| Drilling Method |
Rotary drilling rig with Kelly bar |
Drilling diameter commonly ranges from approximately 0.6–3.0 m;
drilling depth often ranges from approximately 20–100 m, depending on the Kelly bar, tool, and ground conditions.
|
Cast-in-place bored piles, foundation shafts, bridge foundations, and large civil engineering projects. |
Published performance chart, Kelly bar length, crowd force, rated torque, tooling list, and completed project references. |
Usually requires transport planning, service support, drilling tools, casing equipment, and trained operators. |
| Drilling Method |
Continuous flight auger rig |
Produces a continuous auger column while concrete is pumped through the hollow stem.
Common pile diameters are approximately 0.3–1.2 m, subject to equipment configuration.
|
Fast production of continuous flight auger piles in suitable cohesive and granular soils. |
Maximum auger length, concrete pumping capacity, torque curve, soil limitations, and production records. |
Efficient for repetitive piling, but less suitable for unstable boreholes or sites requiring open-hole inspection. |
| Drilling Method |
Micro-pile or compact rotary rig |
Compact units commonly use drilling diameters of approximately 0.1–0.4 m
and are designed for restricted-access or low-headroom work.
|
Underpinning, retrofit projects, confined urban sites, basements, and work near existing structures. |
Overall height and width, minimum working radius, mast angle range, anchoring method, and transport dimensions. |
Lower transport and access requirements may reduce site preparation costs, although output is generally lower than that of large rigs. |
| Drilling Method |
Double rotary or casing oscillator system |
Uses synchronized rotation of casing and drilling tools to control unstable formations.
Casing diameter and depth depend on oscillator size, torque, and ground conditions.
|
Loose fill, groundwater-bearing strata, caving formations, deep foundations, and demanding urban sites. |
Casing torque, maximum casing diameter, oscillator stroke, hydraulic flow requirements, and ground-condition case studies. |
Higher capital and operating cost, but improved borehole stability can reduce collapse, slurry, and rework risks. |
| Power System |
Diesel-hydraulic power unit |
Large foundation rigs commonly use diesel engines in the approximate range of
150–500 kW, depending on rig size and auxiliary systems.
|
Remote sites, high-load drilling, and projects without reliable grid electricity. |
Engine rating, emissions certification, fuel consumption at operating load, hydraulic circuit diagram, and maintenance intervals. |
Confirm local emissions requirements, fuel quality, cold-start performance, filters, and availability of replacement parts. |
| Operating Capacity |
Rated torque and crowd force |
Medium and large rotary rigs may offer rotary torque from approximately
100–500 kN·m; actual capacity varies significantly by drilling mode and tool.
|
Selection for hard soil, weathered rock, large diameters, casing work, and deep piles. |
Torque-speed curve, crowd-force chart, winch line pull, drilling tool compatibility, and tested rock-drilling data. |
Do not compare torque alone; evaluate torque at working speed, crowd force, tool efficiency, and geological conditions together. |
| Ground Conditions |
Soil and rock adaptability |
Tooling may include augers, core barrels, rock buckets, casing tools, drilling hammers, and
replaceable cutting teeth.
|
Projects containing clay, sand, gravel, cobbles, weathered rock, or mixed ground profiles. |
Recommended tool matrix, penetration data, bore logs from comparable sites, and casing or slurry recommendations. |
Budget separately for tools and wear parts; ground conditions often have a greater effect on productivity than nominal machine size. |
| Transportability |
Trailer, modular, or self-propelled configuration |
Transport width, height, length, operating mass, and axle loads vary by model and attachments.
Oversize transport may require permits and route surveys.
|
International projects, urban construction, infrastructure corridors, and sites with restricted access. |
Transport drawings, shipping weight, center of gravity, lifting points, disassembly procedure, and container or break-bulk plan. |
Compare total landed cost rather than machine price alone, including freight, duties, port charges, assembly, and inland delivery. |
| Compliance |
Safety and destination-market conformity |
Documentation may include machinery risk assessment, emergency-stop design, guarding,
hydraulic safety data, electrical conformity documents, and applicable emissions records.
