Building up: The need for more military bridging systems

NATO is currently faced with a shortage of military bridging systems. This state of affairs has been brought sharply into focus by the War in Ukraine where rivers and waterways have become dividing lines between Russian and Ukrainian forces. The inability to cross water gaps is one of the major limiting factors in any offensive operation. In Ukraine, Russia lost many bridging systems during its initial offensive in February 2022, in large part due a to lack of awareness of their opponent’s capacity to detect and engage forces attempting gap crossings.

Despite this, the country still possesses a large inventory. However, the shortage of bridging equipment in NATO member countries’ stocks, poses a considerable risk to ground manoeuvre operations. This article looks at the bridging equipment and capabilities in NATO armies.

NATO forces possess a wide range of different sets of bridging equipment. This can be broadly separated into three different categories: Armoured Vehicle-Launched Bridge (AVLB) systems, truck-based bridge systems, as well as ferry and pontoon bridge systems.

AVLBs are usually based on main battle tank (MBT) platforms, and are used for crossing narrower water gaps or obstacles up to 26 m. Because they are using MBT hulls with tracks, these systems can move alongside and within heavy armoured formations, with roughly the same mobility as the MBTs themselves; they are also armoured and are the only systems capable of laying bridges under fire.

The truck-based systems can deliver similar short bridge spans, or modular bridge platforms to cross narrower water gaps; as they are fitted to trucks, these systems are cheaper and can deploy faster on roads. However, truck-based bridge systems cannot be used in dangerous areas as they are too vulnerable under fire, but they are very useful in establishing a larger number of bridges quickly in safe areas to rapidly improve access to and from the front line to allow faster logistics support.

Ferry and pontoon bridges are used to cross much wider and larger water obstacles. Some ferry systems are based on amphibious vehicles that can work in forward areas to rapidly deliver heavy armour across lakes and rivers to establish a secure position on the opposite bank so that a pontoon bridge can be set up.

Pontoon bridges can be amphibious ferry sections joined together, or floating sections that are delivered by truck, placed into the water and connected together in order to establish a much longer bridge potentially hundreds of metres long.

Falling short

NATO has a shortage of all types of bridging equipment, but in particular there is a lack of ferry and pontoon systems. This is problematic, since the European theatre is full of wide wet gaps that are challenging to cross. Existing civilian bridges and infrastructure could be damaged or destroyed in a conflict or deemed unsafe for heavy armoured vehicles to cross. This means alternatives are needed.

One of the main European amphibious ferry systems is the M3 amphibious rig, which is supplied by General Dynamics European Land Systems (GDELS). The M3 rig is based on a 4×4 amphibious vehicle fitted with aluminium pontoons on the roof that unfold before entry into the water. The floating rigs can be positioned using two traversable pump jets activated from a controlling station topside and then connected together. Each rig has a crane and four folding ramps that can be laid across the topside to either form a 100 m long bridge (in 15 minutes), or 2–6 rigs can be connected to form a ferry of different sizes.

The M3 has a military load classification (MLC) 85, supporting tracked vehicles up to 85 US tons (77 tonnes) and wheeled vehicles up to 132 US tons (120 tonnes). The M3 was first introduced in 1996 and is used by an Anglo-German Multi-National Bridging Amphibious Engineering Battalion (Amph Engr Bn) 130 based in Minden, Germany, which includes British Army Royal Engineers. The battalion was formed following an agreement between UK and Germany in March 2023 and is part of the Bundeswehr’s 1st Panzer Division.

The UK and Germany have plans to replace the existing M3 rigs with new systems under the Next Generation Wide Wet Gap Crossing Capability (NG WWGCC) project run by the British Army in partnership with the Bundeswehr, under a Memorandum of Understanding (MoU) signed by both countries in December 2021. The British Army is expected to procure about 30 platforms with deliveries completed in 2032.

A GDELS spokesperson told ESD: “Today’s focus is on fast ferry operations, and here the M3 is worldwide unique. Its newest generation requires a crew of only two instead of three, the electronic system is fully digitalised, and we have introduced other improvements such as an arctic kit for ice-free walkways, new engine and gearbox.” The spokesperson added: “The M3 can carry every NATO vehicle including the heaviest versions of the Challenger and Abrams MBTs.”

