Driving Marine Construction on Ramhan Island with Al Marwan

Ramhan Island in Abu Dhabi is not a typical jobsite. The master plan combines canals, marinas, bridges, and shore protection across a sensitive mangrove setting. Channels are cut and trimmed to precise depths (largely to around -3.00 m ACD), and long stretches of shoreline must be formed, armored, and stabilized, all while minimizing environmental impact. 

For more information on the Ramhan Island project, check our previous blog.

That combination of precision, reach, flotation, and uptime is exactly why Al Marwan deployed a specialized fleet for marine construction here:

• 6 brand-new SK380 amphibious excavators
• 4 Kobelco SK850 long-boom excavators
• 2 Cat 395 long-boom excavators
• 2 Komatsu PC850 long-boom excavators

Below, we unpack the technical “why” behind each machine, how our workshop customization makes them job-ready for marine and tidal work, and what this fleet mix means for schedule, quality, and sustainability on a landmark Abu Dhabi development.

Why Ramhan Island Needs This Fleet Mix

Marine and near-shore construction demands three things simultaneously:

1. Reach: to excavate from stable causeways/berms or from barges without constantly repositioning.
2. Flotation/low ground pressure: to operate in tidal flats, soft seams, and reclaimed soils with minimal disturbance.
3. Continuous duty: engines, pumps, and cooling systems that run hard in hot, saline, dusty Gulf environments.

Amphibious excavators handle the shallow, soft, and intertidal zones; long-boom (long-reach) 80-90-ton class excavators support deep trimming, canal widening, and shore profiling from land or temporary works. Together, they reduce rehandling, limit barge moves, and keep production steady through tide windows, key to finishing on time.

Built to Fit: In-House Customization by Al Marwan

Our workshops configure standard machines for marine duty and long-reach precision:

• Long-boom front engineering: fabricated with high-tensile steels, internal bulkheads, and gusseting; tuned for stiffness, smooth hydraulics, and line routing to reduce pressure drop and heat build-up on long cycles.
• Amphibious undercarriages: sealed pontoons with wear-resistant plating, heavy-duty bogies/rollers, marine-grade hardware, optional bolt-on side pontoons for extra buoyancy, and hydraulic spud legs for station-holding while digging.
• Attachment kits: wide slope buckets with wear packages, dredging buckets optimized for long fronts (reduced heaped capacity to keep tip load within the safe envelope), rock/stone grapples for placing armor layers, and quick-couplers for fast swaps.
• QA & alignment: jig-based boom/arm alignment, line-boring for pivot points, and NDT on welds to ensure fatigue life.

Result: the exact reach, stability, and duty cycle the project requires without compromising safety or machine longevity.

6× SK380 Amphibious Excavators: Stability and Reach in the Intertidal Zone

Why here: Tidal flats and soft, reclaimed soils around the canals and mangroves demand extremely low ground pressure and buoyancy. Kobelco Amphibious SK380 units can track where conventional crawlers would sink, shaping slopes, cutting trenches for services, and loading barges at the waterline.

Base platform highlights:

• Operating weight: ~37.8 t class (base SK380XDLC)
• Engine output: ~255 hp (Hino J08ETM*)
• Travel speed: ~5.6 km/h
• Fuel capacity: ~503 L

Platform lineage, durability & HD structures: The SK380XDLC base model is designed for tough mining/rock underfoot, with reinforced track links, thicker shoes, and protected hydraulics, useful when a machine alternates between soft silts and shell/coral edges around revetments.

Amphibious undercarriage specifics (Al Marwan workshop build):

• Sealed pontoons sized for the 38-ton class, with internal bulkheads for stiffness and safety.
• High-torque final drives & heavy chains/rollers to handle drag loads in soft mud.
• Optional side pontoons & spuds to hold position for precision dredging and geotextile placement.
• Marine coatings and stainless hardware on exposed fasteners.

On-site roles:

• Tidal-window cut/fill, soft-soil trenching, canal edge trimming to design depth/side slopes (often to ~-3.0 m ACD in this development), silt removal around culverts, and assisting with geotextile and mat placement ahead of rock works.

Attachment set: 0.6 m³ slope buckets with wear strips, long-reach dredging buckets, and stone grapples for light riprap placement from the waterline.

Why it matters: Amphibious stability reduces rework from sinkage/track failure, cuts access prep, and allows continuous production through tide windows, crucial on a site with many internal canals and mangrove edges.

4× Kobelco SK850 Long-Booms: Heavy, Stable, Precise

Why here: From causeways and temporary berms, the Kobelco SK850 long-reach excavators perform deep trimming and mass excavation without frequent repositioning. The 82-ton platform gives the stiffness and counterweight to run long fronts safely with controlled swing.

Core platform specs (standard configuration):

• Engine rated power: ~380 kW (≈510 hp)
• Operating weight: ~82 t
• Standard bucket capacity: ~4.3 – 5.1 m³ (note: long-reach buckets are smaller to respect tip-load limits, around 2.8 m³)

Why the SK850 platform excels with long fronts:

• A high-inertia upper structure and robust X-frame undercarriage resist torsion from long sticks at wide swing radii.
• High-flow hydraulics keep cycle times reasonable even with long cylinders.
• The platform’s counterweight and track gauge help maintain stability with long-reach booms where center-of-gravity shifts forward.

On-site roles: Canal deepening from shore, slope trimming to tolerance, loading high-sided trucks from offset berms, and placing filter layers where reach and control trump brute breakout force.

2× Cat 395 Long-Booms: High Flow, Fast Cycles

Why here: The 395 excavator is known for strong cycle times and robust hydraulics, ideal when long-reach work still needs to hit production rates. In Ramhan’s coarse materials (sands, caliche, and select rock), speed matters.

