Easibridge – Lightweight Tactical Bridging Innovation
EasiBridge offers the world’s first truly man-portable, long-span rescue/assault bridging system. Exploiting the inherent flexibility of the EasiBridge systems, a further eight engineer/infantry “Super-Kit” capabilities can be used.
Key benefits include;
- Portability; weighing just 4kg/m the EasiBridge sections can be easily carried by dismounted personnel and handled without mechanical assistance,
- Span Length; gaps of up to 18m can be installed by a single person, with access from one side only,
- Low Cost; EasiBridge is significantly lower cost than comparable infantry assault bridges,
- Versatility; using common components a wide range of demanding requirements can be addressed.
EasiBridge is 85% lighter and 80% more compact than incumbent Infantry Assault Bridges. EasiBridge is expandable to offer a universal, ground-breaking solution for gap crossing, infantry carriage support, troop protection, logistics handling – even man-portable SVBIED barriers. A multi-function super-kit, ideally suited for the challenges of urban warfare, as well as special-forces, engineer and dismounted infantry operations.
It promises to be revolutionary.
Strategic Trends and Operations in Urban Areas
The 5th Edition of the Global Strategic Trends document describes future urbanisation trends;
Building on this, in September 2017, the Ministry of Defence’s (MOD’s) think tank, the Development, Concepts and Doctrine Centre (DCDC), published Future Force Concept (JCN 1/17).
On the challenges of operating in urban environments.
The Modern Warfare Institute defines the challenge of operating in urban environments:
The subject is vast, with an equally diverse range of observations and lessons to learn, but common to all is the need for dismounted personnel to traverse the hugely variable terrain found in urban areas.
It is this terrain variability that poses significant challenges for forces in urban operations as they seek to gain a manoeuvre advantage, avoid obvious ambush locations, exploit observation vantage points and prevent detection. Urban environments consist of multiple layers; on the ground, above ground and below ground, and each of these will have access constraints for dismounted personnel. Gaining access to subterranean environments such as sewers and tunnels, moving between buildings above ground and reaching roof areas for example.
To do so effectively currently requires a range of different systems and in many cases, mechanical plant and vehicular transport.
Entering target buildings through normal ground-level entry routes can be hazardous. Some advantage may be gained by scaling buildings using ropes or ladders but both techniques can be slow and predictable, leaving personnel exposed and vulnerable. Rope access requires continual training to maintain skill levels and safety. An element of surprise can be gained by entering the target building at high-level with access from adjacent ‘safe’ buildings, rooftop-to-rooftop, or window-to-window. This allows ground-level assaults to be focussed on adjacent “safe” buildings, rather than more fortified “target” buildings. The “safe” building can be retained as an emergency entry/evacuation route.
Current access systems between buildings (ladders) are generally limited to around 6m span. Longer footbridge systems exist but are impractical for rapid assaults or evacuations in urban areas. Rapid assaults require something much quicker and lighter.
EasiBridge solves many of these challenges with the world’s first man-portable, long-span rescue/assault bridge that can also be utilised to access subterranean and above ground environments in the vertical plane. In short, the EasiBridge system combines capability with the versatility to minimise the amount of equipment needed to be carried by dismounted personnel.
The EasiBridge System
EasiBridge uses 1.5m long, optimised ladder sections with a bespoke (EasiLock) jointing system to ensure no loss of strength or stiffness at multiple section joints. Combined with a rope-stiffening system, telescopic masts and variable tensioning elements, EasiBridge structures are half the weight and treble the span of incumbent systems.
Simple short spans, up to 6m, can be formed from plain ladder sections with just three sets of EasiLock joint. Longer spans, up to 18m, use a link tensioning system common to innovative military bridges like the Medium Girder Bridge and General Support Bridge.
EasiBridge, therefore, caters for any span from 1 to 18m using common components.
Key attributes are;
- All EasiBridge structures are man-portable; a 12m bridge can be transported by a single person, 18m bridges transported by just 2 personnel
- 18m bridges can be installed and crossed by a single person in under 20 seconds, with no prior access to the far bank
- Bridges are “launched” into place using a Patented cantilever launch/inversion technique
- Installation is completed entirely from the home-bank and in near silence
- Bridges can be recovered and extracted for re-use as quickly as they are installed.
