 120 mm mortar
Many of those arguments are even very good.
Having both would allow the best of both worlds and as usual, there is no right and wrong answer.
But here is the thing…
We can’t afford both, the L118 is in service, a 120 mm mortar is not.
The cost and effort to remove one item from service and bring a completely different item into service is far from trivial
You all know that.
You all know the complexity of enabling a support infrastructure, training, documentation, support contracts and a plethora of other things.
If we can only have one system, we should go with what provides the most flexibility, and that is not a 120 mm mortar.
For reasons of flexibility and cost-based reality, I discount moving wholesale to 120 mm mortars.
Loitering munitions have many attractions
In some cases, might replace the need for some artillery
But across the broad span, don’t seem to be a replacement for guns.
The problem with precision weapons is you need precision targeting systems and people with eyes on the target
They are vulnerable to adverse weather and enemy air defences
More complicated to operate and expensive for many target sets. They are not discounted completely but viewed as a complementary capability to guns.
Towed or Self Propelled
The next big burning question is towed or self-propelled, tracks or wheels.
Cross-country mobility is limited by the loaded ammunition vehicles, not the gun itself.
Built-up areas are well endowed with suitable gun positions.
In most parts of the world, there is seldom a need to deploy too far from solid surfaces.
‘Into action time’ is a relevant issue.
The faster this is, the faster a battery can respond to calls for fire when travelling.
Self-propelled guns are the fastest, not least because they have ammunition on board.
Traverse also favours self-propelled guns.
Towed guns usually have a top-traverse of about 30 degrees left and right.
Targets outside the top traverse arc require the carriage to be man-handled.
This takes time and delays the response to a call for fire.
This is not a problem with turreted self-propelled guns.
Protection against weather and enemy fire is better with self-propelled guns.
The lower floor of tracked self-propelled guns allows easier ammunition loading.
Tracks are also less likely damaged than tyres by counter-battery fire.
Light role forces are generally not going to have a preponderance of tracked vehicles and for this reason, tracked vehicles are discounted, either a tractor or self-propelled option.
(Yes, I know the Royal Artillery use BV206 vehicles as a towing vehicle for Light Guns but these are the exception)
Wheels become the obvious choice, either as a towing vehicle or if self-propelled.
There are some very interesting options when it comes to self-propelled 105 mm guns.
Both are designed to be mounted on lightweight 4×4 vehicles and use a development of the older XM204 low recoil system.
I even wrote a little about the Mandus Hawkeye in 2012
They have since developed it further, including a 155 mm version.
The 105 mm system uses a variant of the US version of the L118, the M119.
This is not quite as long-range as ours unless rocket-assisted ammunition is used but it does provide a glimpse of what might be possible.
Several countries have also just simply mounted conventional 105 mm guns on truck cargo beds, an example from Hanwha (Republic of Korea) below.
This is a method of improving mobility for their huge fleet of towed 105 mm guns in conventional roles.
Another alternative, from Yugoimport, is shown below
The Mandus Hawkeye is a very interesting system, certainly worthy of consideration.
There would be only a limited advantage if the specific gun system was used (not the recoil mechanism).
Perhaps a combination of our existing L118 guns and the soft recoil mechanism might offer an ideal compromise?
The video below provides a side by side comparison.
Keen-eyed viewers might spot the obvious, those stealthy 105 mm rounds.
Less obvious is that the comparison starts with the M119 barrel in the rear-facing position. This is usually used for the longer road moves, not fast moves between firing locations.
It also means the gun can only be vehicle-mounted.
This compromises flexibility and availability. e.g., inability to be broken down, and only able to be moved by a Chinook as an underslung load, not Merlin.
Because mobility and transportability are, in my view, the key constraints for a Light Gun replacement, going self-propelled is discounted, despite the obvious advantages of something like the Mandus Hawkeye.
A Path Forward for the Light Gun Replacement Project
I have argued above that we stay with 105 mm, and a towed 105 mm of conventional design.
I expect most reading this will disagree.
There are other arguments.
- The British Army has a significant collection of capability gaps and obsolete equipment
- The British Army does not have a bottomless pit of cash
- Light role high mobility forces should attract investment commensurate with their size
- There is only so much technical and commercial risk we can absorb, and let’s be brutally honest, we don’t need another Ajax
This leads me to conclude that the way forward for the Lightweight Fires Platform is a stop.
Then recast as a low risk, affordable, and achievable, series of improvement projects.
The Light Gun is Dead, Long Live the Light Gun
There should be nothing that requires significant research and development.
