A Singapore contractor faced strict vibration limits on a metro tunnel project. The site sat beneath dense commercial buildings. Traditional breakers exceeded the settlement thresholds. The contractor needed a milling head for excavator that could cut granite precisely.
The project was a cross-passage for the Thomson-East Coast Line extension. The cross-passage connects two main tunnels. It sits 30 meters below ground. Nearby buildings rest on shallow foundations. The Land Transport Authority required minimal ground disturbance. Blasting was prohibited.
The contractor first tried a rock grinder attachment for excavator and skid steers. It lacked the torque for hard granite. The unit stalled repeatedly. It also produced uneven cuts. The over-break reached 30%. This wasted shotcrete and slowed the cycle.
Professional insight: Always test a rock grinder attachment on the actual rock type. Trial cuts reveal torque limitations before full mobilisation.
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The Hidden Costs of Breakers: When a Milling Head for Excavator Became the Only Way Forward
Breakers create hidden costs that many contractors overlook. Over-break, vibration, and slow advance rates add up quickly. A milling head for excavator eliminates these costs through precision cutting.
The contractor calculated the breaker’s true cost. Over-break added 30% to shotcrete volume. Vibration monitoring required daily readings. The advance rate was only 1.8 meters per day. The project schedule was at risk.
The contractor evaluated three alternatives. A roadheader was too large. A drum cutter attachment for excavators was considered. But the available width was too wide. The contractor needed a compact, high-torque milling head.
Professional insight: Calculate over-break cost before choosing a method. A 30% over-break on a 100 m³ face means 30 m³ of extra shotcrete and disposal.
From Problem to Solution: How the HX-Z1 Milling Head for Excavator Cut Through Granite
The HX-Z1 milling head provided the exact balance of power and precision required for the project’s demanding ground conditions. Delivering 14,300 Nm of torque, it maintained an efficient cutting rate of 4.2 m³ per hour through hard granite while reducing site vibration levels by 70% and minimizing over-break down to just 8%.
YG Machinery matched the HX-Z1 model to the contractor’s existing fleet of 25-ton excavators (compatible with 20–27 ton carriers). Key features that enabled the team to overcome site challenges included:
- Dual-Drum Configuration: The 850 mm cutting width allowed full-face cutting ideal for tight cross-passage dimensions.
- Tungsten Carbide Picks: Equipped with 64 durable picks, the head efficiently cut through high-strength granite and reinforced concrete.
- Low-Speed High-Torque Drive: Operating at 78 r/min, the direct-drive hydraulic motor optimizes cutting power while minimizing pick wear and eliminating complex gearbox maintenance.
Professional insight: Always verify hydraulic system compatibility before operation. The HX-Z1 requires a dedicated flow rate of 220 L/min at 35 MPa—insufficient flow can cause stalling and accelerate pick wear under heavy rock loads.
Inside the HX-Z1: Milling Head for Excavator Specs That Deliver 14,300 Nm Torque
The HX-Z1 delivers an optimal balance of power and size. Weighing 1,100 kg with an 850 mm cutting width, it generates a robust 14,300 Nm of torque at a hydraulic flow rate of 220 L/min and 35 MPa—making it an ideal attachment for demanding tunneling and trenching applications.
Milling Head for Excavator Specifications
| Parameter | Specification |
|---|---|
| Model | HX-Z1 |
| Applicable Excavator | 20–27 T |
| Machine Weight | 1,100 kg |
| Milling Width | 850 mm |
| Milling Head Diameter | 560 mm |
| Number of Blade Heads | 64 |
| Recommended Speed | 78 r/min |
| Recommended Flow Rate | 220 L/min |
| Maximum Pressure | 35 MPa |
| Maximum Torque | 14,300 Nm |
The unit arrived with 64 carbide picks installed. The mounting bracket fit the contractor’s quick-coupler. YG included hydraulic hoses and a toolkit. The export wooden case had shock-absorbing foam. The contractor also ordered two spare pick sets. A pick removal tool came with the order.
Professional insight: Order spare picks with your initial purchase. Pick replacement is routine. Waiting for spares can halt production for days.
From Shanghai to Singapore: Drum Cutter Attachments for Excavators Arrive and Power Up
YG shipped the HX-Z1 Rotary Drum Cutter from Shanghai to Singapore. Sea freight took 12 days. The unit arrived at the Port of Singapore in good condition. Customs clearance took two days. The contractor transported it to their yard.
Commissioning began with a hydraulic test. The 25-ton excavator delivered 220 L/min at 35 MPa. The milling head rotated at 78 r/min. No leaks or abnormal vibrations occurred. The team then cut a granite test block. The HX-Z1 achieved 4.2 m³ per hour. The cut surface was smooth. Vibration was 70% lower than the breaker. The contractor approved the unit.