EasiBridge is a modular system with maximum component lengths of 1.5m, making bridges extremely versatile, and easy to transport by dismounted personnel.
EasiBridge is compatible with confined space installation, bridges can be carried up building staircases, through ‘mouse holes’ and transported over long distances by just a single operative, then used to covertly cross gaps between buildings or other obstacles, access tunnels and roof areas.
Urban environments require personnel to move in the horizontal and vertical planes, EasiBridge provides a common set of components to address both, offering a step-change improvement over existing products and techniques. EasiBridge packs to 10% of the size of the current Infantry Assault Bridge, offering considerable cost and logistics savings. EasiBridge is 20 times stiffer and offers 3 times the span range of incumbent ladder systems. An innovative cantilever launch/inversion technique is critical to this capability.
EasiBridge components are simple to use and maintain. A typical bridge is formed of 5-to-15 components, each costing less than £1000 to replace. Bridges take less than 5 minutes to assemble. And 20 seconds to install. The training time of just 1 hour has been shown to be sufficient for trial troops.
EasiBridge is capable of operating in a range of extreme environments, including extreme cold. EasiBridge remains operational in CBRN environments. Extreme heat and fire present the only environmental constraint – bridge components may experience a loss of integrity if directly exposed to fire.
EasiBridge can be adapted to form 10 wider structural functions, via a common “Super-Kit” of parts, offering significant cost and logistics efficiencies compared to multiple ranges of disparate, single-function equipment.
Tactical Assault Bridge
The Tactical Assault Bridge (TAB) is the core EasiBridge configuration.
Tactical Assault bridges are designed to be man-portable, with typical system weights 1.5 kg per foot of span, for a design load of 200 kg. A 50-foot bridge weighs 75kg and can be carried by as few as 2 personnel using carriers formed from bridge components themselves. EasiBridge structures are half the weight and treble the span of the incumbent OCS system.
A single Tactical Assault Bridge is designed for low centre-of-gravity trolley loading. The low centre of gravity permits a narrow structure width for maximum portability, even for long-span bridges.
The trolley is used for two purposes; launch and recovery, and personnel movement across the bridge. Walking upright on a ladder over a gap is difficult, especially when encumbered. Adding handrails would mitigate some of the dangers but they add weight and take time to deploy. The trolley lowers the centre of gravity and allows an encumbered person to move quickly and safely across the gap.
What sets the EasiBridge Tactical Assault Bridge (TAB) apart from incumbent systems like the Inch’On GCS or Atlas Tactical Ladder is the long span capability, ease of deployment and low centre of gravity trolley system.
The videos below show launch and crossing techniques for the Atlas REBS ladder system and the Atlas Tactical Ladder.
In the context of urban operations, gaps are likely to be wider and personnel encumbered with weapons, radios, ammunition and other stores, making traversing open ladders dangerous and slow.
For vertical access, the same components are used. Un-tensioned, to a height of 10m and with the tensioning systems, 18m. In most cases, personnel would simply use the ladder sections in a conventional manner.
EasiBridge’ rope tensioning system also allows ladders to be installed at flatter angles, enabling winch or rope ascender movement of stores and weapons, or stretchers via the trolley system.
Shown below during trials
EasiBridge Super-Kit accessories offer further vertical access capabilities:
- Access towers – footbridge decking over ladder towers and platforms.
- Marine boarding ladders – detachable end hooks offer considerable space savings over incumbent systems – supporting RIB-assaults.
- Manhole/tunnel access systems using modular ladder components and detachable top hooks.
- Underbridge access systems, combining marine-boarding hooks, bridging elements and decking platforms.
Although this article is focussed on the military applications of the EasiBridge system, it also has a number of applications in the civilian market. EasiBridge offers further capabilities in fire evacuation, flood-, mud- and mountain- rescue. The addition of a back-pack/infantry carrier system makes the system ideal for remote access, offering significantly improved portability over vehicle-based rescue rafts.
For mountaineering, EasiBridge completely redefines conventional crevasse crossing systems and techniques, bringing ground-breaking improvements in span range, portability and operational safety.
A key EasiBridge innovation is its method of installation – a patented cantilever launch/inversion technique, allowing a single person to install and cross a complete 18m span in under 20 seconds. Bridges are designed for one-man assembly and installation, without engineer support, and with no prior access to the far ‘bank’.