Each spiral or project can stand alone.
They can succeed or fail without impacting others.
Low risk, much easier to deliver.
Using much of the existing training and support infrastructure.
These are just a few ideas.
Refurbish and Upgrade
An assessment of the material state of the guns would determine refurbishment potential.
If they are beyond reasonable cost an external procurement could replace them.
Nexter still makes the LG1 105mm gun, and the newer Boran from Turkey looks good.
With some investment, the Denel G7 looks very capable.
With about 180 guns in service, a programme of component refresh could be completed.
Not only would it support the UK industry, but we could collaborate with the USA to exploit opportunities arising from their M119A3 programme.
We could build up spares and implement a longer-term industry partnership.
A better powerpack or more crack-resistant lower platform is hardly the stuff of sexy PowerPoint presentations but is the path to incremental improvements in reliability and effectiveness.
The Pinzgauer Truck Utility Medium (Heavy Duty) tows the 105 mm Light Gun. It is approximately 5 tonnes, fully laden.
Highly mobile but approaching end of service life.
This is the really important bit though, they can be lifted by both Merlin and Chinook, and this matters.
The Royal Artillery has also recently started to use Supacat Jackals alongside Pinzgauers.
Whilst there are advantages, having two vehicle types in the same battery is not best for support.
An assessment of material state and potential for refurbishment would inform options.
Some years ago, Ricardo completed a concept study for Pinzgauer refurbishment, upgrade and obsolescence mitigation.
New vehicles can be purchased if refurbishment is not practical, there are choices.
Moving beats hiding.
We should aim for movement in high threat situations numbered in minutes.
Hitching the gun to a vehicle and driving away is easy
The vehicle should carry the 6-person detachment, 15-20 ready rounds of ammunition, and a selection of charges.
Neither the Jackal nor Pinzgauer provides this.
Protection from the environment and ballistic protection would be preferred.
Speed and flexibility would improve, and so would survivability.
Wider British Army requirements complicate vehicle choice.
It is not as simple as pointing at a brochure and saying ‘want that one’
Examples are shown below.
Military conversions of 4×4 and 6×6 pickup trucks are available.
Ricardo and Polaris have recently demonstrated a militarised Ford Ranger, although it seems doubtful it could fit 6 persons in the cab, especially if fully equipped.
Cab capacity is unlikely to favour converted pickup trucks.
This concept image from Prospeed in the UK shows a Light Gun vehicle based on a 6×6 with the crew on loadbed seating.
Slightly larger off-road commercial vehicles and light trucks are more likely to meet towing capacity and cab size requirements.
Examples are shown below.
The KMW Mungo is actually based on the Hako Multicar 30 municipal maintenance vehicle. 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. It would need a crew cab fitting, and this removes any ability to offload a pallet of ammunition, but ammunition carriers could be easily fitted to the space remaining.
The Iveco Daily 4×4 has a very large user base and has been widely adopted for the defence and utility sectors.
4 additional seats and 15-20 rounds of ammunition seems eminently feasible with these examples, and they would still retain the transportability of the Pinzgauer, although not perhaps the off-road performance.
There are other manufacturers of similar vehicles in Europe.
One such example is Lindner Unitrac 1 12 L Drive, it 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 tow a maximum weight of 10,000kg.
For snow and very soft terrain, they can also be fitted with tracked wheel replacement units.
It should not be difficult to source a medium mobility vehicle that can be lifted by either a Merlin or Chinook. that can tow the gun, and can carry a crew of 6 plus some ready rounds and associated stores.
All the above options assume the vehicle tows the gun.
A portee style arrangement might be worth investigating to improve time into and out of action but this will either increase the size and weight of the vehicle or force the crew onto a separate vehicle.
The Light Gun uses three types of fuse, two HE shells, and three charge systems, plus smoke rounds that are infrequently used.
Consolidate and improve these with a general investment programme.
Logistics and training become simpler, and effects, you know, more effective.
Am not saying the information below is directly relevant to the UK, not least because the US and UK versions of the Light Gun use different firing mechanisms and ammunition, but it is an illustration of how consolidation and simplification can work.
Although not what we might consider as a precision guidance kit, course-correcting fuses can significantly improve accuracy.
They are available off the shelf from several providers and provide a low-risk method of enhancing capability.
Manufacturers marketing materials tend to point out that more accuracy decreases ammunition expenditure and improves counter-battery resistance by enabling the gun battery to fire and move out of a position quickly by virtue of needing less ammunition for a specific effect.