|
Projects subject to public procurement, contractor safety systems, or regulated construction-site requirements. |
Declaration of conformity where applicable, user manual, inspection certificates, risk assessment, serial-number records, and safety test reports. |
Requirements differ by destination; buyers should confirm local rules before signing the purchase contract. |
| Quality Management |
Manufacturing and inspection controls |
Quality evidence should cover welding procedures, hydraulic testing, dimensional inspection,
non-destructive testing where relevant, and final machine commissioning.
|
Long-term fleet ownership and projects where downtime or structural failure creates major costs. |
Factory acceptance test, inspection checklist, weld quality records, component traceability, and pre-shipment photographs or video. |
Include acceptance criteria, remedy periods, and documentation requirements in the purchase contract. |
| After-Sales Support |
Local service, remote support, and spare-parts supply |
Critical support areas include hydraulic systems, engines, rotary heads, winches,
electrical controls, sensors, and drilling tools.
|
Projects with tight schedules, remote locations, or high daily utilization. |
Service network map, response-time commitment, parts catalog, recommended stock list, troubleshooting procedure, and technician training plan. |
Assess lifecycle support for at least the planned ownership period, not only the warranty duration. |
| Purchase Route |
New machine purchase |
Provides the latest configuration, full commissioning, and the opportunity to specify
drilling diameter, Kelly bar, winch, cab, and safety options.
|
Long-term fleet operation, high annual utilization, and projects requiring predictable uptime. |
Detailed technical specification, factory test report, warranty terms, delivery schedule, and spare-parts quotation. |
Highest initial investment, but normally offers clearer configuration control and lower initial wear risk. |
| Purchase Route |
Used machine purchase |
Condition depends on operating hours, drilling geology, maintenance history, structural wear,
hydraulic health, and previous reconstruction work.
|
Short-term projects, budget-sensitive buyers, or fleet expansion with in-house maintenance capability. |
Independent inspection, engine and hydraulic test, operating-hour verification, service history, oil analysis, and crack inspection. |
Lower purchase price may be offset by refurbishment, transport, missing tools, import duties, and limited warranty coverage. |
| Purchase Route |
Rental or lease |
Commercial terms may be based on rental duration, operating hours, mobilization, demobilization,
maintenance responsibility, and damage liability.
|
Temporary works, uncertain project duration, seasonal demand, or buyers testing a machine category. |
Availability confirmation, maintenance schedule, inspection report, insurance requirements, replacement policy, and hour-meter rules. |
Compare the total rental cost with ownership cost, including transport, operator, fuel, tooling, and standby time. |
| Supplier Evaluation |
Technical proposal quality |
A suitable proposal should match machine capacity with pile diameter, depth, soil profile,
casing method, groundwater conditions, and required production rate.
|
All international procurement projects. |
Site-specific method statement, proposed tooling, production assumptions, risk register, and alternative configuration options. |
Prefer suppliers that identify technical limitations instead of providing only a nominal maximum specification. |
| Supplier Evaluation |
Commercial transparency |
The quotation should separate the base machine, drilling tools, Kelly bar, casing equipment,
spare parts, training, commissioning, freight, insurance, and taxes.
|
Cross-border purchases where hidden costs can materially affect the delivered price. |
Itemized quotation, Incoterms, payment milestones, lead time, warranty exclusions, packing list, and validity period. |
Use the same technical specification and Incoterm when comparing multiple offers. |
| Supplier Evaluation |
Production and delivery schedule |
Delivery time depends on whether the machine is in stock, standard production, or customized.
Additional time may be required for testing, export documentation, and shipping.
|
Projects with fixed mobilization dates or contractual completion deadlines. |
Manufacturing schedule, milestone dates, inspection window, packing date, shipping plan, and delay-management clause. |
Allow time for import clearance, local conformity checks, assembly, operator training, and site commissioning. |
| Lifecycle Cost |
Total cost of ownership |
Relevant cost elements include purchase price, fuel, lubricants, wear parts, tooling,
planned maintenance, unplanned repairs, transport, operators, and residual value.
|
Fleet procurement and projects with high machine utilization. |
Fuel-consumption estimate, maintenance schedule, wear-part life assumptions, parts prices, and recommended annual service budget. |
Evaluate cost per completed pile or drilled metre rather than comparing acquisition price alone. |