Although the trolley is used for moving personnel, its main function is not to move people, but to move the bridge itself. During installation, the structure and the trolley are both inverted. Turning the bridge and trolley upside down transforms the structure from a bridge into a cantilever boom on rollers, giving the structure incredible range. This time, the trolley is static – it is the bridge that moves.
The resulting structure is light and virtually frictionless.
A single operator can launch the bridge to an adjacent building, with up to 18m range. The bridge is then inverted to form a robust truss structure, the trolley placed back on the bridge, and crossed as shown in this video:
All this completed in near silence and in under 20 seconds. Bridges can also be recovered for relocation and re-use by simply reversing the installation procedure:
A full video of Royal Engineer trials of the system is available here:
Confined space launch allows a 12m sectional bridge to be launched with 2m of internal space, bridges being assembled as they are launched.
A demonstration of Urban Access Capabilities is available here:
EasiBridge structures are so light, they are also compatible with aerial emplacement using light helicopters and heavy lift UAV’s or drones. The UK designed and built Malloy Aeronautics Hoverbike can single-handedly lift an 18m Tactical Assault Bridge. A pair of such devices can lift a 10.5m Infantry Assault Bridge, complete with handrails and decking.
Anti-sniper screens can be suspended from the Tactical Assault Bridge.
Transportation and Carriage
EasiBridge is at its core, a man-portable system, components are designed and built to be as low weight as possible, dismounted personnel are increasingly likely to be overburdened so every kg of carried weight is important.
Intra and inter theatre transportation has also been considered as part of the design process.
For transport and carriage in a tactical environment, all Easibridge components are designed to be man-portable with each section weighing only 6kg. Ropes, pulleys and clutches are also designed to balance weight with durability.
For portability inside a building, bridges will be broken down to 2 ladders/man. The 2-ladder standard stacking pattern uses one ladder inverted relative to the next, with clamps inverted on the top unit, relative to the lower unit. Ladders then carried inside Hard-Case-Carrier, supported about the centre rung.
The Infantry Carrier System (ICS) can be used to transport complete (disassembled) bridges over longer distances where mechanical assistance is not available. It features launch nose and wheel system and can also be used to carry Bergen’s, ammunition and other equipment. The ICS reduces carriage burdens by more than 50%, allowing greater loads to be carried over much longer distances, with reduced operator fatigue, and improved combat readiness
The Carrier System avoids the “dead weight” problem associated with alternative carriers if the infantry bridge was being carried anyway. The Carrier attaches to MOLLE on the operator’s hips via quick-release fasteners. ICS allows a single operative to transport a complete 10.5m bridge, or two personnel – bridges up to 18m. The system is reversible to form heavy-duty sack-trucks for short-range logistics handling.
The EasiBridge Infantry carrier offers an Infantry mobility breakthrough. Reducing carriage loads on personnel, whilst simultaneously enhancing forward mobility, emergency evacuation and force protection capabilities.
Where mechanical assistance is available and for carriage over longer distances, light vehicles can be used, right down to quad bike style ATV’s, a single ATV, for example, can transport a complete 10.5m bridge.
EasiBridge components are easily transported vertically on NATO pallets with going over 1.87m in height using pallet wrapping or collars.
They can also be easily carried using 463L pallets, air despatch pallet systems and as a door bundle if needed.
Additional TAB Applications
The wheeled Carrier System also unlocks a unique MEDEVAC/CASEVAC capability, allowing mid-range casualty evacuation by just a single operative. The ladder-stretcher is adaptable for carriage by two or more operatives in a horizontal position, when required.
Using ropes and attachment points, the stretcher assembly can be lowered from buildings or raised from below ground areas, either using winching equipment or manually.
Using easily deployed brackets and lightweight powder actuated fixings, Easibridge TAB sections can be used to create barriers across doorways, mouse-holes and other openings when moving through an urban or underground environment. A similar arrangement can also be used to create rope anchors and lifting spreaders. Stable weapon platforms inside buildings can be constructed of Easibridge TAB sections.
Extending Utility – EasiBridge Super-Kits
Military feedback has stimulated the development of a range of wider EasiBridge capabilities. Individual capabilities are discussed in subsequent sections. All capabilities form part of standard “SuperKit” enhancements of standard bridging system.