Operator training took one day. YG’s technician covered start, stop, and emergency procedures. Operators practiced depth control and profile following. They learned to inspect and replace picks. The safety officer reviewed the manual with the team.
Professional insight: Run a hydraulic flow test before commissioning. Record readings and compare with specifications. Deviations above 10% may indicate pump wear.
4.5 Metres a Day: How the Milling Head for Excavator Smashed the Schedule
The HX-Z1 entered full production in Week 6. The contractor ran it on two 25-ton excavators. The unit worked 14 hours per day in two shifts. Total operating hours reached 420.
Key Results Summary
| Metric | Before (Breaker) | After (HX-Z1) | Improvement |
|---|---|---|---|
| Vibration level | Above threshold | 70% below | 70% reduction |
| Over-break | 30% | 8% | 73% reduction |
| Shotcrete volume | Baseline | -22% | 22% saving |
| Daily advance | 1.8 m | 4.5 m | 150% faster |
| Pick consumption | N/A | 12 per 100 m³ | Baseline |
The daily advance rate hit 4.5 meters. Over-break dropped to 8%. Shotcrete volume fell by 22%. Vibration stayed below thresholds. Settlement monitoring showed no exceedances. The LTA inspector approved the method. Pick consumption averaged 12 per 100 m³. No unplanned downtime occurred.
Professional insight: Track pick consumption weekly. A sudden increase means you hit steel or harder rock. Adjust speed and inspect the face.
The Payback Story: Milling Head for Excavator ROI That Convinced the Contractor
The HX-Z1 delivered a strong return on investment. The unit cost a fraction of a roadheader. It eliminated extra ground support. It also cut material and disposal costs.
The shotcrete savings reached 22%. Over-break reduction lowered transport costs by 25%. The faster advance rate compressed the schedule by three weeks. Avoided delay penalties added more savings. Vibration reduction cut monitoring costs. The contractor reduced monitoring from daily to weekly.
The project manager praised the milling head for excavator. The operator liked the smooth cutting and low noise. The maintenance team appreciated easy pick changes. The contractor ordered two more HX-Z1 units. They are also evaluating the larger HX-Z2.
Professional insight: Include indirect savings in ROI. Reduced monitoring, lower shotcrete, and faster completion often exceed direct savings.
Beyond This Project: Why Excavator Grinding Attachment Technology Is Singapore’s Future
Singapore’s urban projects demand low-vibration excavation. Milling heads meet this need. They cut precisely and produce minimal over-break. The HX-Z1 proved this on a demanding metro tunnel.
YG Machinery offers five milling head models. They suit 6- to 60-ton excavators. The HX-Z1 fits 20–27 ton machines. The HX-D handles 45–60-ton machines. Contractors can match the model to their project. The excavator grinding attachment technology is ready for Singapore’s next infrastructure wave.
For contractors facing strict vibration limits, the milling head for excavator is a proven solution. The HX-Z1 delivered speed, precision, and strong ROI. It is a smart investment for urban excavation.
Project Timeline
- Week 1 – Client inquiry; site assessment
- Week 2 – HX-Z1 recommended; order confirmed
- Week 3- Manufacturing and export packing
- Week 4 – Sea freight Shanghai to Singapore (12 days)
- Week 5 – Customs clearance; delivery to yard
- Week 6 – Hydraulic test; test cuts; operator training
Key Results Summary
| Metric | Result |
|---|---|
| Vibration reduction | 70% below threshold |
| Over-break reduction | 73% (30% to 8%) |
| Advance rate increase | 150% (1.8 m to 4.5 m/day) |
| Shotcrete savings | 22% |
| Schedule | 3 weeks ahead |
| Additional units ordered | 2 more HX-Z1 |
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FAQ About Drum Cutter Attachments
Match weight and flow to your excavator. The HX-Z1 suits 20–27-ton machines at 220 L/min. Verify auxiliary hydraulic capacity first.
A milling head grinds with rotating drums. A breaker impacts. Milling heads produce 70% less vibration and cleaner cuts.
Yes. Carbide picks cut concrete with rebar. Reduce speed when hitting steel. Inspect picks after reinforced sections.
In this project, 12 picks per 100 m³. Track wear weekly to set your replacement schedule.
Use the excavator manufacturer’s specified oil. Check cleanliness monthly. Replace filters as recommended.
Typically 1–2 days. Includes hydraulic test, test cuts, and operator training.
Protective housing over drums. Pressure relief valve. Operators need hearing and eye protection.
Yes. Motor and gearbox are sealed. Avoid submerging. Clean and lubricate picks after wet use.
Want to optimize your trenching and tunneling efficiency? Contact our technical team today to get custom sizing recommendations and a factory quote for the drum cutter attachment!