The US Army uses Improved Ribbon Bridges (IRBs), also manufactured by GDELS, which can be integrated with the M3. The IRB is a pontoon bridge system consisting of floating bay sections that are transported by 6×6 bridge transporter vehicles that use a crane to place them in the water. When linked together, the IRB can form a 100 m long bridge in about 30 minutes, providing a gap crossing capability with MLC 80 for tracked vehicles and MLC 96 for wheeled vehicles. The 6.75 m wide sections also allow for two-way traffic. The Netherlands is the most recent operator of the IRB after it placed an order in July 2023, with deliveries due in 2025–26.

The French Army’s pontoon bridge system, the Engin de Franchissement de l’Avant (EFA), is built by CEFA and based on a 4×4 amphibious vehicle with attachable inflatable pontoons. The EFA has a payload capacity of 70 tonnes and is operated by a crew of four. The pontoons are inflated before deployment and with two large pontoons on either side of the vehicle, with a further four attached to an extendable bridge section that is deployed at either end of the vehicle. This creates a 34.55 m long bridge or ferry, or four of them can be used to set up a 100 m long bridge within 15 minutes. France has 30 EFAs in service.

New options

CNIM has developed the new Pont Flottant Motorisé Nouvelle Génération (PFM NG) system available as the PFM XP (Expeditionary) or PFM LG (Long) to replace the French Army’s existing PFM F1 and F2 pontoon bridge systems. The PFM NG system was first unveiled by CNIM in 2021 and has a rating of MLC90 for tracked vehicles and MLC100 for wheeled vehicles.

The XP is deployed from an 8×8 logistics truck and uses 6.7 m modular floating sections and ramps that are deployed straight into the water using a launching mechanism. In a ferry configuration using four sections, the XP can support MLC90 for tracked vehicles and MLC80 for wheeled vehicles, with lower MLC ratings of 60 and 40 respectively for a shorter ferry configuration comprising two sections.

The PFM LG is deployed from a 6×6 truck and a three-axle semi-trailer that can support 10 m modular floating sections and ramps, which are likewise deployed into the water via a launching system. Each LG unit has an outboard motor for in-water manoeuvring and when sections are fitted together, they can form a 100 m long bridge in 30 minutes or smaller sections that can operate as a ferry. Using four sections, the LG has an MLC 90 for tracked and MLC 80 for wheeled vehicles, with lower MLC ratings of 70 and 60 respectively for the smaller three-section ferry configuration.

In 2015, the DGA contracted CNIM to upgrade ten of its old PFM F1 system to the F2 standard with upgraded ramps and modules. However, the new ramps can only sustain loads of MLC40 and the PFM F2 is still limited to payloads up to MLC65. Whilst the French Army has retained a largely wheeled armoured vehicle fleet, which may come under the payload limit, it still has the Leclerc MBT, which is tracked and cannot be transported by the old PFM.

This is a problem across NATO as armoured vehicles have become much heavier. Modern and upgraded MBTs and IFVs are larger and weigh considerably more than their predecessors some 30–40 years ago. MBTs now typically weigh well in excess of 60 tonnes, sometimes significantly more. Extreme examples include the British Army’s Challenger 2 TES configuration, currently the heaviest in NATO at 74.8 tonnes, with the M1A2 Abrams SEPv3 fitted with the Force Protection (FP) armour kit coming in a close second at 71.6 tonnes.

Revised standards

To meet the challenge of heavier vehicles, NATO has a new minimum MLC of MLC80 to allow for the heaviest of MBTs and Heavy Equipment Transporters (HETs), which carry tanks, to cross bridging systems safely. This will require a massive upgrade or replacement of existing bridging equipment, much of which has an MLC50 or 60. Whilst the MLC standard does not just equate to a vehicle’s tonnage (the calculations are somewhat more complex, particularly for longer wheeled vehicles), it does offer guidance for the ability to transport tracked and wheeled vehicles.

Older AVLBs in service such as the German-built Biber and the US M60 AVLB are being retired, with some being donated to the Ukrainian Armed Forces. The Biber is based on the older Leopard 1 MBT and can launch two 11 m long bridge sections to cross a 20 m wide obstacle within three minutes sustaining loads up to 55 tonnes. Meanwhile, the M60 AVLB is based on the M60 MBT and deploys a scissor bridge 18 m long with, rated at MLC60. These are being replaced since they might not be suitable for the majority of contemporary MBTs, including the newer variants of the Leopard 2 and M1A2 Abrams models.