Fence Breaching System
Using the EasiBridge Fence Breaching System personnel can scale fences up to 4m high without contacting the fence, ensuring no damage or detection at the point of entry. A bespoke mast, central hinge and quick-release rope attachment is used and is based on inclined cantilever launch/inversion technique.
The man-portable modular footbridge (span range 0-18m) is formed via System II Super-Kit, placing 2 standard EasiBridge Tactical Assault Bridges side-by-side, then, connecting bridges together via tie-rods fed through ladder rungs and underslung torsion bars.
A video of the EasiBridge Infantry Assault Bridge system is available here:
This limits relative displacement between the two bridges and mobilises the torsional stiffness of both spans, mitigating any tendency for bridges to overturn under (high centre-of-gravity) walkway loads. Two further Tactical Assault Bridges, on their sides, form the structure handrails. Virendeel stiffness of the ladder handrail also enhances overall bending strength alleviating local bending stresses in the deck.
The Easibridge IAB is half the weight of the incumbent Infantry Assault Bridge, reducing or negating requirements for vehicle transportation. Footbridges are formed from 1.5m x 7kg ladder sections. 90% more compact, and 88% lighter than the incumbent IAB. A dismounted footbridge capability offers a significant enhancement on current vehicle-based systems, whilst maintaining full interoperability with the core assault bridge platform.
The twin TAB with handrail configuration can accommodate pack animals and stretcher trolleys.
Infantry Assault Pontoon Bridge
For wide and wet gaps, the standard Easibridge IAB can be used with demountable pontoons fitted between the mast knee-braces.
Even with the pontoons, the EasiBridge Infantry Assault Pontoon Bridge is deployable and transportable without vehicles or mechanical handling equipment, a significant advantage over the incumbent IAB and one that results in a 75% volume saving compared to current IAB
Quad Bike Crossing and Pontoon/Raft
The existing General Dynamics Quad Bike Bridge (QBB) is quick and easy to use but it can span very short spans.
For dismounted patrols supported by quad bikes, any gap wider than 2.5m must be provided by Royal Engineer bridging support, the next step up from the QBB is either REBS or an Air Portable Ferry Bridge, both requiring considerable support and resources.
Using the EasiBridge system, an 18m long span ‘trackway’ type bridge can be built quickly, without any engineering plant, with minimal personnel and launched from the home bank.
Close Support Bridge
EasiBridge is a modular system. The Close support Bridge (CSB) extends the application of the IAB system by placing 3 or more standard EasiBridge Tactical Assault Bridges side-by-side – allowing bridges of any width to be achieved.
Increasing bridge width increases load rating, giving standard Tactical Assault Bridges a light-vehicle capability, suitable for direct trafficking by quad-bikes and LTMP/SMET transporters.
A video of the EasiBridge Close-Support Bridge system is available here:
Maximum spans of 18m can be achieved using just 1.5m (7kg) ladder and decking sections. The CSB is also compatible with autonomous LTMP/SMET placement and vehicle crossing – another unique EasiBridge capability.
Simple spans up to 6m can be formed from plain ladder sections – no rope tensioning at all, offering very shallow construction depth.
Light Cavalry Vehicle Bridge
The Light Cavalry Vehicle (LCV) Bridge uses enhanced ladder sections to form an 8-tonne capacity bridge – the bridge weighing less than a ½ tonne, dismantling to 4m sections, carried on a vehicle roof. The bridge assembled from (enhanced) 4m EasiBridge sections, assembled and crossed in under 5 minutes. Maximum span range 12m. 4m composite decking planks, spanning between main truss node positions limits local bending in ladders.
Strike Vehicle Bridging
EasiBridge has developed concepts for a new range of Strike Vehicle Bridging platforms. Bridge installation is powered entirely by gravity – no mechanical plant or power required. Bridges up to twice the vehicle length can be carried on lightly-modified Strike vehicles.
EasiBridge combines bridging with extensive force-protection and counter-mobility capabilities. Overhead protection and vehicle barriers can be constructed using EasiBridge sections. Force protection capabilities include basic systems for overhead trench protection to blast-resistant roofing systems for troop-shelters and man-portable troop accommodation and disaster-relief shelters.
Basic cover protection systems utilise bridging ladders and decking panels to form trench cover structures up to 3m span. Ladder sections can be combined with sheet materials to support 300mm of earth fill as shown in two left side images below. For wider positions, ladder sections and joints can be used to create pitched support. The support can be secured by tie rods, thrust blocks or pickets driven into the ground, two right side images below.