Core platform specs (standard configuration):

• Net power (ISO 9249): ~550 hp
• Operating weight: ~94 t
• Typical max digging depth (standard front): ~9.7 m (long-reach fronts extend reach/depth beyond this, with smaller buckets)

Why the 395 platform with long boom:

• High-flow main pumps sustain cylinder speeds on long fronts.
• Efficient cooling package suits long, constant-load cycles in high ambient temperatures.
• Operator-assist electronics (payload assist, grading aids) help keep long-reach cycles consistent day after day.

On-site roles: Long-reach bulk cut from embankments, berm-top loading, and shaping deep canal shoulders where the added flow/cycle speed shortens time per pass.

2× Komatsu PC850 Long-Booms: The Balanced Heavy Hitter

Why here: The Komatsu PC850 excavator platform is a proven 85-ton class excavator with a strong, efficient powertrain and predictable hydraulics, an excellent base for long-reach packages.

Core platform specs (standard configuration):

• Engine output: ~496 hp
• Operating weight: ~85 t
• Typical standard bucket capacity: up to ~3.4 m³ (smaller with long-reach). 

Why the PC850 platform with long boom:

• Rigid upper frame and robust swing bearing to manage long-reach side loads.
• Hydraulic efficiency keeps oil temperature under control in continuous marine shaping.
• Service access and parts support simplify uptime at remote island work faces.

On-site roles: Deep reach for canal bottoms from shore, extended bench trimming, and support to armor placement teams (e.g., handing stone with grapples at reach).

Long-Reach Excavator vs. Standard Front: The Engineering Trade

Long-reach booms/sticks give you more reach and depth but with reduced breakout and smaller buckets to keep tip load within stability envelopes. On Ramhan Island, where shape accuracy and gentle slopes are as important as raw force, long-boom excavators allow fewer relocations, better line-of-sight control for finish work, and safer operations from stable ground. That’s why Al Marwan’s long-boom SK850/395/PC850 units complement the amphibious fleet so well.

Read our article on long boom excavators to learn more about this type of digger.

Attachments & Site Methods That Raise Productivity

1. Wide slope and dredging buckets (long-reach-optimized): thinner lips and lighter structures to maintain cycle speed at long radius; wear packages on cutting edges and heel plates to extend life in sandy aggregates.
2. Stone/rock grapples: accurate placement of underlayers and armor rock on revetments without pushing machines into soft edges.
3. Hydraulic thumbs & quick-couplers: fast changeovers between trimming and handling tasks as the crew moves along canal reaches.
4. Spud legs on amphibious units: hold station to trim to elevation without drift from tide or swing backlash critical when working near culverts and bridge abutments.

Environmental & Quality Outcomes

Working in and around mangroves requires careful control of turbidity, fuel handling, and access. This fleet mix helps by:

• Minimizing access fills (amphibious machines float/track where needed).
• Reducing swing over water by giving long reach from safe set-backs.
• Keeping cycles efficient, so fewer operating hours are needed to achieve the same volume.
• Enabling precise trimming to final design, which reduces rework and aggregate over-use.

These choices align with Ramhan’s canalized, multi-island master plan and the environmental sensitivity of the backwaters.

Planning a Marine or Near-Shore Job in the UAE?

Al Marwan’s approach here applies broadly across marinas, lagoons, island developments, and shoreline protection projects throughout the region. If you’re scoping similar work or building a fleet for one, our team can configure the right combination of amphibious units, long-reach excavators, and attachments to balance reach, production, and ground conditions.

Looking to expand your own fleet? Explore our heavy equipment machinery for sale, including Kobelco excavators for sale and Komatsu excavator options. As a regional Kobelco dealer, we can help you buy Kobelco excavator models best suited to marine and infrastructure work, alongside other construction heavy equipment for sale. For project-based needs, talk to us about heavy machinery rentals and tailored long-reach or amphibious builds, ideal for construction equipment UAE requirements and beyond.

FAQ: Heavy Machinery on the Ramhan Island Project

1. Why are amphibious excavators important for Ramhan Island?

Amphibious units like the Kobelco SK380 work safely on soft soils, tidal flats, and mangrove edges thanks to low ground pressure and high flotation. They’re ideal for canal trimming and near-water excavation, perfect for construction equipment UAE needs.

2. What do long-boom excavators add to marine construction?

Long-boom models such as the Kobelco SK850, Cat 395, and Komatsu PC850 offer extended reach for deep trimming, slope shaping, and loading from stable ground. They reduce machine movement and improve precision for large marine works.

3. How does Al Marwan customize amphibious and long-boom machines?

Al Marwan builds long booms, amphibious pontoons, and spud legs in-house using locally sourced materials, adding upgraded cooling, hydraulics, and wear-resistant buckets. These customizations ensure top performance in marine and infrastructure projects for clients looking to buy Kobelco excavator or explore Kobelco construction machinery.

4. Which machines did Al Marwan deploy on Ramhan Island?

The fleet includes 6 SK380 amphibious excavators, 4 SK850 long-booms, 2 Cat 395 long-booms, and 2 Komatsu PC850 long-booms, covering both intertidal and land-based marine excavation.

5. Are Kobelco excavators suitable for coastal projects?

Yes. Kobelco excavators, especially the SK380 and SK850, offer strong hydraulics and cooling systems, making them reliable for shoreline, canal, and marine works. They’re also available as Kobelco excavators for sale from Al Marwan.

6. Does Al Marwan offer heavy equipment for sale or only rental?

Both. Contractors can find heavy equipment machinery for sale, including Komatsu excavator models, Kobelco excavators, and other long-boom or amphibious setups, plus a large rental fleet for marine and civil projects.