Am not sure of that and it would need testing against real-world examples but certainly, a factor to consider.
Ammunition for any artillery is always a significant challenge.
For the Light Guns, ammunition is generally moved to the Regimental echelon by a dedicated RLC squadron using MAN EPLS hooklift type vehicles.
A JCB Telehandler is then used to move those pallets to a central position from where it is distributed by hand to individual guns.
Air Despatch or support helicopters are also used in some circumstances.
If time is available, ammunition pallets can also be ground dumped at individual gun positions.
Other examples are below.
Can we improve on this with better packaging and handling?
In truth, I don’t know, but one can certainly see a lot of double handling, removing things from boxes that are inside other boxes.
Improving ammunition may resolve some of these challenges but another system worth a look at is the Eclipse Engineering JMIC.
Recognising the poor optimisation of current containers, platforms and boxes the US Defense Standardization Department formed a working group to look at a number of options for improvement
They developed the MIL-STD 3028 JMIC.
The Joint Modular Intermodal Container (JMIC) is a modular stacking container that locks top and bottom to form a single unit.
The basic JMIC box is designed to stack 3 high, be lockable, foldable and has integral tracking.
A series of spacers and forms are used to secure items inside where the objective is to maximise packing density and minimise dunnage and filler materials.
Multiple JMIC’s can be clipped together to form a container for larger items, in multiples, up to two times in width and up to four times in length.
They can be stacked three high without additional securing and can be lifted with forklifts or any crane, hydraulic jib or lifting device by attaching chains or strops to the protruding lift eyes on top of the container.
Two can be sling loaded when clipped together and four JMIC’s are designed to fit onto a 463L pallet.
For each large item like ammunition boxes or artillery shells, a stowage plan was devised and appropriate spacer materials were defined.
Joint Modular Intermodal Platform (JMIP); is an intermodal platform (or rack) with integral locking fittings that allow JMIC’s to be secured without any form of strapping or securing.
JMIP can also be transported on aircraft without a 463L and stacked inside a conventional intermodal container.
This creates a possible replacement for the 463L and the platform to be used end to end, across both land, sea and air supply chains.
I wrote about this in 2014, click here
ECLIPS have developed the JMIC further and developed the Joint Modular Intermodal Logistics System (JMILS).
JMILS streamlines the ‘factory to firing point’ logistics chains.
A single JMIC with JMILS internals could be configured to take a mixed load of shells and charges, sufficient for carriage on the towing and crew vehicle.
This would provide an immediately available supply of ammunition suitable for quick action.
Multiple JMIC’s could still be used for more homogenous loads of shells and charges and treated as existing pallets, moved through the military supply chain to the gun battery.
A battery would still need a telehandler to move the JMIC’s from a central point to individual guns unless some form of small hooklift or pallet trailer was used.
The Dutch company Pallet Trailer produces a number of models for road use, the largest able to lift and carry a 1.8-tonne pallet.
A NATO standard ammunition pallet can carry 36x105mm shells at approximately 1.3 tonnes.
The principle of operation s the same for all of these, reverse onto a pallet load, align the forks, lift, lock and drive away.
The lift mechanism can be manual or electrical.
Small hook lifts may also be used.
Demountable systems have conventionally only been used on larger vehicles but the technology has moved on and the benefits of DROPS/EPLS like systems are now available on smaller vehicles.
Manufacturers make a range of suitable devices, the lightest only lifts 2 tonnes.
These might enable a different method of ammunition distribution to be used
The Auchleitner Carry comes in a double cab version with hooklift.
Tail lifts also provide some potential to offload a pallet or JMIC to the ground adjacent to the gun, without requiring extensive manual handling or a telehandler.
Light Gun Replacement Summary
Hopefully, I have demonstrated that there are no immediate or obvious answers.
Each approach has strengths and weaknesses that go beyond simplistic comparisons.
Ideally, the UK should invest in 120 mm mortars across a range of light-role and mechanised forces.
Hedging that the range and flexibility advantages of 105 mm can be matched with developments in both loitering munitions and conventional mortar ammunition.
If we had lots of money, doing this alongside significant investment in 155 mm and long-range rockets would be the better solution.
But the lack of is why the proposal described above is to take a conservative approach.
It proposes relatively low-cost incremental improvements at low risk in what is, frankly, a niche capability.
That is not to say it is an unimportant niche capability with no utility in the future, but the main artillery event is elsewhere.
And elsewhere should attract the bulk of our investment.
See you in the comments.