More complex roof structures can be constructed for use with Hesco or Defencell, or engineering plant excavated defence positions. Troop shelters use a wire-tensioning system to increase roof span up to 6m – double the span of incumbent systems.
EasiBridge creates an affordable range of rapid-assembly building frameworks, ideally suited for blast-resistant troop shelters, disaster-relief and humanitarian-aid shelters.
All systems formed from 1.5m x 7kg (man-portable) bridging ladders and footbridge decking panels, compatible with plant/equipment-free transport and installation. All components can be placed entirely by hand – no power or mechanical plant required. Earth-fill can be placed by EasiBridge materials-handling (trolley) conveyor, allowing easy placement of blast-protection fill from the ground to the roof apex.
Overhead protection and vehicle barriers can be constructed using Easibridge sections. Troop shelters use a wire-tensioning system to increase roof span up to 6m – double the span of incumbent systems.
EasiBridge can also be used to construct combined Trench Side-Support and Cover Protection frameworks. Ladders and decking panels offering flooring, side-supports and blast-resistant roof covering, accommodating 300mm of earth-fill over. Standard Tactical Assault Bridge and footbridge components used throughout.
In complex urban terrain, contemporary threats include suicide bomber vehicle-borne improvised explosive device (SBVBIED). Creating a physical barrier at checkpoints, road intersections and other vulnerable points is a key element of any operational concept. These barriers have traditionally been prefabricated concrete or gabion type (Hesco and Defencell). The former requires a great deal of logistics and engineering support and the latter needs a great deal of fill material and engineering support.
EasiBridge can also be used for counter-mobility. Placing EasiBridge on its side creates a man-portable, long-span, lightweight barrier.
A more robust barrier configuration can be formed by adding a second span, complete with decking, earth-fill and cross-ties to create a dual-skin, earth-filled (cavity) barrier for heavy, concentrated loads, such as SVBIED barriers. The EasiBridge cavity-barrier forms an extremely robust, yet highly portable force protection barrier system, all elements weighing less than 7kg, with 1.5m component lengths.
This approach allows fill volume to be reduced by 50%, making barriers significantly quicker to deploy and less resource intensive. Barrier deformation under impact is reduced and the barrier can be quickly recovered and re-deployed (leaving the gravity barrier in place)
Engineer Access Platform
The conventional means of accessing underneath bridges to inspect or place demolition charges is with either a vehicle mounted access platform or a combination of ladders and rope access techniques.
EasiBridge can form under-bridge access platforms for Engineer inspection and demolition activities.
The Easibridge Engineer Access Platform is an adaption of the Tactical Assault Bridge (TAB), with a 6m platform configured without a TAB mast and up to 12m with a TAB mast. As with the Tactical Assault bridge (TAB), all components are man-portable and easily moved with light transport vehicles such as quad bikes and small ATV’s.
Access platforms are designed for remote placement from above deck level via a cantilever (gravity-fed, boom-out) launch technique, or via suspension ropes slung over the side of the existing structure. A significant safety innovation, offering plant-free, manual installation.
EasiBridge platforms are self-anchored structures – no requirement for sizeable end anchorages. Suspension ropes from deck level replace/reinforce normal EasiBridge mast/rope tensioning systems. Suspension ropes provide vertical and torsional restraint to high centre-of-gravity platform loads.
Platforms can be fitted with optional decking and handrails, as Infantry Assault Bridges for enhanced safety and stability. End boarding ladders provide access and positional fixity. Additional components such as stabiliser struts further enhance lateral and torsional fixity.
A range of platforms are available, from simple, light-duty, single spans, providing single-user (200kg) capacity, to grillages of heavier duty, multiple-access walkways.
EasiBridge can also be used as utility support structures. Utility structures are available in single or multiple ladder width options, with or without handrails and decking – system weights from 4.5 kg/m on undecked or 11 kg/m on decked structures. Maximum loadings from 40-100 kg/m/span.
Summary and Look Forward
EasiBridge provides a universal, ground-breaking solution for gap crossing, infantry carriage support, troop protection, logistics handling – even man-portable SVBIED barrier protection.