The US Army is introducing the M1074 Joint Assault Bridge (JAB) built by GDLS to replace both the M60 AVLB and M104 Wolverine. It is based on the M1A1 Abrams MBT and can deploy both the legacy 19 m long scissor bridge with MLC 85 and the 18.3 m long MLC 115 Heavy Assault Scissor Bridge (HASC) using a hydraulic bridge launcher system. Deliveries are due to be completed later in 2024. Countries that operate the M1A1 or M1A2 MBTs will want to introduce the JAB to operate alongside its armoured formations and provide them with a gap-crossing capability.

In Germany, the Biber is being replaced with the Leguan (Iguana) AVLB, built by KNDS Deutschland, which is notionally based on the Leopard 2 platform (though alternative base platforms can also be used). With a capacity to hold up to 90 tonnes, Leguan can deploy bridges 14 m, 26 m, and 35 m in length. There are 17 countries operating the Leguan, including Germany, Denmark, Spain and The Netherlands. Finland signed a contract in December 2023 worth EUR 23.6 million (USD 26 million) for six Leguans, which will be mounted to the Leopard 2A4 platform by Patria. Delivery is expected in 2026-28 and will add to the Leguan units that were delivered in 2005-08 and 2018–22.

As a way of expanding gap crossing capabilities on more platforms, KNDS has integrated the Leguan onto the 8×8 Boxer armoured personnel carrier (APC). Demonstrations were carried out in 2020–21 on a trial vehicle. GDELS and Rheinmetall are developing the Cobra bridge system, which is also based on the Boxer APC. Cobra can deploy a 15 m long MLC90 bridge using a bridge-launching mechanism from Pearson Engineering that can deploy in two minutes.

New AVLBs with higher MLCs are part of the equation and more will be needed. Yet these AVLBs only represent a part of the total requirement, as this class of bridging vehicle is primarily intended for front line operations and reserved for use with heavy armoured formations. The majority of bridging systems are truck-based and are deployed away from the front line to replace damaged civilian infrastructure, supplement AVLBs and provide additional bridges over gaps to improve the speed of logistics supply – essential in any war.

Truck-based bridging support

Because of its mainly wheeled armoured vehicle fleet, France does not operate an AVLB; instead, the French Army has procured the Système de Pose Rapide de Travures (SPRAT; ENG: rapid span installation system). SPRAT is based on a Scania R580 10×10 truck fitted with two 14 m long bridge units that are 4 m wide and rated at MLC70. Built by CNIM, the SPRAT also includes a 6×6 semi-trailer to host additional bridge spans. Deliveries were completed in 2011–13.

The US Army has the M18 Dry Support Bridge (DSB) based on an Oshkosh M1078 10×10 truck able to deploy a 40 m long bridge using an A-frame with s mechanical beam and rail system to deploy bridging sections. The DSB is manufactured by WFEL, a UK subsidiary of KNDS. The US Army has over 100 in its inventory and in January 2024, the UK ordered an undisclosed number of DSB units for GBP 150 million. Other operators include Australia, Germany, South Korea, Switzerland, and Türkiye, where they are based on different logistics trucks.

GDELS offers the Python, a light aluminium dry gap bridging system capable of deploying a 13 m long bridge rated at MLC50. The Python can use an 8×8 truck or a Piranha family 8×8 as the host platform. In June 2023, Georgia placed an order for four Python bridging systems from GDELS, with deliveries expected in 2025.

In partnership with Rheinmetall, GDELS has launched the Anaconda tactical bridging system, which has bridging units able to span a 22 m wide gap mounted on an HX2 8×8 truck. The intention is to make it cheaper and easier to increase bridging inventories by integrating bridging systems onto a family of trucks that are more common in service. This reduces the need for support and training as a large number NATO countries already use the HX truck series.

Challenges ahead

A look ahead, as well as an update of inventories, shows the need for more integration of bridging equipment across NATO. This means procuring more, similar equipment able to be used by all NATO members, which could mean that even if NATO armies do not possess much heavy armour, they should still procure MLC80 systems in order for Allied armies to be able to use their bridges.

Another way of increasing interoperability is by developing a Universal Floating Bridge Adaptor (UFBA). Plans for a UFBA were announced as part of NATO’s Gap Crossing High Visibility Project, initiated in February 2023. The intention is to produce an adaptor that can allow all of NATO’s floating bridging equipment to be integrated. However, this effort is still in the pre-concept phase.

Tim Fish