EasiBridge offers the world’s first truly man-portable, long-span rescue/assault bridge. A state-of-the-art solution derived from the novel application of post-tensioning techniques in lightweight materials with an innovative method of installation and operation.
EasiBridge offers four unique user-benefits:
- Portability – user-portable bridges, weighing 4 kg/m of span, complete with Infantry carrier /CASEVAC capability.
- Span – 18m span bridges installed by a single operative, with access from one side, only.
- Cost – Significantly cheaper than incumbent vehicle-borne Infantry Assault Bridges.
- Versatility – a common building block for personnel bridging, quad-bike bridging, Infantry Assault Bridging, carriage-support, force protection shelters, flood barrier, portable ammunition conveyors, fence-breaching and portable access platforms.
Bridges are designed for personnel and quad-bike loading with maximum 1.5m x 7kg components, compatible with personnel/quad-bike carriage. All EasiBridge systems are man-portable and do not require plant or power to operate or install.
EasiBridge provides rapid, covert access between buildings, up to 18m apart – an entirely new means of emergency building evacuation, as well as high-level entry, for counter-terrorism, urban-warfare and emergency services. Existing bridges are impractical for rapid assaults or evacuations in urban areas.
EasiBridge caters for any span from 1-18m, using short (1.5m x 7kg) ladder sections. Bridges are installed by a single operative with access from one side, only – no plant or power required. Bridges can be carried inside building stairwells and launched from a 2m internal space – a unique, highly-portable, new access capability. A step-change improvement over current products and techniques.
Feedback from military trials has inspired the development of numerous wider capabilities. EasiBridge can transform troop mobility and force protection with using short-section ladders as a common building-block for a range of military engineering applications. Extended “Super-Kit” capabilities include:
- Infantry-carrier system for dismounted personnel
- Gap-crossing system for dismounted personnel – personnel & quad-bikes
- Assault-bridge for urban environments – rooftop-to-rooftop, or through windows, ideally suited for urban warfare and counter-terrorism applications
- Rescue access platform for fire, flood, mud & mountain rescue
- A new range of Infantry assault bridges, 90% more compact than existing systems
- Close-support foot/light-vehicle bridges, including autonomous LTMP installation capability
- A versatile range of floating pontoon bridges and access platforms
- Modular rafts for amphibious assaults
- Ladder or conveyor to climb walls (climb heights up to 12m)
- MEDEVAC stretcher platform, offering single-handed casualty evacuation
- Vehicle-portable, light-cavalry bridges
- Lightweight, high-portability access platforms for Engineer inspection and demolition activities
- Utility support structures
- Goods conveyor to move casualties and ammunition from ground-to-roof level
- Troop protection shelters for dismounted personnel
- Rapid installation vehicle (SVBIED), munition protection and flood defence barriers
The system provides a unique, modular-building system, offering simple, realistic and affordable solutions to a broad range of mobility, access and troop protection challenges. It offers a common platform to service each requirement, negating the need for numerous, independent ranges of single-function equipment. A multi-purpose system at a fraction of the size and cost of incumbent systems.
No other system comes close to the span range, portability or breadth of capability of EasiBridge platforms. EasiBridge could transform techniques employed in military engineering for generations to come.
EasiBridge strength and range of capabilities are unique.
It promises to be revolutionary.
Options for Advancing the Project
EasiBridge has been developed by Bright Structures Ltd, a micro-SME founded January 2016.
Doctor Stephen Bright is sole director and employee, with no other stakeholders. All work-to-date has been financed in-house, with recent support from Innovate UK and MoD DASA Accelerator development grants.
Scale-up funding is now sought to bring the Tactical Assault Bridge and wider Super-Kit capabilities to market. EasiBridge offers an exceptional business case for private sector investment. Expressions of interest from prospective backers are now sought – contact email@example.com.
First sales revenue has now been secured, with a sizable order for Engineer Trials from the UK MoD. By 2020, all further growth and R&D activity is expected to be organic & self-financing – EasiBridge® is expected to be self-sufficient from the 2nd quarter of 2019.
New product development will remain a core business activity – Bright Structures was founded on innovation. The broad product range ensures Bright Structures offers an innovative business capable of sustained innovation.
The Army could benefit from a significant increase in capability. EasiBridge is an ideal candidate for streamlined low-cost procurement, capabilities being acquired incrementally as operational circumstances evolve.
Additional videos at the link below